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Ser/Thr protein kinases in mycobacteria
Borovcová, Taťána ; Doubravová, Linda (advisor) ; Konopásek, Ivo (referee)
The Mycobacterium tuberculosis genome encodes 11 Ser/Thr protein kinases. These protein kinases are structurally related to eukaryotic protein kinases. The phosphoproteome contains hundreds of proteins phosphorylated on Ser/Thr residues that influence all aspects of cell biology, which supports the critical role of phosphorylation in the regulation of physiology. Particularly important role in regulation belongs to protein kinases PknA, PknB, PknG and PknL, these protein kinases occur in all species of mycobacteria. Although only PknA and PknB are essencial for the M. tuberculosis, they regulate cell shape through the regulation of cell wall synthesis and cell division. Another important protein kinase is PknG, although not essential for growth it is necessary for virulence, because it promotes the survival of pathogen inside macrophages of the host. As a result, Ser/Thr protein kinases represent an interesting target for inhibitor development that could be used as drugs against tuberculosis.
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Significance of protein phosphorylation for bacterial cell
Gregorová, Michaela ; Branny, Pavel (advisor) ; Lišková, Petra (referee)
Phosphorylation - most common post-translational modification has an important role in many cellular processes of bacteria. Bacteria contain enzymes that are in charge of adding phosphoryl group (kinases) or enzymes with reciprocal activity (phosphatases). Reversible phosphorylation and dephosphorylation of proteins are fundamental for signal transduction from the environment to the cell. These modifications can affect enzymatic activity, protein stability, localization as well as interaction with another protein. Due to the complexity of these phosphorylation networks, bacterial cells are capable to adapt very effectively to changing environmental conditions.
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The role of protein kinase StkP in regulation of the cell division in Streptococcus pneumoniae
Malíková, Eliška ; Doubravová, Linda (advisor) ; Kuthan, Martin (referee)
Protein phosphorylation by protein kinases is a key mechanizm that enables both eukaryotic and prokaryotic organizm sense and read environmental signals and convert these signals into changes in gene expression and thus proper biological response. One of the main phosphorylation systems in bacteria consists of eukaryotic-like Ser/ Thr protein kinases. The genome of human pathogen Streptococcus pneumoniae contains single Ser/ Thr protein kinase StkP. StkP regulates virulence, competence, stress resistance, gene expression and plays an important role in the regulation of cell division cycle. Analysis of phosphoproteome maps of both wild type and ΔstkP mutant strain of S. pneumoniae showed that in vivo StkP phosphorylates several putative substrates including the cell division protein DivIVA (NOVÁKOVÁ et al., 2010). DivIVA in S. pneumoniae is localized at midcell and at the cell poles. It was proposed to be primarily involved in the formation and maturation of the cell poles (FADDA et al., 2007). The aim of this thesis was to investigate phosphorylation of the cell division protein DivIVA in S. pneumoniae. Gene divIVA was cloned, expressed in E. coli and protein was purified via affinity chromatography. Phosphorylation of DivIVA by StkP was examined in a kinase assay. We confirmed that DivIVA is a direct...
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