YHR150w and YDR479c Encode Peroxisomal Integral Membrane Proteins Involved in the Regulation of Peroxisome Number, Size, and Distribution in Saccharomyces cerevisiae

• Published in: The Journal of cell biology 2003-04, Vol.161 (2), p.321-332
• Main Authors: Vizeacoumar, Franco J., Torres-Guzman, Juan C., Yuen Yi C. Tam, Aitchison, John D., Rachubinski, Richard A.
• Format: Article
• Language: English
• Subjects: Amino acids; Antibodies; Cell biology; Cells; Cells, Cultured; Centrifugation; Gene Deletion; Gene Expression Regulation, Fungal - drug effects; Gene Expression Regulation, Fungal - genetics; GTP-Binding Proteins - genetics; GTP-Binding Proteins - metabolism; Membrane proteins; Membrane Proteins - drug effects; Membrane Proteins - genetics; Membrane Proteins - isolation & purification; Membranes; Microscopy, Electron; Molecular Sequence Data; Mutation - drug effects; Mutation - genetics; Oleic Acid - pharmacology; Peroxisomes; Peroxisomes - genetics; Peroxisomes - metabolism; Peroxisomes - ultrastructure; Proteins; Saccharomyces cerevisiae; Saccharomyces cerevisiae - genetics; Saccharomyces cerevisiae - metabolism; Saccharomyces cerevisiae - ultrastructure; Saccharomyces cerevisiae Proteins - drug effects; Saccharomyces cerevisiae Proteins - genetics; Saccharomyces cerevisiae Proteins - isolation & purification; Sequence Homology, Amino Acid; Sequence Homology, Nucleic Acid; Vesicular Transport Proteins; Yeasts
• ISSN: 0021-9525; 1540-8140
• DOI: 10.1083/jcb.200210130

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 Y/Pex24p, both Yhr150p and Ydr479p have been shown to be integral to the peroxisomal membrane, but unlike Y/Pex24p, 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.