Journal articles: 'Extrinsic proteins'

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Ohta, Hisataka, Takehiro Suzuki, Masaji Ueno, Akinori Okumura, Shizue Yoshihara, Jian-Ren Shen, and Isao Enami. "Extrinsic proteins of photosystem II." European Journal of Biochemistry 270, no. 20 (September 26, 2003): 4156–63. http://dx.doi.org/10.1046/j.1432-1033.2003.03810.x.

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Nagao, Ryo, Hanayo Ueoka-Nakanishi, Chihiro Uno, Tatsuya Tomo, and Takumi Noguchi. "1P255 FTIR study on the functions of the extrinsic proteins in cyanobacterial photosystem II: Evolutionary aspect of extrinsic proteins(18B. Photobiology: Photosynthesis,Poster)." Seibutsu Butsuri 53, supplement1-2 (2013): S148. http://dx.doi.org/10.2142/biophys.53.s148_2.

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Bricker, Terry M., Johnna L. Roose, Robert D. Fagerlund, Laurie K. Frankel, and Julian J. Eaton-Rye. "The extrinsic proteins of Photosystem II." Biochimica et Biophysica Acta (BBA) - Bioenergetics 1817, no. 1 (January 2012): 121–42. http://dx.doi.org/10.1016/j.bbabio.2011.07.006.

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Roose, Johnna L., Kimberly M. Wegener, and Himadri B. Pakrasi. "The extrinsic proteins of Photosystem II." Photosynthesis Research 92, no. 3 (January 3, 2007): 369–87. http://dx.doi.org/10.1007/s11120-006-9117-1.

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Tamura, Noriaki, Richard Radmer, Steve Lantz, Kirk Cammarata, and George Cheniae. "Depletion of Photosystem II-extrinsic proteins." Biochimica et Biophysica Acta (BBA) - Bioenergetics 850, no. 2 (July 1986): 369–79. http://dx.doi.org/10.1016/0005-2728(86)90193-3.

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Roose, Johnna L., Laurie K. Frankel, Manjula P. Mummadisetti, and Terry M. Bricker. "The extrinsic proteins of photosystem II: update." Planta 243, no. 4 (January 12, 2016): 889–908. http://dx.doi.org/10.1007/s00425-015-2462-6.

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Burnap, R. L. "Mass spectroscopy locates the extrinsic proteins of photosystem II." Proceedings of the National Academy of Sciences 111, no. 12 (March 14, 2014): 4359–60. http://dx.doi.org/10.1073/pnas.1402022111.

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Murata, Norio, and Mitsue Miyao. "Extrinsic membrane proteins in the photosynthetic oxygen-evolving complex." Trends in Biochemical Sciences 10, no. 3 (March 1985): 122–24. http://dx.doi.org/10.1016/0968-0004(85)90272-5.

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Yi, Xiaoping, Myriam McChargue, Susan Laborde, Laurie K. Frankel, and Terry M. Bricker. "The Manganese-stabilizing Protein Is Required for Photosystem II Assembly/Stability and Photoautotrophy in Higher Plants." Journal of Biological Chemistry 280, no. 16 (February 18, 2005): 16170–74. http://dx.doi.org/10.1074/jbc.m501550200.

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Interfering RNA was used to suppress the expression of two genes that encode the manganese-stabilizing protein of photosystem II inArabidopsis thaliana, MSP-1 (encoded bypsbO-1, At5g66570), and MSP-2 (encoded bypsbO-2, At3g50820). A phenotypic series of transgenic plants was recovered that expressed high, intermediate, and low amounts of these two manganese-stabilizing proteins. Chlorophyll fluorescence induction and decay analyses were performed. Decreasing amounts of expressed protein led to the progressive loss of variable fluorescence and a marked decrease in the fluorescence quantum yield (Fv/Fm) in both the absence and the presence of dichloromethylurea. This result indicated that the amount of functional photosystem II reaction centers was compromised in the plants that exhibited intermediate and low amounts of the manganese-stabilizing proteins. An analysis of the decay of the variable fluorescence in the presence of dichlorophenyldimethylurea indicated that charge recombination between QA–and the S2state of the oxygen-evolving complex was seriously retarded in the plants that expressed low amounts of the manganesestabilizing proteins. This may have indicated a stabilization of the S2state in the absence of the extrinsic component. Immunological analysis of the photosystem II protein complement indicated that significant losses of the CP47, CP43, and D1 proteins occurred upon the loss of the manganese-stabilizing proteins. This indicated that these extrinsic proteins were required for photosystem II core assembly/stability. Additionally, although the quantity of the 24-kDa extrinsic protein was only modestly affected by the loss of the manganese-stabilizing proteins, the 17-kDa extrinsic protein dramatically decreased. The control proteins ribulose bisphosphate carboxylase and cytochromefwere not affected by the loss of the manganese-stabilizing proteins; the photosystem I PsaB protein, however, was significantly reduced in the low expressing transgenic plants. Finally, it was determined that the transgenic plants that expressed low amounts of the manganese-stabilizing proteins could not grow photoautotrophically.

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Putcha, Girish V., Charles A. Harris, Krista L. Moulder, Rachael M. Easton, Craig B. Thompson, and Eugene M. Johnson. "Intrinsic and extrinsic pathway signaling during neuronal apoptosis." Journal of Cell Biology 157, no. 3 (April 29, 2002): 441–53. http://dx.doi.org/10.1083/jcb.200110108.

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Trophic factor deprivation (TFD)-induced apoptosis in sympathetic neurons requires macromolecular synthesis–dependent BAX translocation, cytochrome c (cyt c) release, and caspase activation. Here, we report the contributions of other intrinsic and extrinsic pathway signals to these processes. Sympathetic neurons expressed all antiapoptotic BCL-2 proteins examined, yet expressed only certain BH3-only and multidomain proapoptotic BCL-2 family members. All coexpressed proapoptotic proteins did not, however, exhibit functional redundancy or compensatory expression, at least in the Bax−/−, Bak−/−, Bim−/−, Bid−/−, and Bad−/− neurons examined. Although the subcellular distribution or posttranslational modification of certain BCL-2 proteins changed with TFD, neither transcriptional nor posttranslational mechanisms regulated the expression or subcellular localization of BID, BAD, or BAK in this paradigm. Despite modest induction of Fas and FasL expression, Fas-mediated signaling did not contribute to TFD-induced apoptosis in sympathetic neurons. Similar findings were obtained with K+ withdrawal–induced apoptosis in cerebellar granule neurons, a model for activity-dependent neuronal survival in the CNS. Thus, expression alone does not guarantee functional redundancy (or compensation) among BCL-2 family members, and, at least in some cells, extrinsic pathway signaling and certain BH3-only proteins (i.e., BID and BAD) do not contribute to BAX-dependent cyt c release or apoptosis caused by TFD.

