ARD 1, a 64-kDa guanine nucleotide-binding protein with a carboxyl-terminal ADP-ribosylation factor domain.
Clones referred to as ARD 1 were isolated from human and rat cDNA libraries. ARD 1 genes encode a putative 64-kDa protein that contains an 18-kDa ADP-ribosylation factor (ARF) domain at the carboxyl terminus and is much larger than the other monomeric approximately 20-kDa guanine nucleotide-binding ARF proteins thus far identified. ARD 1 mRNAs of 3.7 and 4.1 kilobases were detected in all rat tissues as well as in mouse and rabbit brain, human fibroblasts, and human neuroblastoma cells but not in HL-60 cells. Based on sequence identities, ARD 1 is highly conserved between rat and human. The ARF domain of ARD 1 contains the consensus sequences believed to be involved in guanine nucleotide binding, which are conserved in the ARFs and other GTP-binding proteins. Recombinant ARD 1 or the ARF domain of ARD 1, which lacks the 15 amino acids corresponding to the amino-terminal regions of ARFs stimulated, in a GTP-dependent manner, cholera toxin ADP-ribosyltransferase activity in the presence of 0.3% Tween 20. It had no effect in the presence of SDS, dimyristoylphosphatidylcholine/cholate, or cardiolipin. These observations are consistent with the conclusion that the amino-terminal region of ARF proteins is not required for activation of cholera toxin. In addition, the characteristic features of ARF proteins may be found as domains of larger mammalian proteins.
Mishima
K
K
Laboratory of Cellular Metabolism, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland 20892.
Tsuchiya
M
M
Nightingale
M S
MS
Moss
J
J
Vaughan
M
M
D020727:ADP-Ribosylation Factors; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D004247:DNA; D004789:Enzyme Activation; D019204:GTP-Binding Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D008969:Molecular Sequence Data; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism; D051381:Rats; D011994:Recombinant Proteins; D017386:Sequence Homology, Amino Acid
D011994:Recombinant Proteins; C080681:TRIM23 protein, human; C498277:Trim23 protein, rat; D004247:DNA; D011065:Poly(ADP-ribose) Polymerases; D019204:GTP-Binding Proteins; D020727:ADP-Ribosylation Factors