SAPK1, p49MAPK, MAPK, Mitogen-activated protein kinase 8, c-Jun N-terminal kinase 1, Stress-activated protein kinase JNK1, Stress-activated protein kinase 1c (SAPK1c), JNK46
The stress-activated protein kinases (SAPK) or Jun-amino-terminal kinases (JNK) are potently activated by stressors such as UV and gamma radiation. Similar to other MAP Kinases, the core signaling unit is composed of a MAPKKK, usually MEKK1-4 or a mixed lineage kinase (MLK), which phosphorylate and activate MKK4-7, leading to dual phosphorylation and activation of JNK kinases. Rho-GTPases (Rac1 and cdc42) can stimulate MEKKs and MLKs, while MKKs can be activated by a GTPase-independent pathway that involves the germinal center kinase family. There are three JNK genes (JNK1, 2, 3) with further diversification resulting from alternative splicing. Active JNK dimers can translocate to the nucleus to regulate transcription through phosphorylation of c-Jun, ATF-2 and other transcription factors.
