Calcium-dependent protein kinase which acts as a sensor and effector of intracellular Ca(2+) levels probably in part downstream of cGMP-activated PKG kinase (PubMed:9247932). During male gametogenesis in the mosquito gut, required for male exflagellation, possibly by regulating male gamete exit from the host erythrocytes. Not required for asexual blood stage proliferation (By similarity). ATP + L-seryl-[protein] = ADP + H(+) + O-phospho-L-seryl-[protein] ATP + L-threonyl-[protein] = ADP + H(+) + O-phospho-L-threonyl-[protein] Activated by calcium (PubMed:9247932). Upon calcium binding to the EF-hand domains, the C-terminus of the junction domain (J domain) undergoes a conformational change which results in the dissociation of the pseudo-substrate inhibitory motif from the catalytic domain. This, in turn, may facilitate the autophosphorylation of the activation loop at Thr-232, which leads to the kinase activation (By similarity). Monomer. Expressed in ring, trophozoite, schizont and segmenter stages. The EF-hand domain 2 appears to lack a functional calcium binding site. The junction domain (J domain) is composed of 2 motifs that maintain the kinase inactive. The N-terminal autoinhibitory motif acts as a pseudosubstrate inhibiting the catalytic domain while the C-terminal motif binds the EF-hand domains. Myristoylated; myristoylation may target it to different subcellular compartments. Autophosphorylated in vitro. Belongs to the protein kinase superfamily. Ser/Thr protein kinase family. CDPK subfamily.