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Inhibitors of rhomboid proteases as tools for cell biology
Kuzmík, Ján ; Stříšovský, Kvido (advisor) ; Hlouchová, Klára (referee)
Rhomboid intramembrane serine proteases cleave polypeptide chains within lipid bilayer. Rhomboid proteases were originally discovered in Drosophila melanogaster where they regulate ontogenesis of the fly, but they are present in all domains of life. Nowadays, various diseases, such as malaria, amoebiasis, Parkinson's disease, various tumour malignancies, and diabetes, have been linked with rhomboid proteases. However, natural substrates and function of most rhomboids remain elusive. Cell biology tools are needed for unravelling functions of rhomboids, as well as for potential pharmacological applications, and this together fuels the effort to develop specific rhomboid inhibitors. The inhibitors known to date always bear an electrophilic warhead attacking the nucleophilic serine of the atypical serine-histidine catalytic dyad of rhomboid. From the various developed inhibitors, peptidyl -ketoamides substituted at the ketoamide nitrogen by hydrophobic groups, discovered in our laboratory, hold the biggest potential. They are potent, reversible, selective, tunable, and are built around a pharmacophore already approved for medical use. Here, I set out to improve peptidyl -ketoamides by exploring the chemical space in the active site of rhomboid and testing substituents of the ketoamide nitrogen of increasing...
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Development of inhibitors of rhomboid proteases as tools for the study of their biological functions
Tichá, Anežka ; Stříšovský, Kvido (advisor) ; Šedo, Aleksi (referee) ; Konvalinka, Jan (referee)
Rhomboids are intramembrane serine proteases that belong to the evolutionarily widespread rhomboid superfamily. Rhomboids developed a slightly different catalytic mechanism compared to classical serine proteases; they utilise a catalytic dyad (Ser/His) instead of the common triad (Ser/His/Asp), and the rhomboid active site is buried in the membrane. This, coupled with their hydrophobicity, makes them quite difficult to study. Therefore, even though they are known to be involved in several important biological processes it is still not clear how exactly most of them are involved in the regulation of or in the pathologies of diseases related to these processes (such as malaria, Parkinson's disease or cancer). Our understanding is hindered by the lack of tools for their characterisation both in vitro and in vivo. In my thesis I present new fluorogenic substrates based on the LacYTM2 sequence, which is hydrolysed by several different rhomboid proteases. Using Förster resonance energy transfer (FRET)-based methods, these substrates are suitable for continuous monitoring of rhomboid activity in vitro. Modifications in the P5-P1 residues can improve selectivity for a specific rhomboid, the choice of FRET pair of fluorophores that absorbes light of longer wavelengths makes them suitable for high throughput...
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Substrate specificity, mechanism and activity regulation of the rhomboid family intramembrane proteases
Škerle, Jan
Intramembrane proteases from the rhomboid-like superfamily are enzymes widely distributed and conserved in all domains of life. They participate in many important processes such as membrane protein quality control or mitochondrial dynamics. Their activity is also linked with diseases like Parkinson's disease or cancer. This makes them potential therapeutic targets. In this work we tried to elucidate in more detail the mechanism of action of the main model intramembrane protease, GlpG from E. coli. We also focused on the mechanism of eukaryotic rhomboid RHBDL2, one of the four mammalian rhomboids, function of which is poorly understood. To acquire more detailed information about substrate-enzyme interaction, we synthesized a series of novel peptidyl-chloromethylketone inhibitors derived from natural rhomboid substrate TatA from P. stuartii. Crystal structure of the complex of GlpG with these inhibitors revealed four substrate binding subsites (S1 to S4) of the enzyme and explained its observed substrate specificity structurally. This study showed that substrate cleavage rate can be dramatically modified by changing the substrate sequence in positions P1 to P5. This helped us develop fluorogenic transmembrane peptide substrates for rhomboid proteases, which are usable in detergent and liposomes, and...
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Rhomboid family intramembrane proteases in prokaryotes: mechanism, substrate repertoires and biological functions in the Gram-positive bacterium Bacillus subtilis.
