title: YHR150w and YDR479c encode peroxisomal integral membrane proteins involved in the regulation of peroxisome number, size, and distribution in Saccharomyces cerevisiae.
abstract: The peroxin Pex24p of the yeast Yarrowia lipolytica exhibits high sequence similarity to two hypothetical proteins, Yhr150p and Ydr479p, encoded by the Saccharomyces cerevisiae genome. Like YlPex24p, both Yhr150p and Ydr479p have been shown to be integral to the peroxisomal membrane, but unlike YlPex24p, their levels of synthesis are not increased upon a shift of cells from glucose- to oleic acid-containing medium. Peroxisomes of cells deleted for either or both of the YHR150w and YDR479c genes are increased in number, exhibit extensive clustering, are smaller in area than peroxisomes of wild-type cells, and often exhibit membrane thickening between adjacent peroxisomes in a cluster. Peroxisomes isolated from cells deleted for both genes have a decreased buoyant density compared with peroxisomes isolated from wild-type cells and still exhibit clustering and peroxisomal membrane thickening. Overexpression of the genes PEX25 or VPS1, but not the gene PEX11, restored the wild-type phenotype to cells deleted for one or both of the YHR150w and YDR479c genes. Together, our data suggest a role for Yhr150p and Ydr479p, together with Pex25p and Vps1p, in regulating peroxisome number, size, and distribution in S. cerevisiae. Because of their role in peroxisome dynamics, YHR150w and YDR479c have been designated as PEX28 and PEX29, respectively, and their encoded peroxins as Pex28p and Pex29p.
authors.affiliation: Department of Cell Biology, University of Alberta, Medical Sciences Building 5-14, Edmonton, Alberta T6G 2H7, Canada.
authors.forename: Franco J
authors.initials: FJ
authors.lastname: Vizeacoumar
authors.forename: Juan C
authors.initials: JC
authors.lastname: Torres-Guzman
authors.forename: Yuen Yi C
authors.initials: YY
authors.lastname: Tam
authors.forename: John D
authors.initials: JD
authors.lastname: Aitchison
authors.forename: Richard A
authors.initials: RA
authors.lastname: Rachubinski
mesh_terms: D002478:Cells, Cultured; D019204:GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism; D017353:Gene Deletion; D015966:Gene Expression Regulation, Fungal / Q000187:drug effects / Q000235:genetics*; D008565:Membrane Proteins / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification*; D008854:Microscopy, Electron; D008969:Molecular Sequence Data; D009154:Mutation / Q000187:drug effects / Q000235:genetics; D019301:Oleic Acid / Q000494:pharmacology; D020675:Peroxisomes / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D029701:Saccharomyces cerevisiae Proteins / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification*; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid; D033921:Vesicular Transport Proteins
chemical_list: D008565:Membrane Proteins; C474734:PEX28 protein, S cerevisiae; C474735:PEX29 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D033921:Vesicular Transport Proteins; D019301:Oleic Acid; D019204:GTP-Binding Proteins; C064553:VPS1 protein, S cerevisiae