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Goelz, Nadine, Julia J. M. Eekels, Milica Pantic, Christoph T. Kamber, Oliver Speer, Francesca D. Franzoso, and Markus Schmugge. "Platelets express adaptor proteins of the extrinsic apoptosis pathway and can activate caspase-8." PLOS ONE 16, no. 1 (January 11, 2021): e0244848. http://dx.doi.org/10.1371/journal.pone.0244848.

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Background Apoptotic pathways in platelets are important for their survival and function. Platelet apoptosis may be involved in the pathogenesis of immune thrombocytopenia (ITP), an autoimmune-mediated disease. In contrast to the intrinsic apoptosis pathway, not much is known about the extrinsic pathway mechanisms in platelets. Objectives To investigate the expression of proteins involved in the extrinsic apoptosis pathway, including the death receptors, adaptor and regulator proteins in human platelets. To determine a possible trigger of the extrinsic apoptosis pathway in platelets. Methods To investigate the expression of key markers of the extrinsic pathway we used targeted immunofluorescence and flow cytometry assays. To study their expression and interaction we performed Western blotting and co-immunoprecipitation. Treated platelets with different apoptosis triggers were subjected to flow cytometry. Results We could identify the protein expression of the pro-apoptotic proteins TRADD (Tumor Necrosis Factor Receptor type 1- Associated DEATH Domain protein), TRAF2/5, (TNF Associated Factor) and DEDAF (Death Effector Domain- Associated Factor), FADD (Fas-Associated protein with death domain) as well as the anti-apoptotic proteins DJ-1 (Deglycase 1) and c-FLIP in human platelets. ABT-737 treatment induced a disruption in the co-localization of DJ-1 with FADD. Platelets treated with ABT-737 showed an activation in caspase-3 and -8. The exposure to TNF (Tumor Necrosis Factor), FasL (Fas ligand), and TWEAK or to plasma derived from ITP patients, did not lead to changes in caspase-3 and -8 activation in platelets. Conclusions Human platelets express some proteins of the extrinsic apoptosis pathway which can be modulated only by ABT-737 treatment. However so far, no other apoptosis trigger or interaction with an external receptor have been yet identified.

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Sasi, Shina, Jelli Venkatesh, Rawya Daneshi, and Mayank Gururani. "Photosystem II Extrinsic Proteins and Their Putative Role in Abiotic Stress Tolerance in Higher Plants." Plants 7, no. 4 (November 14, 2018): 100. http://dx.doi.org/10.3390/plants7040100.

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Abiotic stress remains one of the major challenges in managing and preventing crop loss. Photosystem II (PSII), being the most susceptible component of the photosynthetic machinery, has been studied in great detail over many years. However, much of the emphasis has been placed on intrinsic proteins, particularly with respect to their involvement in the repair of PSII-associated damage. PSII extrinsic proteins include PsbO, PsbP, PsbQ, and PsbR in higher plants, and these are required for oxygen evolution under physiological conditions. Changes in extrinsic protein expression have been reported to either drastically change PSII efficiency or change the PSII repair system. This review discusses the functional role of these proteins in plants and indicates potential areas of further study concerning these proteins.

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Han, Kab-Cho, Jian-Ren Shen, Masahiko Ikeuchi, and Yorinao Inoue. "Chemical crosslinking studies of extrinsic proteins in cyanobacterial photosystem II." FEBS Letters 355, no. 2 (November 28, 1994): 121–24. http://dx.doi.org/10.1016/0014-5793(94)01182-6.

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Rifkin, J. M., and G. E. Olson. "Characterization of maturation-dependent extrinsic proteins of the rat sperm surface." Journal of Cell Biology 100, no. 5 (May 1, 1985): 1582–91. http://dx.doi.org/10.1083/jcb.100.5.1582.

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Mammalian spermatozoa must mature in the epididymis before they can fertilize an egg. It is known that modification of the protein composition of the sperm surface is an important part of the maturation process. In this paper, we present data on two related glycoproteins that can be extracted from mature but not immature spermatozoa. Cell surface radioiodination has shown that these proteins are on the sperm surface, and immunofluorescence microscopy, by use of monospecific antibodies to the proteins, has indicated that their localization is restricted to the periacrosomal region of the sperm head. We have also shown that in vitro, these proteins will bind to the identical region of immature sperm. Immunohistochemical localization of the proteins in the epididymis shows that they are produced and secreted by the cauda region. The significance of the addition of these proteins to the sperm surface in both maturation and fertilization is discussed.

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Ivanov, Alexander G., Mira C. Busheva, and Maya Y. Velitchkova. "Surface Charge Density Changes in Isolated Photosystem II Membranes Induced by Depletion of the Extrinsic Polypeptides of the Oxygen Evolving System." Zeitschrift für Naturforschung C 45, no. 6 (June 1, 1990): 627–32. http://dx.doi.org/10.1515/znc-1990-0611.

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Abstract Treatment of PS II particles with either 1 M NaCl or alkaline Tris (1 M , pH 8.4) caused a considerable decrease in the average net negative surface charge density, concomitant with depletion of the extrinsic 17, 24 and 33 kDa proteins of the oxygen evolving complex from the membranes. The partial recovery of the values for surface charge in both NaCl- and Tris-treated membranes was registered after reconstitution experiments with the three proteins. These results are compared with the data for the charge densities of the thylakoid membranes, to examine the role of the three extrinsic proteins in the formation of heterogeneous arrangement of surface charge across the appressed (granal) thylakoids.

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Bogazzi, Fausto, Dania Russo, Francesco Raggi, Mohammad Bohlooly-Y, Jan Tornell, Chiara Sardella, Martina Lombardi, et al. "Cardiac extrinsic apoptotic pathway is silent in young but activated in elder mice overexpressing bovine GH: interplay with the intrinsic pathway." Journal of Endocrinology 210, no. 2 (May 12, 2011): 231–38. http://dx.doi.org/10.1530/joe-10-0402.

