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Endocytic transport in cytokinesis
Koudelová, Kristina ; Libusová, Lenka (advisor) ; Vosolsobě, Stanislav (referee)
Cytokinesis represents a very complex and highly orchestrated process. For many years, the mechanism of animal cell cytokinesis was described as a result of actomyosin ring constriction. By contrast, in plant cells the division was seen as an outcome of vesicle fusion at the cell plate region between two daughter cells. Recent studies, however, uncover the involvement of vesicular trafficking in animal cell cytokinesis. This thesis aims to highlight the importance of endocytic transport and the necessity of its proper regulation. At first, the origin of vesicles is debated. Afterwards, three main types of endocytic vesicles are examined - Rab11/FIP3 endosomes, Rab35-endosomes and PI(3)P-enriched endosomes, along with their function and interacting partners. Finally, the attention is given to the mechanism of abscission and midbody inheritance. Ongoing processes are accompanied by changes in membrane composition, cytoskeleton reorganization and targeted delivery of distinct cargo molecules. Failure in cytokinesis has been implicated in the etiology of many diseases, such as cancer. Therefore, better understanding of associated endocytic trafficking may provide us with new therapeutic strategies.
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Subcelulární lokalizace a úloha komplexu exocyst v savčích buňkách během cytokineze
Ulrychová, Lenka ; Hudeček, Jiří (advisor) ; Entlicher, Gustav (referee)
Cytokinesis is the last step of cell cycle when two individual daughter cells separate in process called abscission. This process involves various cellular membrane structures such as endoplasmic reticulum or trans-Golgi network. Moreover, recent investigation has also highlighted an important role of recycling endosomes. The membrane dynamics appear to be important during cell division especially for the formation of new plasma membrane between two daughter cells. Numerous studies suggest that cytokinesis is tightly linked with highly sophisticated transmembrane shuttle that is controlled by Ras-superfamily members such as Rab and Ral proteins. Moreover, during last years has also been revealed the involvement of tethering factors which mediate the fusion of intracellular vesicles with the target plasma membrane. The best known tethering factor is the evolutionary conserved exocyst complex found in all eukaryotic cells. This protein complex is composed of eight subunits (Sec3, Sec5, Sec6, Sec8, Sec10, Sec15, Exo70 and Exo84) and was found to interact with members of Ras- superfamily suggesting its involvement in the regulation of cytokinesis. Although the exact mechanism remains shrouded in fog this work suppose the possible interactions among Ras- like proteins and exocyst members which may...
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