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Artykuły w czasopismach na temat "Ser/Thr protein kinases"
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PHALIP, Vincent, Jian-Hong LI i Cheng-Cai ZHANG. "HstK, a cyanobacterial protein with both a serine/threonine kinase domain and a histidine kinase domain: implication for the mechanism of signal transduction". Biochemical Journal 360, nr 3 (10.12.2001): 639–44. http://dx.doi.org/10.1042/bj3600639.
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Two distinct families of protein kinases are involved in signal transduction: Ser, Thr and Tyr kinases, which are predominantly found among eukaryotes, and His kinases, as part of bacterial two-component signalling systems. Genetic studies in Arabidopsis and Saccharomyces have demonstrated that bacterial-type two-component systems may act upstream of Ser/Thr kinases in the same signalling pathway, but how this coupling is accomplished remains unclear. In the present study, we report the characterization of a protein kinase, HstK, from the N2-fixing cyanobacterium Anabaena sp. PCC 7120, that possesses both a Ser/Thr kinase domain and a His kinase domain. Proteins with a structural architecture similar to that of HstK can be found in the eukaryote, Schizosaccharomyces pombe, and the bacterium, Rhodococcus sp. M5. HstK was present in cells grown with NH4+ or N2 as the nitrogen source, but was absent in cells grown with NO3−. The hstK gene was inactivated and the mutant phenotype was characterized. The catalytic domain of the Ser/Thr kinase of HstK functionally replaced that of Hog1p, a well-characterized protein kinase required for the response to high osmolarity in the S. cerevisiae heterologous system. The unusual multidomain structure of HstK suggests that a two-component system could be directly coupled to Ser/Thr kinases in the same signal transduction pathway.
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Mizunuma, Masataka, Atsushi Kaneko, Shunta Imai, Kazuhiro Furukawa i Yoshiro Chuman. "Methods for Identification of Substrates/Inhibitors of FCP/SCP Type Protein Ser/Thr Phosphatases". Processes 8, nr 12 (4.12.2020): 1598. http://dx.doi.org/10.3390/pr8121598.
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Protein phosphorylation is the most widespread type of post-translational modification and is properly controlled by protein kinases and phosphatases. Regarding the phosphorylation of serine (Ser) and threonine (Thr) residues, relatively few protein Ser/Thr phosphatases control the specific dephosphorylation of numerous substrates, in contrast with Ser/Thr kinases. Recently, protein Ser/Thr phosphatases were reported to have rigid substrate recognition and exert various biological functions. Therefore, identification of targeted proteins by individual protein Ser/Thr phosphatases is crucial to clarify their own biological functions. However, to date, information on the development of methods for identification of the substrates of protein Ser/Thr phosphatases remains scarce. In turn, substrate-trapping mutants are powerful tools to search the individual substrates of protein tyrosine (Tyr) phosphatases. This review focuses on the development of novel methods for the identification of Ser/Thr phosphatases, especially small C-terminal domain phosphatase 1 (Scp1), using peptide-displayed phage library with AlF4−/BeF3−, and discusses the identification of putative inhibitors.
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Songyang, Z., K. P. Lu, Y. T. Kwon, L. H. Tsai, O. Filhol, C. Cochet, D. A. Brickey i in. "A structural basis for substrate specificities of protein Ser/Thr kinases: primary sequence preference of casein kinases I and II, NIMA, phosphorylase kinase, calmodulin-dependent kinase II, CDK5, and Erk1." Molecular and Cellular Biology 16, nr 11 (listopad 1996): 6486–93. http://dx.doi.org/10.1128/mcb.16.11.6486.
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We have developed a method to study the primary sequence specificities of protein kinases by using an oriented degenerate peptide library. We report here the substrate specificities of eight protein Ser/Thr kinases. All of the kinases studied selected distinct optimal substrates. The identified substrate specificities of these kinases, together with known crystal structures of protein kinase A, CDK2, Erk2, twitchin, and casein kinase I, provide a structural basis for the substrate recognition of protein Ser/Thr kinases. In particular, the specific selection of amino acids at the +1 and -3 positions to the substrate serine/threonine can be rationalized on the basis of sequences of protein kinases. The identification of optimal peptide substrates of CDK5, casein kinases I and II, NIMA, calmodulin-dependent kinases, Erk1, and phosphorylase kinase makes it possible to predict the potential in vivo targets of these kinases.
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Seok, Seung-Hyeon. "Structural Insights into Protein Regulation by Phosphorylation and Substrate Recognition of Protein Kinases/Phosphatases". Life 11, nr 9 (13.09.2021): 957. http://dx.doi.org/10.3390/life11090957.
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Protein phosphorylation is one of the most widely observed and important post-translational modification (PTM) processes. Protein phosphorylation is regulated by protein kinases, each of which covalently attaches a phosphate group to an amino acid side chain on a serine (Ser), threonine (Thr), or tyrosine (Tyr) residue of a protein, and by protein phosphatases, each of which, conversely, removes a phosphate group from a phosphoprotein. These reversible enzyme activities provide a regulatory mechanism by activating or deactivating many diverse functions of proteins in various cellular processes. In this review, their structures and substrate recognition are described and summarized, focusing on Ser/Thr protein kinases and protein Ser/Thr phosphatases, and the regulation of protein structures by phosphorylation. The studies reviewed here and the resulting information could contribute to further structural, biochemical, and combined studies on the mechanisms of protein phosphorylation and to drug discovery approaches targeting protein kinases or protein phosphatases.
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Blume, Constanze, Peter M. Benz, Ulrich Walter, Joohun Ha, Bruce E. Kemp i Thomas Renné. "AMP-activated Protein Kinase Impairs Endothelial Actin Cytoskeleton Assembly by Phosphorylating Vasodilator-stimulated Phosphoprotein". Journal of Biological Chemistry 282, nr 7 (2.11.2006): 4601–12. http://dx.doi.org/10.1074/jbc.m608866200.
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Vasodilator-stimulated phosphoprotein (VASP) is an actin regulatory protein that links signaling pathways to remodeling of the cytoskeleton. VASP functions are modulated by protein kinases, which phosphorylate the sites Ser-157, Ser-239, and Thr-278. The kinase responsible for Thr-278 phosphorylation, biological functions of the phosphorylation, and association with disease states have remained enigmatic. Using VASP phosphorylation status-specific antibodies, we identified AMP-activated protein kinase (AMPK), a serine-threonine kinase and fundamental sensor of energy homeostasis, in a screen for kinases that phosphorylate the Thr-278 site of VASP in endothelial cells. Pharmacological AMPK inhibitors and activators and AMPK mutants revealed that the kinase specifically targets residue Thr-278 but not Ser-157 or Ser-239. Quantitative fluorescence-activated cell sorter analysis and serum response factor transcriptional reporter assays, which quantify the cellular F-/G-actin equilibrium, indicated that AMPK-mediated VASP phosphorylation impaired actin stress fiber formation and altered cell morphology. In the Zucker Diabetic Fatty (ZDF) rat model for type II diabetes, AMPK activity and Thr-278 phosphorylation were substantially reduced in arterial vessel walls. These findings suggest that VASP is a new AMPK substrate, that VASP Thr-278 phosphorylation translates metabolic signals into actin cytoskeleton rearrangements, and that this signaling system becomes down-regulated in diabetic vessels.
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Prasad, Jayendra, i James L. Manley. "Regulation and Substrate Specificity of the SR Protein Kinase Clk/Sty". Molecular and Cellular Biology 23, nr 12 (15.06.2003): 4139–49. http://dx.doi.org/10.1128/mcb.23.12.4139-4149.2003.
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ABSTRACT SR proteins constitute a family of splicing factors that play key roles in both constitutive and regulated splicing in metazoan organisms. The proteins are extensively phosphorylated, and kinases capable of phosphorylating them have been identified. However, little is known about how these kinases function, for example, whether they target specific SR proteins or whether the kinases themselves are regulated. Here we describe properties of one such kinase, Clk/Sty, the founding member of the Clk/Sty family of dual-specificity kinases. Clk/Sty is autophosphorylated on both Ser/Thr and Thr residues, and using both direct kinase assays and SR protein-dependent splicing assays, we have analyzed the effects of each type of modification. We find not only that the pattern of phosphorylation on a specific SR protein substrate, ASF/SF2, is modulated by autophosphorylation but also that the ability of Clk/Sty to recognize different SR proteins is influenced by the extent and nature of autophosphorylation. Strikingly, phosphorylation of ASF/SF2 is sensitive to changes in Tyr, but not Ser/Thr, autophosphorylation while that of SC35 displays the opposite pattern. In contrast, phosphorylation of a third SR protein, SRp40, is unaffected by autophosphorylation. We also present biochemical data indicating that as expected for a factor directly involved in splicing control (but in contrast to recent reports), Clk/Sty is found in the nucleus of several different cell types.
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THELEN, Jay J., Jan A. MIERNYK i Douglas D. RANDALL. "Pyruvate dehydrogenase kinase from Arabidopsis thaliana: a protein histidine kinase that phosphorylates serine residues". Biochemical Journal 349, nr 1 (26.06.2000): 195–201. http://dx.doi.org/10.1042/bj3490195.
