Molecular and Cellular Biology, May 1999, p. 3588-3599, Vol. 19, No. 5
0270-7306/99/$04.00+0
Copyright © 1999, American Society for Microbiology. All rights reserved.
Department of Molecular Genetics and Microbiology, University of Massachusetts Medical School, Worcester, Massachusetts 01655-0122
Received 21 September 1998/Returned for modification 10 November 1998/Accepted 30 January 1999
Mutations gef1, stp22, STP26,
and STP27 in Saccharomyces cerevisiae were
identified as suppressors of the temperature-sensitive
-factor
receptor (mutation ste2-3) and arginine permease (mutation can1ts). These suppressors inhibited the
elimination of misfolded receptors (synthesized at 34°C) as well as
damaged surface receptors (shifted from 22 to 34°C). The
stp22 mutation (allelic to vps23 [M. Babst and
S. Emr, personal communication] and the STP26
mutation also caused missorting of carboxypeptidase Y, and
ste2-3 was suppressed by mutations vps1,
vps8, vps10, and vps28 but not by
mutation vps3. In the stp22 mutant, both the
mutant and the wild-type receptors (tagged with green fluorescent
protein [GFP]) accumulated within an endosome-like compartment and
were excluded from the vacuole. GFP-tagged Stp22p also accumulated in
this compartment. Upon reaching the vacuole, cytoplasmic domains of
both mutant and wild-type receptors appeared within the vacuolar lumen.
Stp22p and Gef1p are similar to tumor susceptibility protein TSG101 and
voltage-gated chloride channel, respectively. These results
identify potential elements of plasma membrane quality control and
indicate that cytoplasmic domains of membrane proteins are translocated
into the vacuolar lumen.
This article has been cited by other articles:
| J. Bacteriol. | J. Virol. | Eukaryot. Cell |
|---|
| Microbiol. Mol. Biol. Rev. | Clin. Vaccine Immunol. | All ASM Journals |
|---|