|
|
Role of MAPK in regulation of cytoplasmic polyadenylation during meiotic maturation of mammalian oocytes
Kráčmarová, Jana ; Kubelka, Michal (advisor) ; Svoboda, Petr (referee)
Mammalian oocytes undergoing meiotic maturation are transcriptionally silent and gene expression is therefore regulated at the level of translation. One of the well established mechanisms employed in translational regulation of maternal mRNAs in oocytes is cytoplasmic polyadenylation. This process is generally controlled by phosphorylation and activation of cytoplasmic polyadenylation element binding protein (CPEB). The aim of this thesis is to determine the role of mitogen-activated protein kinase (MAPK) in regulation of CPEB-mediated cytoplasmic polyadenylation in maturing mouse and porcine oocytes. For this purpose, MAPK activity was inhibited using its specific inhibitor, GDC-0994 and the effect of MAPK inhibition on cyclin B1 mRNA polyadenylation was monitored. In mouse oocytes, MAPK inhibition impaired neither cyclin B1 mRNA polyadenylation nor its translation and MAPK is thus unlikely to be involved in regulation of cytoplasmic polyadenylation in this species. Based on the results of experiments performed using porcine oocytes, the possible role of MAPK in CPEB-mediated cytoplasmic polyadenylation can neither be confirmed nor ruled out. Keywords: cytoplasmic polyadenylation, mouse oocyte, porcine oocyte, mitogen-activated protein kinase (MAPK), cyclin B1, GDC-0994 inhibitor
|
|
|
Protein diversity in human stress granules
Kráčmarová, Jana ; Frydrýšková, Klára (advisor) ; Motlová, Lucia (referee)
During unfavourable conditions eukaryotic cells inhibit translation of certain mRNAs and preferably synthesize proteins that are involved in the stress response. The saved energy is used for repair of cellular damages. The untranslated mRNAs are accumulated in the form of ribonucleoprotein complexes. This accumulation results in the formation of the cytoplasmic stress granules. These granules are sites of structure remodeling and triage of the ribonucleoprotein complexes - they can be stored, degraded or sent back to the cytoplasm for translation reinitiation. The mRNA molecules carry their associated proteins, which include also proteins implicated in the cell signaling. Stress granules can thus indirectly regulate some processes, such as apoptosis, and play role in the survival of the cell. This thesis focuses on protein content of stress granules in human cell lines, briefly characterizes stress factors that induce their formation and discusses differences between the content of stress granules induced by different stress stimuli. An important part of this thesis is a table summarizing proteins found in the stress granules. The second part of this work is dedicated to the characterization of the proteins of the fragile X mental retardation protein family. It outlines the possible link between...
|
guest ::
