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-212 by STK11 in complex with STE20-related adapter-alpha (STRAD alpha) pseudo kinase and CAB39. Additional isoforms seem to exist. At least one kinase-inactive isoform is believed to be expressed. Expressed in liver, skin, testis, uterus, ovary, adrenal gland and brain (at protein level). Expressed in kidney, heart, skin, spleen, lung, uterus, liver and the exocrine and endocrine compartments of the human pancreas. A kinase-inactive isoform also appears to be expressed in the skin, spleen, lung, uterus, liver and testis. Phosphorylated at Thr-212 by STK11/LKB1 in complex with STE20-related adapter-alpha (STRADA) pseudo kinase and CAB39. Autophosphorylation is also possible at Thr-212. Belongs to the protein kinase superfamily. CAMK Ser/Thr protein kinase family. SNF1 subfamily.