DEF pocket in p38α facilitates substrate selectivity and mediates autophosphorylation.

Signaling processes are primarily promoted by molecular recognition and corresponding protein-protein interactions. One of the key eukaryotic signaling pathways is the MAP kinase cascade involved in vital cellular processes such as cell proliferation, differentiation, apoptosis, and stress response. The principle recognition site of MAP kinases, the common docking (CD) region, forms selective interactions with substrates, upstream activators, and phosphatases.