Calmodulin mediates the control of a large number of enzymes, ion channels, aquaporins and other proteins through calcium-binding. Among the enzymes to be stimulated by the calmodulin-calcium complex are a number of protein kinases and phosphatases. Together with CCP110 and centrin, is involved in a genetic pathway that regulates the centrosome cycle and progression through cytokinesis (PubMed:16760425). Mediates calcium-dependent inactivation of CACNA1C (PubMed:26969752). Positively regulates calcium-activated potassium channel activity of KCNN2 (PubMed:27165696). Interacts with MYO1C, MYO5A and RRAD. Interacts with MYO10 (By similarity). Interacts with CEP97, CCP110, TTN/titin and SRY (PubMed:9804419, PubMed:12871148, PubMed:15746192, PubMed:16760425, PubMed:17719545). Interacts with USP6; the interaction is calcium dependent (PubMed:16127172). Interacts with CDK5RAP2 (PubMed:20466722). Interacts with SCN5A (By similarity). Interacts with RYR1 (PubMed:18650434). Interacts with FCHO1 (PubMed:22484487). Interacts with MIP in a 1:2 stoichiometry; the interaction with the cytoplasmic domains from two MIP subunits promotes MIP water channel closure (By similarity). Interacts with ORAI1; this may play a role in the regulation of ORAI1-mediated calcium transport (By similarity). Interacts with IQCF1 (By similarity). Interacts with SYT7 (By similarity). Interacts with CEACAM1 (via cytoplasmic domain); this interaction is in a calcium dependent manner and reduces homophilic cell adhesion through dissociation of dimer (By similarity). Interacts with RYR2; regulates RYR2 calcium-release channel activity (PubMed:27516456, PubMed:18650434, PubMed:26164367). Interacts with PCP4; regulates calmodulin calcium-binding (PubMed:27876793). Interacts with the heterotetrameric KCNQ2 and KCNQ3 channel; the interaction is calcium-independent, constitutive and participates in the proper assembly of a functional heterotetrameric M channel (PubMed:27564677). Distributed throughout the cell during interphase, but during mitosis becomes dramatically localized to the spindle poles and the spindle microtubules. Ubiquitination results in a strongly decreased activity. Phosphorylation results in a decreased activity. The disease is caused by variants affecting the gene represented in this entry. Mutations in CALM2 are the cause of LQT15. This protein has four functional calcium-binding sites. Belongs to the calmodulin family.