CAMKs are activated by increases in the concentration of intracellular calcium ions (Ca2+) and calmodulin.
Activated CAMK is involved in the phosphorylation of transcription factors and therefore, in the regulation of expression of responding genes.
CAMK removes a phosphate group from ATP, most typically using a Mg2+ ion, and adds it to the CAM protein, rendering it active.
[2] The CAM Kinase contains a highly concentrated glycine loop where the gamma phosphate from the donor ATP molecule is easily able to bind to the enzyme which then utilizes the metal ion to facilitate a smooth phosphate transfer to the target protein.
Figure 1 shows how the presence of calcium or calmodulin allows for the activation of CAM kinases (CAMK II).All kinases have a common structure of a catalytic core including an ATP binding site along with a larger substrate binding site.