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Biogenesis and function of nuclear iron-sulfur proteins
Panova, Ekaterina ; Benda, Martin (advisor) ; Smutná, Tamara (referee)
Iron-sulfur clusters are important inorganic cofactors of many cellular reactions, including those that occur in the nucleus. Nuclear iron-sulfur proteins play an important role in DNA replication, genome repair, and maintenance of genome stability. The biosynthesis of these iron-sulfur clusters is initiated in the mitochondria by the iron-sulfur cluster assembly pathway (ISC), continues in the cytosol by the cytosolic iron-sulfur cluster assembly pathway (CIA), and ends with the incorporation of the clusters into target apoproteins such as polymerases, primases, helicases, endonucleases, or glycosylases. This bachelor thesis summarizes current knowledge about the pathways of iron-sulfur cluster biosynthesis, the functions of nuclear iron-sulfur proteins, and the role of the clusters in these proteins, including the phenotypes and clinical manifestations caused by the absence of iron-sulfur clusters. Keywords: iron-sulfur clusters, metalloproteins, nucleus, DNA replication, DNA repair
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Effect of pathogens on the vaginal microbiome
Procházková, Jana ; Tachezy, Jan (advisor) ; Smutná, Tamara (referee)
The human body is heavily populated with a wide variety of microorganisms. These microorganisms form coherent communities, which in contact with specific human organs form microbiomes. Each microbiome is unique in its composition. The study of microbiomes enables us to describe their composition and to understand the complex interactions that occur between microorganisms and humans. Methods of microbiome analysis are constantly evolving. For example, next-generation sequencing is currently the most widely used method for the characterization of microbiomes. Bacteria of the genus Lactobacillus are the major component of a healthy vaginal microbiome in most women. A healthy vaginal microbiome is essential for maintaining the natural homeostasis and to assure a proper functioning of the female urogenital tract. Lactobacillus is also important for the protection of the vagina from pathogenic agents such as viruses, bacteria, archaea and eukaryotes. In this bachelor's thesis the major pathogens of the Bacteria and the Eukaryota domain are described. Hereby a particular focus is on Trichomonas vaginalis, which is the most prevalent pathogenic agent of the female urogenital tract worldwide. Studying the immunity of the vaginal microbiome to this parasite is therefore essential. Furthermore, the mechanisms of...
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Prokaryotic proteins of antioxidant defense in Trichomonas vaginalis hydrogenosomes
Smutná, Tamara
Parasitic protists with modified mitochondria represent important and exciting group of organisms, not only from the view of eukaryotic cell evolution but also because these parasites are causative agents of serious and widespread diseases. The study and understanding of their biology is thus necessary for the development of new antiparasitic drugs. These organisms reside in host body cavities with low concentrations of oxygen and while they lack typical mitochondria, they possess mitochondrion-related organelles which still integrate many physiologically important processes. Trichomonas vaginalis is an anaerobic flagellate inhabiting mucosal surface of vagina. Instead of canonical mitochondria, T. vaginalis possesses organelles termed hydrogenosomes. These organelles harbor pathways of ATP-generating metabolism via substrate-level phosphorylation, dependent on enzymes prone to oxidative damage, such as pyruvate:ferredoxin oxidoreductase and Fe-Fe hydrogenase. Because the environment of trichomonads is not fully anaerobic, the parasite had to develop complex strategies to cope with both oxygen and reactive oxygen species (ROS) generated by host immune system cells. Recent data from T. vaginalis proteomic and genomic analyses revealed the presence of bacterial-type proteins potentially participating...
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Oxidative stress in pathogenic amoebae
Plíva, Jan ; Šuťák, Róbert (advisor) ; Smutná, Tamara (referee)
Reactive oxygen species are substances that contain an atom of oxygen with an unpaired electron. This substance is highly reactive thanks to that unpaired electron. Organisms are capable of utilizing this reactivity in a lot of reactions. Cells can create reactive oxygen species as a by-product of aerobic respiration or by the action of enzymes such as NADPH oxidase. Reactive oxygen species play a crucial role in host defense against parasitic organisms. During host defense, parasitic organisms are destroyed by immune cells utilizing oxygen species. These reactions are in place also in the case of infection caused by pathogenic amoebae. Amoebae are eukaryotic unicellular organisms that are in some cases capable of causing serious illnesses. During the infections, amoebae must be able to bypass the host immune system, thus reactive oxygen species. This is accomplished by parasitic detoxification systems which helps pathogenic amoebae to overcome oxidative stress induced by reactive oxygen species. However, pathogenic amoebae are also capable of using reactive oxygen species to overcome the host immune system. This fact only confirms how tangled and complicated is the effect of reactive oxygen species during an interaction between the host organism and parasite.
