|
|
Bacterial proteins in the biogenesis of mitochondria of unicellular eukaryotes.
Petrů, Markéta ; Doležal, Pavel (advisor) ; Embley, Martin (referee) ; Hashimi, Hassan (referee)
in English Formation of mitochondria by the conversion of a bacterial endosymbiont is the fundamental moment in the evolution of eukaryotes. An integral part of the organelle genesis was the displacement of the endosymbiont genes to host nucleus and simultaneous creation of new pathways for delivery of proteins synthesized now in the host cytoplasm. Resulting protein translocases are complexes combining original bacterial components and eukaryote-specific proteins. In addition to these novel protein import machines, some components of the original bacterial secretory pathways have remained in the organelle. While the function of a widely distributed mitochondrial homolog of YidC, Oxa1, is well understood, the role of infrequent components of Sec or Tat translocases has not yet been elucidated. So far, more attention has been paid to their abundant plastid homologs, which assemble photosynthetic complexes in the thylakoid membrane. In the thesis, the structure and function of prokaryotic YidC, Sec and Tat machineries and their eukaryotic homologs are described. By comparing both organelles of the endosymbiotic origin, the hypothesis is drawn on why these translocases have been more "evolutionary successful" in plastids than in mitochondria.
|
|
|
Bacterial proteins in the biogenesis of mitochondria of unicellular eukaryotes.
Petrů, Markéta ; Doležal, Pavel (advisor) ; Embley, Martin (referee) ; Hashimi, Hassan (referee)
in English Formation of mitochondria by the conversion of a bacterial endosymbiont is the fundamental moment in the evolution of eukaryotes. An integral part of the organelle genesis was the displacement of the endosymbiont genes to host nucleus and simultaneous creation of new pathways for delivery of proteins synthesized now in the host cytoplasm. Resulting protein translocases are complexes combining original bacterial components and eukaryote-specific proteins. In addition to these novel protein import machines, some components of the original bacterial secretory pathways have remained in the organelle. While the function of a widely distributed mitochondrial homolog of YidC, Oxa1, is well understood, the role of infrequent components of Sec or Tat translocases has not yet been elucidated. So far, more attention has been paid to their abundant plastid homologs, which assemble photosynthetic complexes in the thylakoid membrane. In the thesis, the structure and function of prokaryotic YidC, Sec and Tat machineries and their eukaryotic homologs are described. By comparing both organelles of the endosymbiotic origin, the hypothesis is drawn on why these translocases have been more "evolutionary successful" in plastids than in mitochondria.
|
|
|
Reductive Evolution of Mitochondria - Related Organelles in Anaerobic Protist
Rada, Petr ; Tachezy, Jan (advisor) ; Embley, Martin (referee) ; Eliáš, Marek (referee)
Charles University in Prague, Faculty of Science Department of Parasitology Ph.D. study program: Parasitology Abstract of the Ph.D. Thesis Reductive Evolution of Mitochondria - Related Organelles in Anaerobic Protist Petr Rada Supervisor: Prof. RNDr. Jan Tachezy,Ph.D. Advisor: Doc. RNDr. Ivan Hrdý, Ph.D. Praha, 2011 1 ABSTRACT Trichomonas vaginalis and Giardia intestinalis are parasitic protists of the Excavata group. Both contain anaerobic forms of mitochondria called hydrogenosomes (Trichomonas) and mitosomes (Giardia). Hydrogenosomes produce hydrogen and ATP by substarte level phosphorylation and mitosomes represent the highly-reduced form of mitochondria that do not participate in cellular energy metabolism and ATP generation. Both types of organelles lost the majority of mitochondrial pathways and their genomes during the mitochondrion to hydrogenosome transition. Consequently, hydrogenosomes and mitosomes facilitate translocation of nuclearly encoded proteins into the matrix of the organelle as well as exchange of metabolites and ions across their membranes. Little is known about the membrane machineries required for the biogenesis of the organelle and metabolite exchange and the limited knowledge of mitosomal proteomes has been mostly gained from genomic analysis and localization studies of a few...
|
guest ::
