This gene encodes a calmodulin- and actin-binding protein that plays an essential role inThe regulation of smooth muscle and nonmuscle contraction.The conserved domain of this protein possessesThe binding activities to Ca(2+)-calmodulin, actin, tropomyosin, myosin, and phospholipids. This protein is a potent inhibitor ofThe actin-tropomyosin activated myosin MgATPase, and serves as a mediating factor for Ca(2+)-dependent inhibition of smooth muscle contraction. Alternative splicing of this gene results in multiple transcript variants encoding distinct isoforms. [provided by RefSeq, Jul 2008],