Began, Jakub
Rhomboid proteases are a class of serine intramembrane proteases, a large family of enzymes that catalyze the proteolytic cleavage of membrane proteins within their transmembrane regions, in the hydrophobic environment of cellular lipid membranes. Rhomboid proteases were discovered in 2001 in Drosophila. In their pioneering study, Lee et al. identified the essential role of Rhomboid-1 protein (Rhom-1), which proteolytically activates the epidermal growth factor (EGF) receptor signaling pathway, in the early stages of fly eye development. Members of the rhomboid superfamily - active proteases (rhomboids) as well as their catalytically-dead counterparts (rhomboid-like proteins, including iRhoms and Derlins) - are widely conserved, implying their biological significance. Rhomboids are present in all kingdoms of life from archea to humans, while proteolytically inactive rhomboid-like proteins are present in eukaryotes only. Rhomboid superfamily proteins play roles in a wide range of processes, as diverse as signaling in metazoan development, mitochondrial biogenesis in yeast, host- cell invasion by protozoan parasites, protein quality control in the endoplasmic reticulum (ER) or bacterial quorum sensing. Rhomboids are the best understood intramembrane proteases from a structural and mechanistic points...
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Substrate specificity, mechanism and activity regulation of the rhomboid family intramembrane proteases
Škerle, Jan ; Stříšovský, Kvido (advisor) ; Hof, Martin (referee) ; Heidingsfeld, Olga (referee)
Intramembrane proteases from the rhomboid-like superfamily are enzymes widely distributed and conserved in all domains of life. They participate in many important processes such as membrane protein quality control or mitochondrial dynamics. Their activity is also linked with diseases like Parkinson's disease or cancer. This makes them potential therapeutic targets. In this work we tried to elucidate in more detail the mechanism of action of the main model intramembrane protease, GlpG from E. coli. We also focused on the mechanism of eukaryotic rhomboid RHBDL2, one of the four mammalian rhomboids, function of which is poorly understood. To acquire more detailed information about substrate-enzyme interaction, we synthesized a series of novel peptidyl-chloromethylketone inhibitors derived from natural rhomboid substrate TatA from P. stuartii. Crystal structure of the complex of GlpG with these inhibitors revealed four substrate binding subsites (S1 to S4) of the enzyme and explained its observed substrate specificity structurally. This study showed that substrate cleavage rate can be dramatically modified by changing the substrate sequence in positions P1 to P5. This helped us develop fluorogenic transmembrane peptide substrates for rhomboid proteases, which are usable in detergent and liposomes, and...
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Rhomboid family intramembrane proteases in prokaryotes: mechanism, substrate repertoires and biological functions in the Gram-positive bacterium Bacillus subtilis.
Began, Jakub
Rhomboid proteases are a class of serine intramembrane proteases, a large family of enzymes that catalyze the proteolytic cleavage of membrane proteins within their transmembrane regions, in the hydrophobic environment of cellular lipid membranes. Rhomboid proteases were discovered in 2001 in Drosophila. In their pioneering study, Lee et al. identified the essential role of Rhomboid-1 protein (Rhom-1), which proteolytically activates the epidermal growth factor (EGF) receptor signaling pathway, in the early stages of fly eye development. Members of the rhomboid superfamily - active proteases (rhomboids) as well as their catalytically-dead counterparts (rhomboid-like proteins, including iRhoms and Derlins) - are widely conserved, implying their biological significance. Rhomboids are present in all kingdoms of life from archea to humans, while proteolytically inactive rhomboid-like proteins are present in eukaryotes only. Rhomboid superfamily proteins play roles in a wide range of processes, as diverse as signaling in metazoan development, mitochondrial biogenesis in yeast, host- cell invasion by protozoan parasites, protein quality control in the endoplasmic reticulum (ER) or bacterial quorum sensing. Rhomboids are the best understood intramembrane proteases from a structural and mechanistic points...
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Rhomboid family intramembrane proteases in prokaryotes: mechanism, substrate repertoires and biological functions in the Gram-positive bacterium Bacillus subtilis.
