Nitric oxide stimulates the ADP-ribosylation of actin in human neutrophils.
ADP-ribosylation is an important post-translational protein modification; however, endogenous substrates are poorly characterized. In these studies we examined the effects of nitric oxide on the ADP-ribosylation of neutrophil proteins. Purified cytosol and plasma membrane were incubated with 32P-NAD (5 microM, 1 microCi, 30 min) in the presence or absence of nitric oxide. Nitric oxide induced the ADP-ribosylation of the 37 kD substrate present only in cytosol. Nitric oxide treatment of plasma membrane plus cytosol revealed the ADP-ribosylation of an additional 43 kD protein. This 43 kD substrate was identified as actin by both phalloidin precipitation and immunoblot (2-D) gel using specific anti-actin antibodies. The data indicate that nitric oxide stimulates the ADP-ribosylation of two discrete substrates in fractionated PMN, one of which can be identified as actin. NO-induced ADP-ribosylation may contribute to the modulatory effect of nitric oxide on neutrophil functions, including F-actin assembly.
Clancy
R M
RM
Department of Medicine, NYU Medical Center, Hospital for Joint Diseases, New York 10003.
Leszczynska-Piziak
J
J
Abramson
S B
SB
D000199:Actins / Q000378:metabolism*; D000246:Adenosine Diphosphate Ribose / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D015180:Electrophoresis, Gel, Two-Dimensional; D006801:Humans; D066298:In Vitro Techniques; D009504:Neutrophils / Q000378:metabolism*; D009569:Nitric Oxide / Q000494:pharmacology*; D037342:Pertussis Toxin; D011499:Protein Processing, Post-Translational; D010566:Virulence Factors, Bordetella / Q000494:pharmacology
D000199:Actins; D010566:Virulence Factors, Bordetella; D000246:Adenosine Diphosphate Ribose; D009569:Nitric Oxide; D037342:Pertussis Toxin