velikost textu

Výsledky projektu Hydrogenozomální translokáza vnější membrány (TOM komplex) Trichomonas vaginalis: Rozdíly oproti klasické mitochondrii

Výsledky

▼▲Typ výsledku ▼▲Autor celku ▼▲Název celku
(Celkem 5 zázn.)
Makki, Abhijith; Rada, Petr; Žárský, Vojtěch; Kereïche, Sami; Kováčik, Lubomír; Novotný, Marian; Jores, Tobias; Rapaport, Doron and Tachezy, Jan. Triplet-pore structure of a highly divergent TOM complex of hydrogenosomes in Trichomonas vaginalis. PLOS Biology, 2019, sv. 17, s. 1–32. ISSN 1544-9173. IF 9.163. [Článek v časopise]
Mitochondria originated from proteobacterial endosymbionts, and their transition to organelles was tightly linked to establishment of the protein import pathways. The initial import of most proteins is mediated by the translocase of the outer membrane (TOM). Although TOM is common to all forms of mitochondria, an unexpected diversity of subunits between eukaryotic lineages has been predicted. However, experimental knowledge is limited to a few organisms, and so far, it remains unsettled whether the triplet-pore or the twin-pore structure is the generic form of TOM complex. Here, we analysed the TOM complex in hydrogenosomes, a metabolically specialised anaerobic form of mitochondria found in the excavate Trichomonas vaginalis. We demonstrate that the highly divergent β-barrel TvTom40-2 forms a translocation channel to conduct hydrogenosomal protein import. TvTom40-2 is present in high molecular weight complexes, and their analysis revealed the presence of four tail-anchored (TA) proteins. Two of them, Tom36 and Tom46, with Hsp20 and TPR domains, can bind hydrogenosomal preproteins and most likely function as receptors. A third subunit, Tom22-like protein, has a short cis domain and a conserved Tom22 transmembrane segment but lacks a trans domain. The fourth protein, Homp19 has no known homology. Furthermore, our data indicate that TvTOM is associated with Sam50 that is involved in β-barrel assembly. Visualisation of TvTOM by electron microscopy revealed that it forms three pores and has an unconventional skull-like shape. Although TvTOM seems to lack Tom7, our phylogenetic profiling predicted Tom7 in free-living excavates. Collectively, our results suggest that the triplet-pore TOM complex, composed of three conserved subunits, was present in the last common eukaryotic ancestor (LECA), while receptors responsible for substrate binding evolved independently in different eukaryotic lineages.
Makki, Abhijith; Rada, Petr and Tachezy, Jan, Presented a poster titled, "Translocase of the Outer Membrane (TOM complex) of the Hydrogenosomes of Trichomonas vaginalis" at Gordon Research Seminar and Conference on Protein transport across membranes, 2016, Galveston, USA [Jiný výsledek]
Makki, Abhijith, Oral presentation - “Functional analysis of the Translocase of the Outer Membrane (TOM complex) of the Hydrogenosomes in Trichomonas vaginalis”, International Conference on Protistology, Jul-Aug 2017, Prague, Czech Republic - awarded best oral presentation [Jiný výsledek]
Makki, Abhijith; Rada, Petr and Tachezy, Jan, Presented poster titled, "Translocase of the Outer Membrane of the Hydrogenosomes: Divergence from the classical Mitochondria", EMBO Conference on Regulation and Mechanisms of Protein Translocation 2015, Dubrovnik, Croatia [Jiný výsledek]
Makki, Abhijith, Oral presentation: “A highly divergent protein translocase of the hydrogenosomal outer membrane in Trichomonas vaginalis”, EMBO conference on “Anaerobic protists: Integrating parasitology with mucosal microbiota and immunology”, Newcastle upon Tyne, UK, Aug-Sept 2017 [Jiný výsledek]