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Alcohol dehydrogenases in parasitic protists
Šipková, Anna ; Mach, Jan (advisor) ; Smutná, Tamara (referee)
Bachelor's thesis summarizes alcohol dehydrogenases mainly in parasitic protists. These widespread enzymes have been identified in several organisms ranging from bacteria to human. Thanks to the diversity of the enzyme's structure and substrate specificity is its function variable. Structure of the model zinc-containing Adh1 Saccharomyces cerevisiae is tetrameric. Enzymes are responsible for reversible oxidation of alcohols to aldehydes or ketones with concomitant reduction of NAD(P)+ as a cofactor. In most organisms, Adh appears in several types. Classification of Adhs is quite difficult and incomplete due to the investigation progress. The current classification includes three groups: MDR ("medium chain" Adh), SDR ("small chain" Adh) and iron-containing Adh. Adhs in parasitic protists have a specific role in the flexibility of metabolism and the adaptability to environmental changes in the host. This thesis deals especially with anaerobic parasites, where Adh is important in fermentation metabolism. Adh also figures in the resistance to drugs like in Trypanosoma cruzi or Tritrichomonas foetus. Recently, Adh has become a promising enzyme for a biotechnological application like in pharmaceutical or chemical industry. Keywords: Alcohol dehydrogenases, classification, parasitic protists, resistance
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Prokaryotic proteins of antioxidant defense in Trichomonas vaginalis hydrogenosomes
Smutná, Tamara
Parasitic protists with modified mitochondria represent important and exciting group of organisms, not only from the view of eukaryotic cell evolution but also because these parasites are causative agents of serious and widespread diseases. The study and understanding of their biology is thus necessary for the development of new antiparasitic drugs. These organisms reside in host body cavities with low concentrations of oxygen and while they lack typical mitochondria, they possess mitochondrion-related organelles which still integrate many physiologically important processes. Trichomonas vaginalis is an anaerobic flagellate inhabiting mucosal surface of vagina. Instead of canonical mitochondria, T. vaginalis possesses organelles termed hydrogenosomes. These organelles harbor pathways of ATP-generating metabolism via substrate-level phosphorylation, dependent on enzymes prone to oxidative damage, such as pyruvate:ferredoxin oxidoreductase and Fe-Fe hydrogenase. Because the environment of trichomonads is not fully anaerobic, the parasite had to develop complex strategies to cope with both oxygen and reactive oxygen species (ROS) generated by host immune system cells. Recent data from T. vaginalis proteomic and genomic analyses revealed the presence of bacterial-type proteins potentially participating...
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Prokaryotic proteins of antioxidant defense in Trichomonas vaginalis hydrogenosomes
Smutná, Tamara ; Hrdý, Ivan (advisor) ; Horváth, Anton (referee) ; Kopáček, Petr (referee)
Parasitic protists with modified mitochondria represent important and exciting group of organisms, not only from the view of eukaryotic cell evolution but also because these parasites are causative agents of serious and widespread diseases. The study and understanding of their biology is thus necessary for the development of new antiparasitic drugs. These organisms reside in host body cavities with low concentrations of oxygen and while they lack typical mitochondria, they possess mitochondrion-related organelles which still integrate many physiologically important processes. Trichomonas vaginalis is an anaerobic flagellate inhabiting mucosal surface of vagina. Instead of canonical mitochondria, T. vaginalis possesses organelles termed hydrogenosomes. These organelles harbor pathways of ATP-generating metabolism via substrate-level phosphorylation, dependent on enzymes prone to oxidative damage, such as pyruvate:ferredoxin oxidoreductase and Fe-Fe hydrogenase. Because the environment of trichomonads is not fully anaerobic, the parasite had to develop complex strategies to cope with both oxygen and reactive oxygen species (ROS) generated by host immune system cells. Recent data from T. vaginalis proteomic and genomic analyses revealed the presence of bacterial-type proteins potentially participating...
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Iron as a factor of virulence of parasitic protists
Glavanakovová, Marie ; Šuťák, Róbert (advisor) ; Smutná, Tamara (referee)
Iron is an essential nutrient for metabolism in almost all living organisms. Its importance for many crucial cellular processes originates primarily from the flexibility of available redox potentials. However, the high toxicity of free iron ions is well known. For most organisms, iron is simultaneously and paradoxically essential and toxic. Iron acquisition is crucial for parasitic organisms because it is needed for multiplication in hosts. Many studies have examined the relationship between iron availability and parasite development as a primary factor of virulence. These experiments commonly use chelators, chemical compounds that bind specifically and with high affinity iron ions, and are especially used for iron overload treatment. This thesis summarizes the influence of iron overload or deprivation in the host on the development of parasitic organisms and the impact of chelating agents on the virulence of selected parasitic protists, including the Plasmodium, Leishmania, Trypanosoma, Trichomonas and Tritrichomonas genuses.
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