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Pyruvate dehydrogenase kinase (PDK) is the primary regulator of flux through the mitochondrial pyruvate dehydrogenase complex (PDC). Although PDKs inactivate mitochondrial PDC by phosphorylating specific Ser residues, the primary amino acid sequence indicates that they are more closely related to prokaryotic His kinases than to eukaryotic Ser/Thr kinases. Unlike Ser/Thr kinases, His kinases use a conserved His residue for phosphotransfer to Asp residues. To understand these unique kinases better, a presumptive PDK from Arabidopsis thaliana was heterologously expressed and purified for this investigation. Purified, recombinant A. thaliana PDK could inactivate kinase-depleted maize mitochondrial PDC by phosphorylating Ser residues. Additionally, A. thaliana PDK was capable of autophosphorylating Ser residues near its N-terminus, although this reaction is not part of the phosphotransfer pathway. To elucidate the mechanism involved, we performed site-directed mutagenesis of the canonical His residue likely to be involved in phosphotransfer. When His-121 was mutated to Ala or Gln, Ser-autophosphorylation was decreased by 50% and transphosphorylation of PDC was decreased concomitantly. We postulate that either (1) His-121 is not the sole phosphotransfer His residue or (2) mutagenesis of His-121 exposes an additional otherwise cryptic phosphotransfer His residue. Thus His-121 is one residue involved in kinase function.
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Gangwal, Aakriti, Nitika Sangwan, Neha Dhasmana, Nishant Kumar, Chetkar Chandra Keshavam, Lalit K. Singh, Ankur Bothra i in. "Role of serine/threonine protein phosphatase PrpN in the life cycle of Bacillus anthracis". PLOS Pathogens 18, nr 8 (1.08.2022): e1010729. http://dx.doi.org/10.1371/journal.ppat.1010729.
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Reversible protein phosphorylation at serine/threonine residues is one of the most common protein modifications, widely observed in all kingdoms of life. The catalysts controlling this modification are specific serine/threonine kinases and phosphatases that modulate various cellular pathways ranging from growth to cellular death. Genome sequencing and various omics studies have led to the identification of numerous serine/threonine kinases and cognate phosphatases, yet the physiological relevance of many of these proteins remain enigmatic. In Bacillus anthracis, only one ser/thr phosphatase, PrpC, has been functionally characterized; it was reported to be non-essential for bacterial growth and survival. In the present study, we characterized another ser/thr phosphatase (PrpN) of B. anthracis by various structural and functional approaches. To examine its physiological relevance in B. anthracis, a null mutant strain of prpN was generated and shown to have defects in sporulation and reduced synthesis of toxins (PA and LF) and the toxin activator protein AtxA. We also identified CodY, a global transcriptional regulator, as a target of PrpN and ser/thr kinase PrkC. CodY phosphorylation strongly controlled its binding to the promoter region of atxA, as shown using phosphomimetic and phosphoablative mutants. In nutshell, the present study reports phosphorylation-mediated regulation of CodY activity in the context of anthrax toxin synthesis in B. anthracis by a previously uncharacterized ser/thr protein phosphatase–PrpN.
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Byrne, Dominic P., Safal Shrestha, Martin Galler, Min Cao, Leonard A. Daly, Amy E. Campbell, Claire E. Eyers, Elizabeth A. Veal, Natarajan Kannan i Patrick A. Eyers. "Aurora A regulation by reversible cysteine oxidation reveals evolutionarily conserved redox control of Ser/Thr protein kinase activity". Science Signaling 13, nr 639 (7.07.2020): eaax2713. http://dx.doi.org/10.1126/scisignal.aax2713.
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Reactive oxygen species (ROS) are physiological mediators of cellular signaling and play potentially damaging roles in human diseases. In this study, we found that the catalytic activity of the Ser/Thr kinase Aurora A was inhibited by the oxidation of a conserved cysteine residue (Cys290) that lies adjacent to Thr288, a critical phosphorylation site in the activation segment. Cys is present at the equivalent position in ~100 human Ser/Thr kinases, a residue that we found was important not only for the activity of human Aurora A but also for that of fission yeast MAPK-activated kinase (Srk1) and PKA (Pka1). Moreover, the presence of this conserved Cys predicted biochemical redox sensitivity among a cohort of human CAMK, AGC, and AGC-like kinases. Thus, we predict that redox modulation of the conserved Cys290 of Aurora A may be an underappreciated regulatory mechanism that is widespread in eukaryotic Ser/Thr kinases. Given the key biological roles of these enzymes, these findings have implications for understanding physiological and pathological responses to ROS and highlight the importance of protein kinase regulation through multivalent modification of the activation segment.
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Lutterbach, B., i S. R. Hann. "Hierarchical phosphorylation at N-terminal transformation-sensitive sites in c-Myc protein is regulated by mitogens and in mitosis". Molecular and Cellular Biology 14, nr 8 (sierpień 1994): 5510–22. http://dx.doi.org/10.1128/mcb.14.8.5510-5522.1994.
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The N-terminal domain of the c-Myc protein has been reported to be critical for both the transactivation and biological functions of the c-Myc proteins. Through detailed phosphopeptide mapping analyses, we demonstrate that there is a cluster of four regulated and complex phosphorylation events on the N-terminal domain of Myc proteins, including Thr-58, Ser-62, and Ser-71. An apparent enhancement of Ser-62 phosphorylation occurs on v-Myc proteins having a mutation at Thr-58 which has previously been correlated with increased transforming ability. In contrast, phosphorylation of Thr-58 in cells is dependent on a prior phosphorylation of Ser-62. Hierarchical phosphorylation of c-Myc is also observed in vitro with a specific glycogen synthase kinase 3 alpha, unlike the promiscuous phosphorylation observed with other glycogen synthase kinase 3 alpha and 3 beta preparations. Although both p42 mitogen-activated protein kinase and cdc2 kinase specifically phosphorylate Ser-62 in vitro and cellular phosphorylation of Thr-58/Ser-62 is stimulated by mitogens, other in vivo experiments do not support a role for these kinases in the phosphorylation of Myc proteins. Unexpectedly, both the Thr-58 and Ser-62 phosphorylation events, but not other N-terminal phosphorylation events, can occur in the cytoplasm, suggesting that translocation of the c-Myc proteins to the nucleus is not required for phosphorylation at these sites. In addition, there appears to be an unusual block to the phosphorylation of Ser-62 during mitosis. Finally, although the enhanced transforming properties of Myc proteins correlates with the loss of phosphorylation at Thr-58 and an enhancement of Ser-62 phosphorylation, these phosphorylation events do not alter the ability of c-Myc to transactivate through the CACGTG Myc/Max binding site.
Rozprawy doktorskie na temat "Ser/Thr protein kinases"
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Lee, Guinevere Kwun Wing Queenie. "Serine/threonine phosphorylation in mycobacterium tuberculosis : identification of protein kinase B (PknB) substrates". Thesis, University of British Columbia, 2008. http://hdl.handle.net/2429/693.
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Tuberculosis, caused by the intracellular pathogen Mycobacterium tuberculosis, is one of the most prevalent infectious diseases in our world today. In order to survive within the host the bacteria need to sense and respond to changes in the environment; however, signal transduction in this bacterium is poorly understood. PknB is a serine/threonine kinase essential for the in vitro survival of M. tuberculosis and therefore a potential drug target against the bacteria. It is the goal of the current study to elucidate downstream substrates of PknB. We have found that PknB shares in vitro substrates with another serine/threonine kinase, PknH, implying the potential complexity of the signaling pathways in the bacteria. We have also provided the first description of the coupling between serine/threonine kinases PknB and PknH with a two-component system response regulator DevR, and further proposed Ser/Thr phosphorylation as the negative regulator of DevR transcription activator activity based on LC-MS/MS analysis. Finally, we have identified a previously unknown phosphoprotein glyceraldehyde 3-phosphate dehydrogenase encoded by the ORF Rv1436, which demonstrates autophosphorylation activity and which phosphorylation is independent of PknB. Overall, the current study has contributed to advance our understanding of the signal transduction pathways and phosphoproteome in Mycobacterium tuberculosis.
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Haj, Slimane Ammar Zeineb. "Dynamique Spatiotemporelle de la protéine kinase AMPc dépendante dans les myocytes cardiaques". Phd thesis, Université Paris Sud - Paris XI, 2012. http://tel.archives-ouvertes.fr/tel-00954406.
