title: Saccharomyces cerevisiae porin pore forms complexes with mitochondrial outer membrane proteins Om14p and Om45p.
abstract: Numerous transport processes occur between the two mitochondrial (mt) membranes due to the diverse functions and metabolic processes of the mt organelle. The metabolite and ion transport through the mt outer membrane (OM) is widely assumed to be mediated by the porin pore, whereas in the mt inner membrane (IM) specific carriers are responsible for transport processes. Here, we provide evidence by means of Blue Native (BN)-PAGE analysis, co-immunoprecipitation, and tandem affinity purification that the two mt OM proteins Om14p and Om45p associate with the porin pore. Porin molecules seem to assemble independently to build the core unit. A subpopulation of these core units interacts with Om14p and Om45p. With preparative tandem affinity purification followed by MS analysis, we could identify interaction partners of this OM complex, which are mainly localized within the mt IM and function as carriers for diverse molecules. We propose a model for the role of the two OM proteins in addressing the porin pore to bind to specific channels in the mt IM to facilitate transport of metabolites.
authors.affiliation: Institute of Genetics, Technische Universität Dresden, 01062 Dresden and. Electronic address: Susann.Lauffer@tu-dresden.de.
authors.forename: Susann
authors.initials: S
authors.lastname: Lauffer
authors.affiliation: Institute of Genetics, Technische Universität Dresden, 01062 Dresden and.
authors.forename: Katrin
authors.initials: K
authors.lastname: Mäbert
authors.affiliation: Biotechnology Center, Technische Universität Dresden, Tatzberg 47/49, 01307 Dresden, Germany.
authors.forename: Cornelia
authors.initials: C
authors.lastname: Czupalla
authors.affiliation: Biotechnology Center, Technische Universität Dresden, Tatzberg 47/49, 01307 Dresden, Germany.
authors.forename: Theresia
authors.initials: T
authors.lastname: Pursche
authors.affiliation: Biotechnology Center, Technische Universität Dresden, Tatzberg 47/49, 01307 Dresden, Germany.
authors.forename: Bernard
authors.initials: B
authors.lastname: Hoflack
authors.affiliation: Institute of Genetics, Technische Universität Dresden, 01062 Dresden and.
authors.forename: Gerhard
authors.initials: G
authors.lastname: Rödel
authors.affiliation: Institute of Genetics, Technische Universität Dresden, 01062 Dresden and.
authors.forename: Udo
authors.initials: U
authors.lastname: Krause-Buchholz
mesh_terms: D001692:Biological Transport / Q000502:physiology; D051336:Mitochondrial Membranes / Q000378:metabolism*; D024101:Mitochondrial Proteins / Q000235:genetics / Q000378:metabolism*; D008954:Models, Biological; D018272:Porins / Q000235:genetics / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D024101:Mitochondrial Proteins; D018272:Porins; D029701:Saccharomyces cerevisiae Proteins