title: Identification of the mitochondrial carrier that provides Yarrowia lipolytica with a fatty acid-induced and nucleotide-sensitive uncoupling protein-like activity.
abstract: Uncoupling proteins (UCPs) are mitochondrial carriers distributed throughout the eukaryotic kingdoms. While genes coding for UCPs have been identified in plants and animals, evidences for the presence of UCPs in fungi and protozoa are only functional. Here, it is reported that in the yeast Yarrowia lipolytica there is a fatty acid-promoted and GDP-sensitive uncoupling activity indicating the presence of a UCP. The uncoupling activity is higher in the stationary phase than in the mid-log growth phase. The in silico search on the Y. lipolytica genome led to the selection of two genes with the highest homology to the UCP family, XM_503525 and XM_500457. By phylogenetic analysis, XP_503525 was predicted to be an oxaloacetate carrier while XP_500457 would be a dicarboxylate carrier. Each of these two genes was cloned and heterologously expressed in Saccharomyces cerevisiae and the resulting phenotype was analyzed. The transport activity of the two gene products confirmed the phylogenetic predictions. In addition, only mitochondria isolated from yeasts expressing XP_503525 showed bioenergetic properties characteristic of a UCP: the proton conductance was increased by linoleic acid and inhibited by GDP. It is concluded that the XM_503525 gene from Y. lipolytica encodes for an oxaloacetate carrier although, remarkably, it also displays an uncoupling activity stimulated by fatty acids and inhibited by nucleotides.
authors.affiliation: Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico City, Mexico.
authors.forename: Luis A
authors.initials: LA
authors.lastname: Luévano-Martínez
authors.forename: Eva
authors.initials: E
authors.lastname: Moyano
authors.forename: Mario García
authors.initials: MG
authors.lastname: de Lacoba
authors.forename: Eduardo
authors.initials: E
authors.lastname: Rial
authors.forename: Salvador
authors.initials: S
authors.lastname: Uribe-Carvajal
mesh_terms: D001692:Biological Transport; D005227:Fatty Acids / Q000494:pharmacology; D006153:Guanosine Diphosphate / Q000378:metabolism; D007473:Ion Channels / Q000378:metabolism; D008564:Membrane Potentials / Q000502:physiology; D008928:Mitochondria / Q000378:metabolism* / Q000502:physiology; D024101:Mitochondrial Proteins / Q000378:metabolism; D010101:Oxygen Consumption; D010802:Phylogeny; D013386:Succinates / Q000378:metabolism; D013431:Sulfates / Q000378:metabolism; D000071256:Uncoupling Protein 1; D014640:Vancomycin / Q000494:pharmacology; D025062:Yarrowia / Q000378:metabolism*
chemical_list: D005227:Fatty Acids; D007473:Ion Channels; D024101:Mitochondrial Proteins; D013386:Succinates; D013431:Sulfates; D000071256:Uncoupling Protein 1; D006153:Guanosine Diphosphate; D014640:Vancomycin