A family of serine/threonine protein kinases (jun kinases, c-jun N-terminal kinases, stress-activated protein kinases, SAPKs) involved in intracellular signalling cascades. JNKs, of which there are ten isoforms, are distantly related to ERKs and activated by dual phosphorylation on tyrosine and threonine residues. In addition to phosphorylating c-jun they also phosphorylate p53. JNK1 (mitogen-activated protein kinase-8, EC 126.96.36.199, 427 aa) and JNK2 (MAPK-9, 424 aa) are expressed in a range of different cell types; JNK3 (464 aa) is mainly found in neurons.
Subjects: Medicine and Health — Chemistry.