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Endoplasmic reticulum-associated degradation and its role in virus infection
Svobodová, Terezie ; Forstová, Jitka (advisor) ; Mašek, Tomáš (referee)
The endoplasmic reticulum-associated degradation pathway, ERAD, is an important mechanism for maintaining cellular homeostasis. The function of ERAD is degradation of accumulated unfolded proteins in the endoplasmic reticulum. ERAD is carefully regulated by pathway called "Unfold protein response" and by "ERAD tuning" mechanism. Some viruses have adopted the ways how to exploit this system or its factors for their own benefit. These utilizations include targeting of specific host proteins for degradation, transfer of viral products or virions from the endoplasmic reticulum into the cytoplasm, or the use of a membrane platform arising from the cooperation with "ERAD tuning" for viral replication. Role of ERAD in viral infection can manifest itself in different ways, it can contribute to degradation not only of host proteins but also of viral products. In this work I summarize mechanisms of ERAD pathway and their regulatory pathways. Meanwhile, in the specific examples, I present roles of ERAD pathway and associated systems in viral infections.
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Induction and course of programmed cell death in cancer cells after taxane application."
Kábelová, Adéla ; Jelínek, Michael (advisor) ; Gemperle, Jakub (referee)
The taxanes are a class of commonly used anticancer agents, which are very effective in treatment of breast, ovarian, prostate or lung cancer. Taxanes bind to the β-tubulin subunit of microtubules and lead to their stabilization and inhibition of depolymerization. Such microtubules lose their function to form mitotic spindle, thus arresting cells in G2/M phase and resulting in apoptosis. Unfortunately some cells are able to escape from taxanes-induced apoptosis by developing various mechanisms of resistance including alteration in taxanes target microtubules or upregulation of specific transporters that pump the drug out of cells. Other types of resistance are connected with process of programmed cell death (PCD), especially with proteins that after taxane application participate in its successful progress. Taxanes can directly or indirectly modify the activity of Bcl-2-family proteins that control mitochondrial and endoplasmic reticulum integrity, thus regulating the initiation of PCD. Caspases are executioners of PCD and caspase-2 activated by cytoskeletal disruption seems to be especially important in taxanes- induced apoptosis. In some cases can taxane treatment also result in caspase-independent cell death. Special role has protein p53 that seems to be involved only in apoptosis caused by low taxanes...
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AUXIN BINDING PROTEIN 1 (ABP1) and its role in the auxin management in plant cells
Čovanová, Milada ; Zažímalová, Eva (advisor) ; Lüthen, Hartwig (referee) ; Reinöhl, Vilém (referee)
Conclusions The role of AUXIN BINDING PROTEIN 1 (ABP1) in the auxin management in plant cells was followed using simplified model material of suspension-cultured cells of tobacco BY-2 line. ABP1 is a putative auxin receptor considered to mediate fast non-genomic responses to auxin and it can be involved in every aspect of the regulation of auxin responses, metabolism and transport. There are four major conclusions that could be made based on the results presented in this thesis: 1) Auxin binding protein 1 mediates both cell division and expansion in tobacco BY-2 cells. In standard cultivation conditions or at lower concentrations of 2,4-D in culture medium, ABP1 overexpression had no detectable impact on cell division, cell elongation or cell growth.. 5- times increased 2,4-D concentration stimulated weakly cell elongation. . Antisense suppression of ABP1 expression resulted in disturbance in both cell expansion and cell division intensity, suggesting that ABP1 is essential for the control of balance between cell division and cell elongation during the growth cycle. ABP1 is localized in endoplasmic reticulum of cells cultivated in standard medium supplemented with 1 μM 2,4-D and it appeared also at the plasma membrane following the IAA application. 2) ABP1 mediates intercellular auxin transport. Cells...
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