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La protéine kinase AMPc-dépendante (PKA) joue un rôle crucial dans la régulation neurohormonale de la fonction cardiaque. L'activation aiguë de la PKA est bénéfique car elle conduit à une augmentation de la contraction cardiaque en phosphorylant les acteurs clés du couplage excitation-contraction. En revanche, son activation chronique est délétère et ces effets semblent faire intervenir la régulation de protéines nucléaires pouvant conduire au remodelage hypertrophique et à l'insuffisance cardiaque. La localisation subcellulaire de la PKA, assurée par des protéines d'ancrage (AKAPs), est importante pour la rapidité et la spécificité d'action des hormones mettant en jeu la voie de l'AMPc. Les niveaux d'AMPc sont régulés par l'activité des adénylate cyclases et des phosphodiestérases (PDEs), et l'état de phosphorylation des protéines cibles de la PKA dépend de l'activité des Ser/Thr phosphatases (PPs). Dans le cœur, les PDEs les plus importantes dégradant l'AMPc sont les PDE3 et les PDE4. Les principales PPs cardiaques sont PP1, PP2A et PP2B. Dans une première partie de mon travail, j'ai mis au point, dans les cardiomyocytes de rats adultes, une mesure de l'activité de la PKA en temps réel dans les compartiments cytoplasmiques et nucléaires. J'ai utilisé pour cela des sondes de type AKAR (A-kinase activity reporters) basées sur le transfert d'énergie de fluorescence (FRET) et localisées spécifiquement dans le noyau ou dans le cytoplasme par des séquences d'adressage ou d'exclusion nucléaires. J'ai ainsi pu montrer qu'une stimulation maintenue des récepteurs β-adrénergiques active la PKA de façon plus importante dans le cytoplasme que dans le noyau, et que cette activation se développe lentement au niveau nucléaire que dans le cytoplasme. De ce fait, une stimulation brève des récepteurs β-adrénergiques active maximalement la PKA dans le cytoplasme, mais de façon marginale dans le noyau. Dans une seconde partie de l'étude, je me suis intéressée au rôle des PDE3 et PDE4 ainsi qu'à celui de PP1, PP2A et PP2B dans la régulation de l'activité PKA cytoplasmique et nucléaire, en réponse à une stimulation β-adrénergique. J'ai montré que la PDE4, mais pas la PDE3, régule l'activité de la PKA cytoplasmique et nucléaire. L'utilisation de souris invalidées pour les gènes Pde4b et Pde4d a révélé que l'isoforme PDE4B est prédominante pour la modulation de l'activité PKA cytoplasmique, alors que les deux isoformes PDE4B et PDE4D contribuent à la régulation de l'activité PKA nucléaire. Finalement, j'ai montré que la PP1 et la PP2A, mais pas la PP2B, participent à la terminaison des réponses β-adrénergiques dans le cytoplasme, alors qu'au niveau nucléaire, la PP1 semble jouer un rôle majeur. En conclusion, ce travail a mis en évidence le rôle des phosphodiestérases et des phosphatases dans l'intégration différentielle des réponses PKA à une stimulation β-adrénergique dans le cytoplasme et le noyau de cardiomyocytes adultes.
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GONZALEZ, MAYA LETICIA. "Etude de la transduction du signal impliquant la phospho-proteine pii et des ser/thr-kinases chez les cyanobacteries". Université Louis Pasteur (Strasbourg) (1971-2008), 2000. http://www.theses.fr/2000STR13092.
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Des genes codant pour une famille de ser/thr-kinases chez la cyanobacterie filamenteuse et fixatrice d'azote anabaena sp. Pcc 7120, ont ete isoles dans notre laboratoire. Ces genes sont impliques dans la croissance ou developpement cellulaire. Les substrats de cette famille de ser/thr-kinases sont encore inconnus. Un des substrats potentiels de ces kinases est la proteine pii, connue pour etre phosphorylee sur un residu ser. Cette proteine est impliquee dans la regulation de l'assimilation de l'azote, et dans la coordination des metabolismes azote et carbone. Le gene glnb codant pour pii a ete clone chez anabaena sp. Pcc 7120. La cinetique de modification de pii pendant le developpement des heterocystes est de facon dynamique, ce qui incite a poursuivre l'etude du role eventuel de pii dans la differenciation cellulaire induite par la carence en azote combine. L'une des ser/thr-kinases de cette bacterie, pknc, peut phosphoryler la proteine pii recombinante sur un residu ser in vitro. L'introduction d'une mutation dans le domaine catalytique elimine l'activite de proteine-kinase de pknc. La phosphorylation de pii par pknc est stimulee par l'atp, mais l'-cetoglutarate, glutamate ou glutamine n'ont pas d'effet sur le niveau de phosphorylation de pii in vitro. Un essai de mutagenese suggere que pii est probablement essentielle chez anabaena sp. Pcc 7120. Afin de dissequer la fonction biologique de pii, nous avons construit des mutants ponctuels sur le residu ser qui constitue la cible de phosphorylation. Les resultats d'analyses seront presentes. L'inactivation du gene pknc n'influence pas le niveau de phosphorylation de pii chez anabaena sp. Pcc 7120. De nombreuses observations experimentales suggerent que pii joue des roles differents chez les souches unicellulaires non fixatrices d'azote et chez les souches filamenteuses fixatrices d'azote. Plusieurs hypotheses seront discutees afin de comprendre et d'expliquer le role de pii et pknc chez anabaena sp. Pcc 7120.
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Kobir, Ahasanul. "Physiological roles of Eukaryotic Hanks type Ser/Thr kinase in transition to stationary phase in Bacillus subtilis". Phd thesis, Université Paris Sud - Paris XI, 2012. http://tel.archives-ouvertes.fr/tel-00911812.
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Bacillus subtilis is the model organism for low GC Gram-positive bacteria and is of great biotechnological interest. Protein phosphorylation is an important regulatory mechanism in bacteria and it has not been extensively studied yet. Recent site-specific phosphoproteomic studies identified a large number of novel serine/threonine phosphorylation sites in B. subtilis, including a) two transition phase global gene regulators DegS and AbrB and b) RecA, that plays a major role in double-strand break repair and DNA recombination. .B. subtilis disposes of several putative Ser/Thr kinases like PrkA, YbdM, YabT and a characterizd kinase PrkC, but very few physiological substrates for these have been defined so far. In vitro phosphorylation assays were used to identify which of these kinases were able to phosphorylate DegS, RecA and AbrB. DegS phosphorylation on serine 76 by the kinase YbdM influenced its activity towards DegU both in vitro and in vivo, and expression of DegS S76D( on replacing serine to aspartate) in B. subtilis perturbed cellular processes regulated by the DegS/DegU two component system. This suggests a link between DegS phosphorylation at serine 76 and the level of DegU phosphorylation, establishing this post-translational modification as an additional trigger for this two-component system. At the onset of sporulation, B. subtilis expresses an unusual serine/threonine kinase YabT, which exhibits a septal localization and is activated by non-sequence-specific DNA binding. Activated YabT phosphorylates RecA at the residue serine 2, which in turn promotes the formation of RecA foci at the onset of spore development. On the other hand, non-phosphorylatable RecA or inactivated YabT lead to reduced spore formation in the presence of DNA lesions . This suggests a functional similarity between B. subtilis developmental stage dependent RecA phosphorylation and its eukaryal homologous Rad51 phosphorylation, which leads to its recruitment to the lesion sites. We therefore proposed that RecA phosphorylation serves as an additional signal mechanism that promotes focus formation during spore development. AbrB is phosphorylated by YabT, YbdM and PrkC in vitro and AbrB phosphorylation leads to reduced affinity for its target DNA and abolished binding cooperativity in vitro and in vivo. Expression of the phosphomimetic AbrB-S86D or of the non-phosphorylatable AbrB-S86A mutant protein in B. subtilis disturbed some stationary phase phenomena such as exoprotease production, competence and the onset of sporulation, probably by deregulation of AbrB-target genes and operons. We therefore, proposed that AbrB phosphorylation as an additional regulatory mechanism needed to switch off this ambiactive gene regulator during the transition phase.
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Wehenkel, Annemarie. "Etude structurale et fonctionnelle de Ser/Thr kinases et phosphates mycobactériennes". Paris 6, 2007. http://www.theses.fr/2007PA066177.
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Mycobacterium tuberculosis, le pathogène responsable de la tuberculose, a la capacité d’évader le système immunitaire et rester en état dormant pendant des années pour resurgir suite à un affaiblissement du système immunitaire. Pour comprendre les réponses de la mycobactérie aux changements dans l’environnement de l’hôte, l’étude des protéines régulatrices impliquées dans la transduction des signaux est d’une importance fondamentale. Dans ce contexte, mon projet de thèse visait à étudier la structure et fonction de la Ser/Thr kinase essentielle PknB et de la Ser/Thr phosphatase PstP, afin de comprendre leur rôle dans la signalisation chez M. Tuberculosis et d’identifier des cibles potentielles pour le développement de nouvelles thérapies. Un substrat a été identifié pour PknB et les études d'interaction protéine-protéine ont permis de proposer un modèle de recrutement du substrat via la boucle d'activation de la kinase. Des criblages d'inhibiteurs potentiels ont identifié plusieurs composés qui ont une activité inhibitrice in vitro et sur des cultures de mycobactéries, et les structures de complexes PknB-inhibiteurs ont été déterminées. La caractérisation structurale et fonctionnelle des Ser/Thr phosphatases PstP de M. Tuberculosis et MsPP de M. Smegmatis, a mis en évidence un centre métallique trinucléaire avec des affinités variables pour les métaux, et un possible rôle dans la fixation du substrat pour le troisième métal. Des complexes à résolution atomique de MsPP montrent 3 possibles étapes le long du cycle catalytique, qui nous a permis de proposer un mécanisme de type acide/base pour l'hydrolyse du phosphate, qui passerai par un état intermédiaire associatif.
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Macaccaro, Paolo. "Immunophenotypic characterization of B-lymphopoiesis in KO mice for oncogenic Ser / Thr kinases by multiparameter flow cytometry". Doctoral thesis, Università degli studi di Padova, 2017. http://hdl.handle.net/11577/3422901.
