GBF1: A novel Golgi-associated BFA-resistant guanine nucleotide exchange factor that displays specificity for ADP-ribosylation factor 5.

ABSTRACT: Expression cloning from a cDNA library prepared from a mutant CHO cell line with Golgi-specific resistance to Brefeldin A (BFA) identified a novel 206-kD protein with a Sec7 domain termed GBF1 for Golgi BFA resistance factor 1. Overexpression of GBF1 allowed transfected cells to maintain normal Golgi morphology and grow in the presence of BFA. Golgi- enriched membrane fractions from such transfected cells displayed normal levels of ADP ribosylation factors (ARFs) activation and coat protein recruitment that were, however, BFA resistant. Hexahistidine-tagged-GBF1 exhibited BFA-resistant guanine nucleotide exchange activity that appears specific towards ARF5 at physiological Mg2+concentration. Characterization of cDNAs recovered from the mutant and wild-type parental lines established that t

SUBMITTER: Claude A 

PROVIDER: S-EPMC2199737 | biostudies-literature | 1999 Jul

REPOSITORIES: biostudies-literature