Send to

Choose Destination
EMBO J. 1996 Jan 2;15(1):182-91.

GPI anchor attachment is required for Gas1p transport from the endoplasmic reticulum in COP II vesicles.

Author information

Department of Molecular and Cell Biology, Howard Hughes Research Institute, University of California, Berkeley, 94720, USA.


Inositol starvation of auxotrophic yeast interrupts glycolipid biosynthesis and prevents lipid modification of a normally glycosyl phosphatidylinositol (GPI)-linked protein, Gas1p. The unanchored Gas1p precursor undergoes progressive modification in the endoplasmic reticulum (ER), but is not modified by Golgi-specific glycosylation. Starvation-induced defects in anchor assembly and protein processing are rapid, and occur without altered maturation of other proteins. Cells remain competent to manufacture anchor components and to process Gas1p efficiently once inositol is restored. Newly synthesized Gas1p is packaged into vesicles formed in vitro from perforated yeast spheroplasts incubated with either yeast cytosol or the purified Sec proteins (COP II) required for vesicle budding from the ER. In vitro synthesized vesicles produced by inositol-starved membranes do not contain detectable Gas1p. These studies demonstrate that COP II components fulfill the soluble protein requirements for packaging a GPI-anchored protein into ER-derived transport vesicles. However, GPI anchor attachment is required for this packaging to occur.

[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Wiley Icon for PubMed Central
Loading ...
Support Center