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Protein kinase CK2 and CK1 are a pleiotropic and evolutionary conserved serin-threonin kinase that is involved in several cellular processes. A number of studies revealed many mechanisms through which this kinase regulates cell cycle, apoptosis, cell survival and tumorigenesis.
CK2 participates in many developmental pathways, of which particularly relevant for hemo-lymphopoiesis are those dependent on Hedgehog, NF-κB and STAT3, which regulate cell differentiation, proliferation, self-renewal as well as lineage choice commitment.. CK1 regulates also molecular pathways which are important for multiple myeloma plasma cells survival, like WNT/β-catenin pathway and PI3K/AKT pathway.
However, despite all this data, little is known about the role of CK2 and CK1 in B-lymphopoiesis and lymphomagenesis.
To elucidate the physiological and pathogenetic role of CK2 and CK1 in B-lymphocytes, we generated B cell specific conditional KO mice, were we studied the effects of deletion during normal B cell development with multiparameter flow cytometry analysis.
In the bone marrow (BM), CK2β KO mice displayed a reduction of B cells, especially of the recirculating population of transitional and follicular (FO) B-cells. In peripheral blood and spleen the number of B-cells was markedly reduced. In the spleen of CK2β KO we observed an imbalance between the amount of FO and marginal zone (MZ) B-cells was found with an absolute reduction of FO B cells by approximately 2-folds and an increase of MZ B-cells and MZB cell precursors by up to three folds.. In vitro class-switch recombination assays demonstrated impairment in IgG1 and IgG3 class-switch and a marked reduction of the generation of antibody-producing cells. In CK1 KO mice we observed the totally absence of mature B cells and the presence of early precursors B cells. CK1 HET mice showed a reduction of B cells in bone marrow and an light imbalance of FO B cells an MZB cells in spleen. In vitro class-switch recombination assays doesn’t showed significant difference between HET and CTRL mice in IgG1 and IgG3 class-switch.
Here, we found that the β subunit of protein kinase CK2 is a novel regulator of peripheral B cell differentiation. CK2β has a role in regulation of the GC reaction and in homeostasis of FOB and MZB cells. Furthermore we found that CK1 has a pivotal role in early B cells development. On one side our data enrich the knowledge on the mechanisms regulating B-cell development, on the other side they inform about the potential mechanisms altered by CK2 and CK1 during B-cell tumorigenesis.Protein kinase CK2 and CK1 are a pleiotropic and evolutionary conserved serin-threonin kinase that is involved in several cellular processes. A number of studies revealed many mechanisms through which this kinase regulates cell cycle, apoptosis, cell survival and tumorigenesis. CK2 participates in many developmental pathways, of which particularly relevant for hemo-lymphopoiesis are those dependent on Hedgehog, NF-κB and STAT3, which regulate cell differentiation, proliferation, self-renewal as well as lineage choice commitment.. CK1 regulates also molecular pathways which are important for multiple myeloma plasma cells survival, like WNT/β-catenin pathway and PI3K/AKT pathway. However, despite all this data, little is known about the role of CK2 and CK1 in B-lymphopoiesis and lymphomagenesis. To elucidate the physiological and pathogenetic role of CK2 and CK1 in B-lymphocytes, we generated B cell specific conditional KO mice, were we studied the effects of deletion during normal B cell development with multiparameter flow cytometry analysis. In the bone marrow (BM), CK2β KO mice displayed a reduction of B cells, especially of the recirculating population of transitional and follicular (FO) B-cells. In peripheral blood and spleen the number of B-cells was markedly reduced. In the spleen of CK2β KO we observed an imbalance between the amount of FO and marginal zone (MZ) B-cells was found with an absolute reduction of FO B cells by approximately 2-folds and an increase of MZ B-cells and MZB cell precursors by up to three folds.. In vitro class-switch recombination assays demonstrated impairment in IgG1 and IgG3 class-switch and a marked reduction of the generation of antibody-producing cells. In CK1 KO mice we observed the totally absence of mature B cells and the presence of early precursors B cells. CK1 HET mice showed a reduction of B cells in bone marrow and an light imbalance of FO B cells an MZB cells in spleen. In vitro class-switch recombination assays doesn’t showed significant difference between HET and CTRL mice in IgG1 and IgG3 class-switch. Here, we found that the β subunit of protein kinase CK2 is a novel regulator of peripheral B cell differentiation. CK2β has a role in regulation of the GC reaction and in homeostasis of FOB and MZB cells. Furthermore we found that CK1 has a pivotal role in early B cells development. On one side our data enrich the knowledge on the mechanisms regulating B-cell development, on the other side they inform about the potential mechanisms altered by CK2 and CK1 during B-cell tumorigenesis.
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石崎, 敏理. "The small GTP-binding protein Rho binds to and activates a 160kDa Ser/Thr protein kinase homologous to myotonic dystrophy kinaseに関する研究(myotonic dystrophy kinaseに相同性を有し,低分子量GTP結合蛋白質Rhoに結合,活性化される160kDaセリン/スレオニンキナーゼ)". Kyoto University, 1997. http://hdl.handle.net/2433/202205.
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Kyoto University (京都大学)0048
新制・課程博士
博士(医学)
甲第6788号
医博第1888号
新制||医||664(附属図書館)
15860
UT51-97-H172
京都大学大学院医学研究科分子医学系専攻
(主査)教授 月田 承一郎, 教授 永田 和宏, 教授 中西 重忠, 教授 成宮 周
学位規則第4条第1項該当
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Deupí, i. Corral Xavier. "Influence of Ser and Thr residues in the geometry of transmembrane helices: implications on the structure and function of G protein-coupled receptors". Doctoral thesis, Universitat Autònoma de Barcelona, 2003. http://hdl.handle.net/10803/4426.
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En aquesta tesi s'apliquen eines bioinformàtiques a l'estudi de determinats sistemes biològics. En particular, l'estudi teòric de la influència de determinats aminoàcids sobre l'estructura i la dinàmica dels elements d'estructura secundària de les proteïnes s'aplica a la modelització per homologia dels receptors acoblats a proteïna G (GPCRs) i a l'estudi dels seus mecanismes d'activació.Se sap que determinats residus, com prolina, serina o treonina, provoquen distorsions locals en l'estructura de les hèlices a. L'anàlisi de bases de dades de seqüències de segments transmembrana mostra com certes combinacions d'aquests residus són més comunes que d'altres, i que algunes d'elles estan sobre-representades de manera significativa, mentre que d'altres estan clarament sots-representades. La restricció d'aquesta anàlisi de seqüències a la regió transmembrana dels GPCRs de la Classe A mostra com aquestes combinacions es troben en posicions específiques i, a més, es troben conservades en certes subfamílies de receptors.
L'estructura i la dinàmica de les hèlices transmembrana que contenen aquestes combinacions de prolina i serina o treonina s'han estudiat mitjançant simulacions de dinàmica molecular en un entorn hidrofòbic explícit. Els resultats mostren com algunes d'aquestes combinacions indueixen distorsions importants en l'estructura de l'hèlix a, degut al seu efecte desestabilitzador de la xarxa de ponts d'hidrogen que dóna estabilitat a l'hèlix.
Aquests resultats s'han aplicat a la construcció d'un model tridimensional del receptor de quimiocines CCR5 , utilitzant tècniques de modelització molecular per homologia. En aquest model es proposa que les hèlices transmembrana (TMH) 2 i 3 del receptor CCR5 són estructuralment diferents del patró de rodopsina. TMH2 està més doblegada degut a la presència d'un motiu Thr-X-Pro, que, a més, fa que aquesta hèlix es doblegui cap a TMH3. Així doncs, es proposa que, en aquest receptor, aquestes dues hèlices interaccionen. Aquesta interacció estaria mediada per la presència de residus hidrofòbics conservats i específics en les dues hèlices. Aquestes hipòtesis han estat posades a prova mitjançant experiments de mutagènesi dirigida, gràcies a la col·laboració amb l'Institut de Recherche Interdisciplinaire en Biologie Humaine et Nucléaire (IRIBHN), Université Libre de Bruxelles. Els resultats experimentals permeten establir la hipòtesi que la interfície TMH2-TMH3 participa en l'activació induïda per quimiocines del receptor CCR5.
Com a conclusió, aquesta tesi pretén mostrar com, mitjançant la utilització d'eines bioinformàtiques, és possible traduir les seqüències primàries de proteïnes i les interaccions a nivell atòmic en estructures tridimensionals de proteïnes. A més, aquesta tesi mostra que, encara que l'estructura tridimensional de la rodopsina bovina és un patró útil per la modelització per homologia de GPCRs, s'han de tenir en compte de manera explícita les especificitats de seqüència de cada receptor per tal de construir models de receptors particulars. Aquestes especificitats de seqüència consisteixen en patrons de seqüència conservats en determinades famílies, que es tradueixen en divergències estructurals. Entre aquests patrons de seqüència, es proposa que els residus de serina i treonina, sols o combinats amb residus de prolina propers, poden modular la geometria de les TMHs, degut a la seva capacitat d'interferir amb la xarxa de ponts d'hidrogen que dóna estabilitat a les hèlices a.
