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Caveolae and caveosoms
Galica, Tomáš ; Černý, Jan (advisor) ; Forstová, Jitka (referee)
Caevolae are remarkably stable structures at the plasma membrane. They form specific domains distinct in lipid composition from the rest of plasma membrane. Many diverse functions are assigned to Caevolae. They play role in modulation of cellular surface, signalization and well regulated endocytosis. Caveosomes suppose to be large intracellular vesicular structures potentialy new membrane organels. They are derived from internalized caveolae. Tohether with caveolae they are proposed to form a separeted system of intracellular vesicles. However recent evidence suggests that caveolae can fuse with endosomes immediately after internalization. If this is true, then the system of vesicles derived from caveolae, including caveosomes, can be considered a regular component of endosomal system. Isolation of caveosomes from endosomes has been seen mainly in experiments where polyomavirus SV40 was used. Thus the question, if this isolation is not just a result of SV40 infection, arises. It has been shown recently that SV40 virus is capable of inducing caveosome-like structures even in the absence of caveolae. Consequently existence and properties of caveosomes are being questioned. The problem of high importance is the genesis of caveosomes and their existence in SV40 non-infected cells. In this thesis...
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The role of endocytosis in Wnt signaling pathway
Matějů, Daniel ; Libusová, Lenka (advisor) ; Doubravská, Lenka (referee)
Endocytosis and cell signaling are tightly connected processes. This connection is most obvious at the level of endocytosis of signaling receptors and ligands. For many years, endocytosis of signaling receptors was considered as a negative feedback loop mechanism, which desensitizes the cell after prolonged stimulation by ligand. Now it is evident that the situation is more complex and endocytosis can affect cell signaling both negatively and positively. In this thesis, I will summarize how Wnt signaling can be affected by endocytosis of receptors and ligands of this signaling pathway. Wnt signaling is one of the most important and intensively studied signaling pathways in the metazoan development. Several possible roles of endocytosis in Wnt signaling were uncovered in recent years, some of them unique among other signaling pathways. Understanding the relationship between endocytosis and Wnt signaling will thus help not only to deepen the knowledge of Wnt signaling but also to shed light on the possible roles of endocytosis in regulation of cell signaling in general.
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Caveolae and caveosoms
Galica, Tomáš ; Forstová, Jitka (referee) ; Černý, Jan (advisor)
Caevolae are remarkably stable structures at the plasma membrane. They form specific domains distinct in lipid composition from the rest of plasma membrane. Many diverse functions are assigned to Caevolae. They play role in modulation of cellular surface, signalization and well regulated endocytosis. Caveosomes suppose to be large intracellular vesicular structures potentialy new membrane organels. They are derived from internalized caveolae. Tohether with caveolae they are proposed to form a separeted system of intracellular vesicles. However recent evidence suggests that caveolae can fuse with endosomes immediately after internalization. If this is true, then the system of vesicles derived from caveolae, including caveosomes, can be considered a regular component of endosomal system. Isolation of caveosomes from endosomes has been seen mainly in experiments where polyomavirus SV40 was used. Thus the question, if this isolation is not just a result of SV40 infection, arises. It has been shown recently that SV40 virus is capable of inducing caveosome-like structures even in the absence of caveolae. Consequently existence and properties of caveosomes are being questioned. The problem of high importance is the genesis of caveosomes and their existence in SV40 non-infected cells. In this thesis...
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