CELL-SURFACE ADP-RIBOSYLATION OF FIBROBLAST GROWTH FACTOR-II BY AN ARGININE-SPECIFIC ADP-RIBOSYLTRANSFERASE

Basic fibroblast growth factor (FGF-2) appeared to be ADP-ribosylated on the surface of adult bovine aortic arch endothelial and human hepat oma cells, Further characterization of this reaction with cells expres sing an arginine-specific, glycosyl-phosphatidylinositol-anchored, mon o-ADP-ribosyltransferase demonstrated that FGF-2 is ADP-ribosylated on arginine. Incubation of transformed cells with FGF-2 and [adenylate-P -32]nicotinamide-adenine dinucleotide (NAD) resulted in the rapid inco rporation of [P-32]ADP-ribose into FGF-2 in a time- and concentration- dependent manner, with labelling averaging 3 mol of ADP-ribose/mol of FGF-2. Excess ADP-ribose had no effect on these reactions, whereas exc ess NAD inhibited the ADP-ribosylation of FGF-2, consistent with an en zymic rather than a non-enzymic ADP-ribosylation reaction. Heparin als o inhibited the ADP-ribosylation reaction, whereas a neutralizing poly clonal anti-peptide antibody had no effect. Furthermore, the addition of putative receptor binding domain peptide analogues of FGF-2 reduced the maximal ADP-ribosylation of FGF-2. These results identify the cel l-surface ADP-ribosylation of FGF-2 as a potentially ubiquitous event.