Finalment, es proposa que la influència dels motius de serina, treonina i prolina en l'estructura de les TMHs pot estar relacionada amb els processos d'activació dels GPCRs de la Classe A i, possiblement, d'altres proteïnes de membrana. En els GPCRs, aquests motius poden haver evolucionat per tal d'adaptar uns mecanismes d'activació conservats als lligands característics de cada família de receptors.
This thesis is framed in the study of particular biological systems through the use of bioinformatics. In particular, the theoretical study of the influence of certain amino acids on the structure and dynamics of the secondary structure elements of proteins has been applied to homology modelling of G protein-coupled receptors (GPCRs) and to the study of their mechanisms of activation.
Certain residues, as proline, serine or threonine, are known to induce local distortions in the a-helical structure. Analysis of sequence databases of transmembrane segments evidence that certain combinations of these residues are more common than others, and that some of them are significantly over-represented, while others are clearly under-represented. The focusing this sequence analysis on the transmembrane region of Class A GPCRs illustrates that these combinations are located in some specific locations and conserved within certain subfamilies of receptors.
The structure and dynamics of transmembrane a-helices containing these combinations of proline and serine or threonine have been studied using molecular dynamics simulations in an explicit hydrophobic environment. The results show how some of these combinations induce significant distortions in the a-helical structure, due to their effect on the hydrogen bond network that stabilizes the helix.
These results have been applied to the building of a three-dimensional model of the chemokine CCR5 receptor, using homology modelling techniques. In this model, transmembrane helices (TMH) 2 and 3 of CCR5 are proposed to be different from the bovine rhodopsin template. TMH2 is more bent due to the presence of a Thr-X-Pro motif, which, in turn, induces this helix to lean towards TMH3. As a consequence, an interaction between these two helices is proposed for this particular receptor. This interaction would be mediated through the presence of specific and conserved hydrophobic and aromatic residues in both helices. These hypothesis have been tested through site-directed mutagenesis experiments, thanks to a collaboration with the Institut de Recherche Interdisciplinaire en Biologie Humaine et Nucléaire (IRIBHN), Université Libre de Bruxelles. The experimental results let us to hypothesize that the TMH2-TMH3 interface is involved in the chemokine-induced activation of the CCR5 receptor.
As a conclusion, this thesis aims to show how through the use of bioinformatics tools, primary sequences of proteins and interactions at an atomic level can be translated to three-dimensional protein structures. In addition, this thesis illustrates that, even though the three-dimensional structure of bovine rhodopsin is a very useful template for homology modelling of GPCRs, the sequence specificities of each receptor have to be explicitly taken into account in order to build models. These sequence specificities consist in sequence patterns conserved within certain families, which are translated into structural divergences. Among these sequence patterns, we hypothesize that serine and threonine, alone or combined with nearby proline residues, can modulate the geometry of TMHs, due to its capability to interfere with the hydrogen bond network that stabilize a-helices.
Finally, we propose that the influence of serine, threonine and proline motifs in the structure of TMHs may be related to processes of activation in the Class A of GPCRs, and, possibly, other membrane proteins as well. In GPCRs, these motifs may have evolved in order to adapt a conserved mechanism of activation of the G protein to the cognate ligands of each receptor family.
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Shor, Audrey Cathryn. "Src kinase inhibitors for the treatment of sarcomas : cellular and molecular mechanisms of action". [Tampa, Fla] : University of South Florida, 2007. http://purl.fcla.edu/usf/dc/et/SFE0001906.
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Unsworth, Amanda J. "The role of protein kinase C in platelet activation". Thesis, University of Oxford, 2012. http://ora.ox.ac.uk/objects/uuid:114582b8-185a-41f5-958c-77038fb185df.
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The Protein kinase C (PKC) superfamily is a key regulator in platelet activation with individual isoforms playing distinct roles. This thesis focuses on the role of the novel PKC isoforms downstream of several agonists using both pharmacological and genetic approaches and human and mouse platelets. Quantification of the protein levels of PKC isoforms identified different levels of the five major PKC isoforms expressed in human platelets and also differences between levels of the same isoform in human and mouse platelets. Use of a selection of broad spectrum and isoform-specific inhibitors, identified both positive and negative novel roles for PKC in the regulation of human and mouse platelets. A net positive role for PKC was found in GPVI, Clec-2, and PAR receptor signalling, with classical isoforms of PKC playing a major role in aggregation and dense granule secretion. A novel negative regulatory role was also identified in the regulation of ADP-induced platelet activation for PKC~, and both PKCE and PKC~ in human and mouse platelets respectively. Gene knock-out mouse models confirmed a positive regulatory role for PKCe in allb~3 outside-in signalling but identified no other regulatory role for PKCe in agonist induced platelet activation. Despite this relatively minor role, functional redundancy was identified between PKCe and PKCE isoforms in haemostasis, as tail bleeding was significantly increased in mice deficient in both novel isoforms. The work presented here identifies key roles for the PKC superfamily in the complex regulation of platelet activation, with different isoforms supporting and limiting the process of thrombus formation and haemostasis.
Książki na temat "Ser/Thr protein kinases"
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Takao, Kumazawa, Kruger Lawrence i Mizumura Kazue, red. The polymodal receptor: A gateway to pathological pain. Amsterdam: Elsevier, 1996.
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Kung, Hsien-Jien. Protein Kinases (Journal of Biomedical Science Ser. 2). S Karger Pub, 1998.
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Journal of Molecular Microbiology and Biotechnology: Ser/Thr/tyr Protein Phosphorylation in Bacteria (Journal of Molecular Microbiology and Biotechnology). Not Avail, 2006.
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Johnston, Michael V. Coffin-Lowry Syndrome. Oxford University Press, 2017. http://dx.doi.org/10.1093/med/9780199937837.003.0057.
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Coffin-Lowry syndrome (CLS) is a relatively rare (1:50,000-100,000 incidence) sex-linked neurodevelopmental disorder that includes severe intellectual disability, dysmorphic features including facial and digital abnormalities, growth retardation, and skeletal changes. Most cases are sporadic with only 20% to 30% of cases having an additional family member. CLS is caused by variable loss of function mutations in the RPS6KA3 gene that maps to Xp22.2 and codes for the hRSK2 S6 kinase that phosphorylates the transcription factor CREB (cAMP response element binding protein) as well as other nuclear transcription factors. Phosphorylated CREB (pCREB) plays a major role in memory formation in fruit flies and mammals by activating specific genes through epigenetic histone acetylation.
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(Editor), T. Kumazawa, L. Kruger (Editor) i K. Mizumura (Editor), red. The Polymodal Receptor - A Gateway to Pathological Pain (Progress in Brain Research). Elsevier Science, 1996.
Znajdź pełny tekst źródłaCzęści książek na temat "Ser/Thr protein kinases"
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Inouye, Sumiko, Hirofumi Nariya i José Muñoz-Dorado. "Protein Ser/Thr Kinases and Phosphatases in Myxococcus xanthus". W Myxobacteria, 191–210. Washington, DC, USA: ASM Press, 2014. http://dx.doi.org/10.1128/9781555815677.ch11.
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Zorina, Anna A., Galina V. Novikova i Dmitry A. Los. "Participation of Ser-Thr Protein Kinases in Regulation of Heat Stress Responses inSynechocystis". W Stress and Environmental Regulation of Gene Expression and Adaptation in Bacteria, 766–80. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2016. http://dx.doi.org/10.1002/9781119004813.ch74.
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Ariño, Joaquin, Francesc Posas i Josep Clotet. "The Search for the Biological Function of Novel Yeast Ser/Thr Phosphatases". W Protein Phosphatase Protocols, 305–13. Totowa, NJ: Humana Press, 1998. http://dx.doi.org/10.1385/0-89603-468-2:305.
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Shen, Sheldon S. "Protein Kinase C and Regulation of the Na+−H+ Antiporter Activity During Fertilization of the Sea Urchin Egg". W Mechanisms of Egg Activation, 173–99. Boston, MA: Springer US, 1989. http://dx.doi.org/10.1007/978-1-4757-0881-3_9.
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"Ser/Thr-Specific Protein Kinases and Protein Phosphatases". W Biochemistry of Signal Transduction and Regulation, 269–309. Weinheim, FRG: Wiley-VCH Verlag GmbH & Co. KGaA, 2004. http://dx.doi.org/10.1002/3527601864.ch7.
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"Ser/Thr-Specific Protein Kinases and Protein Phosphatases". W Biochemistry of Signal Transduction and Regulation, 417–72. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA, 2014. http://dx.doi.org/10.1002/9783527667475.ch09.
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"Ser-Thr Protein Kinase PK428". W Encyclopedia of Signaling Molecules, 4913. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-67199-4_103474.
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"Ser-Thr Protein Kinase Related to the Myotonic Dystrophy Protein Kinase". W Encyclopedia of Signaling Molecules, 4913. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-67199-4_103475.
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Huff, Janice, i Thomas Parsons. "Sea". W The Protein Kinase FactsBook, 221–22. Elsevier, 1995. http://dx.doi.org/10.1016/b978-012324719-3/50200-4.
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Geoghegan, Kieran F., i Mary E. Kelly. "Selective Sequencing of Peptides with N-Terminal Ser or Thr in Mixtures". W Techniques in Protein Chemistry, 151–58. Elsevier, 1994. http://dx.doi.org/10.1016/b978-0-12-194710-1.50022-9.
