Mitogen-activated protein kinase 8 (JNK1) (JNK1)

Mitogen-activated protein kinase 8 (MAPK8), commonly known as c-Jun N-terminal kinase 1 (JNK1), is a member of the mitogen-activated protein kinase family and a key component of the stress-activated protein kinase (SAPK) signaling pathway [1, 3]. It is ubiquitously expressed and is activated by a variety of environmental stresses, pro-inflammatory cytokines, and growth factors through a phosphorylation cascade involving MKK4 and MKK7 [1, 13]. Once activated, JNK1 phosphorylates several transcription factors, most notably c-Jun, thereby regulating gene expression programs involved in cell proliferation, differentiation, and apoptosis [1, 7]. JNK1 is implicated in the pathogenesis of numerous diseases, including Type 2 diabetes, where it promotes insulin resistance, and neurodegenerative conditions like Alzheimer's disease, where it contributes to tau hyperphosphorylation [4, 13, 15]. In oncology, JNK1 exhibits a complex role, acting as either a tumor promoter or a suppressor depending on the tissue type and stage of cancer [2, 7]. Therapeutic targeting of JNK1 has focused on small-molecule inhibitors and peptides, though clinical progress has been hampered by challenges related to isoform selectivity and systemic toxicity, particularly hepatotoxicity [5, 13, 14].

Other names

c-Jun N-terminal kinase 1JNK1Stress-activated protein kinase 1SAPK1PRKM8JNK-46

ATP-competitive inhibition of kinase activity, covalent inhibition of the ATP-binding site, and peptide-mediated disruption of JNK-scaffold protein interactions.