Calcium/calmodulin-dependent protein kinase that operates in the calcium-triggered CaMKK-CaMK1 signaling cascade and, upon calcium influx, regulates transcription activators activity, cell cycle, hormone production, cell differentiation, actin filament organization and neurite outgrowth (By similarity). Involved in molting (Probable). 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 results in conformational change that relieves intrasteric autoinhibition. Highly expressed in hepatopancreas and to a lesser extent in gills. Low expression in hemocytes, testis, ovary, heart, eyestalk, muscle and epidermis. Higher expression level in the premolt stage in hepatopancreas (2.7-fold), muscle (5.2-fold) and epidermis (2.3-fold) compared to the intermolt stage. Expression is down-regulated in the postmolt stage in hepatopancreas and muscle, but remains high in epidermis. During molting and in response to eyestalk ablation. The autoinhibitory domain overlaps with the calmodulin binding region and interacts in the inactive folded state with the catalytic domain as a pseudosubstrate. Belongs to the protein kinase superfamily. CAMK Ser/Thr protein kinase family. CaMK subfamily.