Kliknij ten link, aby zobaczyć inne rodzaje publikacji na ten temat: Protein and mRNA levels.
Rozprawy doktorskie na temat „Protein and mRNA levels”
Utwórz poprawne odniesienie w stylach APA, MLA, Chicago, Harvard i wielu innych
Sprawdź 50 najlepszych rozpraw doktorskich naukowych na temat „Protein and mRNA levels”.
Przycisk „Dodaj do bibliografii” jest dostępny obok każdej pracy w bibliografii. Użyj go – a my automatycznie utworzymy odniesienie bibliograficzne do wybranej pracy w stylu cytowania, którego potrzebujesz: APA, MLA, Harvard, Chicago, Vancouver itp.
Możesz również pobrać pełny tekst publikacji naukowej w formacie „.pdf” i przeczytać adnotację do pracy online, jeśli odpowiednie parametry są dostępne w metadanych.
Przeglądaj rozprawy doktorskie z różnych dziedzin i twórz odpowiednie bibliografie.
1
Simion, Oana-Maria. "Uncoupling proteins mRNA levels in mice lacking acylation-stimulating protein." Thesis, McGill University, 2001. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=33018.
Pełny tekst źródłaStreszczenie:
The etiology of obesity involves imbalanced energy intake and utilization. ASP is an adipose tissue hormone that facilitates adipocyte uptake of serum fatty acids and their storage. Mice lacking ASP have less adipose tissue mass, despite increased food intake, than wild-type littermates. We hypothesize that the unstored fuels are oxidized through UCP (thermogenic mitochondrial carriers).<br>In male ASP-deficient mice mRNA levels were measured by semi-quantitative RT-PCR and the following changes were observed: UCP-1 decreased in all tested tissues, UCP-2 increased by 15% and 6 fold in muscle and white adipose tissue and UCP-3 increased 2.5 and 10 fold in muscle and epididymal adipose tissue, respectively. In female ASP-deficient mice UCP-1 decreased in all tissues, UCP-2 increased by 10% and 40% in inguinal and brown adipose tissue, respectively, and UCP-3 remained stable in all tissues. High fat diet nullified these differences, and decreased all wild-type UCP levels.<br>We propose that UCP-2 and 3 assume the role of UCP-1 in fuel utilization, thus helping mice face an increased energy load in the absence of ASP.
2
Byström, Jonas. "Eosinophil Cationic Protein : Expression Levels and Polymorphisms." Doctoral thesis, Uppsala University, Department of Medical Sciences, 2002. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-2059.
Pełny tekst źródłaStreszczenie:
<p>The eosinophil cationic protein (ECP) is usually associated with the eosinophil granulocyte. In this thesis the presence and production of this protein has been studied in two other cells. The circulating monocyte was found to contain ECP mRNA and small amounts of ECP, one thousand times less than that found in the eosinophil. The production decreased by differentiation of the myelomonoblastic cell line U937 into a macrophage phenotype. Submucosal lung macrophages did not stain for ECP and alveolar macrophages did not contain ECP mRNA. The circulating neutrophil contains ECP at a level hundred fold less than the eosinophil. We found that the protein is located to the primary granules of the neutrophil but could detect no ECP mRNA in the cell. It was shown in vitro that the protein was taken up by the cell and partly transported to the primary granules. The uptake did not seem to be receptor mediated. Upon stimulation of the neutrophils, ECP previously taken up, was re-secreted. </p><p>The ECP protein is heterogeneous both to molecular characteristics and to function. To evaluate if a genetic component is involved, the ECP gene was analysed in 70 individuals. Three single nucleotide polymorphisms (SNP´s) were found, denoted 277(C>T), 434(G>C) and 562(G>C). The two first were located to the mature peptide-coding region and would change the amino acids, arg45cys and arg97thr. The prevalence of the most common SNP, 434, was evaluated in two eosinophil-related diseases, allergy/asthma and Hodgkin Lymphoma (HL). Forty-three HL patients were evaluated and it was found that the 434GG was significantly more prevalent in patients having nodular sclerosis (NS) as compared to other histologies (p=0.03). Erythrocyte sedimentation rate was also related to the 434GG genotype (p=0.009). In 209 medical students 434GG was more common (p=0.002) in those who indicated allergy. The genotype was unrelated to the production of IgE antibodies to allergens. In analysis of 76 subjects with asthma it was found that the 434GG genotype was significantly more common among allergic asthmatics (p=0.04). Asthma and HL-NS are characterized by fibrosis and eosinophils and ECP has been suggested in fibrosis development. </p>
3
Kachra, Zarin. "Regulation of insulin-like growth factor-I (IGF-I) and IGF-binding protein-1 (IGFBP-1) mRNA levels in cultured rat hepatocytes." Thesis, McGill University, 1993. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=41300.
Pełny tekst źródłaStreszczenie:
The liver is a major site of production of circulating levels of insulin-like growth factor-I (IGF-I) and IGF-binding proteins (IGFBPs). We have used primary cultured rat hepatocytes maintained under serum free conditions to explore the regulatory role of various hormones on hepatic IGF-I and IGFBP-1 mRNA levels.<br>IGF-I mRNA levels were stimulated 2.0 to 2.5 fold by bovine growth hormone (bGH) and 1.8 to 2.0 fold by glucagon but on combining bGH and glucagon, a synergistic effect was observed and IGF-I mRNA level was augmented 10 to 12 fold. Octreotide blocked the hGH induced stimulation of IGF-I production in serum and hepatic IGF-I mRNA levels in hypophysectomized rats. This effect could have been partly due to the low levels of glucagon in serum when hypophysectomized rats were treated with hGH and octreotide. Octreotide was also found to inhibit GH stimulated IGF-I mRNA levels in rat hepatocytes.<br>The unique synergy observed with glucagon and bGH on IGF-I mRNA levels in hepatocytes was not reproduced by T$ sb3$, oPRL, dexamethasone, EGF or insulin when each was added in combination with bGH or glucagon. Like glucagon, the addition of IBMX or (Bu)$ sb2$cAMP stimulated IGF-I mRNA levels 1.8 to 2.0 fold, but in the presence of bGH, IGF-I mRNA levels were stimulated 10 to 12 fold. PMA stimulated IGF-I mRNA levels 1.2 to 1.4 fold but displayed no synergism when added with bGH. The stimulatory effect of bGH plus glucagon on IGF-I mRNA levels was inhibited in PKC depleted cells, in the presence of inhibitors of PKC and in the presence of cycloheximide. bGH had no posttranscriptional effect on IGF-I mRNA stability whereas glucagon or (Bu)$ sb2$cAMP stabilized IGF-I mRNA at a posttranscriptional level.<br>In summary, the major hormonal regulators of hepatic IGF-I mRNA levels appear to be GH and glucagon. Hepatic IGF-I mRNA levels are regulated by pathways involving protein kinase C and, protein kinase A as well as by synthesis of one or more protein(s).<br>Glucagon and dexamethasone each stimulated IGFBP-1 mRNA levels 3 to 4 fold whereas bGH and T$ sb3$ each inhibited IGFBP-1 mRNA levels 45 to 70%. Insulin, which inhibited IGFBP-1 mRNA levels 95%, was the most powerful inhibitor and was also found to inhibit IGFBP-1 mRNA levels in the presence of dexamethasone. IBMX and (Bu)$ sb2$cAMP stimulated IGFBP-1 mRNA levels 6 to 8 fold whereas PMA inhibited IGFBP-1 mRNA levels 40 to 50%. The inhibitory effect of bGH on IGFBP-1 mRNA levels was abolished in PKC depleted cells and also in the presence of inhibitors of PKC. In the presence of cycloheximide, IGFBP-1 mRNA was superinduced by bGH. bGH had no posttranscriptional effect on IGFBP-1 mRNA whereas glucagon and (Bu)$ sb2$cAMP stabilized IGFBP-1 mRNA at a postranscriptional level.<br>In summary, bGH, T$ sb3$ and insulin inhibited whereas dexamethasone and glucagon stimulated IGFBP-1 mRNA levels in hepatocytes. Effect of glucagon may be via elevation of cAMP levels, whereas the effect of bGH may be via activation of PKC levels. The inhibitory effect of bGH appears to require synthesis of one or more protein(s) besides stimulation of PKC levels.
4
Schwanhäußer, Björn. "Global analysis of cellular protein dynamics by pulse-labeling and quanti tati ve mass spectrometry." Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät I, 2011. http://dx.doi.org/10.18452/16305.
