[Polyamine modulation of phosphorylation of channel-forming cytosolic protein in bovine brain]

Phosphorylation of the bovine brain TTX-sensitive cytosolic protein which is similar in several functional properties to the membrane potential-dependent sodium channel has been studied. The results obtained indicate that the cytosolic protein is a substrate for cAMP-dependent phosphorylation. Polyamines at a concentration of 5.0 mmol/l inhibit markedly phosphorylation of the cytosolic protein. Spermine is shown to be the most effective inhibitor. It is suggested that polyamines may modulate the cell sodium channel function.