Molecular and Cellular Biochemistry

, Volume 138, Issue 1, pp 157–166

ADP-ribosylation factors: a family of ∼20-kDa guanine nucleotide-binding proteins that activate cholera toxin

  • Catherine F. Welsh
  • Joel Moss
  • Martha Vaughan
Part IV: Toxin Mono-ADP-ribosylation

DOI: 10.1007/BF00928458

Cite this article as:
Welsh, C.F., Moss, J. & Vaughan, M. Mol Cell Biochem (1994) 138: 157. doi:10.1007/BF00928458

Abstract

ADP-ribosylation factors (ARFs) comprise a family of ∼20 kDa guanine nucleotide-binding proteins that were discovered as one of several cofactors required in cholera toxin-catalyzed ADP-ribosylation of G, the guanine nucleotide-binding protein responsible for stimulation of adenylyl cyclase, and was subsequently found to enhance all cholera toxin-catalyzed reactions and to directly interact with, and activate the toxin. ARF is dependent on GTP or its analogues for activity, binds GTP with high affinity in the presence of dimyristoylphosphatidylcholine/cholate and contains consensus sequences for GTP-binding and hydrolysis. Six mammalian family members have been identified which have been classified into three groups (Class I, II, and III) based on size, deduced amino acid sequence identity, phylogenetic analysis and gene structure. ARFs are ubiquitous among eukaryotes, with a deduced amino acid sequence that is highly conserved across diverse species. They have recently been shown to associate with phospholipid and Golgi membranes in a GTP-dependent manner and are involved in regulating vesicular transport.

Key words

cholera toxinadenylyl cyclaseADP-ribosylation factorsguanine nucleotide-binding (G) proteinsvesicular trafficking

Abbreviations

ARF

ADP-ribosylation factor

sARF I and sARF II

soluble ADP-ribosylation factors purified from bovine brain

mARF

purified membrane-associated ARF

hARF

human ARF

bARF

bovine ARF

yARF

yeast ARF

ARF

bacterially-expressed recombinant ARF

gARF

Giardia ARF

dARF

Drosophila ARF

G protein

guanine nucleotide-binding protein

Gs

G protein responsible for stimulation of adenylyl cyclase

GTPγS

guanosine-5′-O-(3-thio-triphosphate)

CIAI

cholera toxin A1 subunit

DMPC

dimyristoylphosphatidylcholine

SDS

sodium dodecyl sulfate

Copyright information

© Kluwer Academic Publishers 1994

Authors and Affiliations

  • Catherine F. Welsh
    • 1
  • Joel Moss
    • 1
  • Martha Vaughan
    • 1
  1. 1.Laboratory of Cellular Metabolism, National Heart, Lung, and Blood InstituteNational Institutes of HealthBethesdaUSA