S‐100b protein regulates the activity of skeletal muscle adenylate cyclase in vitro

Abstract
We have investigated the effect of the b isoform of S‐100 proteins on adenylate cyclase activity of rat skeletal muscle. S‐100b inhibits the adenylate cyclase activity in the presence of Mg2+ (5.0–50 mM), while it activates the same enzyme in the presence of Ca2+ (0.1–1.0 mM) dose‐dependently in both cases. S‐100b counteracts the stimulatory effect of NaF on adenylate cyclase in the presence of Mg2+ and the inhibitory effect of RMI 12330 A in the presence of Ca2+.