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A Novel ADP/ATP Transporter in the Mitosome of the Microaerophilic Human Parasite Entamoeba histolytica

2005; Elsevier BV; Volume: 15; Issue: 8 Linguagem: Inglês

10.1016/j.cub.2005.02.068

1879-0445

Ka Wai Chan, Dirk-Jan Slotboom, Siân Cox, T. Martin Embley, Olivier Fabre, Mark van der Giezen, Marilyn Harding, David S. Horner, Edmund R.S. Kunji, Gloria León-Ávila, Jorge Tovar,

Superconductivity in MgB2 and Alloys

Recent data suggest that microaerophilic and parasitic protozoa, which lack oxidative phosphorylation, nevertheless contain mitochondrial homologs [1Tovar J. Leon-Avila G. Sanchez L.B. Sutak R. Tachezy J. Van Der Giezen M. Hernandez M. Muller M. Lucocq J.M. Mitochondrial remnant organelles of Giardia function in iron-sulphur protein maturation.Nature. 2003; 426: 172-176Crossref PubMed Scopus (394) Google Scholar, 2Embley T.M. van der Giezen M. Horner D.S. Dyal P.L. Bell S. Foster P.G. Hydrogenosomes, mitochondria and early eukaryotic evolution.IUBMB Life. 2003; 55: 387-395Crossref PubMed Scopus (103) Google Scholar, 3Tovar J. Fischer A. Clark C.G. The mitosome, a novel organelle related to mitochondria in the amitochondrial parasite Entamoeba histolytica.Mol. Microbiol. 1999; 32: 1013-1021Crossref PubMed Scopus (278) Google Scholar, 4Williams B.A. Hirt R.P. Lucocq J.M. Embley T.M. A mitochondrial remnant in the microsporidian Trachipleistophora hominis.Nature. 2002; 418: 865-869Crossref PubMed Scopus (319) Google Scholar, 5Mai Z. Ghosh S. Frisardi M. Rosenthal B. Rogers R. Samuelson J. Hsp60 is targeted to a cryptic mitochondrion-derived organelle (“crypton”) in the microaerophilic protozoan parasite Entamoeba histolytica.Mol. Cell. Biol. 1999; 19: 2198-2205Crossref PubMed Scopus (148) Google Scholar, 6Hrdy I. Hirt R.P. Dolezal P. Bardonova L. Foster P.G. Tachezy J. Embley T.M. Trichomonas hydrogenosomes contain the NADH dehydrogenase module of mitochondrial complex I.Nature. 2004; 432: 618-622Crossref PubMed Scopus (190) Google Scholar], organelles that share common ancestry with mitochondria. Such widespread retention suggests there may be a common function for mitochondrial homologs that makes them essential for eukaryotic cells. We determined the mitochondrial carrier family (MCF) complement of the Entamoeba histolytica mitochondrial homolog, also known as a crypton [5Mai Z. Ghosh S. Frisardi M. Rosenthal B. Rogers R. Samuelson J. Hsp60 is targeted to a cryptic mitochondrion-derived organelle (“crypton”) in the microaerophilic protozoan parasite Entamoeba histolytica.Mol. Cell. Biol. 1999; 19: 2198-2205Crossref PubMed Scopus (148) Google Scholar] or more commonly as a mitosome [3Tovar J. Fischer A. Clark C.G. The mitosome, a novel organelle related to mitochondria in the amitochondrial parasite Entamoeba histolytica.Mol. Microbiol. 1999; 32: 1013-1021Crossref PubMed Scopus (278) Google Scholar]. MCF proteins support mitochondrial metabolic energy generation, DNA replication, and amino-acid metabolism by linking biochemical pathways in the mitochondrial matrix with those in the cytosol [7Kunji E.R. The role and structure of mitochondrial carriers.FEBS Lett. 2004; 564: 239-244Abstract Full Text Full Text PDF PubMed Scopus (125) Google Scholar]. MCF diversity thus closely mirrors important facets of mitochondrial metabolic diversity. The Entamoeba histolytica mitosome has lost all but a single type of MCF protein, which transports ATP and ADP via a novel mechanism that is not reliant on a membrane potential. Phylogenetic analyses confirm that the Entamoeba ADP/ATP carrier is distinct from archetypal mitochondrial ADP/ATP carriers, an observation that is supported by its different substrate and inhibitor specificity. Because many functions of yeast and human mitochondria rely on solutes transported by specialized members of this family, the Entamoeba mitosome must contain only a small subset of these processes requiring adenine nucleotide exchange.