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Liang, Chengwei, i Xiaowen Zhang. "Evidence for Positive Selection in Ser/Thr Protein Kinases (STKs) Genes of Trichodesmium erythraeum". W 2009 3rd International Conference on Bioinformatics and Biomedical Engineering (iCBBE). IEEE, 2009. http://dx.doi.org/10.1109/icbbe.2009.5162808.
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Vasilevich, Natalya, Elena Aksenova, Denis Kazyulkin i Ilya Afanasyev. "Search For Potent And Selective Aurora A Inhibitors Based On General Ser/Thr Kinases Pharmacophore Model". W 1st International Electronic Conference on Medicinal Chemistry. Basel, Switzerland: MDPI, 2015. http://dx.doi.org/10.3390/ecmc-1-a036.
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Gear, LR A., D. Freas i J. D. Carty. "EARLY (< 5 SEC) PHOSPHORYLATIONS OF PLATELET PROTEINS FOLLOWING ACTIVATION BY ADP AND ADRENALIN, SEPARATELY AND IN COMBINATION". W XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1643640.
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Understanding the earliest events (< 1 sec) in signal transduction of platelets is important, since there is evicenee that “shape change,” aggregation and secretion can all begin within this period. We have employed a guenched-flow approach to study these early events and found that thrombin can induce rapid phosphorylation of myosin light-chain kinase (20K) and a 47K protein (Blood, 67, 1738, 1986). To investigate the role of rapid phosphorylations in platelet activation, we have studied the influence of adrenalin and ADP during early (0.3 to 5 sec) stimulation. Aggregation in washed human platelets was assessed by following the loss of single particles and phosphorylation by analysing 32P-labeled proteins after gel electrophoresis. 15 µM adrenalin (without ADP) did not initiate significant aggregation or phosphorylation of myosin light chain (MLC). Phosphorylation of the 47K protein was increased by 20% at 5 sec. 0.5 µM ADP did not induce significant aggregation, but increased phosphorylation of MLC by 130% and the 47 protein by 20%. The combination of 0.5 µM ADP and 15 uM adrenalin induced significant aggregation by 0,3 sec (7.6%), which increased to 25.6% by 5 sec. Interestingly, MLC or 47K protein phosphorylation was not increased above control levels. However, the phosphorylation of four other proteins (77K, 102K, 140K and 185K), which previously had been very rapid (<1 sec) and reversible with 0.5 µM ADP alone, was now maintained, peaking at 3 sec. 10 µM ADP caused small sustained increases in phosphorylation of the same proteins. Adrenalin also caused rapid increases in the phosphorylation of 27K, 213 and 250K proteins. High levels of ADP (10 µM) only increased the 213 and 250K proteins; therefore the 27K protein appears adrenalin specific. Analysis of these early platelet phosphorylations will help understand how they are linked to initiation and maintenance of aggregation. Supported by NIH HL-27014.
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Suzuki, Koji, Yoshihiro Deyashiki, Junji Nishioka, Kazunori Toma i Shuji Yamamoto. "THE INHIBITOR OF ACTIVATED PROTEIN C: STRUCTURE AND FUNCTION". W XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1642963.
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In the final step of protein C pathway, activated protein C (APC) is neutralized with a plasma inhibitor, termed protein C inhibitor (PCI). PCI was first described by Marlar and Griffin (1980) and then isolated from human plasma as a homogeneous form and characterized by the authors (1983). PCI is a single chain glycoprotein with M 57,000 and a plasma concentration of 5 ug/ml. Analysis of a cDNA nucleotide sequence has clarified that a precursor of human PCI consists of a mature protein of 387 amino acid residues (M 43,759) and a signal peptide of 19 amino acid residues. Only one cysteine residue is present in the entire protein as in α1antitrypsin (α1AT) and α1antichymotrypsin (α1ACT). Three Asn-X-Ser/Thr sequences and two Ser/Thr-X-X-Pro sequences are present as potential attachment sites of carbohydrate chains. Based on the amino acid sequence of the carboxyl-terminal peptide released from the inhibitor by APC digestion, the reactive site peptide bond of PCI was found to be Arg(354)-Ser(355). It is similar to the reactive sites of the other serine protease inhibitors which are located to their carboxyl-terminal Arg(393)-Ser (394), Met(358)-Ser(359) and Leu(358)-Ser(359) in antithrombin III, α1AT and α1ACT, respectively. The alignment of the amino acid sequence of PCI with heparin cofactor II, α1plasmin inhibitor, ovalbumin, angiotensinogen and the above noted plasma inhibitors showed that PCI is a member of serine protease inhibitor superfamily. PCI inhibits APC noncompetitively in a 1:1 stoichiometry and forms a covalent acyl-bond with a Ser residue in the active center of APC. The half life of APC in plasma approximately 30 min, which is rather slow compared with the other protease inhibitors. However, optimal concentrations of heparin, dextran sulfate and its derivatives potentiate the rate of inhibition 30-60 fold. PCI has Ki of 10-8m for APC, and can inhibit thrombin, Factor Xa, urokinase and tissue plasminogen activator as well in the presence of heparin or dextran sulfate, though the Ki for these enzymes is slightly higher. During the complex formation with APC, PCI is cleaved by the complexed APC to form a modified form with M 54,000. PCI is synthesized in several hepatoma cell lines and decreased in plasma of patients with liver cirrhosis. It is also decreased in patients with DIC or those during cardiopulmonary bypass in parallel with the decrease in protein C, suggesting that PCI participates in regulation of the protein C pathway in intravascular coagulation. Recently, we have obtained the recombinant PCI from COS-1 cells which were transfected with expression vector pSV2 containing the cDNA of PCI. The recombinant PCI had the same Mr and specific activity as the protein purified from plasma. It also had an affinity for heparin and dextran sulfate. Moreover, we have predicted a three dimentional structure of the proteolytically modified PCI with computer graphics based on its amino acid sequence homology with the modified α1AT whose structure had been elucidated with X-ray crystallography. All potential carbohydrate attachment sites were estimated to exist on the surface of the protein. Succesively we have constructed the interaction model between the intact PCI predicted from the modified form and the active center of APC which was simulated from that of trypsin. From the model, it was observed that the amino-group of Arg (354, PI site) of PCI could strongly interact with the carboxy1-group of Asp (88, SI site) of the heavy chain of APC at the base of the active center pocket of the enzyme.
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Williams, Christopher Charles, Michelyn C. Patton i Melody M. Campbell. "Abstract B67: Phenotype-specific role for protein kinase CK2 in luminal and basal-like breast cancer cells". W Abstracts: AACR International Conference on the Science of Cancer Health Disparities‐‐ Sep 18-Sep 21, 2011; Washington, DC. American Association for Cancer Research, 2011. http://dx.doi.org/10.1158/1055-9965.disp-11-b67.
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Demolle, D., E. J. Cragoe i J. M. Boeynaems. "MECHANISMS INVOLVED IN 5-HT STIMULATION OF PROSTACYCLIN PRODUCTION BY BOVINE AORTIC SMOOTH MUSCLE CELLS". W XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1642841.
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Serotonin (5-HT) stimulates prostacyclin (PGI2) production by bovine aortic smooth muscle cells in culture via 5-HT2 receptors (1). These cells express a synthetic phenotype (2), whereas the majority of the smooth muscle cells in the media from adult arteries are in a contractile state. We have now shown that 5-HT (1-10 μM) also stimulates PGI2 production by a preparation of contractile smooth muscle cells : explants from bovine aortic media cultured for short periods. This effect is independent from 5-HT2 receptors : it is only partially inhibited (±30%) by ketan-serin (a selective and potent 5-HT2 antagonist) and is perfectly mimicked by a 5-HT1 agonist, 5-carboxamidotryptamine. 5-HT2 receptors seem to be linked to a phospholipase C (3), with subsequent accumulation of inositol tr isphosphate , Ins(1,4,5)P3, and diacylglycerol, an activator of protein kinase C. We have observed a stimulatory effect of phorbol 12-myristate, 13-acetate (a selective activator of kinase C) on PGI2 production by the bovine aortic smooth muscle cells (synthetic state), whereas it was totally ineffective on media explants preparation (contractile state). Furthermore, in the smooth muscle cells in culture, the 5-HT effect can be inhibited by (ethyl-isopropyl)amiloride, a potent and selective inhibitor of the Na+/H+ antiporter. In conclusion it appears that the regulation mechanisms of PGI2 production in arterial smooth muscle cells are strongly dependent an the phenotypic state of these cells. The control of PGI2 release via 5-HT2 receptors seems to involve a cytoplasmic alkalinization, via the activation of protein kinase C. The mechanism of 5-HT action in the media explants remains to be elucidated.(1) Coughlin, S.R. et al.: Proc . Natl. Acad. Sci. USA 78(11), 7134-7138, 1981.(2) Chamley-Campbell, J.H. and Campbell, G.K.: Atherosclerosis 40, 347-357, 1981.(3) Roth, B.L. et al.: J. Pharm. Exp. Ther. 238(2), 480-485, 1986.
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Wallace, Robert W., E. Ann Tallant i Lynn M. Brumley. "POSSIBLE ROLE FOR THE CA2+-DEPENDENT PROTEASE (CALPAIN I) AS AN IRREVERSIBLE ACTIVATOR OF CA2+/CALMODULIN-MEDIATED REACTIONS IN THE HUMAN PLATELET". W XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1644528.
