Mitogen-activated protein kinase 9 (MAPK9)

Serine/threonine-protein kinase involved in a variety of processes such as cell proliferation, differentiation, migration, transformation and programmed cell death. Extracellular stimuli such as proinflammatory cytokines or physical stress stimulate the stress-activated protein kinase/c-Jun N-terminal kinase (SAP/JNK) signaling pathway.

In turn, MAPK9/JNK2 phosphorylates a range of transcription factors, primarily components of AP-1 such as JUN and ATF2 and thus regulates AP-1 transcriptional activity. Promotes stressed cell apoptosis by phosphorylating key regulatory factors such as TP53 and YAP1.