Modification of hippocampal synaptic proteins by nitric oxide-stimulated ADP ribosylation.
Nitric oxide has been shown to be an important neuronal signaling molecule that participates in both behavioral and synaptic plasticity. To better understand the potential mechanisms by which NO regulates synaptic function, the ability of NO to stimulate the modification of synaptic proteins by ADP ribosylation was examined. Two NO donors, sodium nitroprusside and 3-morpholinosydnonimine, stimulated the ADP ribosylation of proteins at apparent molecular masses of 42, 48, 51, 54, and 74 kD in hippocampal synaptosomes. This stimulation was likely owing to the production of NO by the donors; ADP ribosylation was not stimulated by non-NO decomposition products of sodium nitroprusside, and quenching of superoxide anion did not inhibit Sin-1-induced ADP ribosylation. Experiments using NAD+ that was radiolabeled on the nicotinamide moiety demonstrated that the modification of proteins of molecular masses of 30, 33, and 38 kD are not true ADP ribosylation, whereas labeling of the 42-, 48-, 51-, 54-, and 74-kD proteins likely represent ADP ribosylation. Some of the substrates were brain specific (54 and 74 kD), whereas others (42 and 51 kD) were present in multiple nonbrain tissues.
Sullivan
B M
BM
Division of Biology, California Institute of Technology, Pasadena 91125, USA.
Wong
S
S
Schuman
E M
EM
D000246:Adenosine Diphosphate Ribose / Q000378:metabolism*; D000818:Animals; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D008981:Molsidomine / Q000031:analogs & derivatives / Q000494:pharmacology; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D009569:Nitric Oxide / Q000494:pharmacology*; D020030:Nitric Oxide Donors / Q000494:pharmacology; D009599:Nitroprusside / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013347:Subcellular Fractions / Q000378:metabolism; D013569:Synapses / Q000187:drug effects / Q000378:metabolism*; D014018:Tissue Distribution / Q000502:physiology
D009419:Nerve Tissue Proteins; D020030:Nitric Oxide Donors; D009599:Nitroprusside; D000246:Adenosine Diphosphate Ribose; D009569:Nitric Oxide; C002385:linsidomine; D008981:Molsidomine