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Apoptosis may occur through the mitochondrial (intrinsic) pathway and activation of death receptors (extrinsic pathway). Young acromegalic mice have reduced cardiac apoptosis whereas elder animals have increased cardiac apoptosis. Multiple intrinsic apoptotic pathways have been shown to be modulated by GH and other stimuli in the heart of acromegalic mice. However, the role of the extrinsic apoptotic pathways in acromegalic hearts is currently unknown. In young (3-month-old) acromegalic mice, expression of proteins of the extrinsic apoptotic pathway did not differ from that of wild-type animals, suggesting that this mechanism did not participate in the lower cardiac apoptosis levels observed at this age. On the contrary, the extrinsic pathway was active in elder (9-month-old) animals (as shown by increased expression of TRAIL, FADD, TRADD and increased activation of death inducing signaling complex) leading to increased levels of active caspase 8. It is worth noting that changes of some pro-apoptotic proteins were induced by GH, which seemed to have, in this context, pro-apoptotic effects. The extrinsic pathway influenced the intrinsic pathway by modulating t-Bid, the cellular levels of which were reduced in young and increased in elder animals. However, in young animals this effect was due to reduced levels of Bid regulated by the extrinsic pathway, whereas in elder animals the increased levels of t-Bid were due to the increased levels of active caspase 8. In conclusion, the extrinsic pathway participates in the cardiac pro-apoptotic phenotype of elder acromegalic animals either directly, enhancing caspase 8 levels or indirectly, increasing t-Bid levels and conveying death signals to the intrinsic pathway.

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Hunashal, Yamanappa, Cristina Cantarutti, Sofia Giorgetti, Loredana Marchese, Henriette Molinari, Neri Niccolai, Federico Fogolari, and Gennaro Esposito. "Exploring exchange processes in proteins by paramagnetic perturbation of NMR spectra." Physical Chemistry Chemical Physics 22, no. 11 (2020): 6247–59. http://dx.doi.org/10.1039/c9cp06950j.

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The effects induced by extrinsic paramagnetic probes on protein NMR spectra, widely used for surface mapping, can also be exploited to detect the sites of slow and intermediate exchange due to structural or intermolecular interaction dynamics.

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Andreea, Smărăndescu Raluca, Mircea-Constantin Diaconu, Claudia-Mariana Handra, and Agripina Rașcu. "Occupational Extrinsic Allergic Alveolitis in a poultry farmer." Romanian Journal of Occupational Medicine 71, no. 1 (December 1, 2020): 69–73. http://dx.doi.org/10.2478/rjom-2020-0010.

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AbstractHypersensitivity pneumonitis is a group of inflammatory interstitial lung diseases caused by hypersensitivity immune reactions to the inhalation of various antigens: fungal, bacterial, animal protein, or chemical sources, finely dispersed, with aerodynamic diameter <5μ, representing the respirable fraction. The national register for interstitial lung diseases records very few cases of hypersensitivity pneumonitis (extrinsec allergic alveolitis), a well defined occupational disease. Although not an eminently of occupational origin, the extrinsec allergic alveolitis can occur secondary to occupational exposure to organic substances (animal or insect proteins, bacteria, fungi) or inorganic (low molecular weight chemical compounds) and the occupational doctor is a key actor in the diagnosys. The disease has chronic evolution and exposure avoidance, as early as possible, has major prognostic influence. The occupational anamnesis remains the most important step and the occupational physician is the one in charge for monitoring and detection of the presence of respiratory symptoms in all employees with risk exposure. Next, we present the case of a farmer, without other comorbidities, who develops various respiratory and systemic diseases and manifestations due to repeated exposure to animal proteins and molds, in order to review the risk factors and the consequences of exposure in poultry farms.

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Seibert, M., M. DeWit, and L. A. Staehelin. "Structural localization of the O2-evolving apparatus to multimeric (tetrameric) particles on the lumenal surface of freeze-etched photosynthetic membranes." Journal of Cell Biology 105, no. 5 (November 1, 1987): 2257–65. http://dx.doi.org/10.1083/jcb.105.5.2257.

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Isolated appressed chloroplast membranes, highly enriched in photosystem II (PSII) activity, were examined by freeze-etch electron microscopy. The exposed surfaces of these Triton X-100 solubilized membrane fragments correspond to the lumenal or ESs surface of intact stacked thylakoid membrane regions (Dunahay, T. G., L. A. Staehelin, M. Seibert, P. D. Ogilvie, and S. P. Berg. 1984. Biochim. Biophys. Acta. 764:179-193). The sequential removal from this sample of three extrinsic proteins (17, 23, and 33 kD) associated with the O2-evolving apparatus and the concomitant loss of O2 evolution, was related to subtle changes in the height and substructure of characteristic multimeric (often tetrameric) particles that protrude from the ESs membrane surface. After removal of these proteins, the multimeric particles disappeared and dimeric particles of similar diameter but of lesser height (6.1 vs. 8.2 nm in the controls) were observed. Reconstitution of the depleted membrane fragments with the extrinsic proteins led to rebinding of the three proteins, to a 63% recovery of the control rates of O2 evolution, and to the reappearance of the larger multimeric particles. Analysis of the structural changes associated with the loss and rebinding of the extrinsic proteins is consistent with a stoichiometry of one PSII complex for either one or two copies of the 17-, 23-, and 33-kD proteins, and these are symmetrically arranged on the lumenal surface of the complex. These results demonstrate that the multimeric ESs particles correspond to part of the intact O2-evolving apparatus of PSII, thus confirming previous indirect studies relating these particles to PSII. The dimeric particles probably contain the rest of the O2-evolving complex.

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Warn-Cramer, B. J., and S. P. Bajaj. "Intrinsic versus extrinsic coagulation Kinetic considerations." Biochemical Journal 239, no. 3 (November 1, 1986): 757–62. http://dx.doi.org/10.1042/bj2390757.

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A study to compare the kinetics of activation of factor IX by Factor XIa/Ca2+ and by Factor VIIa/tissue factor/Ca2+ has been undertaken. When purified human proteins, detergent-extracted brain tissue factor and tritiated-activation-peptide-release assays were utilized, the kinetic constants obtained were: Km = 310 nM, kcat. = 25 min-1 for Factor XIa and Km = 210 nM, kcat. = 15 min-1 for Factor VIIa. The kinetic constants for the activation of Factor X by Factor VIIa/brain tissue factor were: Km = 205 nM, kcat. = 70 min-1. Predicted rates for the generation of Factor IXa and Factor Xa were obtained when human monocytic tumour U937 cells (source of tissue factor) and Factor VIIa were used to form the activator. In other experiments, inclusion of high-Mr kininogen did not increase the activation rates of Factor IX by Factor XIa in the presence or absence of platelets and/or denuded rabbit aorta. These kinetic data strongly indicate that both Factor XIa and Factor VIIa play physiologically significant roles in the activation of Factor IX.

