title: Effect of ADP-ribosylation factor amino-terminal deletions on its GTP-dependent stimulation of cholera toxin activity.
abstract: It has been proposed that the amino-terminal domain of ADP-ribosylation factor (ARF) is critical for its stimulation of cholera toxin ADP-ribosyltransferase activity. In this study, recombinant ARF1 (rARF1), r delta 13ARF1 (recombinant ARF1 lacking the first 13 amino acids) and rPKA14ARF1 (recombinant ARF1 in which the first 14 amino acids were replaced by the first 7 amino acids of the cAMP-dependent protein kinase catalytic subunit) were used to assess the effect of the amino terminus on the ability of ARF to enhance ADP-ribosylation of agmatine by the cholera toxin A subunit. The GTP-dependent ARF activities of r delta 13ARF1 and rPKA14ARF1 were similar to that of rARF1, whereas the GTP requirement for half-maximal activation of cholera toxin A, was somewhat higher for rARF1 than it was for r delta 13ARF1 and rPKA14ARF1. These results are consistent with the view that the amino terminus of ARF1 is not critical for its action as a GTP-dependent activator of cholera toxin.
authors.affiliation: Laboratory of Cellular Metabolism, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland 20892.
authors.forename: J X
authors.initials: JX
authors.lastname: Hong
authors.forename: R S
authors.initials: RS
authors.lastname: Haun
authors.forename: S C
authors.initials: SC
authors.lastname: Tsai
authors.forename: J
authors.initials: J
authors.lastname: Moss
authors.forename: M
authors.initials: M
authors.lastname: Vaughan
mesh_terms: D020823:ADP-Ribosylation Factor 1; D020727:ADP-Ribosylation Factors; D000246:Adenosine Diphosphate Ribose / Q000378:metabolism; D001483:Base Sequence; D002352:Carrier Proteins / Q000378:metabolism; D002772:Cholera Toxin / Q000494:pharmacology*; D003001:Cloning, Molecular; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism; D017931:DNA Primers; D019204:GTP-Binding Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D005822:Genetic Vectors; D016244:Guanosine 5'-O-(3-Thiotriphosphate) / Q000494:pharmacology; D006160:Guanosine Triphosphate / Q000378:metabolism*; D006801:Humans; D007700:Kinetics; D008969:Molecular Sequence Data; D011993:Recombinant Fusion Proteins / Q000302:isolation & purification / Q000378:metabolism; D011994:Recombinant Proteins / Q000378:metabolism / Q000494:pharmacology; D017384:Sequence Deletion
chemical_list: D002352:Carrier Proteins; D017931:DNA Primers; D011993:Recombinant Fusion Proteins; D011994:Recombinant Proteins; D000246:Adenosine Diphosphate Ribose; D016244:Guanosine 5'-O-(3-Thiotriphosphate); D006160:Guanosine Triphosphate; D002772:Cholera Toxin; D017868:Cyclic AMP-Dependent Protein Kinases; D019204:GTP-Binding Proteins; D020823:ADP-Ribosylation Factor 1; D020727:ADP-Ribosylation Factors