|
|
Biogenesis and function of peroxisomes in parasitic protists
Nguyen, Thu Duong ; Tachezy, Jan (advisor) ; Verner, Zdeněk (referee)
Peroxisomes are found in majority of eukaryotes and possibly originate from the last eukaryotic common ancestor, as the proteins involved in their biogenesis are highly conserved. Enzymatic content of peroxisomes is highly diverse and their metabolic activity may vary depending on the cell type. Metabolically, peroxisomes interact with mitochondria and these organelles are functionally linked. Peroxisomes in unicellular eukaryotes are very diverse. The peroxisomes in kinetoplastids are named glycosomes because they contain several glycolic enzymes. The loss of peroxisomes occurs in certain representatives of Alveolata, and peroxisomes are entirely absent in Metamonada group. Anaerobic peroxisomes were found in Archamoebidae. They are metabolically quite distinct from their aerobic counterparts. The properties of these peroxisomes are related to the lifestyle of these protists. This work briefly summarizes information regarding the biogenesis of peroxisomes and their functions, their functional connection with mitochondria and then provide characteristics of peroxisomes in selected protists.
|
|
|
Yeast retrograde signaling pathway between mitochondria and the nucleus
Podholová, Kristýna ; Palková, Zdena (advisor) ; Fraiberk, Martin (referee)
Retrograde signaling pathway is the pathway between mitochondria and nucleus. This pathway helps Saccharomyces cerevisiae to cope with worsening of conditions of life, such as depletion of rich nutrient sources and necessity of use poor resources, reduction of mitochondrial membrane potential, or loss of mitochondrial DNA causing disturbances in the citric acid cycle. Most of these conditions are associated with aging yeast populations. Key retrograde pathway proteins include RTG transcription factors Rtg1p/Rtg3p and cytoplasmic protein Rtg2p. Retrograde pathway is upregulated by several positive and negative regulators including the TOR pathway, which negatively regulates retrograde pathway. The retrograde pathway target genes include genes coding for tricarboxylic cycle enzymes, peroxisomal enzymes, transporters and other enzymes of anaplerotic pathways. Retrograde response help cells to modify their metabolism so that they are able to overcome unfavorable environmental conditions in which they live. Powered by TCPDF (www.tcpdf.org)
|
|
|
Anaerobic peroxisomes in Archamoebae
Le, Tien ; Tachezy, Jan (advisor) ; Michels, Paul A. M. (referee) ; Yurchenko, Vyacheslav (referee)
Peroxisomes and mitochondria play a key role in oxygen metabolism. It was widely accepted that the evolutionary adaptation of eukaryotes to anaerobiosis is reflected by the metabolic reduction of mitochondria, and concomitant loss of peroxisomes. The anaerobic protists Mastigamoeba balamuthi (Mb), Pelomyxa schiedti (Ps), and Entamoeba histolytica (Eh) contradict this paradigm. They possess anaerobic types of mitochondria (hydrogenosomes, mitosomes) but also host "anaerobic peroxisomes". Mb/Ps peroxisomes contain a common set of 13 peroxins (Pexs) that retain the core members of each functional category including components of both PTS1 and PTS2 machinery for matrix protein import. However, Eh peroxisomes harbour a reduced set of 7 known Pexs and lacks several components that are highly conserved among most eukaryotic lineages, including components of PTS2 machinery (Pex7), the RING complex (Pex2/10/12), docking complex (Pex13), and peroxisomal membrane protein import receptor (Pex3). Concerning the functional annotation, no clear biochemical context has been found in these anaerobic peroxisomes. They are diverse in enzymatic contents and are involved in various metabolic reactions, while catalase and typical peroxisomal enzymes of fatty acid beta-oxidation are absent. Mb peroxisomes appear to be involved in...