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O'Connell, D. J., F. Baldelli Bombelli, A. S. Pitek, M. P. Monopoli, D. J. Cahill, and K. A. Dawson. "Characterization of the bionano interface and mapping extrinsic interactions of the corona of nanomaterials." Nanoscale 7, no. 37 (2015): 15268–76. http://dx.doi.org/10.1039/c5nr01970b.

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Yoo, Yoon Seon, Hye Gyeong Han, and Young Joo Jeon. "Unfolded Protein Response of the Endoplasmic Reticulum in Tumor Progression and Immunogenicity." Oxidative Medicine and Cellular Longevity 2017 (December 21, 2017): 1–18. http://dx.doi.org/10.1155/2017/2969271.

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The endoplasmic reticulum (ER) is a pivotal regulator of folding, quality control, trafficking, and targeting of secreted and transmembrane proteins, and accordingly, eukaryotic cells have evolved specialized machinery to ensure that the ER enables these proteins to acquire adequate folding and maturation in the presence of intrinsic and extrinsic insults. This adaptive capacity of the ER to intrinsic and extrinsic perturbations is important for maintaining protein homeostasis, which is termed proteostasis. Failure in adaptation to these perturbations leads to accumulation of misfolded or unassembled proteins in the ER, which is termed ER stress, resulting in the activation of unfolded protein response (UPR) of the ER and the execution of ER-associated degradation (ERAD) to restore homeostasis. Furthermore, both of the two axes play key roles in the control of tumor progression, inflammation, immunity, and aging. Therefore, understanding UPR of the ER and subsequent ERAD will provide new insights into the pathogenesis of many human diseases and contribute to therapeutic intervention in these diseases.

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De Las Rivas, Javier, Mónica Balsera, and James Barber. "Evolution of oxygenic photosynthesis: genome-wide analysis of the OEC extrinsic proteins." Trends in Plant Science 9, no. 1 (January 2004): 18–25. http://dx.doi.org/10.1016/j.tplants.2003.11.007.

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De Las Rivas, Javier, Pedro Heredia, and Angel Roman. "Oxygen-evolving extrinsic proteins (PsbO,P,Q,R): Bioinformatic and functional analysis." Biochimica et Biophysica Acta (BBA) - Bioenergetics 1767, no. 6 (June 2007): 575–82. http://dx.doi.org/10.1016/j.bbabio.2007.01.018.

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Sapp, Valerie, Mohit Jain, and Ronglih Liao. "Viewing Extrinsic Proteotoxic Stress Through the Lens of Amyloid Cardiomyopathy." Physiology 31, no. 4 (July 2016): 294–99. http://dx.doi.org/10.1152/physiol.00047.2015.

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Proteotoxicity refers to toxic stress caused by misfolded proteins of extrinsic or intrinsic origin and plays an integral role in the pathogenesis of cardiovascular diseases. Herein, we provide an overview of the current understanding of mechanisms underlying proteotoxicity and its contribution in the pathogenesis of amyloid cardiomyopathy.

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He, Caimei, Jun Deng, Xin Hu, Sichun Zhou, Jingtao Wu, Di Xiao, Kwame Oteng Darko, et al. "Vitamin A inhibits the action of LPS on the intestinal epithelial barrier function and tight junction proteins." Food & Function 10, no. 2 (2019): 1235–42. http://dx.doi.org/10.1039/c8fo01123k.

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Holzhüter, Katharina, and Eric R. Geertsma. "Functional (un)cooperativity in elevator transport proteins." Biochemical Society Transactions 48, no. 3 (June 23, 2020): 1047–55. http://dx.doi.org/10.1042/bst20190970.

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The activity of enzymes is subject to regulation at multiple levels. Cooperativity, the interconnected behavior of active sites within a protein complex, directly affects protein activity. Cooperativity is a mode of regulation that requires neither extrinsic factors nor protein modifications. Instead, it allows enzymes themselves to modulate reaction rates. Cooperativity is an important regulatory mechanism in soluble proteins, but also examples of cooperative membrane proteins have been described. In this review, we summarize the current knowledge on interprotomer cooperativity in elevator-type proteins, a class of membrane transporters characterized by large rigid-body movements perpendicular to the membrane, and highlight well-studied examples and experimental approaches.

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Gao, Jin-Peng, Zhen-Hua Yong, Feng Zhang, Kang-Cheng Ruan, Chun-He Xu, and Gen-Yun Chen. "Positive Charges on Lysine Residues of the Extrinsic 18 kDa Protein Are Important to Its Electrostatic Interaction with Spinach Photosystem II Membranes." Acta Biochimica et Biophysica Sinica 37, no. 11 (November 1, 2005): 737–42. http://dx.doi.org/10.1111/j.1745-7270.2005.00103.x.

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Abstract To determine the contribution of charged amino acids to binding with the photosystem II complex (PSII), the amino or carboxyl groups of the extrinsic 18 kDa protein were modified with Nsuccinimidyl propionate (NSP) or glycine methyl ester (GME) in the presence of a water-soluble carbodiimide, respectively. Based on isoelectric point shift, 4–10 and 10–14 amino groups were modified in the presence of 2 and 4 mM NSP, respectively. Similarly, 3–4 carboxyl groups were modified by reaction with 100 mM GME. Neutralization of negatively charged carboxyl groups with GME did not alter the binding activity of the extrinsic 18 kDa protein. However, the NSP-modified 18 kDa protein, in which the positively charged amino groups had been modified to uncharged methyl esters, failed to bind with the PSII membrane in the presence of the extrinsic 23 kDa protein. This defect can not be attributed to structural or conformational alterations imposed by chemical modification, as the fluorescence and circular dichroism spectra among native, GME and NSP-modified extrinsic 18 kDa proteins were similar. Thus, we have concluded that the positive charges of lysyl residues in the extrinsic 18 kDa protein are important for its interaction with PSII membranes in the presence of the extrinsic 23 kDa protein. Furthermore, it was found that the negative charges of carboxyl groups of this protein did not participate in binding with the extrinsic 23 kDa protein associated with PSII membranes.

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Brennan, M. Jane, Sydney E. Hollingshead, Jonathan J. Wilker, and Julie C. Liu. "Critical factors for the bulk adhesion of engineered elastomeric proteins." Royal Society Open Science 5, no. 5 (May 2018): 171225. http://dx.doi.org/10.1098/rsos.171225.

