Threonine kinase that regulates protein synthesis by controlling the rate of peptide chain elongation. Upon activation by a variety of upstream kinases including AMPK or TRPM7, phosphorylates the elongation factor EEF2 at a single site, renders it unable to bind ribosomes and thus inactive. In turn, the rate of protein synthesis is reduced (By similarity). [translation elongation factor 2] + ATP = [translation elongation factor 2]-phosphate + ADP + H(+) Undergoes calcium/calmodulin-dependent intramolecular autophosphorylation, and this results in it becoming partially calcium/calmodulin-independent. Monomer or homodimer (Probable). Interacts with Calmodulin/CALM1; this interaction is strictly required for phosphorylation activity (By similarity). Widely expressed, with high levels in reticulocytes and skeletal muscle. The catalytic domain is located to N-terminal region. The neighbor region contains the calmodulin-binding domain (By similarity). The N-terminus is blocked. Autophosphorylated at multiple residues, Thr-347 being the major site. Phosphorylated by AMP-activated protein kinase AMPK at Ser-397 leading to EEF2K activation and protein synthesis inhibition. Phosphorylated by TRPM7 at Ser-77 resulting in improved protein stability, higher EE2F phosphorylated and subsequently reduced rate of protein synthesis. Phosphorylation by other kinases such as CDK1 and MAPK13 at Ser-358 or RPS6KA1 and RPS6KB1 at Ser-365 instead decrease EEF2K activity and promote protein synthesis (By similarity). Belongs to the protein kinase superfamily. Alpha-type protein kinase family.