Pełny tekst źródłaStreszczenie:
Der erste Teil der Arbeit beschreibt die Etablierung einer modifizierten Form des klassichen SILAC-Verfahrens, das in der quantitativen Massenspektrometrie zur Bestimmung von relativen Änderungen in Proteinmengen benutzt wird. Im sog. „pulsed SILAC (pSILAC)“ Verfahren werden Zellen im Zuge einer differentiellen Behandlung in Kulturmedien transferiert, die unterschiedlich Isotop-markierte Aminosäuren enthalten. Da hier die Quantifizierung auf dem Verhältnis der neusynthetisierten Proteinmengen beruht, können gezielt Unterschiede in der Proteinproduktion bestimmt werden. Mit Hilfe von pSILAC konnte im zweiten Teil der Arbeit erstmals quantitativ erfasst werden, welchen Einfluss microRNAs auf die Proteinsynthese ausüben. So konnte gezeigt werden, dass sowohl die Überexpression als auch die Repression einzelner microRNAs die Produktion hunderter Proteine beeinflussen kann. Außerdem konnten Genprodukte identifiziert werden, die ausschließlich translational reguliert werden. Die Messung von Proteinneusynthese ermöglichte auch die Bestimmung von Proteinumsatzraten, dargestellt im dritten Teil der Arbeit. Zusammen mit mRNA-Umsatzraten sowie Protein- und mRNA-Mengen bilden sie die Grundlage für eine dynamische Beschreibung zelluärer Genexpression. Durch den gleichzeitigen Einsatz des Nukleosidanalogons 4-Thiouridin (4sU) und von schweren Aminosäuren (SILAC) konnte eine metabolische Markierung neusynthetiserter mRNAs und Proteine in murinen Fibroblasten erreicht und damit eine Berechnung von Protein- und mRNA-Halbwertszeiten und absoluten Mengen für ca. 5,000 Gene ermöglicht werden. Während mRNA- und Proteinenmengen deutlich korrelierten, war zwischen mRNA- und Proteinhalbwertszeiten nur eine äußerste schwache Korrelation zu erkennen. Dennoch stehen mRNA- und Proteinumsatzraten nicht einem willkürlichen Zusammhang zu einander, da bestimmte Kombinationen von mRNA- und Proteinhalbwertszeiten eine Optimierung von Genen hinsichtlich ihrer biologischen Funktionen erkennen ließen.<br>The first part of the thesis describes the establishment of a modified version of the classic SILAC approach routinely used in quantitative mass spectrometry (MS) to assay relative changes in protein levels. In the newly-devised approach termed pulsed SILAC (pSILAC) differentially treated cells are transferred to culture medium supplemented with different versions of stable-isotope labeled heavy amino acids. As MS-based relative quantification is exclusively based on the newly-synthesized heavy protein amounts the method enables the detection of differences in protein production resulting from the treatment. The second part of the thesis shows the use of pSILAC to globally quantify the impact of microRNAs onto the proteome. Ectopic over-expression or knock-down of a single microRNA both affected protein production of hundreds of proteins. pSILAC identified several target genes as exclusively translationally regulated as changes in corresponding transcript levels were virtually absent. Measuring newly-synthesized protein amounts with heavy amino acids in a pulsed-labeling fashion has also been used to determine turnover rates of individual proteins, described in the third part of the present work. Along with transcript turnover as well as mRNA and protein levels they are essential for a dynamic description of gene expression. Simultaneous application of the nucleoside analogue 4-thiouridine (4sU) and heavy amino acids (SILAC) to metabolically label newly-produced mRNAs and proteins in mouse fibroblasts resulted in the calculation of mRNA and protein lifetimes and absolute levels for approximately 5,000 genes. While mRNA and protein levels were overall well correlated, a correlation between mRNA and protein half-lives was virtually absent. Yet this seemingly chaotic distribution of mRNA and protein half-lives was highly instructive since specific gene subsets have obviously evolved distinct combinations of half-lives that relate to their biological functions.
5
Van, Rooyen Marina. "The modulating effect of myo-inositol and other antidepressants on the mRNA levels and protein expression of selected subcellular enzymes / Marina van Rooyen." Thesis, North-West University, 2005. http://hdl.handle.net/10394/504.
Pełny tekst źródłaStreszczenie:
myo-lnositol (mIns), a natural component of the human diet and essential precursor of
several signalling pathways, including that of G protein-coupled receptors, has also been
shown to be effective in the treatment of psychiatric disorders such as depression, obsessive
compulsive disorder and panic disorder. Most likely since mlns is a simple isomer of
glucose, no serious side effects have been reported with its use, even at high oral doses of
mlns. Previous studies suggest that the therapeutic action of mlns may include reduced
serotonin 5HTzA and muscarinic acetylcholine receptor function. An important signal
transduction system that may possibly be involved in the mechanism of action of
antidepressants is phosphoinositide (PI) turnover. In this signalling system PI-phospholipase
C (PLCpl), that is implicated in the in the mechanism of action of antidepressants and
anxiolytics, is activated.
The mechanism of action of mlns, however, still remains elusive and needs further
investigation. In this study a possible modulatory role of 24-hour pre-treatment of human
neuroblastoma cell line (SH-SY5Y) with mlns on mRNA levels and protein expression of
phospholipase C-p1 (PLCP1) and glycogen synthase kinase 3P (GSK3p) was investigated.
The effects of mlns were also compared to that of other prototype antidepressants, such as
fluoxetine (a selective serotonin reuptake inhibitor), imipramine (a tricyclic antidepressant),
lithium and another drug with potential antidepressant effects, sildenafil (phosphodiesterase
5-type (PDE5) inhibitor). Real-time reverse transcription Polymerase Chain Reaction (RTPCR)
was performed in order to investigate the mRNA levels, while protein expression in
membranes and the cytosol fraction of cells were quantified with Western blots.
The expression of PLCPl was decreased after pre-treatments with imipramine or myoinositol
in combination with fluoxetine. In addition, sildenafil alone or in combination with
myo-inositol, also decreased the expression of membrane-bound PLCp1. However, a 24-
hour pre-treatment with lithium did not alter PLCPl expression significantly. Determined
mRNA levels for the expression of PLCPl were consistent in these findings, except for the
inhibition of the mRNA for the expression of PLCPl also after lithium treatment. The reduced
PLCpl mRNA levels after lithium pre-treatment may suggest the involvement of posttranscriptional
modification (or delayed translational effects) of PLCpl after lithium treatment.
The data from the current study suggest that antidepressant action may include
downregulation of PLCPl expression and that modulators of the nitric oxidecGMP pathway
(e.g. sildenafil as a PDE5 inhibitor) may exhibit similar properties.<br>Thesis (M.Sc. (Pharmacology))--North-West University, Potchefstroom Campus, 2005.
6
Peter, Martina Andrea. "Growth hormone-dependent expression and regulation of insulin-like growth factor (IGF) I and IGF binding protein mRNA levels in rat tissues in vivo /." [S.l.] : [s.n.], 1993. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=10291.
Pełny tekst źródła
7
Kogan, Cary. "The expression of neurofilament protein and mRNA levels in the lateral geniculate nucleus and area V1 of the developing and adult vervet monkey (Ceorcopithicus aethiops) /." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape10/PQDD_0028/MQ50807.pdf.
Pełny tekst źródła
8
Beyerle, Jolantha [Verfasser], and Heinz [Akademischer Betreuer] Schmeiser. "Assessment of mRNA, protein levels and activities of xenobiotic metabolizing enzymes in colon and rectal mucosa of colorectal cancer patients / Jolantha Beyerle ; Betreuer: Heinz Schmeiser." Heidelberg : Universitätsbibliothek Heidelberg, 2016. http://d-nb.info/1180736281/34.
Pełny tekst źródła
9
Arslan, Sevki. "Effects Of Benzene On Liver, Kidney And Lung Cyp1a, Cyp2b4, Cyp2e1 And Cyp3a6 Mrna, Protein Level, And Drug Metabolizing Enzyme Activities And Toxicity In Diabetic Rabbits." Phd thesis, METU, 2008. http://etd.lib.metu.edu.tr/upload/3/12609446/index.pdf.
Pełny tekst źródłaStreszczenie:
The effects of diabetes on cytochrome P450 dependent drug metabolizing enzymes have not to be clarified yet. The most widely used animals in these studies have been rats, and information regarding the effects of diabetes on cytochrome P450 dependent procarcinogen/carcinogen metabolism in rabbits is limited. In the present study, we investigated, for the first time, the influence of benzene on liver, kidney and lung microsomal cytochrome P450 dependent drug metabolizing enzyme activities, protein and mRNA levels in diabetic and non-diabetic rabbits.
Male New Zealand rabbits were made diabetic by a single dose of alloxan treatment in this study. AST, ALT and LDH enzyme activities in the blood serum and lipid peroxidation in liver microsomes were found to increase in diabetic, benzene treated and benzene treated diabetic rabbits. Besides these, CYP2E1 dependent NDMA N-demethylase and p-nitrophenol hydroxylase activities and CYP2E1 protein level were found to increase in liver and kidney of diabetic and benzene-treated rabbits. The combined effects of benzene and diabetes on these activities and protein level were found to be additive. Although diabetes caused induction of pulmonary CYP2E1 protein level and associated enzyme activities, benzene treatment of rabbits resulted in no change in enzyme activities and protein level in lung. The level of mRNA was investigated by Real-Time PCR. Accordingly, hepatic CYP2E1 mRNA level was increased 6.71-, 10.53- and 12.93-fold in diabetic, benzene treated and benzene treated diabetic rabbits with respect to the control animals. Similarly, renal CYP2E1 mRNA level was found in increase in these rabbits. In addition to CYP2E1, CYP3A6 associated enzyme activity, erythromycin N-demethylase, CYP3A6 protein and mRNA level were found to increase in diabetic rabbit liver and lung. Unlike diabetes, benzene treatment caused suppression of CYP3A6 protein and inhibition of associated enzyme activity in liver. There was no significant change in the erythromycin N-demethylase activity and CYP3A6 level of liver and lung as a result of benzene treatment of diabetic rabbits. Moreover, diabetes induced CYP1A2 protein and mRNA level and CYP1A associated enzyme activities in the rabbit liver. On the other hand, benzene caused statistically insignificant decreases in CYP1A dependent enzyme activities and CYP1A2 protein level in liver. CYP1A associated enzyme activities, CYP1A2 protein and mRNA levels were not changed in the liver of benzene treated diabetics.
The results of the present work indicate that both diabetes and benzene stimulate metabolic activation toxic chemicals metabolized by CYP2E1 such as NDMA and benzene by inducing CYP2E1 which results in the formation of increased amounts of reactive metabolites. Application of benzene to diabetic rabbits further elevates expression and activities of the CYP2E1. As a result of additive induction of the CYP2E1 in benzene treated diabetics, further increase the risk of hepatotoxicity produced by toxins may be observed when compared to the separate treatments. This may in turn further potentiate the risk of organ toxicity and mutagenesis in liver and kidney of these subjects. As in the case of CYP2E1, the risk of carcinogenesis due to induction of CYP1A may be increased in diabetic subjects. Moreover, in diabetic and benzene exposed subjects, alteration of drug clearance and clinical drug toxicity may be observed due to induction or suppression of CYP3A.