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Many protein-based materials, such as soy and mussel adhesive proteins, have been the subject of scientific and commercial interest. Recently, a variety of protein adhesives have been isolated from diverse sources such as insects, frogs and squid ring teeth. Many of these adhesives have similar amino acid compositions to elastomeric proteins such as elastin. Although elastin is widely investigated for a structural biomaterial, little work has been done to assess its adhesive potential. In this study, recombinant elastin-like polypeptides were created to probe the factors affecting adhesion strength. Lap shear adhesion was used to examine the effects of both extrinsic factors (pH, concentration, cross-linker, humidity, cure time and cure temperature) and intrinsic factors (protein sequence, structure and molecular weight). Of the extrinsic factors tested, only humidity, cure time and cure temperature had a significant effect on adhesion strength. As water content was reduced, adhesion strength increased. Of the intrinsic factors tested, amino acid sequence did not significantly affect adhesion strength, but less protein structure and higher molecular weights increased adhesion strength directly. The strengths of proteins in this study (greater than 2 MPa) were comparable to or higher than those of two commercially available protein-based adhesives, hide glue and a fibrin sealant. These results may provide general rules for the design of adhesives from elastomeric proteins.

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Ettinger, W. F., and S. M. Theg. "Physiologically active chloroplasts contain pools of unassembled extrinsic proteins of the photosynthetic oxygen-evolving enzyme complex in the thylakoid lumen." Journal of Cell Biology 115, no. 2 (October 15, 1991): 321–28. http://dx.doi.org/10.1083/jcb.115.2.321.

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The oxygen-evolving complex (OEC) of photosystem II (PS II) consists of at least three extrinsic membrane-associated protein subunits, OE33, OE23, and OE17, with associated Mn2+, Ca2+, and Cl- ions. These subunits are bound to the lumen side of PS II core proteins embedded in the thylakoid membrane. Our experiments reveal that a significant fraction of each subunit is normally present in unassembled pools within the thylakoid lumen. This conclusion was supported by immunological detection of free subunits after freshly isolated pea thylakoids were fractionated with low levels of Triton X-100. Plastocyanin, a soluble lumen protein, was completely released from the lumen by 0.04% Triton X-100. This gentle detergent treatment also caused the release from the thylakoids of between 10 and 20%, 40 and 60%, and 15 and 50% of OE33, OE23, and OE17, respectively. Measurements of the rates of oxygen evolution from Triton-treated thylakoids, both in the presence and absence of Ca2+, and before and after incubation with hydroquinone, demonstrated that the OEC was not dissociated by the detergent treatment. Thylakoids isolated from spinach released similar amounts of extrinsic proteins after Triton treatment. These data demonstrate that physiologically active chloroplasts contain significant pools of unassembled extrinsic OEC polypeptide subunits free in the lumen of the thylakoids.

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Kutinová, Luda, Viera Ludvíková, Lucie Marešová, šárka Němečková, Jaroslav Brouček, Petr Hainz, and Vladimír Vonka. "Effect of virulence on immunogenicity of single and double vaccinia virus recombinants expressing differently immunogenic antigens: antibody-response inhibition induced by immunization with a mixture of recombinants differing in virulence." Journal of General Virology 80, no. 11 (November 1, 1999): 2901–8. http://dx.doi.org/10.1099/0022-1317-80-11-2901.

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It has been shown recently that the residual virulence of vaccinia virus (VV) is an important factor that influences the outcome of immunization with VV recombinants. This study focused on the correlation of the residual virulence of several VV recombinants with antibody responses against the strongly immunogenic extrinsic glycoprotein E of varicella-zoster virus and the weakly immunogenic extrinsic protein preS2–S of hepatitis B virus and against VV proteins, with mice used as a model organism. Furthermore, the effects of mixing different recombinants on the antibody response were studied. The results obtained indicated that: (i) the antibody response depended on the residual virulence of the recombinants, more so in the case of the weakly immunogenic protein; (ii) the residual virulence, the growth rate of the VV recombinants in extraneural tissues and the immunogenicity were associated features; (iii) immunization with mixtures of two differently virulent recombinants or with unequal amounts of two similarly virulent recombinants sometimes led to the suppression of antibody response. The appearance of this suppression was dependent on three factors: the residual virulence of the recombinants, the immunogenicity of the extrinsic proteins and the ratio of the recombinants in the mixtures. Thus, the data obtained demonstrate that there are various limitations to the use of replicating VV recombinants for immunization purposes.

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Lossi, Laura. "The concept of intrinsic versus extrinsic apoptosis." Biochemical Journal 479, no. 3 (February 11, 2022): 357–84. http://dx.doi.org/10.1042/bcj20210854.

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Regulated cell death is a vital and dynamic process in multicellular organisms that maintains tissue homeostasis and eliminates potentially dangerous cells. Apoptosis, one of the better-known forms of regulated cell death, is activated when cell-surface death receptors like Fas are engaged by their ligands (the extrinsic pathway) or when BCL-2-family pro-apoptotic proteins cause the permeabilization of the mitochondrial outer membrane (the intrinsic pathway). Both the intrinsic and extrinsic pathways of apoptosis lead to the activation of a family of proteases, the caspases, which are responsible for the final cell demise in the so-called execution phase of apoptosis. In this review, I will first discuss the most common types of regulated cell death on a morphological basis. I will then consider in detail the molecular pathways of intrinsic and extrinsic apoptosis, discussing how they are activated in response to specific stimuli and are sometimes overlapping. In-depth knowledge of the cellular mechanisms of apoptosis is becoming more and more important not only in the field of cellular and molecular biology but also for its translational potential in several pathologies, including neurodegeneration and cancer.

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Redner, Robert L., Anuja Chattopadhyay, Brian L. Hood, and Thomas P. Conrads. "NPM-RAR Binds to Tradd and Impedes the Extrinsic Apoptotic Pathway." Blood 120, no. 21 (November 16, 2012): 5126. http://dx.doi.org/10.1182/blood.v120.21.5126.5126.

