c-Jun N-terminal kinase (JNK)

The c-Jun N-terminal kinase (JNK), also known as stress-activated protein kinase (SAPK), is a critical member of the mitogen-activated protein kinase (MAPK) family that orchestrates cellular responses to a wide array of environmental and physiological stimuli [3, 15, 17]. Comprising three isoforms (JNK1, JNK2, and JNK3), this pathway is primarily activated by stress cues such as UV radiation, inflammatory cytokines, and metabolic disturbances [2, 4, 18]. Once activated, JNK phosphorylates a variety of nuclear and cytoplasmic substrates, most notably the transcription factor c-Jun, to regulate genes involved in apoptosis, proliferation, and differentiation [1, 15, 23]. In the context of disease, dysregulated JNK signaling is a major contributor to the pathogenesis of various cancers, neurodegenerative disorders like Alzheimer's and Parkinson's, and chronic inflammatory conditions such as rheumatoid arthritis [3, 11, 12, 19]. It also plays a significant role in metabolic diseases, particularly in promoting insulin resistance and obesity-related inflammation [3, 6, 12]. Due to its central position in pathological signaling, JNK has been extensively targeted for therapeutic intervention using small-molecule inhibitors and peptide mimetics, although achieving isoform specificity remains a primary pharmacological challenge [1, 5, 11, 12]. Current research focuses on balancing the pathway's dual roles in cell survival and death to minimize off-target toxicity while maximizing therapeutic efficacy [1, 12, 16].

Other names

Stress-activated protein kinaseSAPKMitogen-activated protein kinase 8Mitogen-activated protein kinase 9Mitogen-activated protein kinase 10JNK1JNK2JNK3MAPK8MAPK9MAPK10c-Jun N-terminal kinase signaling pathway

ATP-competitive kinase inhibition, Peptide-mediated inhibition of JNK-substrate interaction, Allosteric inhibition of JNK signaling cascades