Dynamic fatty acylation of p21N-ras.

摘要: To study the acylation of p21N-ras with palmitic acid we have used cells which express human N-ras gene to high levels under control steroid-inducible MMTV--LTR promoter. Addition [3H]palmitate these resulted in detectable incorporation label into within 5 min, continued linearly for 30-60 min. Inhibition protein synthesis up 24 h before addition had no effect on p21N-ras, suggesting that this can occur as a late post-translational event. Acylated SDS--PAGE mobility is found only membrane fraction, whereas approximately 50% [35S]methionine-labelled cytoplasmic and has lower mobility. Conversion acylated form deacylated slightly be achieved neutral hydroxylamine, known cleave thioesters. This treatment also results partial removal from membranes. A remarkably rate turnover palmitate moiety demonstrated by pulse--chase studies (t1/2 20 min serum-containing medium) cannot attributed degradation. The data suggest an active acylation--deacylation cycle may involved its proposed function signal transducing protein.