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Abstract Abstract 5126 The t(5;17)(q35;q21) variant of Acute Promyelocytic Leukemia fuses nucleophosmin (NPM) to the retinoic acid receptor alpha (RARA). The resultant NPM-RAR fusion protein blocks myeloid differentiation, and leads to a leukemic phenotype similar to that caused by the t(15;17)(q22;q21) PML-RAR fusion. The contribution of the N-terminal 117 amino acids of NPM contained within NPM-RAR has not been well studied. NPM is a molecular chaperone, and binds to a variety of proteins implicated in leukemogenesis. We performed a proteomic analysis to identify NPM-RAR interacting proteins. Vectors encoding NPM-RAR or RARA (as control) fused in frame to calmodulin binding peptide and Protein A were expressed in HEK293 cells, and interacting proteins subjected to tryptic digest. Peptides were analyzed by nanoflow reversed-phase liquid chromatography-mass spectrometry. Amongst other targets, we identified tumor necrosis factor receptor type 1-associated DEATH domain protein (TRADD) as a distinct binding partner for NPM-RAR. TRADD did not bind to wild-type RARA or NPM, suggesting that the interaction was unique to the fusion protein. The NPM-RAR/TRADD interaction was verified by reciprocal co-precipitation. Though NPM-RAR localizes primarily in the nucleoplasm, we also found a low level of NPM-RAR/TRADD dimer in the cytoplasm utilizing confocal microscopy. Expression of NPM-RAR in U937 cells impaired TNF activation of caspase 8 and caspase 3. TNF-induced acquisition of Annexin V, generation of sub-G0/G1 nuclear content, and cleavage of PARP were all blunted, indicating that NPM-RAR blocks TNF-induced apoptosis. Our studies identify a novel mechanism through which NPM-RAR impacts leukemogenesis. Disclosures: No relevant conflicts of interest to declare.

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Shen, Jian-Ren, and Yorinao Inoue. "Low pH-Induced Dissociation of Three Extrinsic Proteins from O2-Evolving Photosystem II." Plant and Cell Physiology 32, no. 3 (April 1991): 453–57. http://dx.doi.org/10.1093/oxfordjournals.pcp.a078101.

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De Las Rivas, Javier, and Angel Roman. "Structure and evolution of the extrinsic proteins that stabilize the oxygen-evolving engine." Photochemical & Photobiological Sciences 4, no. 12 (2005): 1003. http://dx.doi.org/10.1039/b506874f.

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Zhao, Luping, Yeming Chen, Yanyun Cao, Xiangzhen Kong, and Yufei Hua. "The Integral and Extrinsic Bioactive Proteins in the Aqueous Extracted Soybean Oil Bodies." Journal of Agricultural and Food Chemistry 61, no. 40 (October 9, 2013): 9727–33. http://dx.doi.org/10.1021/jf403327e.

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Burghardt, Thomas P., and Katalin Ajtai. "Mapping global angular transitions of proteins in assemblies using multiple extrinsic reporter groups." Biochemistry 31, no. 1 (January 14, 1992): 200–206. http://dx.doi.org/10.1021/bi00116a029.

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Murata, N., P. S. Mohanty, H. Hayashi, and G. C. Papageorgiou. "Glycinebetaine stabilizes the association of extrinsic proteins with the photosynthetic oxygen-evolving complex." FEBS Letters 296, no. 2 (January 20, 1992): 187–89. http://dx.doi.org/10.1016/0014-5793(92)80376-r.

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Enami, Isao, Akinori Okumura, Ryo Nagao, Takehiro Suzuki, Masako Iwai, and Jian-Ren Shen. "Structures and functions of the extrinsic proteins of photosystem II from different species." Photosynthesis Research 98, no. 1-3 (August 21, 2008): 349–63. http://dx.doi.org/10.1007/s11120-008-9343-9.

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Simonin, Yannick, Olivier Disson, Hervé Lerat, Etienne Antoine, Fabien Binamé, Arielle R. Rosenberg, Solange Desagher, Patrice Lassus, Paulette Bioulac-Sage, and Urszula Hibner. "Calpain activation by hepatitis C virus proteins inhibits the extrinsic apoptotic signaling pathway." Hepatology 50, no. 5 (July 20, 2009): 1370–79. http://dx.doi.org/10.1002/hep.23169.

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Chapman, D. J., J. De Felice, K. Davis, and J. Barber. "Effect of alkaline pH on photosynthetic water oxidation and the association of extrinsic proteins with Photosystem Two." Biochemical Journal 258, no. 2 (March 1, 1989): 357–62. http://dx.doi.org/10.1042/bj2580357.

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Incubation of a membrane preparation enriched in Photosystem Two (PSII) at alkaline pH inhibited the water-splitting reactions in two distinct steps. Up to pH 8.5 the inhibition was reversible, whereas at higher alkalinities it was irreversible. It was shown that the reversible phase correlated with loss and rebinding of the 23 kDa extrinsic polypeptide. However, after mild alkaline treatments a partial recovery was possible without the binding of the 23 kDa polypeptide when the assay was at the optimal pH of 6.5 and in a medium containing excess Cl-. The irreversible phase was found to be closely linked with the removal of the 33 kDa extrinsic protein of PSII. Treatments with pH values above 8.5 not only caused the 33 kDa protein to be displaced from the PSII-enriched membranes, but also resulted in an irreversible modification of the binding sites such that the extrinsic 33 kDa protein could not reassociate with PSII when the pH was lowered to 6.5. The results obtained with these more extreme alkaline pH treatments support the notion that the 23 kDa protein cannot bind to PSII unless the 33 kDa protein is already bound. The differential effect of pH on the removal of the 23 kDa and 33 kDa proteins contrasted with the data of Kuwabara & Murata [(1983) Plant Cell Physiol. 24, 741-747], but this discrepancy was accounted for by the use of glycerol in the incubation media.

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Branford, O. A., D. A. Lee, K. J. Rolfe, and A. O. Grobbelaar. "The attachment of intrinsic and extrinsic, mobilized and immobilized adhesion cells to collagen and fibronectin." Journal of Hand Surgery (European Volume) 37, no. 6 (November 17, 2011): 564–72. http://dx.doi.org/10.1177/1753193411428994.

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This study investigated the attachment of intrinsic and extrinsic, mobilized and immobilized adhesion cells to the extracellular matrix. Five New Zealand White rabbit forepaws were dissected to isolate the flexor tendon core, tendon surface and synovial sheath, which were explanted separately. A further 10 animals were subjected to flexor tendon injuries, randomized to either mobilization or immobilization, and adhesions were explanted at 2 weeks. Cell groups were tested for attachment to collagen type-I or fibronectin and morphometric analysis was made. The attachment of intrinsic tendon cells and adhesion cells from mobilized tendons to both matrix proteins was statistically significantly greater than that of extrinsic tendon cells and adhesion cells from immobilized tendons. Adhesion cells from mobilized tendons were statistically significantly more elongated, which may correlate with the deposition of a more organized matrix. Because the synovial sheath cells were least attached to matrix proteins, selective treatments that reduce cell attachment may be used to exclude them, without inhibiting intrinsic tendon healing.

