Format

Send to:

Choose Destination
See comment in PubMed Commons below
J Biol Chem. 2003 Jul 11;278(28):25688-99. Epub 2003 May 2.

The Vid vesicle to vacuole trafficking event requires components of the SNARE membrane fusion machinery.

Author information

  • 1Department of Cellular and Molecular Physiology, Penn State College of Medicine, Hershey, Pennsylvania 17033, USA. crb13@psu.edu

Abstract

The key gluconeogenic enzyme fructose-1,6-bisphosphatase (FBPase) is targeted to Vid vesicles when glucose-starved cells are replenished with glucose. Vid vesicles then deliver FBPase to the vacuole for degradation. A modified alkaline phosphatase assay was developed to study the trafficking of Vid vesicles to the vacuole. For this assay, FBPase was fused with a truncated form of alkaline phosphatase. Under in vivo conditions, FBPase-delta60Pho8p was targeted to the vacuole via Vid vesicles, and it exhibited Pep4p- and Vid24p-dependent alkaline phosphatase activation. Vid vesicle-vacuole targeting was reconstituted using Vid vesicles that contained FBPase-delta60Pho8p. These vesicles were incubated with vacuoles in the presence of cytosol and an ATP-regenerating system. Under in vitro conditions, alkaline phosphatase was also activated in a Pep4p- and Vid24p-dependent manner. The GTPase Ypt7p was identified as an essential component in Vid vesicle-vacuole trafficking. Likewise, a number of v-SNAREs (Ykt6p, Nyv1p, Vti1p) and homotypic fusion vacuole protein sorting complex family members (Vps39p and Vps41p) were required for the proper function of Vid vesicles. In contrast, the t-SNARE Vam3p was a necessary vacuolar component. Vid vesicle-vacuole trafficking exhibits characteristics similar to heterotypic membrane fusion events.

PMID:
12730205
[PubMed - indexed for MEDLINE]
Free full text
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for HighWire
    Loading ...
    Write to the Help Desk