10
Beresford, Guy William. "Control of glucokinase and mRNA levels in hepatocytes." Thesis, University of Newcastle Upon Tyne, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.386292.
Pełny tekst źródła
11
Alqara, Yazan Ali. "Protein Interactions in mRNA Methylation Complexes." ScholarWorks@UNO, 2013. http://scholarworks.uno.edu/honors_theses/28.
Pełny tekst źródłaStreszczenie:
Experiments were performed to test sequence and structural specific interactions of proteins with a conserved RNA modification enzyme, which is known as Ime4 in yeast and Mettl3 in mammals. Ime4 methylates N6-adenosine bases on mRNA molecules. The goal of this project is to gain direct insights into how novel proteins interact with Ime4 to form the methyltranferase (MTase) complex and to identify proteins that are essential for Ime4 activity. It has been recognized that there are two proteins that interact within the Ime4 complex, which are known as Mum2 (a cytoplasmic protein essential for meiotic DNA replication within yeast) and Slz1 (a transcription factor). We hypothesize that the N-terminal domain of Ime4 is the location of binding of the aforementioned proteins in this complex. Similarly, we tested whether the human ortholog of Ime4 (Mettl3) forms an analogous complex that includes an ortholog of Mum2, known as WTAP, and its binding partner WT1. The major approaches include in vivo genetic assays in yeast to test protein-protein interactions and the use of recombinant DNA technology to construct fusion genes/deletions. The results demonstrate that Mum2 interacts with a specific, non-conserved region in the Ime4 N-terminal domain. Furthermore, we discovered a new binding partner, Ygl036w, which also interacts with Ime4. Currently, several experiments are being carried out with the Mettl3 complex and its hypothesized protein binding partners to assess the interactions of this complex.
12
Jones, David G. L. "Regulation of chick fibronectin mRNA levels by steroid hormones." Thesis, University of Manchester, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.277354.
Pełny tekst źródła
13
Vail, Daniel Robert. "Artemisinin Biosynthesis: Developmental and Sugar Regulation of mRNA Levels." Digital WPI, 2008. https://digitalcommons.wpi.edu/etd-theses/415.
Pełny tekst źródłaStreszczenie:
Artemisinin, produced by the plant Artemisia annua, is a sesquiterpene anti-malarial therapeutic. Due to the medicinal relevance of this plant product, there is significant interest in understanding how the biosynthetic pathway is regulated at several key steps. The objective of this study is to examine several factors known to influence artemisinin yields to determine if those effects are occurring at the transcriptional level of the biosynthetic pathway. Artemisinin content has been shown to increase as the plant shifts from vegetative growth to reproductive, flowering growth. To test whether there is a corresponding increase in terpenoid gene expression during the shift to reproductive growth, levels of mRNA of terpenoid genes were measured during flowering budding and full flowering and compared to those measured during vegetative growth. Results indicate that in response to the photoperiod signal to shift to reproductive growth, early cytosolic pathway genes were highly upregulated, while there was no change in early plastidic pathway genes. Late pathway genes specific to artemisinin synthesis were upregulated >6-fold. Furthermore, glucose has also been shown to stimulate artemisinin production compared to sucrose. To test whether glucose is acting as signal to increase terpenoid gene expression, levels of mRNA of terpenoid genes were measured in glucose- and fructose-treated seedlings and compared to those in sucrose-treated seedlings. Results indicate that in response to treatment with glucose, compared with sucrose, early pathway genes in both compartments were initially upregulated. Transcript levels subsequently decreased to levels similar to those in sucrose-treated seedlings. ADS was upregulated by glucose, compared with sucrose, reaching a peak at day 7. Finally, coordinate control of sterol and sesquiterpene synthesis at a critical branch-point in the terpenoid biosynthetic pathway has been demonstrated. To test whether amorpha-4,11-diene synthase (ADS) and squalene sythase (SQS) are coordinately regulated, levels of mRNA of those two genes were measured and compared in both experimental conditions. Results indicate that under the conditions used in this study, ADS and SQS did not show coordinate regulation. This study was the first to demonstrate that: 1. terpenoid genes relating to artemisinin biosynthesis are regulated at the level of transcript accumulation as the plant shifts from vegetative to reproductive growth; 2. glucose is acting as a signal in artemisinin biosynthesis by upregulating transcript levels for several terpenoid genes.
14
Wilson, Timothy Craig. "The role of mRNA stability and Fos protein in transient c-fos mRNA accumulation." Thesis, University of Cambridge, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.304567.
Pełny tekst źródła
15
Chernov, Konstantin Grigorievich. "Interplay of YB-1 between tubulin and mRNA." Thesis, Evry-Val d'Essonne, 2008. http://www.theses.fr/2008EVRY0040/document.
Pełny tekst źródłaStreszczenie:
YB-1 est un régulateur important de l’expression des gènes dans les cellules eucaryotes. En plus de son rôle dans la transcription, YB-1 joue un rôle clé dans la traduction et la stabilisation des ARN messagers. Nous avons identifié plusieurs nouveaux partenaires de la protéine YB-1 par chromatographie d’affinité à partir de différents extraits tissulaires. Parmi ces partenaires, nous avons démontré que YB-1 interagit avec la tubuline et les microtubules et stimule fortement l'assemblage des microtubules in vitro. Les microtubules assemblés en présence de YB-1 ont une ultrastructure normale, et les données montrent que YB-1 recouvre probablement la surface extérieure des microtubules. De la même façon YB-1 stimule aussi l'assemblage de la tubuline-MAP qui est plus proche des complexes protéiques qui existent dans la cellule, et de la tubuline clivée par subtilisine ce qui suggère que son interaction avec la tubuline ne relève pas seulement d’effets électrostatiques. Nous avons enfin découvert que la tubuline interfère avec la formation des complexes ARNm:YB-1. Ces résultats suggèrent que YB-1 peut réguler l'assemblage des microtubules in vivo et que son interaction avec la tubuline peut contribuer à la régulation de la traduction des ARN messagers. En effet, in vivo, la traduction des mRNPs dépend de l’état de saturation de l’ARN messager par YB-1. Nous avons montré ici que lorsque le rapport YB-1:ARNm est faible, les complexes mRNPs possèdent des structures non-compactes, alors que les mRNPs saturés sont compacts. Ce changement structural est observé de façon parallèle à l'inhibition de la traduction des ARN messagers lorsqu’ils passent des polysomes (traduits) aux mRNPs libres (non traduits). De façon intéressante, nous avons découvert que les mRNPs saturés se lient aux microtubules via des interactions protéine:protéine et ont tendance à former des agrégats sur la surface des microtubules. Cette dernière propriété pourrait contribuer à la formation de granules de stress et à la localisation des mRNPs dans le cytoplasme. Finalement, un modèle de diffusion facilité a été développé pour expliquer l'assemblage des microtubules orchestré par les polyamines naturelles (telles que YB-1 qui sont positivement chargées dans la cellules). L’ensemble de ces données contribuent à une meilleure compréhension de processus biologiques fondamentaux concernant l’assemblage de la tubuline en microtubules et le trafic des ARN dans la cellule. Ils pourraient avoir un intérêt pour développer de nouveaux médicaments qui ciblent les microtubules<br>YB-1 is a major regulator of gene expression in eukaryotic cells. In addition to its role in transcription, YB-1 plays a key role in translation and stabilization of mRNAs. We identify several novels YB-1 protein partners by affinity chromatography of different tissue extracts. We observed that YB-1 interacts with tubulin and microtubules and stimulates microtubule assembly in vitro. Microtubules assembled in the presence of YB-1 exhibited a normal single wall ultrastructure where YB-1 probably coats the outer microtubule wall. Furthermore, we found that YB-1 also promotes the assembly of MAPs-tubulin and subtilisin-treated tubulin. Additionally, we demonstrated that tubulin interferes with mRNA:YB-1 complexes. These results suggest that YB-1 may regulate microtubule assembly in vivo and that its interaction with tubulin may contribute to the control of mRNA translation. The translational status of mRNPs in vivo depends on amount of YB-1 associated with mRNA. We show here that at low YB-1:mRNA ratios mRNP complexes possess an incompact structures, whereas saturated mRNPs are compact. This structural change corresponds to translation inhibition when mRNA moves from polysomal (translatable) to free (untranslatable) mRNPs. Saturated mRNPs bind to microtubules via protein:protein interactions and tend to self-aggregate on microtubule surface. This property could contribute to stress granule formation, mRNPs traffic and localization of translation apparatus within cytoplasm. Finally, the facilitated diffusion model was developed to explain enhancement of microtubule assembly by positively charged natural polyamines in living cells. Altogether our data contribute to the understanding of fundamental biological processes
16
Zhang, Jingji. "Accuracy of mRNA Translation in Bacterial Protein Synthesis." Doctoral thesis, Uppsala universitet, Struktur- och molekylärbiologi, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-262901.
