Calcium/calmodulin-dependent protein kinase that belongs to a proposed calcium-triggered signaling cascade involved in a number of cellular processes. Phosphorylates CAMK1, CAMK1D, CAMK1G and CAMK4. Involved in regulating cell apoptosis. Promotes cell survival by phosphorylating AKT1/PKB that inhibits pro-apoptotic BAD/Bcl2-antagonist of cell death. ATP + L-seryl-[protein] = ADP + H(+) + O-phospho-L-seryl-[protein] ATP + L-threonyl-[protein] = ADP + H(+) + O-phospho-L-threonyl-[protein] Activated by Ca(2+)/calmodulin. Binding of calmodulin may relieve intrasteric autoinhibition. Partially inhibited upon phosphorylation by PRCAKA/PKA (By similarity). May be regulated through phosphorylation by CAMK1 and CAMK4. Interacts with CAMK4 and calmodulin. The autoinhibitory domain overlaps with the calmodulin binding region and may be involved in intrasteric autoinhibition. The RP domain (arginine/proline-rich) is involved in the recognition of CAMKI and CAMK4 as substrates. Appears to be autophosphorylated in a Ca(2+)/calmodulin-dependent manner. Phosphorylated at multiple sites by PRCAKA/PKA. Phosphorylation of Ser-458 is blocked upon binding to Ca(2+)/calmodulin. In vitro, phosphorylated by CAMK1 and CAMK4 (By similarity). Belongs to the protein kinase superfamily. Ser/Thr protein kinase family.