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Calmodulin (CaM)-binding proteins have been identified in human platelets using Western blotting techniques and 125I-CaM. Ten proteins of 245, 225. 175, 150, 90. 82(2), 60 and 41(2) kilodaltons (kDa) bind 125I-CaM in a Ca2+-dependent manner; the binding is blocked by both trifluoperazine and nonradiolabeled CaM. The 225 and 90 kDa proteins are labeled by antisera against myosin light chain kinase (MLCK); the 60 kDa and one of the 82 kDa proteins have been identified as the CaM-dependent phosphatase (calcineurin) and caldesmon. The other proteins are presumed to be other Ca2+/CaM regulated enzymes and proteins which may be important in platelet function. Most of the CaM-binding proteins are degraded upon addition of Ca2+ to a platelet homogenate; the degradation may be blocked by either EGTA, leupeptin or N-ethylmaleimide which suggests that the degradation is due to a Ca2+-dependent protease. Activation of intact platelets under conditions which promote platelet aggregation (i.e. stirring with extracellular Ca2+) also results in limited proteolysis of CaM-binding proteins including those labeled with anti sera against MLCK and the phosphatase. In vitro studies utilizing purified phosphatase and calpain I indicate that the phosphatase is irreversibly activated upon Ca2+-dependent proteolysis. The proteolytically-activated enzyme is insensitive to either Ca2+ or Ca2+/CaM; in addition, its activity in the absence of Ca2+ is even greater than the activity of the unproteolyzed enzyme in the presence of Ca2+ and CaM. Proteolytic stimulation of the phosphatase is accompanied by degradation of the 60 kDa subunit of the enzyme (subunit A) to 56, 52 and 45 kDa fragments, sequentially; proteolysis results in the loss of CaM binding to the enzyme. These results suggest that the Ca2+-dependent protease may have a physiological role in platelet activation as an irreversible activator of Ca2+/ CaM-dependent reactions. Supported by NIH grant HL29766.
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Piliouras, Teresa, Kun Zack Liu, Yiwei Jia, Pui Lam Raymond Yu, Qian Zeng, Jeanne Lauer, Maigh Attre i Julie Ortiz. "“Others may see someone eating a cookie — I see the start of a protein kinase cascade reaction”". W 2014 IEEE Integrated STEM Education Conference (ISEC). IEEE, 2014. http://dx.doi.org/10.1109/isecon.2014.6891042.
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Holderness, Nina, Howard Donninger, Michael J. Birrer i Virna Leaner. "The role of p21-activated kinase 3 (PAK3) in activating protein 1 (AP-1) induced oncogenesis". W AACR International Conference: Molecular Diagnostics in Cancer Therapeutic Development– Sep 27-30, 2010; Denver, CO. American Association for Cancer Research, 2010. http://dx.doi.org/10.1158/diag-10-a36.
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Baker, J. B., M. P. McGrogan, C. Simonsen, R. L. Gronke i B. W. Festoff. "STRUCTURE AND PROPERTIES OF PROTEASE NEXIN I". W XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1644765.
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Human foreskin fibroblasts secrete several different serine protease inhibitors which differ in size and protease specificities. These proteins, called protease nexins (PNs) all form SDS-resistant complexes with their protease targets. Fibroblast surface receptors recognize the protease-PN complexes and mediate their delivery to lysosomes. PNI is a 45 kilodalton glycoprotein that rapidly inhibits several arg or lys-specific proteases including trypsin, thrombin, and urokinase (k assoc.∼ 4×l06,∼ 6×105 and ∼ 2×105, m−1s−1 respectively). Like antithrombin III, PNI binds heparin and inhibits thrombin at a vastly accelerated rate in the presence of this glycoaminoglycan. Immunofluorescence studies show that in addition to secreting PNI foreskin fibroblasts carry this inhibitor on their surfaces. PNI cDNA has been cloned and sequenced. A mixed oligonucleotide probe derived from PNI N-terminal sequence was used to probe a foreskin fibroblast cDNA library constructed with λGT10. Identification of PNI cDNAs has been verified by sequencing and by expressing active PNI protein in mammalian cells. The full amino acid sequence of PNI, deduced from cDNA sequencing, is 392 residues long and has 30% homology to antithrombin III. An arg-ser pair 32 residues from the C-terminus of the inhibitor is proposed as the reactive center P1-P1 residues. In the hinge region a lys residue is present in a position occupied by a ginor glu residue in other serpins. PNI mRNA exists in 2 slightly different forms:One (αPNI) yields a thr-arg-ser sequence wherethe other βPNI) yields a thr-thr-gly-ser sequence. The presence of the appropriate splice acceptor sites in the genome indicates that these forms are generated from a single gene by alternative splicing. Expressed aPNI and 0PNI proteins both bind thrombin and urokinase. In foreskin fibroblaststhe α form of PNI mRNA predominates over the β form by about 2:1. In foreskin fibroblast cultures secreted PNI inhibits the mitogenic response to thrombin and regulate secreted urokinase. Purified PNI added to human fibrosarcoma (HT1080) cells inhibitsthe tumor cell-mediated destruction of extracellular matrix and transiently, but dramatically, inhibits tumor cell growth. PNI or PNI-like inhibitors may function at multiple physiological sites. The β form of PNI is virtually identical to a glia-derived neurite promoting factor, the cDNA for which has been recently cloned and sequenced by Gloor et al (1). The neurite outgrowth activity of PNI may result from inhibition of a thrombin-like protease that is associated with neurons, since a number of thrombin inhibitors stimulate neurite extension. Recent immunofluoresence experiments, carried out with D. Hantai (Inserm; Paris) demonstrate that anti-PNI antibody intensely stains neuromuscular synapses. In addition, a PNI-like inhibitor is associated with platelets. At low (0.5 nM <) 125I-thrombin concentrations formation of 125I-thrombin-platelet PNI complexes accounts for most of the specific binding of 125I-thrombin to platelets (2). Although the platelet-associated form of PNI is electrophoretically and immunologically indistinguishable from fibroblast PNI, it does not bind urokinase, suggesting that it may be distinct.(1) Gloor, S., K. Odink, J. Guenther, H. Nick, and D. Monard. (1986) Cell 47:687-693.(2) Gronke, R.S., B.L. Bergman, and J.B. Baker. (1987) J. Biol. Chem. (in press)
Raporty organizacyjne na temat "Ser/Thr protein kinases"
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Dickman, Martin B., i Oded Yarden. Regulation of Early Events in Hyphal Elongation, Branching and Differentiation of Filamentous Fungi. United States Department of Agriculture, 2000. http://dx.doi.org/10.32747/2000.7580674.bard.
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In filamentous fungi, hyphal elongation, branching and morphogenesis are in many cases the key to successful saprophytic and pathogenic fungal proliferation. The understanding of the fungal morphogenetic response to environmental cues is in its infancy. Studies concerning the regulation of fungal growth and development (some of which have been obtained by the participating collaborators in this project) point to the fact that ser/thr protein kinases and phosphatases are (i) involved in the regulation of such processes and (ii) share common structural and functional features between saprophytes and pathogens. It is our objective to combine a pharmaceutical and a genetic approach in order to identify, characterize and functionally dissect some of the regulatory factors involved in hyphal growth, branching and differentiation. Using an immunohistochemical approach, a ser/thr protein kinase involved in hyphal elongation in both Neurospora crassa and Colletotrichum trifolii has been localized in order to identify the physical arena of regulation of hyphal elongation. The analysis of additional kinases and phosphatases (e.g. Protein kinase C, cAMP-dependent kinase, lipid-activated protein kinase, components of the type 2A protein phosphatase) as well as a RAS-related gene (an additional key participant in signal transduction) has been performed. In order to succeed in advancing the goals of this project, we have taken advantage of available elongation/branching mutants in N. crassa and continuously combined the accumulated information obtained while studying the two systems in order to dissect the elements involved in these processes. The various inhibitors/effectors analyzed can serve as a basis for modification to be used as anti-fungal compounds. Understanding the regulation of hyphal proliferation is a key requirement for identifying novel target points for either curbing fungal growth (as in the case of pathogenesis) or affecting growth patterns in various biotechnological processes. The major objective of our joint project was to advance our understanding of regulation of hyphal growth, especially during early events of fungal germination. Towards achieving this goal, we have coupled the analysis of a genetically tractable organism (N. crassa) with a plant pathogen o economic importance (C. trifolii). As the project progressed we believe that the results obtained have provided a reinforcement to our basic approach which called for combining the two fungal systems for a joint research project. On the one hand, we feel that much of the advance made was possible due to the amenability of N. crassa to genetic manipulations. The relevance of some of the initial findings obtained in Neurospora have been proven to be relevant to the plant pathogen while unique features of the pathogen have been identified in Colletotrichum. Most of the results obtained from this research project have been published. Thus, the main volume of this report is comprised of the relevant publications describing the research and results obtained.
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Dickman, Martin B., i Oded Yarden. Role of Phosphorylation in Fungal Spore Germination. United States Department of Agriculture, sierpień 1993. http://dx.doi.org/10.32747/1993.7568761.bard.