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Lu, I.-Ta, Shih-Chao Lin, Yi-Chia Chu, Ya Wen, You-Cheng Lin, Wen-Chien Cheng, Jyh-Horng Sheu, and Chi-Chien Lin. "(−)-Agelasidine A Induces Endoplasmic Reticulum Stress-Dependent Apoptosis in Human Hepatocellular Carcinoma." Marine Drugs 20, no. 2 (January 29, 2022): 109. http://dx.doi.org/10.3390/md20020109.

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Liver cancers, such as hepatocellular carcinoma (HCC), are a highly prevalent cause of cancer-related deaths. Current treatments to combat liver cancer are limited. (−)-Agelasidine A, a compound isolated from the methanol extract of Agelasnakamurai, a sesquiterpene guanidine derived from sea sponge, has antibacterial activity. We demonstrated its anticancer capabilities by researching the associated mechanism of (−)-agelasidine A in human liver cancer cells. We found that (−)-agelasidine A significantly reduced viability in Hep3B and HepG2 cells, and we determined that apoptosis was involved in the (−)-agelasidine A-induced Hep3B cell deaths. (−)-Agelasidine A activated caspases 9, 8, and 3, as well as PARP. This effect was reversed by caspase inhibitors, suggesting caspase-mediated apoptosis in the (−)-agelasidine A-treated Hep3B cells. Moreover, the reduced mitochondrial membrane potential (MMP) and the release of cytochrome c indicated that the (−)-agelasidine A-mediated mitochondrial apoptosis was mechanistic. (−)-Agelasidine A also increased apoptosis-associated proteins (DR4, DR5, FAS), which are related to extrinsic pathways. These events were accompanied by an increase in Bim and Bax, proteins that promote apoptosis, and a decrease in the antiapoptotic protein, Bcl-2. Furthermore, our results presented that (−)-agelasidine A treatment bridged the intrinsic and extrinsic apoptotic pathways. Western blot analysis of Hep3B cells treated with (−)-agelasidine A showed that endoplasmic reticulum (ER) stress-related proteins (GRP78, phosphorylated PERK, phosphorylated eIF2α, ATF4, truncated ATF6, and CHOP) were upregulated. Moreover, 4-PBA, an ER stress inhibitor, could also abrogate (−)-agelasidine A-induced cell viability reduction, annexin V+ apoptosis, death receptor (DR4, DR5, FAS) expression, mitochondrial dysfunction, and cytochrome c release. In conclusion, by activating ER stress, (−)-agelasidine A induced the extrinsic and intrinsic apoptotic pathways of human HCC.

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Konopleva, Marina Y., and Craig T. Jordan. "Leukemia Stem Cells and Microenvironment: Biology and Therapeutic Targeting." Journal of Clinical Oncology 29, no. 5 (February 10, 2011): 591–99. http://dx.doi.org/10.1200/jco.2010.31.0904.

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Acute myelogenous leukemia is propagated by a subpopulation of leukemia stem cells (LSCs). In this article, we review both the intrinsic and extrinsic components that are known to influence the survival of human LSCs. The intrinsic factors encompass regulators of cell cycle and prosurvival pathways (such as nuclear factor kappa B [NF-κB], AKT), pathways regulating oxidative stress, and specific molecular components promoting self-renewal. The extrinsic components are generated by the bone marrow microenvironment and include chemokine receptors (CXCR4), adhesion molecules (VLA-4 and CD44), and hypoxia-related proteins. New strategies that exploit potentially unique properties of the LSCs and their microenvironment are discussed.

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Vannakambadi, Ganesh, Magnus Höök, Pietro Speziale, and Jose Rivera. "Fibrinogen-binding proteins of Gram-positive bacteria." Thrombosis and Haemostasis 98, no. 09 (2007): 503–11. http://dx.doi.org/10.1160/th07-03-0233.

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SummaryFibrinogen (Fg), the major clotting protein in blood plasma, plays key roles in blood coagulation and thrombosis. In addition, this 340 kD glycoprotein is a stress inducible protein; its synthesis is dramatically upregulated during inflammation or under exposure to stress such systemic infections.This regulation of Fg expression indicates that Fg also participates in the host defense system against infections. In fact, a number of reported studies have demonstrated the involvement of both the intrinsic and extrinsic pathways of coagulation; the thrombotic and the fibrinolytic systems in the pathophysiology of infectious diseases. It is, therefore, perhaps not surprising that many pathogenic bacteria can interact with Fg and manipulate its biology.This review focuses on the major Fg-binding proteins (Fgbps) from Gram-positive bacteria with an emphasis on those that are known to have an effect on coagulation and thrombosis

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Resanović, Ivana, Emina Sudar-Milovanović, Nikola Bogdanović, Aleksandra Jovanović, Sonja Zafirović, Anastasija Panić, and Esma Isenović. "Fundamentals of apoptosis." Medicinska istrazivanja 49, no. 3 (2015): 42–45. http://dx.doi.org/10.5937/medist1502042r.

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Apoptosis is evolutionary conserved, programmed pattern of cell death with an essential role in various physiological processes, such as normal cell turnover and embryonic development, hormone-regulated cell demise, aging, immune system functioning and development and removal of defective and harmful cells. There are two general pathways for activation of apoptosis: the intrinsic and extrinsic pathways. While the intrinsic apoptotic pathway can be triggered by a cytotoxic accumulation of intracellular Ca 2+ , followed permeabilization of mitochondrial membrane and release of pro-apoptotic proteins into the cytosol from mitochondria, the extrinsic mechanisms of apoptosis include the participation of death receptors of tumor necrosis factor-a (TNF-a), receptor superfamily such as TNFR-1, Fas, and TNF-related apoptosis-inducing ligand receptors (TRAIL-R) located on the plasma membrane. There is also the perforin-granzyme pathway that involves T-cell mediated cytotoxicity. All three pathways converge on the same execution pathway, resulting in DNA fragmentation, degradation of cytoskeletal and nuclear proteins, cross-linking of proteins, formation of apoptotic bodies, expression of ligands for phagocytic cell receptors and finally uptake by phagocytic cells. In this review we summarize data from recent studies focusing on apoptotic proteins that have been identified and molecular mechanisms of apoptosis. Understanding apoptotic mechanism might provide useful information and a new approach to prevention and development of new therapies for variety of diseases.

