Nitric oxide and NAD-dependent protein modification.
Nitric oxide (NO) has been suggested to act as a regulator of endogenous intracellular ADP-ribosylation, based on radiolabelling of proteins in tissue homogenates incubated with [32P]NAD and NO. After the NO-stimulated modification was replicated in a defined system containing only the purified acceptor protein, glyceraldehyde-3-phosphate dehydrogenase (GAPDH), the hypothesis of NO-stimulation of an endogenous ADP-ribosyltransferase became moot. The NO-stimulated, NAD-dependent modification of GAPDH was recently characterized as covalent binding of the whole NAD molecule to the enzyme, not ADP-ribosylation. With this result, along with the knowledge that GAPDH is stoichiometrically S-nitrosylated, the role of NO in protein modification with NAD may be viewed as the conferring of an unexpected chemical reactivity upon GAPDH, possibly due to nitrosylation of a cysteine in the enzyme active site.
McDonald
L J
LJ
Laboratory of Cellular Metabolism, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892.
Moss
J
J
D000246:Adenosine Diphosphate Ribose / Q000378:metabolism*; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases / Q000378:metabolism*; D009243:NAD / Q000378:metabolism*; D009569:Nitric Oxide / Q000502:physiology*; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism
D009243:NAD; D000246:Adenosine Diphosphate Ribose; D009569:Nitric Oxide; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases; D011065:Poly(ADP-ribose) Polymerases