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Structure and Function of the C-terminal Domain of the HsdR Subunit from the Type I Restriction-Modification System EcoR124
GRINKEVICH, Pavel
The Type I restriction-modification enzyme EcoR124 is a pentameric complex consisting of one specificity subunit, two methylation subunits and two motor subunits (HsdR) that can recognize specific DNA sequences and perform double-stranded DNA cleavage and modification. The HsdR subunit is responsible for ATP-dependent DNA translocation and DNA cleavage. Even though the first crystal structure of HsdR was obtained ten years ago, a large part of the C-terminus has not been resolved in any HsdR structures to date. This dissertation aims to elucidate its role within the HsdR subunit and the whole pentameric complex by solving the structure of the C-terminus by means of X-ray diffraction crystallography and explore its function using biochemical, microbiological, bioinformatical and computational methods.
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The influence of heterodimezation of splicing variants of metobotropic glutamate receptor 1a and 1b on the intracellular distribution of receptor complexes
Dvořáková, Michaela ; Konvalinka, Jan (advisor) ; Vaněk, Ondřej (referee)
L-glutamate is a major excitatory neurotransmitter in vertebrate central nervous system. L-glutamate enables synaptic transmission through ionotropic and metabotropic glutamate receptors. These receptors are indispensable in the brain. The main role of metabotropic glutamate receptors is to mediate slow excitatory and inhibitory responses by activation of intracellular messengers and to regulate cationic channels. Metabotropic glutamate receptors are involved in synaptic plasticity, different types of memory, learning, motoric coordination and neural development. On the other hand excitotoxicity of glutamate is often associated with neurodegenerative processes such as Alzheimer, Huntington and Parkinson disease. Metabotropic glutamate receptors are promising therapeutic targets for a treatment of psychiatric and neurological diseases. Targeted trafficking of metabotropic glutamate receptors to distinct parts of neurons is influenced by neuronal polarity and thus regulates sensing and transmission of extracellular signals. Newly detected heterodimeric receptors might be trafficked in a different way than homodimers and therefore our knowledge of molecular pathways of these complexes could help us with subsequent drug targeting. This work confirms heterodimerization of metabotropic glutamate receptor 1 into...
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The role of charged residues in the activation and modulation of the TRPA1 ion channel
Zímová, Lucie ; Vlachová, Viktorie (advisor) ; Doležal, Vladimír (referee) ; Rokyta, Richard (referee)
Important receptor for sensing painful stimuli is ion channel TRPA1, which is expressed in peripheral endings of nociceptive neurons, where it serves as transducer of physical and chemical environmental signals to the language of the nervous system. The effort to understand the mechanisms of its activity on a molecular level is driven by the vision of progress in treatment of chronic pain in humans. Our work focused on C-terminal cytoplasmic domain of TRPA1 receptor, where we described i.a. the probable binding site for calcium, which is the most important TRPA1 modulator. Using the combination of homology modeling and molecular dynamic simulations with electrophysiological measurements we were able to explain molecular basis of familial pain syndrome caused by TRPA1 point mutation. We contributed to the understanding of the TRPA1 voltage-dependent activation mechanism by describing the amino acids in proximal C-terminus and in S4-S5 linker of transmembrane domain that are directly involved in voltage-dependent gating. Powered by TCPDF (www.tcpdf.org)
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The role of charged residues in the activation and modulation of the TRPA1 ion channel
Zímová, Lucie ; Vlachová, Viktorie (advisor) ; Doležal, Vladimír (referee) ; Rokyta, Richard (referee)
Important receptor for sensing painful stimuli is ion channel TRPA1, which is expressed in peripheral endings of nociceptive neurons, where it serves as transducer of physical and chemical environmental signals to the language of the nervous system. The effort to understand the mechanisms of its activity on a molecular level is driven by the vision of progress in treatment of chronic pain in humans. Our work focused on C-terminal cytoplasmic domain of TRPA1 receptor, where we described i.a. the probable binding site for calcium, which is the most important TRPA1 modulator. Using the combination of homology modeling and molecular dynamic simulations with electrophysiological measurements we were able to explain molecular basis of familial pain syndrome caused by TRPA1 point mutation. We contributed to the understanding of the TRPA1 voltage-dependent activation mechanism by describing the amino acids in proximal C-terminus and in S4-S5 linker of transmembrane domain that are directly involved in voltage-dependent gating. Powered by TCPDF (www.tcpdf.org)
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The influence of heterodimezation of splicing variants of metobotropic glutamate receptor 1a and 1b on the intracellular distribution of receptor complexes
Dvořáková, Michaela ; Konvalinka, Jan (advisor) ; Vaněk, Ondřej (referee)
L-glutamate is a major excitatory neurotransmitter in vertebrate central nervous system. L-glutamate enables synaptic transmission through ionotropic and metabotropic glutamate receptors. These receptors are indispensable in the brain. The main role of metabotropic glutamate receptors is to mediate slow excitatory and inhibitory responses by activation of intracellular messengers and to regulate cationic channels. Metabotropic glutamate receptors are involved in synaptic plasticity, different types of memory, learning, motoric coordination and neural development. On the other hand excitotoxicity of glutamate is often associated with neurodegenerative processes such as Alzheimer, Huntington and Parkinson disease. Metabotropic glutamate receptors are promising therapeutic targets for a treatment of psychiatric and neurological diseases. Targeted trafficking of metabotropic glutamate receptors to distinct parts of neurons is influenced by neuronal polarity and thus regulates sensing and transmission of extracellular signals. Newly detected heterodimeric receptors might be trafficked in a different way than homodimers and therefore our knowledge of molecular pathways of these complexes could help us with subsequent drug targeting. This work confirms heterodimerization of metabotropic glutamate receptor 1 into...
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