title: Endogenous ADP-ribosylation of glyceraldehyde-3-phosphate dehydrogenase that is not regulated by nitric oxide in Dictyostelium discoideum.
abstract: A 41,000 M(r) cytosolic protein (p41) in Dictyostelium discoideum was shown to be modified by ADP-ribosylation that was not regulated by nitric oxide (NO). This endogenous ADP-ribosylation was optimal at conditions distinct from those optimal for the NO-stimulated ADP-ribosylation of p41. These two activities were also differentially sensitive to reducing agents and modified different amino acids. The addition of haemoglobin, which sequesters NO, and of NO synthase inhibitors failed to block the endogenous ADP-ribosylation. P41 was purified to homogeneity. The N-terminal sequence of the purified protein was shown to be highly homologous to glyceraldehyde-3-phosphate dehydrogenase (GAPDH). Both endogenous and NO-stimulated activities ADP-ribosylated three isoforms of the protein, with pI values of 6.6, 6.8 and 7.0. In each case, the isoform with pI 6.8 was preferentially modified. Experiments using purified GAPDH indicate that both the endogenous and NO-stimulated ADP-ribosylation are self-catalysed modifications.
authors.affiliation: Department of Biochemistry and Molecular Biology, St. Louis University School of Medicine, MO 63104.
authors.forename: Y
authors.initials: Y
authors.lastname: Tao
authors.forename: A C
authors.initials: AC
authors.lastname: Howlett
authors.forename: C
authors.initials: C
authors.lastname: Klein
mesh_terms: D000244:Adenosine Diphosphate / Q000378:metabolism*; D000818:Animals; D006152:Cyclic GMP / Q000378:metabolism; D003600:Cytosol / Q000737:chemistry / Q000378:metabolism; D004023:Dictyostelium / Q000378:metabolism*; D008040:Genetic Linkage; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases / Q000378:metabolism*; D006162:Guanylate Cyclase / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism*; D010446:Peptide Fragments / Q000378:metabolism*; D010449:Peptide Mapping
chemical_list: D010446:Peptide Fragments; C068142:glyceraldehyde 3-phosphate dehydrogenase (304-313); D009569:Nitric Oxide; D000244:Adenosine Diphosphate; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases; D006162:Guanylate Cyclase; D006152:Cyclic GMP