Background：

Serine/threonine-protein kinase involved in various processes such as p38/MAPK14 stress-activated MAPK cascade， DNA damage response and regulation of cytoskeleton stability. Phosphorylates MAP2K3， MAP2K6 and MARK2. Acts as an activator of the p38/MAPK14 stress-activated MAPK cascade by mediating phosphorylation and subsequent activation of the upstream MAP2K3 and MAP2K6 kinases. Involved in G-protein coupled receptor signaling to p38/MAPK14. In response to DNA damage， involved in the G2/M transition DNA damage checkpoint by activating the p38/MAPK14 stress-activated MAPK cascade， probably by mediating phosphorylation of MAP2K3 and MAP2K6. Acts as a regulator of cytoskeleton stability by phosphorylating ’Thr-208’ of MARK2， leading to activate MARK2 kinase activity and subsequent phosphorylation and detachment of MAPT/TAU from microtubules. Also acts as a regulator of apoptosis: regulates apoptotic morphological changes， including cell contraction， membrane blebbing and apoptotic bodies format