Function
Calcium/calmodulin-dependent protein kinase 2 (CAMKK2) is a key component of a proposed calcium-triggered signaling cascade involved in various cellular processes. CAMKK2 exists in multiple isoforms, each with unique functions. Isoforms 1, 2, and 3 phosphorylate CAMK1 and CAMK4. Isoform 3 also phosphorylates CAMK1D. However, isoforms 4, 5, and 6 lack a portion of the calmodulin-binding domain, rendering them inactive.
Notably, CAMKK2 efficiently phosphorylates the 5'-AMP-activated protein kinase (AMPK) trimer, particularly the one composed of PRKAA1, PRKAB1, and PRKAG1. This phosphorylation is stimulated in response to Ca(2+) signals. CAMKK2 is also implicated in hippocampal activation of CREB1 and potentially plays a role in neurite growth. Isoform 3 may promote neurite elongation, while isoform 1 might facilitate neurite branching.