The p24 proteins are not essential for vesicular transport in Saccharomyces cerevisiae
- Sebastian Springer*,
- Eric Chen*,
- Rainer Duden†,
- Martina Marzioch‡,
- Adele Rowley‡,
- Susan Hamamoto*,
- Sabeeha Merchant§, and
- Randy Schekman*,¶
- *Howard Hughes Medical Institute and Department of Molecular and Cell Biology, 401 Barker Hall #3202, University of California, Berkeley, CA 94720-3202; †Department of Clinical Biochemistry, Cambridge Institute for Medical Research, University of Cambridge, Cambridge CB2 2XY, United Kingdom; ‡Cell Biology Unit, Glaxo–Wellcome Research and Development, Stevenage, Hertfordshire SG1 2NY, United Kingdom; and §Department of Chemistryand Biochemistry, University of California, Box 951569, Los Angeles, CA 90095-1569
-
Contributed by Randy Schekman
Abstract
To investigate the factors involved in the sorting of cargo proteins into COPII endoplasmic reticulum (ER) to Golgi apparatus transport vesicles, we have created a strain of S. cerevisiae (p24Δ8) that lacks all eight members of the p24 family of transmembrane proteins (Emp24p, Erv25p, and Erp1p to Erp6p). The p24 proteins have been implicated in COPI and COPII vesicle formation, cargo protein sorting, and regulation of vesicular transport in eukaryotic cells. We find that p24Δ8 cells grow identically to wild type and show delays of invertase and Gas1p ER-to-Golgi transport identical to those seen in a single Δemp24 deletion strain. Thus, p24 proteins do not have an essential function in the secretory pathway. Instead, they may serve as quality control factors to restrict the entry of proteins into COPII vesicles.
Footnotes
-
↵ ¶ To whom reprint requests should be addressed. E-mail: schekman{at}uclink4.berkeley.edu.
-
Article published online before print: Proc. Natl. Acad. Sci. USA, 10.1073/pnas.070044097.
-
Article and publication date are at www.pnas.org/cgi/doi/10.1073/pnas.070044097
- Abbreviations:
- ER,
- endoplasmic reticulum;
- CPY,
- carboxypeptidase Y;
- UPR,
- unfolded protein response
- Copyright © The National Academy of Sciences
