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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 remain at constant levels during incubation of S. cerevisiae in oleic acid–containing medium. Cells were grown for 16 h in glucose-containing YPD medium and then transferred to, and incubated in, oleic acid–containing YPBO medium. Aliquots of cells were removed from the YPBO medium at the times indicated, and total cell lysates were prepared. Equal amounts of protein from the total cell lysates were analyzed by SDS-PAGE and immunoblotting to visualize the protein A fusions. Antibodies directed against glucose-6-phosphatase (G6PDH) were used to confirm the loading of equal protein in each lane.
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fig2: Yhr150p-prA and Ydr479p-prA remain at constant levels during incubation of S. cerevisiae in oleic acid–containing medium. Cells were grown for 16 h in glucose-containing YPD medium and then transferred to, and incubated in, oleic acid–containing YPBO medium. Aliquots of cells were removed from the YPBO medium at the times indicated, and total cell lysates were prepared. Equal amounts of protein from the total cell lysates were analyzed by SDS-PAGE and immunoblotting to visualize the protein A fusions. Antibodies directed against glucose-6-phosphatase (G6PDH) were used to confirm the loading of equal protein in each lane.

Mentions: The synthesis of many peroxisomal proteins is induced by the incubation of yeast cells in oleic acid-containing medium. Genomically encoded protein A chimeras of Yhr150p and Ydr479p were monitored to analyze the expression of YHR150w and YDR479c, respectively, under the control of their endogenous gene promoters. Yeast strains synthesizing Yhr150p-prA, Ydr479p-prA, thiolase-prA, and Pex17p-prA were grown in glucose-containing YPD medium and then shifted to oleic acid–containing YPBO medium. Aliquots of cells were removed at various times after the shift to YPBO medium, and their lysates were subjected to SDS-PAGE and immunoblotting (Fig. 2) . Yhr150p-prA and Ydr479-prA, as well as Pex17p-prA (Huhse et al., 1998), were detected in glucose-containing YPD medium at the time of transfer, and their respective levels did not increase with time of incubation of cells in YPBO medium. In contrast, thiolase-prA was barely detectable in cells at the time of transfer to YPBO medium, and its levels were substantially increased with time of incubation in YPBO medium.


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 remain at constant levels during incubation of S. cerevisiae in oleic acid–containing medium. Cells were grown for 16 h in glucose-containing YPD medium and then transferred to, and incubated in, oleic acid–containing YPBO medium. Aliquots of cells were removed from the YPBO medium at the times indicated, and total cell lysates were prepared. Equal amounts of protein from the total cell lysates were analyzed by SDS-PAGE and immunoblotting to visualize the protein A fusions. Antibodies directed against glucose-6-phosphatase (G6PDH) were used to confirm the loading of equal protein in each lane.
© Copyright Policy
Related In: Results  -  Collection

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

fig2: Yhr150p-prA and Ydr479p-prA remain at constant levels during incubation of S. cerevisiae in oleic acid–containing medium. Cells were grown for 16 h in glucose-containing YPD medium and then transferred to, and incubated in, oleic acid–containing YPBO medium. Aliquots of cells were removed from the YPBO medium at the times indicated, and total cell lysates were prepared. Equal amounts of protein from the total cell lysates were analyzed by SDS-PAGE and immunoblotting to visualize the protein A fusions. Antibodies directed against glucose-6-phosphatase (G6PDH) were used to confirm the loading of equal protein in each lane.
Mentions: The synthesis of many peroxisomal proteins is induced by the incubation of yeast cells in oleic acid-containing medium. Genomically encoded protein A chimeras of Yhr150p and Ydr479p were monitored to analyze the expression of YHR150w and YDR479c, respectively, under the control of their endogenous gene promoters. Yeast strains synthesizing Yhr150p-prA, Ydr479p-prA, thiolase-prA, and Pex17p-prA were grown in glucose-containing YPD medium and then shifted to oleic acid–containing YPBO medium. Aliquots of cells were removed at various times after the shift to YPBO medium, and their lysates were subjected to SDS-PAGE and immunoblotting (Fig. 2) . Yhr150p-prA and Ydr479-prA, as well as Pex17p-prA (Huhse et al., 1998), were detected in glucose-containing YPD medium at the time of transfer, and their respective levels did not increase with time of incubation of cells in YPBO medium. In contrast, thiolase-prA was barely detectable in cells at the time of transfer to YPBO medium, and its levels were substantially increased with time of incubation in YPBO medium.

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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