Pełny tekst źródłaStreszczenie:
Reading of messenger RNA (mRNA) by aminoacyl-tRNAs (aa-tRNAs) on the ribosomes in the bacterial cell occurs with high accuracy. It follows from the physical chemistry of enzymatic reactions that there must be a trade-off between rate and accuracy of initial tRNA selection in protein synthesis: when the current accuracy, the A-value, approaches its maximal possible value, the d-value, the kinetic efficiency of the reaction approaches zero. We have used an in vitro system for mRNA translation with purified E. coli components to estimate the d- and A-values by which aa-tRNAs discriminate between their cognate and near cognate codons displayed in the ribosomal A site. In the case of tRNALys, we verified the prediction of a linear trade-off between kinetic efficiency of cognate codon reading and the accuracy of codon selection. These experiments have been extended to a larger set of tRNAs, including tRNAPhe, tRNAGlu, tRNAHis, tRNACys, tRNAAsp and tRNATyr, and linear efficiency-accuracy trade-off was observed in all cases. Similar to tRNALys, tRNAPhe discriminated with higher accuracy against a particular mismatch in the second than in the first codon position. Remarkably high d-values were observed for tRNAGlu discrimination against a C-C mismatch in the first codon position (70 000) and for tRNAPhe discrimination against an A-G mismatch in the second codon position (79 000). At the same time, we have found a remarkably small d-value (200) for tRNAGlu misreading G in the middle position of the codon (U-G mismatch). Aminoglycoside antibiotics induce large codon reading errors by tRNAs. We have studied the mechanism of aminoglycoside action and found that the drug stabilized aminoacyl-tRNA in a codon selective in relation to a codon non-selective state. This greatly enhanced the probability of near cognate aminoacyl-tRNAs to successfully transcend the initial selection step of the translating ribosome. We showed that Mg2+ ions, in contrast, favour codon non-selective states and thus induce errors in a principally different way than aminoglycosides. We also designed experiments to estimate the overall accuracy of peptide bond formation with, including initial selection accuracy and proofreading of tRNAs after GTP hydrolysis on EF-Tu. Our experiments have now made it possible to calibrate the accuracy of tRNA selection in the test tube to that in the living cells. We will now also be able to investigate the degree to which the accuracy of tRNA selection has been optimized for maximal fitness.
17
Glatz, Elisabeth. "Bacillus subtilis GlpP protein, antitermination and mRNA stability." Lund : Lund University, 1998. http://catalog.hathitrust.org/api/volumes/oclc/68945078.html.
Pełny tekst źródła
18
Karmouch, Jennifer. "Deciphering ColQ induced mechanisms in the control of AChR mRNA levels." Thesis, Paris 5, 2014. http://www.theses.fr/2014PA05T007/document.
Pełny tekst źródłaStreszczenie:
ColQ est un collagène spécifique qui ancre l’acétylcholinestérase (AChE) dans la fente synaptique de la jonction neuromusculaire (JNM). L'importance du complexe AChE-ColQ dans la physiologie humaine de cette synapse est soulignée par l’identification de mutations dans le gène codant pour ColQ qui conduisent à un syndrome myasthénique congénital (SMC) associé à une déficience en AChE. Le déficit en AChE a, jusqu’à présent, été considéré comme l’unique facteur responsable des symptômes observés chez les patients ainsi que des défauts de la JMN chez le modèle de souris SMC (souris déficiente pour ColQ). Toutefois, ces symptômes sont complexes et l’absence d’AChE ne peut probablement pas expliquer tous les symptômes. Nous avons montré auparavant que ColQ participait à la formation de la synapse ce qui expliquerait les symptômes observés chez les patients et la souris modèle. En effet, nous avons pu montrer que ColQ contrôle l’agrégation du récepteur à l’acétylcholine (RACh) et de l’expression de gènes spécifiques de la synapse. En particulier, nous avons montré in vitro et in vivo, que l’absence de ColQ induit une augmentation du niveau des ARNm codant pour toutes les sous-unités de RACh et une expression réduite du niveau de leurs protéines. Des résultats préliminaires indiquent que cette augmentation de ces ARNm n’est pas transcriptionnelle. L’objectif de cette thèse est d’expliquer les mécanismes qui induisent l’augmentation du niveau des ARNm de AChR en l’absence de ColQ et les voies de signalisation qui relient ColQ au métabolisme des ARN du RACh. Notre hypothèse de travail a été que l'absence de ColQ stimule la stabilisation post-transcriptionnelle des ARNm codant pour les sous-unités du RACh via la protéine HuR. HuR est une protéine qui stabilise les ARNm quand elle se fixe sur les AU-richelement (ARE) dans la séquence 3’UTR. HuR est une protéine clé dans la myogenèse et la formation de la JNM parce qu’elle stabilise de manière post-transcriptionnelle de nombreux transcrits tels que myogénine, MyoD et AChE. Dans cette étude, nous montrons pour la première fois qu’un mécanisme post-transcriptionnel de stabilisation des ARNm est responsable de l’augmentation du niveau des ARNm du RACh via ColQ. De plus, nous constatons qu’en absence de ColQ, il y a une augmentation aux niveaux d’ARNm et de protéine de HuR. HuR est également capable de se lier au domaine ARE dans le 3’UTR des ARNm des sous-unités de AChR. De plus, l’interaction entre HuR et les ARNm du RACh augmente la stabilité et par conséquence les niveaux des transcrits du RACh. Trois conclusions importantes ressortent de ma thèse : nous démontrons que (1) en plus de la régulation transcriptionnelle, il existe des mécanismes de régulation post-transcriptionnlle du RACh (2) ColQ régule la stabilité des ARNm RACh via HuR médiée par MuSK (3) la voie de signalisation p38 contrôle les niveaux de HuR de manière dépendante de ColQ. Ensemble, ces résultats donnent un aperçu des voies de signalisation du muscle qui sont affectées par les mutations de ColQ conduisant à des SMC avec une déficience en AChE. Nos résultats mettront en évidence des nouvelles cibles moléculaires spécifiques qui peuvent conduire au développement des interventions thérapeutiques dans le cadre de myasthénies congénitales<br>ColQ is a specific collagen that anchors acetylcholinesterase (AChE) in the synaptic cleft of the neuromuscular junction (NMJ). The importance of AChE-ColQ complex in the physiology of this synapse has been highlighted by the identification of COLQ mutations in the human gene, leading to a congenital myasthenic syndrome (CMS) with AChE deficiency. The lack of AChE has been incriminated for the symptoms observed in patients along with NMJ defects in the CMS mouse model (ColQ-deficient). However, symptoms observed in the patients and mouse model of CMS with AChE deficiency are complex and AChE deficiency cannot account for all of them. We have demonstrated that ColQ could play a role per se in synapse formation which would explain some of the defects observed in patients and model mice. Indeed, we have shown that ColQ controls the clustering of Acetylcholine Receptors (AChR) and the expression of a number of specific synaptic genes. The most striking effect of the absence of ColQ is an upregulation of all AChR subunit mRNAs correlated by an increase in their protein levels. Preliminary results indicate that AChR mRNA upregulation is not transcriptional. This thesis deciphers the mechanisms that drive AChR mRNA upregulation in the absence of ColQ and the pathways that connect ColQ to the AChR RNA metabolism. Accordingly, we hypothesize that the absence of ColQ induces an upregulation of the stabilization of AChR subunit mRNAs, a post-transcriptional mechanism mediated by HuR. HuR is an RNA binding protein which stabilizes its target transcript by binding AU-rich elements (AREs) in their 3’UTR. HuR is critical during skeletal myogenesis and post-synaptic NMJ formation due to its stabilization of such transcripts as myogenin, MyoD and AChE. In this study, we show for the first time that a post-transcriptional mechanism of AChR mRNA stabilization is responsible for the ColQ mediated increase of AChR mRNAs. In support of these findings, the absence of ColQ also increased HuR mRNA and protein levels. We demonstrate that HuR is capable of binding to conserved ARE elements in the 3’UTR of AChR subunit mRNA. HuR’s interaction with AChR mRNA increased the stability of the transcripts, resulting in an increase in mRNA levels. Three major conclusions emerge from my thesis: we provide evidence that (1) in addition to transcriptional and assembly regulation of AChR, post-transcriptional mechanisms of AChR mRNA exist (2) ColQ regulates HuR mediated AChR stability through MuSK and (3) the p38 signalling pathway controls the levels of HuR in a ColQ dependent manner. Collectively, our data provides insight into the muscle signaling pathways which are affected by ColQ mutations leading to CMS with AChE deficiency. Thus, we have identified specific new molecular targets that may become important for the development of therapeutic interventions for patients with CMS
19
Spangler, Jacob Brian. "Conserved noncoding sequences regulate steady-state mRNA levels in Arabidopsis thaliana." Thesis, Clemson University, 2013. http://pqdtopen.proquest.com/#viewpdf?dispub=3565242.
Pełny tekst źródłaStreszczenie:
<p> <i>Arabidopsis thaliana</i> has undergone three whole genome duplications within its ancestry, and these events have dramatically affected its gene complement. Of the most recent whole genome duplication events (α event), there remain 11,452 conserved noncoding sequences (CNSs) that have been retained proximal to α duplicate gene pairs. As functional DNA elements are expected to diverge in sequence at a slower rate than nonfunctional DNA elements, the retained CNSs likely encode gene regulatory function. Within this dissertation I provide evidence for the regulatory role of CNSs within <i> Arabidopsis thaliana</i>. Using a collection of over 5,000 microarray RNA expression profiling datasets, I demonstrate that the presence of CNSs near α duplicate pairs is correlated with changes in average expression intensity (AEI), α duplicate pair co-expression, mRNA stability, and breadth of gene expression. The effects of CNSs on AEI, co-expression, and mRNA stability vary relative to their subgene position, because they are located in nontranscribed (5’-upstream and 3’-downstream) and transcribed (5’- UTR, intronic and 3’-UTR) regions. Modeling gene interactions through the generation of co-expression networks, I also demonstrate that a portion of CNSs participate in known gene regulatory networks. Collectively, this body of work demonstrates that CNSs regulate steady-state mRNA levels within Arabidopsis thailiana through both transcriptional and post-transcriptional mechanisms.</p>
20
Smith, Paul Andrew. "Protein-protein interactions of Prp2p : a pre-mRNA splicing factor of Saccharomyces cerevisiae." Thesis, University of Edinburgh, 2000. http://hdl.handle.net/1842/12988.
