Journal
JOURNAL OF CELL BIOLOGY
Volume 159, Issue 6, Pages 915-921Publisher
ROCKEFELLER UNIV PRESS
DOI: 10.1083/jcb.200208074
Keywords
intracellular membranes; endoplasmic reticulum; COPII-coated vesicle; protein transport; protein sorting signals
Categories
Ask authors/readers for more resources
Here, we show that efficient transport of membrane and secretory proteins from the ER of Saccharomyces cerevisiae requires concentrative and signal-mediated sorting. Three independent markers of bulk flow transport out of the ER indicate that in the absence of an ER export signal, molecules are inefficiently captured into coat protein complex II (COPII)-coated vesicles. A soluble secretory protein, glycosylated pro-alpha-factor (gpalphaf), was enriched similar to20 fold in these vesicles relative to bulk flow markers. In the absence of Erv29p, a membrane protein that facilitates gpalphaf transport (Belden and Barlowe, 2001), gpalphaf is packaged into COPII vesicles as inefficiently as soluble bulk flow markers. We also found that a plasma membrane protein, the general amino acid permease (Gap1p), is enriched approximately threefold in COPII vesicles relative to membrane phospholipids. Mutation of a diacidic sequence present in the COOH-terminal cytosolic domain of Gap1p eliminated concentrative sorting of this protein.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available