Mediation of intracellular calcium: variances on a common theme.

The discovery of troponin C and calmodulin set the tenor for understanding the intracellular mechanism of action of calcium. These proteins represent cellular receptors and distinct mediators of calcium. More recently, additional calcium-binding proteins have been identified. Immunological and sequence data suggest that these proteins represent a novel family of calcium mediators. The precise pathways in which these proteins are involved are not known. However, function by inference, the mediation of intracellular calcium, provides new avenues in which to better understand the complex cellular role calcium plays in regulating cell function.