Pełny tekst źródłaStreszczenie:
A two-fold strategy was adopted to identify factors which functionally interact with Prp2p: 1) the yeast two-hybrid system was utilised to identify Prp2p interacting proteins and, 2) the technique of high copy-number suppression screening was used to search for suppressors of dominant negative <i>PRP2</i> mutations. An exhaustive two-hybrid screen with Prp2p as the bait isolated Spp2p, another step 1 splicing factor that was originally identified as a high copy-number suppressor of a <i>prp2-1</i> mutation. Subsequently the reciprocal interaction was observed in a two-hybrid screen with Spp2p as the bait. Surprisingly the most statistically significant result of the Prp2p screen was Sec59p, an endoplasmic reticulum membrane protein involved in core glycosylation. The functional significance of this interaction was investigated by a variety of biochemical and genetic techniques but no evidence implicating Sec59p in pre-mRNA splicing was obtained. An interesting finding from the Spp2p screen was a novel protein Yor093p, which had also been isolated from a two-hybrid screen with Prp17p (a step 2 splicing factor) as the bait. Deletion of the entire open reading frame encoding Yor093p revealed that <i>YOR093c</i> is dispensable for cell growth under all conditions tested. A yeast strain was constructed in which an HA-tagged Yor093p fusion protein was expressed from a chromosomal locus. This strain was subsequently used in coimmunoprecipitation experiments to demonstrate that Yor093p does not stably associate with spliceosomes. A two-hybrid screen with Yor093p as the bait failed to identify any interactions with known splicing factors. The potential role of Yor093p as the bait failed to identify any interactions with known splicing factors. The potential role of Yor093p in pre-mRNA splicing therefore remains unclear. High copy-number suppression screens were performed to isolate putative suppressors of dominant negative <i>PRP2 </i>alleles.
21
Wüst, Michaela [Verfasser]. "The protein interactome of human SOD2 mRNA / Michaela Wüst." Tübingen : Universitätsbibliothek Tübingen, 2021. http://d-nb.info/1226756166/34.
Pełny tekst źródła
22
Naski, Nadia. "The p53, Mdm2 and Mdmx protein and mRNA interplay." Paris 7, 2010. http://www.theses.fr/2010PA077158.
Pełny tekst źródłaStreszczenie:
Le facteur de transcription p53 est étudié dans le monde entier pour son rôle clé de suppresseur de tumeurs. En effet, le gène codant pour p53 est muté dans plus de 50% des cancers humains. Cependant, des transformations malignes peuvent aussi avoir lieu en présence d'une protéine p53 intacte. Celles-ci seraient causées par l'altération des voies de régulation en amont ou en aval de p53. Cette protéine est, en effet, finement régulée par une multitude de régulateurs positifs et négatifs. Mdm2 et son homologue Mdmx (aussi appelé Mdm4) sont les deux régulateurs négatifs majeurs de p53; ils peuvent se lier au suppresseur de tumeur et induire respectivement sa dégradation ou sa trans-répression. De plus, sous certaines conditions, p53 peut transactiver les gènes mdm2 et mdmx, impliquant ainsi les trois protéines dans des boucles de rétro-action négatives. Notre groupe a récemment montré qu'en plus de sa fonction inhibitrice, Mdm2 pouvait réguler p53 positivement en induisant la traduction de son ARNm. Mes résultats montrent que l'interaction entre la protéine Mdm2 et l'ARNm de p53 est strictement indépendante de l'interaction des deux protéines. Par contre, la conformation de l'ARNm de p53 semble jouer un rôle majeur dans son interaction avec Mdm2. De plus, étant donné l'importante homologie structurale que partagent Mdm2 et Mdmx, il nous semblait intéressant de vérifier si les deux protéines avaient des fonctions similaires. De façon surprenante, nous avons pu montrer que malgré sa capacité à se lier à l'ARNm de p53, Mdmx est incapable d'induire, à lui seul, la synthèse de p53, contrairement à Mdm2. Cependant, nous montrons que la protéine p53 est capable de lier la partie 5'UTR de l'ARNm de Mdmx et d'inhiber sa traduction de manière drastique, en conditions normales ou de stress génotoxique. Ces résultats ajoutent de nouvelles boucles de rétro-action au complexe réseau de régulation de p53<br>The p53 transcription factor is studied Worldwide for its key fonction as a tumour suppressor protein. Importantly, the gene coding for p53 is mutated in around 50% of human cancers. However, malignant transformation can also occur in a p53 WT context, and this is believed to be caused by the abrogation of the regulatory pathways upstream or downstream of p53. Indeed, p53 is tightly regulated by aplethora of positive and negative regulatory factors. Mdm2 and its homolog Mdmx (also called Mdm4) are two major negative regulators of p53. They can bind to the p53 protein and induce respectively its degradation or its transrepression. In addition, under specific conditions, p53 can transactivate the mdm2 and mdmx genes, thus implicating the three proteins in negative feedback loops. Interestingly, our group has also shown recently that in addition to its inhibitory function, Mdm2 could positively regulate p53 by enhancing its mRNA translation. Here, we show that the capacity of Mdm2 to bind to the/?53 mRNA is independent of their protein-protein interaction. However, the conformation of the p53 mRNA seems to play a key role in its interaction with Mdm2. Moreover, since Mdm2 and Mdmx share a high structural homology, it was interesting to investigate whether Mdmx could play similar functions. Surprisingly, even though it also binds to the p53 mRNA, Mdmx, by its own, is unable to trigger p53 synthesis, contrary to Mdm2. However, we show that the p53 protein is able to bind to the Mdmx transcript (on its 5'UTR) and drastically inhibit its translation, under normal and genotoxic conditions. Altogether, these data add new feedback loops into the intricate p53 regulatory network
23
SALADINO, Patrizia. "ROLE OF RNA BINDING PROTEIN IN THE NERVE CELL DIFFERENTIATION." Doctoral thesis, Università degli Studi di Palermo, 2014. http://hdl.handle.net/10447/91214.
Pełny tekst źródłaStreszczenie:
Synthesis of H1˚ and H3.3 histone proteins, in the developing rat brain, seems to be regulated mainly at the post-transcriptional level. Since regulation of RNA metabolism depends on a series of RNA-binding proteins (RBPs), we have been searching for RBPs involved in the post-transcriptional regulation of the H1˚ and H3.3 genes. Previously, we reported isolation, from a cDNA expression library, of an insert encoding a novel protein, the C-terminal half of which is identical to that of PEP-19, a brain-specific protein involved in calcium metabolism. The novel protein was called long PEP-19 isoform (LPI). We showed that LPI, as well as PEP-19, can bind H1˚ RNA. Since PEP19 and LPI contain a calmodulin binding domain, we also investigated whether their ability to bind RNA is affected by calmodulin. Our results show that calmodulin interferes with binding of H1˚ RNA to both PEP-19 and LPI, while it is not able to bind RNA on its own. Pep-19/calmodulin high affinity binding has been demonstrated by Biolayer interferometry (BLI). This finding suggests that calcium/calmodulin may have a role in controlling H1˚ mRNA metabolism in the developing brain. Moreover, in order to improve production of functional LPI/PEP-19, we modified the protocol normally adopted for preparing histidine tagged-proteins from bacteria, by adding an additional purification step.
Furthermore, we found that both LPI and PEP-19 can compete for H1˚ RNA binding with PIPPin (also known as CSD-C2), another RBP previously discovered in our laboratory. PIPPin/CSD-C2 binds with high specificity to the mRNAs encoding H1° and H3.3 histone variants, undergoes thyroid hormone-dependent SUMOylation, and has been recently demonstrated to interact with other RBPs. PIPPin belongs to the CSD-containing class of RBPs, also called Y-box proteins, that play a key role in controlling the recruitment of mRNAs to the translational machinery, in response to environmental cues, both in development and in differentiated cells.
Another aspect of this study was to confirm histone mRNAs-PIPPin interactions and to describe binding properties through streptavidin-biotin conjugation method, by BLI.
We report the data obtained in the case of H3.3 and H1° mRNA-PIPPin interactions, and the specific affinity constant for these bindings. In order to identify RNA portions involved in binding, we used different RNA probes for H3.3 and H1°. In summary, we were able to confirm that PIPPin binds H3.3 and H1° mRNA with very high affinity.
Searching for other RBPs, we used in vitro transcribed, biotinylated H1° RNA as bait to isolate, by a chromatographic approach, proteins which interact with this mRNA, in the nuclei of brain cells. Abundant RBPs, such as heterogeneous nuclear ribonucleoprotein (hnRNP) K and hnRNP A1, and molecular chaperones (heat shock cognate 70, Hsc70) were identified by mass spectrometry. Western blot analysis also revealed the presence of CSD-C2. Co-immunoprecipitation assays were performed to investigate the possibility that identified proteins interact with each other and with other nuclear proteins. We found that hnRNP K interacts with both hnRNP A1 and Hsc70, whereas there is no interaction between hnRNP A1 and Hsc70. Moreover, CSD-C2 interacts with hnRNP A1, Y box-binding protein 1 (YB-1), and hnRNP K. We also have indications that CSD-C2 interacts with Hsc70.
24
Ulbricht, Randi J. "Puf1p-mediated mRNA decay and combinatorial control of mRNA stability by the yeast Puf proteins." Diss., St. Louis, Mo. : University of Missouri--St. Louis, 2008. http://etd.umsl.edu/r2761.
