Nitric oxide stimulates the phosphorylation of rap1b in human platelets and acts synergistically with iloprost.

Autor: Reep BR; Division of Cell Biology, Glaxo Wellcome Co., Research Triangle Park, North Carolina 27709, USA., Lapetina EG
Jazyk: angličtina
Zdroj: Biochemical and biophysical research communications [Biochem Biophys Res Commun] 1996 Feb 06; Vol. 219 (1), pp. 1-5.
DOI: 10.1006/bbrc.1996.0171
Abstrakt: Phosphorylation of rap 1b in human platelets correlates with both an upward shift of the protein on sodium dodecyl sulfate polyacrylamide gels and the translocation of the phosphorylated protein to the cytosolic fraction of platelets. We reported that this phenomenon occurs in platelets in response to agents that stimulate adenylate cyclase and thereby activate the cyclic AMP-dependent protein kinase. We now have evidence that phosphorylation of rap1b in platelets is also induced by nitric oxide generating compounds through stimulation of guanylate cyclase and activation of the cyclic GMP-dependent protein kinase. We observed time-dependent phosphorylation of rap1b and dose-dependent inhibition of collagen-stimulated aggregation in washed platelets incubated with S-nitroso serum albumin. In the presence of a combination of iloprost and 3-morpholinosydnonimine, when both PKA and PKG are activated, phosphorylation of rap1b increased synergistically to a level three times higher than the sum of their individual actions.
Databáze: MEDLINE