Format

Send to

Choose Destination
EMBO J. 1999 Jul 15;18(14):3934-46.

Got1p and Sft2p: membrane proteins involved in traffic to the Golgi complex.

Author information

1
MRC Laboratory of Molecular Biology, Hills Road, Cambridge CB2 2QH, UK.

Abstract

Traffic through the yeast Golgi complex depends on a member of the syntaxin family of SNARE proteins, Sed5p, present in early Golgi cisternae. Sft2p is a non-essential tetra-spanning membrane protein, found mostly in the late Golgi, that can suppress some sed5 alleles. We screened for mutations that show synthetic lethality with sft2 and found one that affects a previously uncharacterized membrane protein, Got1p, as well as new alleles of sed5 and vps3. Got1p is an evolutionarily conserved non-essential protein with a membrane topology similar to that of Sft2p. Immunofluorescence and subcellular fractionation indicate that it is present in early Golgi cisternae. got1 mutants, but not sft2 mutants, show a defect in an in vitro assay for ER-Golgi transport at a step after vesicle tethering to Golgi membranes. In vivo, inactivation of both Got1p and Sft2p results in phenotypes ascribable to a defect in endosome-Golgi traffic, while their complete removal results in an ER-Golgi transport defect. Thus the presence of either Got1p or Sft2p is required for vesicle fusion with the Golgi complex in vivo. We suggest that Got1p normally facilitates Sed5p-dependent fusion events, while Sft2p performs a related function in the late Golgi.

PMID:
10406798
PMCID:
PMC1171469
DOI:
10.1093/emboj/18.14.3934
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

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