Stress-activated kinase involved in tolerance to glucose starvation. Induces cell-cell detachment by increasing F-actin conversion to G-actin. Expression is induced by CD95 or TNF-alpha, via NF-kappa-B. Protects cells from CD95-mediated apoptosis and is required for the increased motility and invasiveness of CD95-activated tumor cells. Phosphorylates LATS1 and LATS2. Plays a key role in neural tube closure during embryonic development through LATS2 phosphorylation and regulation of the nuclear localization of YAP1 a critical downstream regulatory target in the Hippo signaling pathway. ATP + L-seryl-[protein] = ADP + H(+) + O-phospho-L-seryl-[protein] ATP + L-threonyl-[protein] = ADP + H(+) + O-phospho-L-threonyl-[protein] Activated by phosphorylation on Thr-220. First expressed in the anterior neuroectoderm at 7.5 dpc. At 8.5 dpc, the expression is present in future forebrain and midbrain regions. At 9.5 dpc, the expression is intense in the forebrain and midbrain with a sharp caudal boundary at the isthmic region; a low level of the expression is found throughout the neuroectoderm. Not expressed in the ventral body wall. Phosphorylated at Thr-220 by STK11/LKB1 in complex with STE20-related adapter-alpha (STRADA) pseudo kinase and CAB39. Autophosphorylation is also possible at Thr-220. Belongs to the protein kinase superfamily. CAMK Ser/Thr protein kinase family. SNF1 subfamily.