ADP-RIBOSYLATION FACTORS - ARF STRUCTURE AND FUNCTION

作者：TSAI SC^*; ADAMIK R; MOSS J; VAUGHAN M

来源：Zoological Studies, 1995, 34(1): 1-9.

• CHOLERA TOXIN
• ADP-RIBOSYLATION FACTORS
• GUANINE NUCLEOTIDE-BINDING PROTEINS
• BREFELDIN A
• PHOSPHOLIPASE D

ADP-ribosylation factors: ARF structure and function. Zoological Studies 34(1): 1-9. ADP-ribosylation factors (ARFs) are similar to 20-kDa guanine nucleotide-binding proteins initially discovered by their ability to activate cholera toxin ADP-ribosyltransferase activity. Subsequently they were shown to be present in the Golgi and to participate in vesicular trafficking in eukaryotic cells. ARFs are highly conserved from Giardia to mammals. Mammalian and Drosophila ARFs fall into three classes based on size, amino acid sequence, and gene structure. The ability of ARFs to activate cholera toxin requires GTP or an analogue and is promoted by phospholipids and detergents. Toxin activation is independent of the amino terminal thirteen amino acids. However, myristoylation at the amino terminus promotes association of ARFs with Golgi and other membranes. Binding to membranes appears to be enhanced by GTP and a soluble complex in a process inhibited by brefeldin A (BFA), a fungal metabolite known to disrupt Golgi. One component of the soluble complex is a phospholipid-dependent guanine nucleotide-exchange protein, which, in a purified state, is independent of BFA and enhances ARF binding of GTP. Activation of ARF by GTP binding promotes its association with Golgi and the subsequent binding of the coatomer proteins, which initiate the vesicular budding process. ARFs have recently been shown to activate phospholipase D which, through the generation of phosphatidate and its metabolites, may be responsible for some of the ARF-initiated membrane trafficking events.

• 出版日期1995-1