FIGURE 1.

Structure of CaMKII isoforms and splice variants. (A) General structure of CaMKII protein including the different functional domains and main key regulatory sites. K42 denotes the lysine residue that allows ATP binding. T286 and T287 are the threonine residues that are autophosphorylated upon calcium binding. Other sites not mentioned in the text are T305–T306 present in the Ca/CaM binding domain, which can be phosphorylated after CaMKII autophosphorylation and negatively regulates its activity by preventing further calcium binding (Coultrap and Bayer, 2012). (B) Splice variants for α, β, δ, and γ isoforms that have been described in neurons. V denotes variable region and V3_N represents the variable region containing the nuclear localization signal. “e” Denotes that these isoforms are expressed in embryonic stages (adapted from Tombes et al., 2003).