The calmodulin-dependent kinase, CaMKII, is enriched in postsynaptic density (PSD) and co-localizes with NMDA receptors. CaMKII can independently bind to alpha-actinin-2 (ACTN2), densin-180 (LRRC7) and the NMDA receptor subunit GluN2B (GRIN2B). Any of the four CAMK2 isoforms, CAMK2A, CAMK2B, CAMK2D or CAMK2G, which associate to form homomeric or heteromeric CaMKII dodecamers, can bind to ACTN2 and GluN2B, while LRRC7 shows the highest affinity for CAMK2A. Binding of CaMKII to the NMDA receptor-associated proteins is independent of CaMKII phosphorylation (Robison et al. 2005).