Began, Jakub ; Stříšovský, Kvido (advisor) ; Bařinka, Cyril (referee) ; Krásný, Libor (referee)
Rhomboid proteases are a class of serine intramembrane proteases, a large family of enzymes that catalyze the proteolytic cleavage of membrane proteins within their transmembrane regions, in the hydrophobic environment of cellular lipid membranes. Rhomboid proteases were discovered in 2001 in Drosophila. In their pioneering study, Lee et al. identified the essential role of Rhomboid-1 protein (Rhom-1), which proteolytically activates the epidermal growth factor (EGF) receptor signaling pathway, in the early stages of fly eye development. Members of the rhomboid superfamily - active proteases (rhomboids) as well as their catalytically-dead counterparts (rhomboid-like proteins, including iRhoms and Derlins) - are widely conserved, implying their biological significance. Rhomboids are present in all kingdoms of life from archea to humans, while proteolytically inactive rhomboid-like proteins are present in eukaryotes only. Rhomboid superfamily proteins play roles in a wide range of processes, as diverse as signaling in metazoan development, mitochondrial biogenesis in yeast, host- cell invasion by protozoan parasites, protein quality control in the endoplasmic reticulum (ER) or bacterial quorum sensing. Rhomboids are the best understood intramembrane proteases from a structural and mechanistic points...
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Inhibitors of rhomboid proteases as tools for cell biology
Kuzmík, Ján ; Stříšovský, Kvido (advisor) ; Hlouchová, Klára (referee)
Rhomboid intramembrane serine proteases cleave polypeptide chains within lipid bilayer. Rhomboid proteases were originally discovered in Drosophila melanogaster where they regulate ontogenesis of the fly, but they are present in all domains of life. Nowadays, various diseases, such as malaria, amoebiasis, Parkinson's disease, various tumour malignancies, and diabetes, have been linked with rhomboid proteases. However, natural substrates and function of most rhomboids remain elusive. Cell biology tools are needed for unravelling functions of rhomboids, as well as for potential pharmacological applications, and this together fuels the effort to develop specific rhomboid inhibitors. The inhibitors known to date always bear an electrophilic warhead attacking the nucleophilic serine of the atypical serine-histidine catalytic dyad of rhomboid. From the various developed inhibitors, peptidyl -ketoamides substituted at the ketoamide nitrogen by hydrophobic groups, discovered in our laboratory, hold the biggest potential. They are potent, reversible, selective, tunable, and are built around a pharmacophore already approved for medical use. Here, I set out to improve peptidyl -ketoamides by exploring the chemical space in the active site of rhomboid and testing substituents of the ketoamide nitrogen of increasing...
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Development of inhibitors of rhomboid proteases as tools for the study of their biological functions
Tichá, Anežka ; Stříšovský, Kvido (advisor) ; Šedo, Aleksi (referee) ; Konvalinka, Jan (referee)
Rhomboids are intramembrane serine proteases that belong to the evolutionarily widespread rhomboid superfamily. Rhomboids developed a slightly different catalytic mechanism compared to classical serine proteases; they utilise a catalytic dyad (Ser/His) instead of the common triad (Ser/His/Asp), and the rhomboid active site is buried in the membrane. This, coupled with their hydrophobicity, makes them quite difficult to study. Therefore, even though they are known to be involved in several important biological processes it is still not clear how exactly most of them are involved in the regulation of or in the pathologies of diseases related to these processes (such as malaria, Parkinson's disease or cancer). Our understanding is hindered by the lack of tools for their characterisation both in vitro and in vivo. In my thesis I present new fluorogenic substrates based on the LacYTM2 sequence, which is hydrolysed by several different rhomboid proteases. Using Förster resonance energy transfer (FRET)-based methods, these substrates are suitable for continuous monitoring of rhomboid activity in vitro. Modifications in the P5-P1 residues can improve selectivity for a specific rhomboid, the choice of FRET pair of fluorophores that absorbes light of longer wavelengths makes them suitable for high throughput...
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Evolution of regulatory mechanisms of EGF receptor activation
Trávníčková, Květa ; Stříšovský, Kvido (advisor) ; Koudelková, Lenka (referee)
Signalling through EGF receptor is crucial both for ontogenesis and for maintaining homeostasis in adult organisms. It is involved in controlling cellular behaviours such as proliferation, migration or differentiation. This thesis provides an insight into evolution of the regulatory mechanisms of EGF receptor activation by discussing their principles in C. elegans, D. melanogaster and H. sapiens sapiens, on the basis of which conclusions about their evolutionary tendencies are made. Attention is focused on the roles of the rhomboid family of proteins, whose activity is tightly associated with EGF receptor signalling. Dysregulation of the EGF receptor unnegligibly contributes to the development of various diseases, mainly many types of cancer, but also schizophrenia, psoriasis and cardiovascular disorders. Experimental results obtained on this field of research therefore have the potential to be applied in drug design.
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