Mitogen-activated protein kinase 8 (MAPK8)

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

Subsequently, MAPK8/JNK1 phosphorylates a range of transcription factors, primarily components of AP-1 like JUN, JDP2 and ATF2 and thus regulates AP-1 transcriptional activity. Loss of this interaction abrogates the acetylation required for replication initiation.