Pełny tekst źródła
25
Cass, Danielle Marie. "Role of two RNA binding properties in pre-mRNA splicing /." view abstract or download file of text, 2007. http://proquest.umi.com/pqdweb?did=1400950811&sid=2&Fmt=2&clientId=11238&RQT=309&VName=PQD.
Pełny tekst źródłaStreszczenie:
Thesis (Ph. D.)--University of Oregon, 2007.<br>Typescript. Includes vita and abstract. Includes bibliographical references (leaves 67-80). Also available for download via the World Wide Web; free to University of Oregon users.
26
Mitchell, Michael Robert. "Local Control of Translation and mRNA and Protein Decay is Sufficient for Protein Localization." Thesis, The University of Arizona, 2011. http://hdl.handle.net/10150/144847.
Pełny tekst źródła
27
Pryor, Anne M. "Growth-regulated expression and G0-specific turnover of the mRNA that encodes AH49, a mammalian protein highly related to the mRNA export protein UAP56." Connect to this title online, 2003. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1069259604.
Pełny tekst źródłaStreszczenie:
Thesis (Ph. D.)--Ohio State University, 2003.<br>Title from first page of PDF file. Document formatted into pages; contains xii, 187 p.; also includes graphics (some col.) Includes bibliographical references (p. 175-187). Available online via OhioLINK's ETD Center
28
LU, Zhibo, Mayumi HOJO, Kenji YASUI, Itsuo KODAMA, and Kaichiro KAMIYA. "mRNA Levels of ERG, KVLQT1 and minK in Rabbit Right and Left Ventricles." Research Institute of Environmental Medicine, Nagoya University, 2002. http://hdl.handle.net/2237/2801.
Pełny tekst źródła
29
Pettersson, Erik. "Investigation of tissue factor mRNA levels in human platelets using real-time PCR." Thesis, Uppsala universitet, Institutionen för medicinsk biokemi och mikrobiologi, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-180831.
Pełny tekst źródłaStreszczenie:
Tissue factor (TF), a 47 kDa glycoprotein, is the initiator of the extrinsic pathway of blood coagulation and consequently of the upmost importance when damage to blood vessel occurs. The source of TF in circulation has been investigated. However, the source of TF is still not clear. One theory is that platelets express and increases the expression of TF after stimulation and the aim of our report was to investigate whether platelets really are a source for TF in circulation. Using specific primers for TF mRNA, platelets in plasma from healthy volunteers and from patients suffering from cardiac infarction were analyzed by using real-time polymerase chain reaction (PCR). Gel electrophoresis was performed after amplification of TF mRNA to verify the results. The samples were negative for TF when using real-time PCR and the few positive all had cycle threshold (Ct) values above 35. The contamination by monocytes was analyzed by using real-time PCR, with primers for CD14 and showed low amounts. After analysis, our conclusion was that platelets do not express TF. Although some samples had positive real-time PCR, the Ct values were all above 35, meaning they had very few transcripts in the initial samples and that the biological importance is uncertain. Since contamination of CD14 positive cells were found in most samples it can’t be ruled out that the origin of the positive TF mRNA is from monocytes.
30
Tanay, Véronique Anne-Marie Isabelle. "The action of antidepressant/antipanic drugs on GABA(A) receptor subunit mRNA levels." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape17/PQDD_0009/NQ34845.pdf.
Pełny tekst źródła
31
Jagiełło, Bogumiła 1987. "Investigating protein complexes potentially governing microtubule-dependent MBP mRNA distribution." Doctoral thesis, Universitat Pompeu Fabra, 2018. http://hdl.handle.net/10803/665721.
Pełny tekst źródłaStreszczenie:
La localització de molècules d'ARNm permet regular la síntesi de proteïnes localment i temporalment i això és vital per molts processos cel·lular fonamentals. A Oligodendròcits el transport de l'ARNm de la proteïna bàsica de la mielina (MBP) permet la síntesi local d'aquesta. MBP té una funció essencial en la formació de la beina de mielina que envolta els exons, nodreix les cel·les nervioses i permet la rapida transmissió dels estímuls. Tot i la intensa recerca feta sobre els mecanismes moleculars que condueixen el transport i l'expressió local MBP-ARNm, encara no està clar com l'ARNm és transportat fins al seu destí i com es controla la traducció de la proteïna al lloc adequat. Fent servir informació de dades publicades i el cribratge d'interaccions entre proteïnes realitzat al laboratori hem seleccionat dos complexos proteics essencials per a la localització de l'ARNm de la MBP i hem intentat construir-los des de la base. Des d'aquest enfocament la reconstrucció in vitro dels complexos ens permet analitzar la funcio de cada component del complex i entendre més profundament com es controla aquest procés biològic.
La síntesi de l'ARNm de la MBP és parcialment depenent de la interacció entre la proteïna d'unió a ARN, hnRNPA2, i una polimerasa de microtúbuls, chTOG. Per aclarir el mecanisme pel qual aquesta interacció desencadena la traducció de la MBP vam decidir analitzar les conseqüències funcionals d'aquesta nova interacció entre una proteïna d'unió a microtúbul i una proteïna d'unió a ARN. He aconseguit amb èxit proteïna recombinant funcional de hnRNPA2 I chTOG. La interacció entre aquestes dues proteïnes va resultar no especifica. Hipotetitzo que és degut a la conformació que adquireix la proteïna hnRNPA2 en els grànuls de ribonucleoproteines o depenent d'altres components. Degut a la falta de recursos per investigar-ho vam suspendre aquest projecte.
El procés de lliurament de l'ARNm de MBP a oligodendròcits és mantingut per kinesines
dependents de microtúbuls. La kinesina Kif1Bβ s'ha vist que fa el transport però els adaptadors que uneixen l'ARNm al motor(kinesina) resten desconeguts. Kif1Bβ se sap que és responsable del transport d'orgànuls de membrana com precursors de vesícules sinàptiques. Evidencies de la bibliografia i del cribratge d'interaccions entre proteïnes realitzat al laboratori suggereixen que Kif1Bβ podria realitzar el transport de l'ARN per captura de les vesícules. La regulació de les kinesines no és del tot conegut per això vaig decidir investigar primer aquest aspecte. Per aquesta raó vaig provar de construir i caracteritzar el sistema de transport de vesícules depenent de Kif1Bβ in vitro.
Vaig aconseguir produir i caracteritzar la proteïna recombinant Kif1Bβ. Kif1Bβ es capaç de formar un dímer en solució de forma independent i en aquest estat de dímer moure's al llarg de microtúbuls. Vaig detectar la preferència de Kif1Bβ per certs lípids que després vaig fer servir per produir vesícules sintètiques. Les vesícules es van fer servir per caracteritzar in vitro el seu transport per Kif1Bβ. La reconstrucció de les interaccions entre proteïnes implicades en el transport de complexos van demostrar ser més problemàtiques. Esforços addicionals serien necessaris en el futur per aconseguir aquest repte i millor caracterització del proposat complex.
Tot i els meus esforços no vaig poder reconstruir completament cap dels dos complexos d'interès. Tot i així, presento en aquesta tesi una descripció detallada dels enfocaments i els complexes parcials que nosaltres vam aconseguir construir i caracteritzar.<br>Localization of mRNA molecules enables locally and temporally regulated protein synthesis, which is vital for many fundamental cellular processes. In oligodendrocytes transport of myelin basic protein (MBP) mRNA to myelinating processes allows for local synthesis of MBP. MBP has an essential function if forming the myelin sheath that surrounds axons, nurtures the nerve cells and allows for fast stimuli transmission. Despite extensive research about the molecular mechanisms that guide the transport and local expression of MBP-mRNA it is still not clear how this mRNA is transported to its destination and how activation of translation at the right place is controlled. Using the information from published data and an interaction screen performed in the lab we selected two protein complexes essential for MBP mRNA localisation and attempted to build them from bottom-up. In this approach in vitro reconstitution of the minimal complexes allows us to analyse the function of each component of the complex and understanding better how biological processes are regulated.
MBP mRNA synthesis is partially dependent on the interaction between an RNA binding protein, hnRNPA2, and a microtubule polymerase, chTOG. To elucidate the mechanism by which this interaction triggers MBP mRNA translation we decided to analyse the functional consequences of this entirely novel interaction between a microtubule binding and RNA binding protein. I successfully produced functional recombinant hnRNPA2 and chTOG. The interaction detected between those two proteins turned out to be unspecific. I hypothesize it is due to the conformation that hnRNPA2 acquires in the RNP granule or depends on other components. Due to the lack of resources to investigate this further we suspended this project.
Delivery of MBP mRNA to the oligodendrocytes processes is maintained by microtubule-dependent kinesin motors. The kinesin Kif1Bβ has been shown to carry out the transport but the adaptors, which link the mRNA to the motor, remain unknown. Kif1Bβ is known to be responsible for transport of membranous organelles such as synaptic vesicle (SV) precursors. Evidence from literature and protein interaction screen performed in the lab suggests that Kif1Bβ could achieve mRNA transport by vesicle hitchhiking. The regulation of the kinesin is not fully understood therefore I decided to investigate this aspect first.
For this reason I sought to build and characterize a Kif1Bβ-dependent vesicle transport system in vitro. I produced recombinant protein and achieved characterization of the Kif1Bβ motor. Kif1Bβ is able to independently form a dimer in solution and in the dimeric state processively moves on microtubules. I detected the preference of Kif1Bβ for certain lipids, which were then used to produce synthetic vesicles. In in vitro motility assays I characterized the Kif1Bβ-driven transport of synthetic vesicles. The reconstitution of the interactions between proteins involved in vesicle transporting complex proved to be more problematic. Additional efforts are needed to achieve this goal and further characterize the proposed complex in the future.
