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Assessing biochemical properties of PDE8A1: Design of experimental system in living cells"
Galica, Tomáš ; Černý, Jan (advisor) ; Mašek, Tomáš (referee)
4 Abstract Phosphodiesterases (PDEs), enzymes that hydrolyze cyclic nucleotides, are important components of signal transduction pathways in eukaryotic cells. Second messenger 3'-5'- cyclic adenosine monophosphate (cAMP) is hydrolyzed by specific PDEs. By controlling concentration levels of cAMP in cell, PDEs preserve favorable environment for successful transmission of the cAMP signal. Moreover, PDEs are activated by protein kinase A (PKA) in response to elevated cAMP concentration, which is a feature crucial for signal termination. PDE8A1 is a high-affinity cAMP-specific IBMX insensitive phosphodiesterase, an enzyme important for cAMP signaling. However, mostly due to a lack of specific inhibitor, its role has not been assessed in detail. This thesis reports cloning of PDE8A1, identification of its posttranslational modifications and subcellular localization, as well as an alternative approach to address PDE biology by the use of cyclase toxin from Bordetella pertussis. Keywords: phosphodiesterase, cAMP, posttranslational modification, myristoylation, palmitoylation, adenylate cyclase toxin
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The function of palmitoylation of membrane proteins in immune cells
Hanusová, Zdeňka ; Otáhal, Pavel (advisor) ; Pavlů, Barbora (referee)
Protein palmitoylation is a post-translation modification, which typically regulates the protein interaction with a membrane; apart from that, it can have various functions in protein regulation. Process of this modification covers covalent attachment of palmitate to an aminoacid residue in the target protein; identity of the aminoacid than determines the palmitoylation type. Most common is modification of a cystein residue - in that case we speak about so-called S-palmitoiyation. The exceptionality of this lipid modification type is in the reversibility of the whole process; this enables for example trafficking regulation of many proteins between various membrane compartments and ragulation of proteins' function. In vivo, palmitoylation of many proteins is mediated by enzymes protein acyltransferases, while depalmitoylation is mediated by enzymes acylprotein thioesterases. Palmitoylated proteins can be identified in wide spectrum of cellular types, also in immune cells. Palmitoylation plays here an important role, especially in interaction of signal proteins with lipid rafts and the related modulation of protein's function. Significance has palmitoylation also as a dynamic process, which mediates the right identification of protein's subcellular localization. This work is a review and it's aim is...
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Different charged short lipopeptides
Ježek, R. ; Slaninová, Jiřina ; Králová, M. ; Macková, M.
Series of short peptides palmitoylated in different positions was designed, synthesized and tested for antimicrobial activities. The palmitoyl group was situated either on the alpha - amino group in position 1 or on the epsilon - amino group of lysine in position 3. The peptide charge ranged from –3 to +4. The peptide part of the lipopeptides constituted mainly from lysine, arginine and glutamic acid.
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