Mediates the control of a large number of enzymes, ion channels and other proteins by Ca(2+) ions. Among the enzymes to be stimulated by the calmodulin-Ca(2+) complex are a number of protein kinases and phosphatases (By similarity). The calB transcript is very low in vegetative cells, it accumulates to higher levels during aggregation and during slug formation. It is present in its highest level in spores. Belongs to the calmodulin family.