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Spore germination is a common and fundamental event in fungal development and in many instances an essential phase of fungal infection and dissemination. Spore germination is also critical for hyperparasites to function as biocontrol agents as well as in fermentation proceses. Our common objective is to understand the mechanisms which regulated spore germination and identify factors involved in pathogenicity related prepenetration development. Our approach is to exploit the overall similarity among filamentous fungi using both a plant pathogen (Colletotricum trifolii) and a model system that is genetically sophisticated (Neurospora crassa). The simulataneous use of two organisms has the advantage of the available tools in Neurospora to rapidly advance the functional analysis of genes involved in spore germination and development of an economically important fungal phytopathogen. Towards this we have isolated a protein kinase gene from C. trifolii (TB3) that is maximally expressed during the first hour of conidial germination and prior to any visible gene tube formation. Based on sequence similarities with other organisms, this gene is likely to be involved in the proliferative response in the fungus. In addition, TB3 was able to functionally complement a N. crassa mutant (COT-1). Pharmacological studies indicated the importance of calmodulin in both germination and appressorium differentiation. Using an antisense vector from N. crassa, direct inhibition of calmodulin results in prevention of differentiation as well as pathogenicity. Both cAMP dependent protein kinase (PKA) and protein kinase C (PKC) like genes have been cloned from C. trifolii. Biochemical inhibition of PKA prevents germination; biochemical inhibitors of PKC prevents appressorium differentiation. In order to analyze reversible phosphorylation as a regulatory mechanism, some ser.thr dephosphorylative events have also been analyzed. Type 2A and Type 2B (calcineurin) phosphatases have been identified and structurally and functionally analyzed in N. crassa during this project. Both phosphatases are essential for hyphal growth and maintenance of proper hyphal architecture. In addition, a first novel-type (PPT/PP5-like) ser/thr phosphatase has been identified in a filamentous fungus. The highly collaborative project has improved our understanding of a fundamental process in fungi, and has identified targets which can be used to develop new approaches for control of fungal plant pathogens as well as improve the performance of beneficial fungi in the field and in industry. In addition, the feasibility of molecular technology transfer in comparative mycology has been demonstrated.
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Epel, Bernard L., Roger N. Beachy, A. Katz, G. Kotlinzky, M. Erlanger, A. Yahalom, M. Erlanger i J. Szecsi. Isolation and Characterization of Plasmodesmata Components by Association with Tobacco Mosaic Virus Movement Proteins Fused with the Green Fluorescent Protein from Aequorea victoria. United States Department of Agriculture, wrzesień 1999. http://dx.doi.org/10.32747/1999.7573996.bard.
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The coordination and regulation of growth and development in multicellular organisms is dependent, in part, on the controlled short and long-distance transport of signaling molecule: In plants, symplastic communication is provided by trans-wall co-axial membranous tunnels termed plasmodesmata (Pd). Plant viruses spread cell-to-cell by altering Pd. This movement scenario necessitates a targeting mechanism that delivers the virus to a Pd and a transport mechanism to move the virion or viral nucleic acid through the Pd channel. The identity of host proteins with which MP interacts, the mechanism of the targeting of the MP to the Pd and biochemical information on how Pd are alter are questions which have been dealt with during this BARD project. The research objectives of the two labs were to continue their biochemical, cellular and molecular studies of Pd composition and function by employing infectious modified clones of TMV in which MP is fused with GFP. We examined Pd composition, and studied the intra- and intercellular targeting mechanism of MP during the infection cycle. Most of the goals we set for ourselves were met. The Israeli PI and collaborators (Oparka et al., 1999) demonstrated that Pd permeability is under developmental control, that Pd in sink tissues indiscriminately traffic proteins of sizes of up to 50 kDa and that during the sink to source transition there is a substantial decrease in Pd permeability. It was shown that companion cells in source phloem tissue export proteins which traffic in phloem and which unload in sink tissue and move cell to cell. The TAU group employing MP:GFP as a fluorescence probe for optimized the procedure for Pd isolation. At least two proteins kinases found to be associated with Pd isolated from source leaves of N. benthamiana, one being a calcium dependent protein kinase. A number of proteins were microsequenced and identified. Polyclonal antibodies were generated against proteins in a purified Pd fraction. A T-7 phage display library was created and used to "biopan" for Pd genes using these antibodies. Selected isolates are being sequenced. The TAU group also examined whether the subcellular targeting of MP:GFP was dependent on processes that occurred only in the presence of the virus or whether targeting was a property indigenous to MP. Mutant non-functional movement proteins were also employed to study partial reactions. Subcellular targeting and movement were shown to be properties indigenous to MP and that these processes do not require other viral elements. The data also suggest post-translational modification of MP is required before the MP can move cell to cell. The USA group monitored the development of the infection and local movement of TMV in N. benthamiana, using viral constructs expressing GFP either fused to the MP of TMV or expressing GFP as a free protein. The fusion protein and/or the free GFP were expressed from either the movement protein subgenomic promoter or from the subgenomic promoter of the coat protein. Observations supported the hypothesis that expression from the cp sgp is regulated differently than expression from the mp sgp (Szecsi et al., 1999). Using immunocytochemistry and electron microscopy, it was determined that paired wall-appressed bodies behind the leading edge of the fluorescent ring induced by TMV-(mp)-MP:GFP contain MP:GFP and the viral replicase. These data suggest that viral spread may be a consequence of the replication process. Observation point out that expression of proteins from the mp sgp is temporary regulated, and degradation of the proteins occurs rapidly or more slowly, depending on protein stability. It is suggested that the MP contains an external degradation signal that contributes to rapid degradation of the protein even if expressed from the constitutive cp sgp. Experiments conducted to determine whether the degradation of GFP and MP:GFP was regulated at the protein or RNA level, indicated that regulation was at the protein level. RNA accumulation in infected protoplast was not always in correlation with protein accumulation, indicating that other mechanisms together with RNA production determine the final intensity and stability of the fluorescent proteins.
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Sessa, Guido, i Gregory Martin. A functional genomics approach to dissect resistance of tomato to bacterial spot disease. United States Department of Agriculture, styczeń 2004. http://dx.doi.org/10.32747/2004.7695876.bard.
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The research problem. Bacterial spot disease in tomato is of great economic importance worldwide and it is particularly severe in warm and moist areas affecting yield and quality of tomato fruits. Causal agent of spot disease is the Gram-negative bacterium Xanthomonas campestris pv. vesicatoria (Xcv), which can be a contaminant on tomato seeds, or survive in plant debris and in association with certain weeds. Despite the economic significance of spot disease, plant protection against Xcvby cultural practices and chemical control have so far proven unsuccessful. In addition, breeding for resistance to bacterial spot in tomato has been undermined by the genetic complexity of the available sources of resistance and by the multiple races of the pathogen. Genetic resistance to specific Xcvraces have been identified in tomato lines that develop a hypersensitive response and additional defense responses upon bacterial challenge. Central goals of this research were: 1. To identify plant genes involved in signaling and defense responses that result in the onset of resistance. 2. To characterize molecular properties and mode of action of bacterial proteins, which function as avirulence or virulence factors during the interaction between Xcvand resistant or susceptible tomato plants, respectively. Our main achievements during this research program are in three major areas: 1. Identification of differentially expressed genes during the resistance response of tomato to Xcvrace T3. A combination of suppression subtractive hybridization and microarray analysis identified a large set of tomato genes that are induced or repressed during the response of resistant plants to avirulent XcvT3 bacteria. These genes were grouped in clusters based on coordinate expression kinetics, and classified into over 20 functional classes. Among them we identified genes that are directly modulated by expression of the type III effector protein AvrXv3 and genes that are induced also during the tomato resistance response to Pseudomonas syringae pv. tomato. 2. Characterization of molecular and biochemical properties of the tomato LeMPK3MAP kinase. A detailed molecular and biochemical analysis was performed for LeMPK3 MAP kinase, which was among the genes induced by XcvT3 in resistant tomato plants. LeMPK3 was induced at the mRNA level by different pathogens, elicitors, and wounding, but not by defense-related plant hormones. Moreover, an induction of LeMPK3 kinase activity was observed in resistant tomato plants upon Xcvinfection. LeMPK3 was biochemically defined as a dual-specificity MAP kinase, and extensively characterized in vitro in terms of kinase activity, sites and mechanism of autophosphorylation, divalent cation preference, Kₘand Vₘₐₓ values for ATP. 3. Characteriztion of molecular properties of the Xcveffector protein AvrRxv. The avirulence gene avrRxvis involved in the genetic interaction that determines tomato resistance to Xcvrace T1. We found that AvrRxv functions inside the plant cell, localizes to the cytoplasm, and is sufficient to confer avirulence to virulent Xcvstrains. In addition, we showed that the AvrRxv cysteine protease catalytic core is essential for host recognition. Finally, insights into cellular processes activated by AvrRxv expression in resistant plants were obtained by microarray analysis of 8,600 tomato genes. Scientific and agricultural significance: The findings of these activities depict a comprehensive and detailed picture of cellular processes taking place during the onset of tomato resistance to Xcv. In this research, a large pool of genes, which may be involved in the control and execution of plant defense responses, was identified and the stage is set for the dissection of signaling pathways specifically triggered by Xcv.