Calmodulin mediates the control of a large number of enzymes, ion channels and other proteins by Ca(2+). Among the enzymes to be stimulated by the calmodulin-Ca(2+) complex are a number of protein kinases and phosphatases. Expression of PCM4 very low in stolon tips, stems, roots, leaves and tubers. PCM2 not detected in the organs tested. This protein may have four calcium-binding sites. Belongs to the calmodulin family. The possibility that PCM2 is a pseudogene cannot be ruled out.