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Concentration of GPI‐Anchored Proteins upon ER Exit in Yeast
Author(s) -
Castillon Guillaume A.,
Watanabe Reika,
Taylor Marcia,
Schwabe Tatjana M. E.,
Riezman Howard
Publication year - 2009
Publication title -
traffic
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.677
H-Index - 130
eISSN - 1600-0854
pISSN - 1398-9219
DOI - 10.1111/j.1600-0854.2008.00857.x
Subject(s) - copii , endoplasmic reticulum , biology , saccharomyces cerevisiae , microbiology and biotechnology , copi , vesicular transport proteins , yeast , transmembrane protein , mutant , membrane protein , transport protein , secretory pathway , golgi apparatus , biochemistry , gene , membrane , receptor , vacuolar protein sorting
Previous biochemical work has revealed two parallel routes of exit from the endoplasmic reticulum (ER) in the yeast Saccharomyces cerevisiae , one seemingly specific for glycosyl‐phosphatidylinositol (GPI)‐anchored proteins. Using the coat protein II (COPII) mutant sec31‐1 , we visualized ER exit sites (ERES) and identified three distinct ERES populations in vivo. One contains glycosylated pro‐α‐factor, the second contains the GPI‐anchored proteins Cwp2p, Ccw14p and Tos6p and the third is enriched with the hexose transporter, Hxt1p. Concentration of GPI‐anchored proteins prior to budding requires anchor remodeling, and Hxt1p incorporation into ERES requires the COPII components Sec12p and Sec16p. Additionally, we have found that GPI‐anchored protein ER exit is controlled by the p24 family member Emp24p, whereas ER export of most transmembrane proteins requires the Cornichon homologue Erv14p.