|
|
|
The role of energy metabolism in cardioprotection induced by the adaptation to chronic hypoxia
Kolář, David ; Žurmanová, Jitka (advisor) ; Adamcová, Michaela (referee) ; Bardová, Kristina (referee)
Cardiac energy metabolism is the one of the most complex system in the body. To sustain life, but also to respond quickly to any sudden changes (e.g. running, emotional stress), the heart has developed a unique ability and has become a metabolic "omnivore". At physiological conditions, long chain fatty acids (LCFAs) present the major energetic source for the adult myocardium. However, the cardiac energy metabolism may be compromised during pathophysiological states. One of the most dangerous is, undoubtedly, ischaemia-reperfusion injury with its acute form, myocardial infarction. However, the adaptation to chronic hypoxia has been known for decades for its cardioprotective effect against I/R. Changes of cardiac energy metabolism induced by the adaptation have not been fully explored and the system conceals still too many secrets. This thesis has aimed to determine how adaptation to chronic hypoxia affects the cardiac metabolism of the rat LVs in the following set-ups: 1. The effect of chronic normobaric hypoxia (CNH; 3 weeks, 5500m) during a brief I/R protocol in vitro on the protein kinase B/hexokinase (Akt/HK) pathway, including the expression and phosphorylation of Akt, the expression and localization of HK, the expression of mitochondrial creatine kinase (mtCKS), and the level of Bcl-2 family...
|
|
|
Plant peroxisomes: structure, localization, function.
Pivoňka, Jaroslav ; Schwarzerová, Kateřina (advisor) ; Kutík, Jaromír (referee)
Plant cell is a complex and complicated environment where countless biochemical processes and metabolic pathways take place independently of each other. Some of them could pose a threat to a plant cell or be a cause of organism lethality altogether, mainly because of their antagonistic character or by their toxicity. To eliminate this danger and ensure the most effective course of these reactions, a separation into properly separated and safe compartments is being applied. This phenomenon is called cellular compartmentalization and these sections are called organelles. Peroxisomes are one of them. They are highly dynamic and metabolically diverse vesicles of spherical nature, formed by a single-layered membrane. They contain crucial enzymes that operate in processes such as reactive oxygen species (ROS) metabolism, photorespiration, storage oils breakdown followed by β-oxidation of fatty acids, glyoxylate cycle, phytohormones biosynthesis, and more and more of other metabolic pathways. By that, they stand as an essential imaginary crossroad connecting these critical processes in plant development and physiological responses to abiotic and biotic stresses. This work is focused on reviewing these peroxisomal functions in plant cells, as well as the peroxisomal structure, its proteome and biogenesis....
|
|
|
The role of energy metabolism in cardioprotection induced by the adaptation to chronic hypoxia
Kolář, David
Cardiac energy metabolism is the one of the most complex system in the body. To sustain life, but also to respond quickly to any sudden changes (e.g. running, emotional stress), the heart has developed a unique ability and has become a metabolic "omnivore". At physiological conditions, long chain fatty acids (LCFAs) present the major energetic source for the adult myocardium. However, the cardiac energy metabolism may be compromised during pathophysiological states. One of the most dangerous is, undoubtedly, ischaemia-reperfusion injury with its acute form, myocardial infarction. However, the adaptation to chronic hypoxia has been known for decades for its cardioprotective effect against I/R. Changes of cardiac energy metabolism induced by the adaptation have not been fully explored and the system conceals still too many secrets. This thesis has aimed to determine how adaptation to chronic hypoxia affects the cardiac metabolism of the rat LVs in the following set-ups: 1. The effect of chronic normobaric hypoxia (CNH; 3 weeks, 5500m) during a brief I/R protocol in vitro on the protein kinase B/hexokinase (Akt/HK) pathway, including the expression and phosphorylation of Akt, the expression and localization of HK, the expression of mitochondrial creatine kinase (mtCKS), and the level of Bcl-2 family...
|
|
|
The role of energy metabolism in cardioprotection induced by the adaptation to chronic hypoxia
Kolář, David
Cardiac energy metabolism is the one of the most complex system in the body. To sustain life, but also to respond quickly to any sudden changes (e.g. running, emotional stress), the heart has developed a unique ability and has become a metabolic "omnivore". At physiological conditions, long chain fatty acids (LCFAs) present the major energetic source for the adult myocardium. However, the cardiac energy metabolism may be compromised during pathophysiological states. One of the most dangerous is, undoubtedly, ischaemia-reperfusion injury with its acute form, myocardial infarction. However, the adaptation to chronic hypoxia has been known for decades for its cardioprotective effect against I/R. Changes of cardiac energy metabolism induced by the adaptation have not been fully explored and the system conceals still too many secrets. This thesis has aimed to determine how adaptation to chronic hypoxia affects the cardiac metabolism of the rat LVs in the following set-ups: 1. The effect of chronic normobaric hypoxia (CNH; 3 weeks, 5500m) during a brief I/R protocol in vitro on the protein kinase B/hexokinase (Akt/HK) pathway, including the expression and phosphorylation of Akt, the expression and localization of HK, the expression of mitochondrial creatine kinase (mtCKS), and the level of Bcl-2 family...
