Trypanosoma brucei is an important human pathogen. In this study, we have focused on the characterization of FtsH protease, ATP-dependent membrane-bound mitochondrial enzyme important for regulation of protein abundance. We have determined localization and orientation of all six putative T.brucei FtsH homologs in the inner mitochondrial membrane by in silico analyses, by immunofluorescence, and with protease assay. The evolutionary origin of these homologs has been tested by comparative phylogenetic analysis. Surprisingly, some kinetoplastid FtsH proteins display inverted orientation in the mitochondrial membrane compared to related proteins of other examined eukaryotes. Moreover, our data strongly suggest that during evolution the orientation of FtsH protease in T. brucei varied due to both loss and acquisition of the transmembrane domain.

• Klíčová slova
• AAA protease, Evolution, FtsH, Mitochondrion, Phylogeny, Trypanosoma,
• MeSH
• Arabidopsis klasifikace   enzymologie   genetika   MeSH
• Euglena gracilis klasifikace   enzymologie   genetika   MeSH
• Euglena longa klasifikace   enzymologie   genetika   MeSH
• exprese genu MeSH
• fylogeneze MeSH
• izoenzymy chemie   genetika   metabolismus   MeSH
• konzervovaná sekvence MeSH
• Leishmania major klasifikace   enzymologie   genetika   MeSH
• lidé MeSH
• mitochondriální membrány chemie   enzymologie   MeSH
• mitochondriální proteiny chemie   genetika   metabolismus   MeSH
• mitochondrie enzymologie   genetika   MeSH
• molekulární evoluce * MeSH
• myši MeSH
• proteasy chemie   genetika   metabolismus   MeSH
• proteinové domény MeSH
• protozoální proteiny chemie   genetika   metabolismus   MeSH
• Saccharomyces cerevisiae klasifikace   enzymologie   genetika   MeSH
• Trypanosoma brucei brucei klasifikace   enzymologie   genetika   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• izoenzymy MeSH
• mitochondriální proteiny MeSH
• proteasy MeSH
• protozoální proteiny MeSH

Genes encoding enzymes of the tetrapyrrole biosynthetic pathway were searched within Euglena gracilis EST databases and 454 genome reads and their 5' end regions were sequenced when not available. Phylogenetic analyses and protein localization predictions support the hypothesis concerning the presence of two separated tetrapyrrole pathways in E. gracilis. One of these pathways resembles the heme synthesis in primarily heterotrophic eukaryotes and was presumably present in the host cell prior to secondary endosymbiosis with a green alga. The second pathway is similar to the plastid-localized tetrapyrrole syntheses in plants and photosynthetic algae. It appears to be localized to the secondary plastid, presumably derived from an algal endosymbiont and probably serves only for the production of plastidial heme and chlorophyll. Thus, E. gracilis represents an evolutionary intermediate in a metabolic transformation of a primary heterotroph to a photoautotroph through secondary endosymbiosis. We propose here that the tetrapyrrole pathway serves as a highly informative marker for the evolution of plastids and plays a crucial role in the loss of plastids.

• MeSH
• biologická evoluce * MeSH
• biosyntetické dráhy * MeSH
• Chlorophyta fyziologie   MeSH
• Euglena gracilis klasifikace   genetika   fyziologie   MeSH
• fylogeneze MeSH
• molekulární sekvence - údaje MeSH
• plastidy genetika   metabolismus   MeSH
• protozoální proteiny genetika   metabolismus   MeSH
• symbióza MeSH
• tetrapyrroly biosyntéza   MeSH
• Publikační typ
• dopisy MeSH
• práce podpořená grantem MeSH
• Názvy látek
• protozoální proteiny MeSH
• tetrapyrroly MeSH