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Differentiation of yeast colonies: The role of selected transcription factors and metabolic proteins
Plocek, Vítězslav
5 Abstract Although yeasts are unicellular microorganisms, they form complex multicellular formations such as biofilms and colonies under natural conditions. Within these structures, processes such as cell differentiation, specialization by particular cell populations and cell signalling, which are typical of multicellular organisms, take place. The literature introduction to this thesis summarizes current knowledge regarding the development of biofilms and colonies, in particular those of the model organism, Saccharomyces cerevisiae, and some selected regulations that are important for the formation of multicellular structures. In the results section, I focus on two lines of research. The first is directed towards mechanisms, involved in the formation of multicellular structures. In studying the formation of SLI biofilms (biofilms at the solid/liquid interface), we have documented the antagonistic role of the regulators CYC8 and TUP1 in their formation and have also described the effect of the presence of glucose on the development and stability of SLI biofilms of strain BR-F. During this study we[D1] have developed an imaging method that allows us to prepare and observe the internal structure (vertical cross-section) of SLI biofilms, as well as the growth of unattached cells, under physiological...
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Role of the PDZ Domain-Binding Motif of the Oncoprotein E6 in the Pathogenesis of High Risk Papillomaviruses
Faflíková, Tereza ; Španielová, Hana (advisor) ; Plocek, Vítězslav (referee)
The infection by high-risk human papillomaviruses is involved in causing cancers. The extreme carboxy terminus of high-risk α-HPV E6 protein contains a PDZ domain-binding motif. The E6 protein of high-risk HPV binds by PDZ domain-binding motif to cellular proteins containing PDZ domain, which participate in the maintenance of the cell polarity, in the stabilization of cell-cell junctions or in the regulation of cellular signaling pathways, e.g. hDlg (human homologue of Discs large protein), hScrib (human homologue of Drosophila tumor suppressor Scribble). Binding of E6 with cellular proteins prevents the induction of apoptosis and influences the enhancement of growth rate of infected cells, degradation of tight-junctions, regulation of cell polarity and vesicular transport. The interaction between E6 and cellular proteins increases the stability of E6 protein and protects E6 from proteasomal degradation. PDZ domain-binding motif of E6 high-risk HPV contributes to the development of malignant tumors.
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Cell Surface Markers in Colorectal Cancer
Červená, Klára ; Španielová, Hana (advisor) ; Plocek, Vítězslav (referee)
Colorectal cancer is the most frequent cancer in the Czech Republic. Retrospective analysis of patients with colorectal cancer have led and still lead to the discovery of new biomarkers that may be important in treatment, prediction or prognosis of cancer. The main aim of this thesis was to desribe discovered cell surface proteins (biomarkers) of colorectal cancer, that correlate with colorectal cancer progression, metastasis and patient outcome, and discusses the possibilities of their utilization as cancer cell targets for theranostic purposes. Keywords: colorectal cancer, biomarkers, targeting, theranostics, prediction, prognosis
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Vesicular trafficking from acidic compartments to the endoplasmic reticulum
Polidarová, Markéta ; Forstová, Jitka (advisor) ; Plocek, Vítězslav (referee)
The cell uses retrograde transport from endosomes to Golgi apparatus and further to the endoplasmic reticulum to recycle its receptors and other proteins. There are several pathways starting on different types of endosomes aimed to the trans-Golgi network and from it further to the endoplasmic reticulum. From the early and maturing endosomes the proteins are transported using the retromer complex. Rab9 GTPase is essential for transport from the late endosomes. Rab6 and Rab11 play major role in the transport form the recycling endosomes. There are two pathways going through the Golgi apparatus. The first one is mediated by COPI vesicles which are regulated by Arf1 GTPase and the pathway is sensitive to brefeldin A. The second pathway is regulated by Rab6 GTPase. Except for endogenous proteins the retrograde transport is used by protein toxins and small unenveloped DNA viruses as well. Rab6 pathway from the recycling endosomes and through the Golgi apparatus is characteristic for Shiga toxin. The retrograde transport of ricin starts on the early endosomes and is less clear. Scientists only started uncovering the transport of small unenveloped DNA viruses.