|
|
|
The role of energy metabolism in cardioprotection induced by the adaptation to chronic hypoxia
Kolář, David ; Žurmanová, Jitka (advisor) ; Adamcová, Michaela (referee) ; Bardová, Kristina (referee)
Cardiac energy metabolism is the one of the most complex system in the body. To sustain life, but also to respond quickly to any sudden changes (e.g. running, emotional stress), the heart has developed a unique ability and has become a metabolic "omnivore". At physiological conditions, long chain fatty acids (LCFAs) present the major energetic source for the adult myocardium. However, the cardiac energy metabolism may be compromised during pathophysiological states. One of the most dangerous is, undoubtedly, ischaemia-reperfusion injury with its acute form, myocardial infarction. However, the adaptation to chronic hypoxia has been known for decades for its cardioprotective effect against I/R. Changes of cardiac energy metabolism induced by the adaptation have not been fully explored and the system conceals still too many secrets. This thesis has aimed to determine how adaptation to chronic hypoxia affects the cardiac metabolism of the rat LVs in the following set-ups: 1. The effect of chronic normobaric hypoxia (CNH; 3 weeks, 5500m) during a brief I/R protocol in vitro on the protein kinase B/hexokinase (Akt/HK) pathway, including the expression and phosphorylation of Akt, the expression and localization of HK, the expression of mitochondrial creatine kinase (mtCKS), and the level of Bcl-2 family...
|
|
|
Biogenesis and function of peroxisomes, particularly in parasitic protists
Kočířová, Eliška ; Hrdý, Ivan (advisor) ; Novák, Lukáš (referee)
Peroxisomes are eukaryotic cellular organelles of a spherical shape surrounded by a single membrane. Peroxisomes contain no DNA nor ribosomes and all the peroxisomal proteins are encoded in the nucleus. Peroxisomal proteins are posttranslationally imported into peroxisomes via group of peroxisomal biogenetic factors called peroxins. The most common functions include peroxisomal beta oxidation of fatty acids, detoxification of reactive oxygen species metabolism of purines and synthesis of ether lipids. Some specialized functions are found in derived peroxisomes - glycosomes, glyoxysomech and Woronin bodies. Glycosomes, occurring in group Kinetoplastida, contains a substantial part of glycolysis, Woronin bodies, found in filamentous fungi, have a mechanical function and plant glyoxysomes contain the glyoxylate cycle. Previously, peroxisomes together with glyoxysomy and glycosomes were called microspheres or microbodies. Key words: peroxisome, Pex proteins, glykosomes, Trypanosoma, Leishmania
|
|
|
Yeast retrograde signaling pathway between mitochondria and the nucleus
Podholová, Kristýna ; Palková, Zdena (advisor) ; Fraiberk, Martin (referee)
Retrograde signaling pathway is the pathway between mitochondria and nucleus. This pathway helps Saccharomyces cerevisiae to cope with worsening of conditions of life, such as depletion of rich nutrient sources and necessity of use poor resources, reduction of mitochondrial membrane potential, or loss of mitochondrial DNA causing disturbances in the citric acid cycle. Most of these conditions are associated with aging yeast populations. Key retrograde pathway proteins include RTG transcription factors Rtg1p/Rtg3p and cytoplasmic protein Rtg2p. Retrograde pathway is upregulated by several positive and negative regulators including the TOR pathway, which negatively regulates retrograde pathway. The retrograde pathway target genes include genes coding for tricarboxylic cycle enzymes, peroxisomal enzymes, transporters and other enzymes of anaplerotic pathways. Retrograde response help cells to modify their metabolism so that they are able to overcome unfavorable environmental conditions in which they live. Powered by TCPDF (www.tcpdf.org)
|
guest ::
