title: Characterization of two different acyl carrier proteins in complex I from Yarrowia lipolytica.
abstract: Acyl carrier proteins of mitochondria (ACPMs) are small (approximately 10 kDa) acidic proteins that are homologous to the corresponding central components of prokaryotic fatty acid synthase complexes. Genomic deletions of the two genes ACPM1 and ACPM2 in the strictly aerobic yeast Yarrowia lipolytica resulted in strains that were not viable or retained only trace amounts of assembled mitochondrial complex I, respectively. This suggested different functions for the two proteins that despite high similarity could not be complemented by the respective other homolog still expressed in the deletion strains. Remarkably, the same phenotypes were observed if just the conserved serine carrying the phosphopantethein moiety was exchanged with alanine. Although this suggested a functional link to the lipid metabolism of mitochondria, no changes in the lipid composition of the organelles were found. Proteomic analysis revealed that both ACPMs were tightly bound to purified mitochondrial complex I. Western blot analysis revealed that the affinity tagged ACPM1 and ACPM2 proteins were exclusively detectable in mitochondrial membranes but not in the mitochondrial matrix as reported for other organisms. Hence we conclude that the ACPMs can serve all their possible functions in mitochondrial lipid metabolism and complex I assembly and stabilization as subunits bound to complex I.
authors.affiliation: Molecular Bioenergetics Group, Medical School, Cluster of Excellence Frankfurt Macromolecular Complexes, Centre for Membrane Proteomics, Johann Wolfgang Goethe-Universität, Frankfurt am Main, Germany.
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Dobrynin
authors.forename: Albina
authors.initials: A
authors.lastname: Abdrakhmanova
authors.forename: Sebastian
authors.initials: S
authors.lastname: Richers
authors.forename: Carola
authors.initials: C
authors.lastname: Hunte
authors.forename: Stefan
authors.initials: S
authors.lastname: Kerscher
authors.forename: Ulrich
authors.initials: U
authors.lastname: Brandt
mesh_terms: D000213:Acyl Carrier Protein / Q000502:physiology*; D015153:Blotting, Western; D003001:Cloning, Molecular; D042967:Electron Transport Complex I / Q000378:metabolism*; D015180:Electrophoresis, Gel, Two-Dimensional; D005656:Fungal Proteins / Q000502:physiology; D017353:Gene Deletion; D050356:Lipid Metabolism; D008928:Mitochondria / Q000378:metabolism*; D051336:Mitochondrial Membranes / Q000378:metabolism; D024101:Mitochondrial Proteins / Q000235:genetics / Q000378:metabolism; D010766:Phosphorylation; D021122:Protein Subunits; D040901:Proteomics; D025062:Yarrowia / Q000201:enzymology* / Q000235:genetics
chemical_list: D000213:Acyl Carrier Protein; D005656:Fungal Proteins; D024101:Mitochondrial Proteins; D021122:Protein Subunits; D042967:Electron Transport Complex I