Despite my efforts I did not manage to fully reconstitute any of the two complexes of interest. However, I report in this thesis a detailed description of the approaches and the partial complexes I managed to build and characterise.
32
Stojdl, David F. "Protein kinases and the regulation of mRNA splicing and translation." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape2/PQDD_0016/NQ58294.pdf.
Pełny tekst źródła
33
Persdotter, Hedlund Gabriella. "Protein and mRNA Studies of Rat FA1/Pref-1/dlk." Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-7773.
Pełny tekst źródła
34
Kinney, Emma. "Decoupling of HSV1 Vhs protein mRNA decay and translation stimulation." Thesis, University of Missouri - Kansas City, 2013. http://pqdtopen.proquest.com/#viewpdf?dispub=1543940.
Pełny tekst źródłaStreszczenie:
<p> Herpes Simplex Virus Type 1 is a member of the <i>alphaherpesvirinae </i> subfamily within the family <i>Herpesviridae</i>. This virus has both a lytic and latent cycle. Primary infection occurs when the virus enters epithelial cells around the mucosal lining of the nose and mouth. Within the epithelial cells, the virus undergoes an active lytic infection, causing an ulcerated blister, more famously known as a 'cold sore' or 'fever blister'. Once HSV enters the nearby sensory neurons the genome is transported to the neuronal cell body where its latency associated transcripts are activated and the virus remains in a dormant latent cycle until reactivation, when the virus is transported back down the axon to the epithelial cells at or near the site of initial infection. The Virion Host Shutoff protein is a tegument protein from HSV1 and acts as a ribonuclease, degrading both cellular and viral mRNAs, making the course of viral infection more efficient. A study by Saffran, Read and Smiley uncovered an unexpected new function of Vhs: stimulation of translation from some IRESs. An IRES is a section of mRNA with a high level of secondary structure, capable of inducing cap-independent translation. In similar experiments utilizing a bicistronic reporter transcript, I sought to discover whether or not these two functions of the Vhs protein could be de-coupled. Experiments involved dually transfecting HeLa cells with different Vhs mutants across a range of Vhs plasmid concentrations and the bicistronic reporter construct. Levels of reporter activity were measured from cell lysates 36 hours after transfections and provided a measurement of the control at the level of translation. As the cellular Bip IRES element was present between the cistrons, the 3' cistron provided a measure of IRES stimulation. The Results revealed examples of Vhs mutants in which the two activities had been separated. It is unknown what role IRES stimulation could play during Herpesvirus infection, although it is interesting to note that some HSV1 genes have IRES like elements within the 5' UTR. Future experiments can be done to investigate whether or not Vhs is actively recruiting transcription initiation factors to these IRES elements.</p>
35
Lemay, Guy. "Study of a reovirus protein involved in viral mRNA translation." Thesis, McGill University, 1987. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=75419.
Pełny tekst źródłaStreszczenie:
This thesis concerns the mechanisms responsible for preferential translation of reovirus mRNA in infected cells. The absence of a poly(A) tract at the $3 sp prime$-end is one of the structural differences that distinguishes reovirus mRNA from cellular mRNA. Addition of free poly(A) inhibits in vitro translation at the level of initiation of protein synthesis, probably by competition between free poly(A) and mRNA. Reovirus mRNA is resistant to this inhibition and this property might confer a translational advantage to the viral mRNA. Another difference between reovirus mRNA and cellular mRNA is the absence of a $5 sp prime$-cap structure on late viral mRNA. This mRNA is translated much more efficiently in lysates from infected than uninfected cells, even in the absence of inhibition of host cell protein synthesis. Addition to uninfected cell lysates of proteins from infected cells stimulates translation of late viral mRNA without effect on other mRNAs; the presence of the sigma 3 viral protein is shown to account for the stimulation of translation. Sigma 3 binds to ribosomes, probably during initiation of protein synthesis, but apparently does not interact directly with mRNA. The sigma 3 protein exists in multiple forms, differing in isoelectric point but possessing all the known properties of sigma 3. These forms possibly result from mutations in the gene encoding sigma 3. The cloned gene which encodes sigma 3 was expressed in L cells without apparent detrimental effect on the cells. Lysates prepared from these cells translate late viral mRNA with an increased efficiency. The sigma 3 protein is associated with the ribosomes in these cells even if no viral mRNA is present. It is suggested that the sigma 3 protein acts as a viral-specific initiation factor of protein synthesis.
36
Belmont, Brian J. (Brian Joshua). "Engineered mRNA regulation using an inducible protein-RNA aptamer interaction." Thesis, Massachusetts Institute of Technology, 2012. http://hdl.handle.net/1721.1/78136.
Pełny tekst źródłaStreszczenie:
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Biological Engineering, 2012.<br>Cataloged from PDF version of thesis.<br>Includes bibliographical references (p. 114-131).<br>The importance and pervasiveness of naturally occurring regulation of RNA function in biology is increasingly being recognized. A common regulatory mechanism uses inducible protein-RNA interactions to shape diverse aspects of cellular RNA fate. Recapitulating this using a novel set of protein-RNA interactions is appealing given the potential to subsequently modulate RNA biology in a manner decoupled from normal cellular physiology. We describe a ligand-responsive protein-RNA interaction module that can be used to target a specific RNA for subsequent regulation. Using the Systematic Evolution of Ligands by Exponential Enrichment (SELEX) method, RNA aptamers binding to the bacterial Tet Repressor protein (TetR) with low- to sub- nanomolar affinities were identified. This interaction is reversibly controlled by tetracycline in a manner analogous to the interaction of TetR with its cognate DNA operator. Aptamer minimization and mutational analyses support a functional role for conserved sequence and structural motifs in TetR binding. We illustrate the utility of this chemically-inducible RNA-protein interaction to directly regulate translation in both a prokaryotic and eukaryotic organism. By genetically encoding TetR-binding RNA elements into the 5'-untranslated region (5'-UTR) of a given mRNA, translation of a downstream coding sequence is directly controlled by TetR and tetracycline analogs. In endogenous and synthetic 5'-UTR contexts, this modular system efficiently regulates the expression of multiple target genes, and is sufficiently stringent to distinguish functional from nonfunctional RNA-TetR interactions. We also demonstrate engineering this TetR-aptamer module to regulate subcellular mRNA localization. This is efficiently achieved by fusing TetR to proteins natively involved in localizing endogenous transcripts, and genetically encoding TetR-binding RNA aptamers into the target transcript. Using this platform, we achieve tetracycline-regulated enhancement of target transcript subcellular localization. We also systematically examine some rules for successfully forward engineering this RNA localization system. Altogether, these results define and validate an inducible protein-RNA interaction module that incorporates desirable aspects of a ubiquitous mechanism for regulating RNA function in Nature and that can be used as a foundation for functionally and reversibly controlling multiple fates of RNA in cells.<br>by Brian J. Belmont.<br>Ph.D.
37
Bourdeau-Julien, Isabelle. "ALS-associated RNA-binding protein FUS and mRNA translation regulation." Master's thesis, Université Laval, 2020. http://hdl.handle.net/20.500.11794/68742.
Pełny tekst źródłaStreszczenie:
Des mutations dans plusieurs gènes ont été liés à la sclérose latérale amyotrophique (SLA),en particulier dans celui codant pour la protéine Fused in Sarcoma (FUS). Les mutations sont retrouvées dans la partie codant pour le signal de localisation nucléaire, rendant la protéine anormalement abondante dans le cytoplasme. Combiné à d’autres observations, ça suggère qu’un gain de fonction toxique de FUS dans le cytoplasme serait à l’origine de la neurodégénérescence. La SLA est une maladie neurodégénérative qui affecte les neurones moteurs et cause une paralysie progressive. Les mécanismes moléculaires causant la maladies ont toujours inconnus. Une des pistes serait la perturbation de la traduction locale desARNm, qui permet aux synapses de répondre rapidement et indépendamment du corps cellulaire. Une traduction locale insuffisante pour soutenir l’activité synaptique à long terme mènerait à la perte des synapses et à la neurodégénérescence. Mon objectif est donc de déterminer le rôle de FUS dans régulation de la traduction des ARNm en caractérisant son interaction avec les composantes traductionnelles et d’évaluer sa fonction dans une condition reproduisant les caractéristiques de la SLA. J’ai montré que FUS s’associe aux polyribosomes inactifs, ce qui suggère que FUS jouerait un rôle dans la régulation de la traduction des ARNm en interagissant avec le cœur de la traduction. Il est également possible d’observer une augmentation de la présence de FUS dans le cytoplasme et de son interaction avec les polyribosomes suite à une inhibition de la traduction par mTOR, suggérant son rôle de régulateur négatif. De plus, les mutations liées à la SLA amplifient la fonction inhibitrice de FUS en rendant FUS cytoplasmique et en réduisant la synthèse des protéines. Mes résultats montrent que la protéine FUS aurait un rôle d’inhibiteur de la traduction quand celle-ci est cytoplasmique. Par conséquent, l’augmentation de la présence de FUS dans le cytoplasme dans la SLA entrainerait une inhibition de la traduction importante, à un niveau insuffisant pour soutenir l’activité synaptique.<br>Mutations in several genes have been linked to amyotrophic lateral sclerosis (ALS),particularly in the gene coding for the Fused in Sarcoma protein (FUS). Those mutations are found in the part encoding for the nuclear localization signal, making the protein abnormallyabundant in the cytoplasm. Combined with other observations, it suggests that a toxic gainof function of FUS in the cytoplasm would be the cause of the neurodegeneration. ALS is a neurodegenerative disease that affects motor neurons and causes progressive paralysis. The molecular mechanisms causing the disease are still unknown. One of the hypotheses is the disruption of local translation of mRNAs, which allows synapses to respond quickly and independently from the cell body. Insufficient local translation to support long-term synapticactivity would lead to synaptic loss and neurodegeneration. Thereby, the objective of mystudy is to determine the role of FUS in the regulation of mRNA translation by characterizing its interaction with translational components and evaluate its function in an ALS-linked condition. I have shown that FUS is associated with stalled polyribosomes, which suggests that it plays a role in regulating mRNA translation by interacting with the core of translation.There is also an increase in the presence of FUS in the cytoplasm and in its interaction with polyribosomes following inhibition of translation through mTOR, suggesting its role as anegative regulator. In addition, ALS-related mutations amplify FUS inhibitory function bymaking FUS cytoplasmic and reducing protein synthesis. My results show that the FUSprotein would have a role as a translation inhibitor when it is cytoplasmic. There fore, increasing the presence of FUS in the cytoplasm in ALS would result in significant translation inhibition, at a level insufficient to support synaptic activity.
