S‐100a0 protein stimulates the basal (Mg2+‐activated) adenylate cyclase activity associated with skeletal muscle membranes

Abstract

S-100a₀, protein, the αα isoform of the S-100 family, stimulates basal (Mg²⁺-activated) adenylate cyclase (AC) activity associated with the sarcolemma, longitudinal tubules and terminal cisternae of rat skeletal muscle cells. The stimulatory effect of S-100a₀ on AC activity is maximal around 5μM S-100a₀ and half-maximal around 0.2 μM S-100a₀. Also, the stimulatory effect is greatest on the AC activity associated with the terminal cisternae than on the other membrane fractions studied. These data are discussed in relation to the subcellular localization of S-100a₀ in muscle cells.