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McNulty, A. K., and M. J. Saunders. "Purification and immunological detection of pea nuclear intermediate filaments: evidence for plant nuclear lamins." Journal of Cell Science 103, no. 2 (October 1, 1992): 407–14. http://dx.doi.org/10.1242/jcs.103.2.407.

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A major structural component of the inner face of the nuclear envelope in vertebrates and invertebrates is the nuclear lamina, an array of 1–3 extrinsic membrane proteins, lamins A, B and C. These proteins are highly homologous to intermediate filaments and are classified as type V. We report the first purification, antigenic characterization and immunocytochemical localization of putative plant lamin proteins from pea nuclei. We conclude that plant cells contain this ancestral class of intermediate filaments in their nuclei and that regulation of nuclear envelope assembly/disassembly and mitosis in plants may be similar to that in animal cells.

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Kang, Tse Siang, Wan Chen, Leng Chuan Goh, and Manjunatha Kini. "Identification and characterisation of novel inhibitors on extrinsic tenase complex from Bungarus fasciatus (banded krait) venom." Thrombosis and Haemostasis 112, no. 10 (2014): 700–715. http://dx.doi.org/10.1160/th13-12-1063.

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SummarySnake venoms are excellent sources of pharmacologically active proteins and peptides, and hence are potential sources of leads for drug developments. It has been previously established that krait (Bungarus genus) venoms contain mainly neurotoxins. A screening for anticoagulants showed that Bungarus fasciatus venom exhibits potent anticoagulant effect in standard clotting assays. Through sequential fractionation of the venom by size exclusion and high performance liquid chromatographies, coupled with functional screening for anticoagulant activities, we have isolated and purified two anticoagulant proteins, termed BF-AC1 ( Bungarus fasciatus anticoagulant 1) and BFAC2. They have potent inhibitory activities (IC50 of 10 nM) on the extrinsic tenase complex. Structurally, these proteins each has two subunits covalently held together by disulfide bond(s). The N-terminal sequences of the individual subunits of BF-AC1 and BF-AC2 showed that the larger subunit is homologous to phospholipase A2, while the smaller subunit is homologous to Kunitz type serine proteinase inhibitor. Functionally, in addition to their anticoagulant activity, these proteins showed presynaptic neurotoxic effects in both in vivo and ex vivo experiments. Thus, BF-AC1 and BF-AC2 are structurally and functionally similar to β-bungarotoxins, a class of neurotoxins. The enzymatic activity of phospholipase A2 subunit plays a significant role in the anticoagulant activities. This is the first report on the anticoagulant activity of β-bungarotoxins and these results expand on the existing catalogue of haemostatically active snake venom proteins.

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Stillman, J. H., and G. N. Somero. "A comparative analysis of the evolutionary patterning and mechanistic bases of lactate dehydrogenase thermal stability in porcelain crabs, genus Petrolisthes." Journal of Experimental Biology 204, no. 4 (February 15, 2001): 767–76. http://dx.doi.org/10.1242/jeb.204.4.767.

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The kinetic properties of orthologous homologs (orthologs) of enzymes are typically correlated with environmental temperatures in species adapted to different thermal regimes, but correlations between adaptation temperature and enzyme thermal stability are less clear. Although the thermal stability of a protein is related chiefly to its primary structure (including post-translational modification), thermal stability can also be altered by extrinsic factors present in the intracellular milieu. Here, we present a comparative analysis of the thermal stability of lactate dehydrogenase (LDH) orthologs from 22 congeneric species of porcelain crab (genera Petrolisthes and Allopetrolisthes) from a broad range of thermal habitats. Interspecific diversity of LDH stability is high: temperatures required for a 50 % loss of activity in 10 min ranged from 65 to 75.5 degrees C, corresponding to half-lives of less than 1 min to more than 3 h at 70 degrees C. Although stability is positively correlated with maximal habitat temperature in some sister taxa, phylogenetic comparative analysis incorporating all 22 species does not indicate that the interspecific diversity of LDH stability represents an adaptive response to current thermal habitats. Examination of the mechanistic bases of LDH stabilization indicates that differences in stability are related both to properties of the LDH molecule itself (intrinsic stability) and to the effects of extrinsic protein(s). Intrinsic differences were shown by the unfolding of structure during heating, as measured by circular dichroism spectroscopy. Stabilizing effects of extrinsic proteins are implied by the results of cellular fractionation experiments that removed low-molecular-mass solutes and proteins from the muscle homogenates. We conclude that the overall structural stability and functional properties of proteins can evolve independently and that in vivo protein-protein interactions can provide another means to regulate protein stability selectively.

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Shirakawa, Yuki, Kunimasa Ohta, Shunsuke Miyake, Ayumi Kanemaru, Akari Kuwano, Kou Yonemaru, Shota Uchino, et al. "Glioma Cells Acquire Stem-like Characters by Extrinsic Ribosome Stimuli." Cells 10, no. 11 (November 1, 2021): 2970. http://dx.doi.org/10.3390/cells10112970.

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Although glioblastoma (GBM) stem-like cells (GSCs), which retain chemo-radio resistance and recurrence, are key prognostic factors in GBM patients, the molecular mechanisms of GSC development are largely unknown. Recently, several studies revealed that extrinsic ribosome incorporation into somatic cells resulted in stem cell properties and served as a key trigger and factor for the cell reprogramming process. In this study, we aimed to investigate the mechanisms underlying GSCs development by focusing on extrinsic ribosome incorporation into GBM cells. Ribosome-induced cancer cell spheroid (RICCS) formation was significantly upregulated by ribosome incorporation. RICCS showed the stem-like cell characters (number of cell spheroid, stem cell markers, and ability for trans differentiation towards adipocytes and osteocytes). In RICCS, the phosphorylation and protein expression of ribosomal protein S6 (RPS6), an intrinsic ribosomal protein, and STAT3 phosphorylation were upregulated, and involved in the regulation of cell spheroid formation. Consistent with those results, glioma-derived extrinsic ribosome also promoted GBM-RICCS formation through intrinsic RPS6 phosphorylation. Moreover, in glioma patients, RPS6 phosphorylation was dominantly observed in high-grade glioma tissues, and predominantly upregulated in GSCs niches, such as the perinecrosis niche and perivascular niche. Those results indicate the potential biological and clinical significance of extrinsic ribosomal proteins in GSC development.

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Journal articles on the topic 'Extrinsic proteins'

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