38
Thumdee, Patama. "The prenatal expression of mRNA and protein of the prion protein gene, PRNP, in sheep." [S.l.] : [s.n.], 2007. http://deposit.ddb.de/cgi-bin/dokserv?idn=983755728.
Pełny tekst źródła
39
Wang, Jingwei. "Alterations in protein kinase A and protein kinase C activities and protein levels in cardiomyopathy." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape17/PQDD_0001/MQ32280.pdf.
Pełny tekst źródła
40
Le, Cras Timothy David. "Regulation of the levels of mRNA for the LDL receptor and HMG CoA reductase." Thesis, University of Cambridge, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.239497.
Pełny tekst źródła
41
Henscheid, Kristy L. "Functional conservation and RNA binding of the pre-mRNA splicing factor U2AF65 /." view abstract or download file of text, 2007. http://proquest.umi.com/pqdweb?did=1400950821&sid=5&Fmt=2&clientId=11238&RQT=309&VName=PQD.
Pełny tekst źródłaStreszczenie:
Thesis (Ph. D.)--University of Oregon, 2007.<br>Typescript. Includes vita and abstract. Includes bibliographical references (leaves 129-141). Also available for download via the World Wide Web; free to University of Oregon users.
42
Frey, Steffen. "Charakterisierung von Scp160p, einem mRNA- und ribosomenassoziierten Protein in Saccharomyces cerevisiae." [S.l. : s.n.], 2002. http://deposit.ddb.de/cgi-bin/dokserv?idn=966002172.
Pełny tekst źródła
43
Singh, Mamata. "Insights into the Renal Protective Mechanisms of mRNA Binding Protein HuR." The Ohio State University, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=osu1300995188.
Pełny tekst źródła
44
Turk, Casey M. "Paralemmin splice variants and mRNA and protein expression in breast cancers." Connect to this title, 2008. http://scholarworks.umass.edu/theses/194/.
Pełny tekst źródła
45
Fernandes, Pereira Carina. "The influenza A virus NS1 protein and viral mRNA nuclear export." Thesis, University of Cambridge, 2018. https://www.repository.cam.ac.uk/handle/1810/275570.
Pełny tekst źródłaStreszczenie:
Influenza A virus (IAV) replication and transcription occur in the host cell nucleus; a feature which means both the viral genome (vRNA) and mRNA must be exported from the nucleus to the cytoplasm. The mechanism by which vRNA nuclear export is achieved has been well characterised, but how viral mRNAs are exported is poorly understood. The cellular NXF1-dependent mRNA export pathway has been shown to be involved in the export of some viral mRNAs, but how they are recruited to this pathway is unknown. Prior work from our laboratory showed that segment 7 mRNA was inefficiently exported to the cytoplasm in a sub-viral ‘minireplicon’ system, providing the first indication that there were viral requirements for IAV mRNA nuclear export. Further addition of individual viral polypeptides was tested and the effect on segment 7 mRNA export was analysed by fluorescent in situ hybridization (FISH) and confocal microscopy. This identified the NS1 protein as the viral factor required for efficient segment 7 nuclear export. Mutational studies on NS1 were carried out to unveil the mechanistic role of this protein in viral mRNA nuclear export, by plasmid transfection as well as in the context of recombinant viruses. These approaches indicated that both functional domains of NS1 were necessary to preserve the mRNA export function. Furthermore, these mutant proteins were used to examine the association between NS1 and the NXF1-dependent pathway in the context of mRNA nuclear export. Protein-protein and protein-RNA binding assays indicated that interactions between NXF1 and NS1, and NXF1 and segment 7 mRNA were necessary, but not sufficient to promote segment 7 viral mRNA export. Lastly, the role of NS1 protein in the nuclear export of viral mRNAs from other genome segments was studied. The intracellular localisation of most viral mRNAs was not affected by the absence of NS1 or the presence of an export-incompetent NS1 mutant protein. However, segment 4 mRNA exhibited a similar phenotype to segment 7 mRNA in showing a dependence on NS1 for efficient nuclear export. Overall, the results presented in this dissertation suggest that NS1 acts as an adaptor protein between the viral RNA synthesis machinery and cellular export pathway. This provides deeper insights for the characterization of a recently identified function of the IAV NS1 protein, of being required for the efficient nuclear export of mRNA from “late” kinetic class viral genes.
46
Guzella, Thiago dos Santos. "Variation in protein expression levels in cell populations." Doctoral thesis, Universidade Nova de Lisboa. Instituto de Tecnologia Química e Biológica, 2013. http://hdl.handle.net/10362/11968.
Pełny tekst źródłaStreszczenie:
Dissertation presented to obtain the Ph.D degree in Systems Biology<br>A widespread observation is that of variation in the expression levels of a molecule when
analyzing a snapshot of single cells from a population. One possible explanation for this
variation is that there are asynchronous fluctuations throughout time in the expression level
of each cell, for example due to noise in gene expression. Another explanation is that there
are so-called stable variants, groups of cells that have a permanent bias for a limited range
of expression levels compared with the levels observed in a snapshot of the population.
In an extreme scenario, each cell of the population would be a single stable variant with
an expression level that is constant as a function of time, without any fluctuations. Stable
variants could occur if the population is genetically diverse, with each clone being associated
with a particular expression level.(...)
47
Chen, Jinyun. "REGULATION OF INTRACELLULAR ARYL HYDROCARBON RECEPTOR PROTEIN LEVELS." Scholarly Commons, 2020. https://scholarlycommons.pacific.edu/uop_etds/3675.
Pełny tekst źródłaStreszczenie:
The aryl hydrocarbon receptor (AHR) is a ligand-activated signaling molecule which controls tumor growth and metastasis, T cell differentiation, and liver development. Expression levels of this receptor protein are sensitive to the cellular p23 protein levels in immortalized cancer cell lines. As little as 30% reduction of the p23 cellular content can suppress the AHR function. Here we reported that down-regulation of the p23 protein content in normal, untransformed human bronchial/tracheal epithelial cells to 48% of its content also suppresses the AHR protein levels to 54% of its content. This p23-mediated suppression of AHR is responsible for the repression of (1) the ligand-dependent induction of the cyp1a1 gene transcription; (2) the benzo[a]pyrene- or cigarette smoke condensate-induced CYP1A1 enzyme activity, and (3) the benzo[a]pyrene and cigarette smoke condensate-mediated production of reactive oxygen species. Reduction of the p23 content does not alter expression of oxidative stress genes or production of PGE2. Down-regulation of p23 suppresses the AHR protein levels in two other untransformed cell types, namely human breast MCF-10A and mouse immune regulatory Tr1 cells. Collectively, down-regulation of p23 suppresses the AHR protein levels in normal and untransformed cells and can in principle protect our lung epithelial cells from AHR-dependent oxidative damage caused by exposure to agents from environment and cigarette smoking.
The AHR is expressed in triple-negative and non-triple-negative breast cancer cells. It affects breast cancer growth and crosstalk with the estrogen receptor signaling. Normally the AHR is degraded shortly after ligand activation via the action of 26S proteasome. Here we report that the piperazinylpyrimidine compound Q18 triggers AHR protein degradation which is mediated through chaperone-mediated autophagy in triple-negative breast cancer cells (MDA-MB-468 and MDA-MB-231). This lysosomal degradation of AHR exhibits the following characteristics: (1) not observed in non-triple-negative breast cancer cells (MCF-7, T47D, and MDA-MB-361); (2) inhibited by progesterone receptor B but not estrogen receptor alpha; (3) reversed by chloroquine but not MG132; (4) required LAMP2A; (5) triggered by 6 amino-nicotinamide and starvation and (6) involved AHR-LAMP2A interaction mediated by 6 amino-nicotinamide and starvation. The NEKFF sequence localized at amino acid 558 of human AHR is a KFERQ-like motif of chaperone-mediated autophagy, essential for the LAMP2A-mediated AHR protein degradation.
48
Ohlmann, Theophile. "The role of eIF4F in IRES-driven and uncapped mRNA translation." Thesis, University of Sussex, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.336325.
Pełny tekst źródła
49
Sampson, Natalie D. "Identification and functional characterisation of the novel pre-mRNA processing factor SCAF6." Thesis, University of Nottingham, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.272374.
Pełny tekst źródła
50
Wang, Weizhong. "Nuclear galectins and their role in pre-mRNA splicing." Diss., Connect to online resource - MSU authorized users, 2006.
Znajdź pełny tekst źródłaStreszczenie:
Thesis (Ph. D.)--Michigan State University. Dept. of Microbiology and Molecular Genetics, 2006.<br>Title from PDF t.p. (viewed on Nov. 20, 2008) Includes bibliographical references. Also issued in print.