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YHR150w and YDR479c encode peroxisomal integral membrane proteins involved in the regulation of peroxisome number, size, and distribution in Saccharomyces cerevisiae.

Vizeacoumar FJ, Torres-Guzman JC, Tam YY, Aitchison JD, Rachubinski RA - J. Cell Biol. (2003)

Bottom Line: 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.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.

View Article: PubMed Central - PubMed

Affiliation: Department of Cell Biology, University of Alberta, Medical Sciences Building 5-14, Edmonton, Alberta T6G 2H7, Canada.

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.

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Yhr150p-prA and Ydr479p-prA are peroxisomal proteins by microscopy. The subcellular distributions of protein A chimeras were compared with that of DsRed–PTS1 in oleic acid– incubated cells by double labeling, indirect immunofluorescence microscopy. Yhr150p-prA and Ydr479p-prA colocalize with DsRed–PTS1 in punctate structures characteristic of peroxisomes. There is no colocalization of DsRed–PTS1 and the protein A chimera of the mitochondrial protein Tom20p. Protein A chimeras were detected with rabbit antibodies to mouse IgG and FITC-conjugated goat anti–rabbit IgG secondary antibodies.
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fig3: Yhr150p-prA and Ydr479p-prA are peroxisomal proteins by microscopy. The subcellular distributions of protein A chimeras were compared with that of DsRed–PTS1 in oleic acid– incubated cells by double labeling, indirect immunofluorescence microscopy. Yhr150p-prA and Ydr479p-prA colocalize with DsRed–PTS1 in punctate structures characteristic of peroxisomes. There is no colocalization of DsRed–PTS1 and the protein A chimera of the mitochondrial protein Tom20p. Protein A chimeras were detected with rabbit antibodies to mouse IgG and FITC-conjugated goat anti–rabbit IgG secondary antibodies.

Mentions: A carboxy-terminal PTS1 is sufficient to direct a reporter protein to peroxisomes (for review see Purdue and Lazarow, 2001). A fluorescent chimera between Discosoma sp. red fluorescent protein (DsRed) and the PTS1 Ser-Lys-Leu has been shown to target to peroxisomes of S. cerevisiae (Smith et al., 2002). Genomically encoded protein A chimeras of Yhr150p, Ydr479p, the peroxisomal peroxin Pex17p, (Huhse et al., 1998) and the mitochondrial translocon protein Tom20p (Lithgow et al., 1994) were localized in oleic acid–induced cells by indirect immunofluorescence microscopy combined with direct fluorescence from DsRed–PTS1 to identify peroxisomes (Fig. 3) . Yhr150p-prA, Ydr479p-prA, and Pex17p-prA colocalized with DsRed–PTS1 to small punctate structures characteristic of peroxisomes by confocal microcopy. As expected, Tom20p-prA did not colocalize with DsRed–PTS1, as the respective individual green and red signals for these proteins remained separate in confocal microscopy.


YHR150w and YDR479c encode peroxisomal integral membrane proteins involved in the regulation of peroxisome number, size, and distribution in Saccharomyces cerevisiae.

Vizeacoumar FJ, Torres-Guzman JC, Tam YY, Aitchison JD, Rachubinski RA - J. Cell Biol. (2003)

Yhr150p-prA and Ydr479p-prA are peroxisomal proteins by microscopy. The subcellular distributions of protein A chimeras were compared with that of DsRed–PTS1 in oleic acid– incubated cells by double labeling, indirect immunofluorescence microscopy. Yhr150p-prA and Ydr479p-prA colocalize with DsRed–PTS1 in punctate structures characteristic of peroxisomes. There is no colocalization of DsRed–PTS1 and the protein A chimera of the mitochondrial protein Tom20p. Protein A chimeras were detected with rabbit antibodies to mouse IgG and FITC-conjugated goat anti–rabbit IgG secondary antibodies.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2172915&req=5

fig3: Yhr150p-prA and Ydr479p-prA are peroxisomal proteins by microscopy. The subcellular distributions of protein A chimeras were compared with that of DsRed–PTS1 in oleic acid– incubated cells by double labeling, indirect immunofluorescence microscopy. Yhr150p-prA and Ydr479p-prA colocalize with DsRed–PTS1 in punctate structures characteristic of peroxisomes. There is no colocalization of DsRed–PTS1 and the protein A chimera of the mitochondrial protein Tom20p. Protein A chimeras were detected with rabbit antibodies to mouse IgG and FITC-conjugated goat anti–rabbit IgG secondary antibodies.
Mentions: A carboxy-terminal PTS1 is sufficient to direct a reporter protein to peroxisomes (for review see Purdue and Lazarow, 2001). A fluorescent chimera between Discosoma sp. red fluorescent protein (DsRed) and the PTS1 Ser-Lys-Leu has been shown to target to peroxisomes of S. cerevisiae (Smith et al., 2002). Genomically encoded protein A chimeras of Yhr150p, Ydr479p, the peroxisomal peroxin Pex17p, (Huhse et al., 1998) and the mitochondrial translocon protein Tom20p (Lithgow et al., 1994) were localized in oleic acid–induced cells by indirect immunofluorescence microscopy combined with direct fluorescence from DsRed–PTS1 to identify peroxisomes (Fig. 3) . Yhr150p-prA, Ydr479p-prA, and Pex17p-prA colocalized with DsRed–PTS1 to small punctate structures characteristic of peroxisomes by confocal microcopy. As expected, Tom20p-prA did not colocalize with DsRed–PTS1, as the respective individual green and red signals for these proteins remained separate in confocal microscopy.

Bottom Line: 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.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.

View Article: PubMed Central - PubMed

Affiliation: Department of Cell Biology, University of Alberta, Medical Sciences Building 5-14, Edmonton, Alberta T6G 2H7, Canada.

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.

Show MeSH
Related in: MedlinePlus