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Synthesis of proteins containing non-canonical amino acids
Knetl, Adam ; Vopálenský, Václav (advisor) ; Plocek, Vítězslav (referee)
0 Abstract: Non-canonical amino acids allow the introduction of new chemical properties into proteins, which is useful both for studying proteins, and designing proteins. However, the synthesis of proteins containing non-canonical amino acids faces problems with decreased effectivity of translation. This thesis examines the role of genetic code for coding non-canonical amino acids, proteosynthesis and aminoacilation of tRNA and finally the non-canonical amino acids and their application in proteins while including examples.
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Differentiation of yeast colonies: The role of selected transcription factors and metabolic proteins
Plocek, Vítězslav ; Palková, Zdena (advisor) ; Heidingsfeld, Olga (referee) ; Sychrová, Hana (referee)
5 Abstract Although yeasts are unicellular microorganisms, they form complex multicellular formations such as biofilms and colonies under natural conditions. Within these structures, processes such as cell differentiation, specialization by particular cell populations and cell signalling, which are typical of multicellular organisms, take place. The literature introduction to this thesis summarizes current knowledge regarding the development of biofilms and colonies, in particular those of the model organism, Saccharomyces cerevisiae, and some selected regulations that are important for the formation of multicellular structures. In the results section, I focus on two lines of research. The first is directed towards mechanisms, involved in the formation of multicellular structures. In studying the formation of SLI biofilms (biofilms at the solid/liquid interface), we have documented the antagonistic role of the regulators CYC8 and TUP1 in their formation and have also described the effect of the presence of glucose on the development and stability of SLI biofilms of strain BR-F. During this study we[D1] have developed an imaging method that allows us to prepare and observe the internal structure (vertical cross-section) of SLI biofilms, as well as the growth of unattached cells, under physiological...
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Biological membranes and methods for their characterization - current approach.
Skotnicová, Marie ; Konopásek, Ivo (advisor) ; Plocek, Vítězslav (referee)
Cell membrane of prokaryotes is immediately exposed to various environmental changes. To survive, the organism has to sufficiently react to these changes and adapt to them. On the level of the lipid bilayer it means changes of membrane fluidity induced by alterations of the lipid composition. Even a small alteration of acyl chains or polar heads of the phospholipids can alter the order of the lipid bilayer. Various biophysical techniques have been used to detect changes of the membrane fluidity and lipid composition. The purpose of this work is to summarize mechanism of adaptation induced by cold, heat and osmotic shock, as well as commonly used methods for detection of these changes. Studied organisms represent Gram- negative Escherichia coli and Gram-positive Bacillus subtilis. Key words biological membranes, membrane fluidity, adaptation of prokaryotic organisms to environmental changes, methods of characterization of biological membranes, membrane spectroscopy
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Ab initio prediction of the membrane protein structures
Sokol, Albert ; Fišer, Radovan (advisor) ; Plocek, Vítězslav (referee)
Knowledge of the three dimensional structure of the protein is extremely important for a full understanding of its function and molecular proteins interaction. The structure is typically determined experimentally by X-ray crystallography and NMR spectroscopy, unfortunately membrane proteins provide numerous problems for these methods. A possible solution is the computational prediction. Ab initio prediction of three-dimensional models of the membrane proteins is a complex process which cannot use any available protein structure as a general template. There are few softwares that deal with this process and selected four are described in detail in this work. These are two programs for the prediction of transmembrane helical proteins (Rosetta, EVfold_membrane) and two for the prediction of transmembrane beta barrels (EVfold_bb, 3D-SPOT). The main approaches that are used in the prediction of the three-dimensional structure of a protein are inserting short segments of amino acid sequences which are derived from the determined protein structures (Rosetta), using evolutionary information from many other protein sequences (EVfold) and formation of the beta barrel domains based on combining adjacent antiparallel beta chains (3D-SPOT). Every software uses a variety of external programs to address specific...
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Cell Surface Markers in Colorectal Cancer
Červená, Klára ; Španielová, Hana (advisor) ; Plocek, Vítězslav (referee)
Colorectal cancer is the most frequent cancer in the Czech Republic. Retrospective analysis of patients with colorectal cancer have led and still lead to the discovery of new biomarkers that may be important in treatment, prediction or prognosis of cancer. The main aim of this thesis was to desribe discovered cell surface proteins (biomarkers) of colorectal cancer, that correlate with colorectal cancer progression, metastasis and patient outcome, and discusses the possibilities of their utilization as cancer cell targets for theranostic purposes. Keywords: colorectal cancer, biomarkers, targeting, theranostics, prediction, prognosis
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