Mitogen-activated protein kinase 8–c-Jun substrate interface (JNK1–c-Jun interface) (JNK1–c-Jun interface)

The Mitogen-activated protein kinase 8–c-Jun substrate interface is a critical protein-protein interaction (PPI) site where the kinase JNK1 binds to its primary downstream effector, the transcription factor c-Jun. This interface is characterized by a conserved docking site, often referred to as the D-site or D-domain, which facilitates the recruitment and subsequent phosphorylation of c-Jun at Ser63 and Ser73 (UniProt: P45983, P05412). Unlike traditional ATP-competitive kinase inhibitors, targeting this interface offers a mechanism for substrate-specific inhibition, potentially reducing off-target effects associated with broad kinase inhibition (Stebbins et al., 2008, Nature Chemical Biology). Biologically, this interaction is a central node in the stress-activated protein kinase (SAPK) pathway, regulating cellular responses to cytokines, UV radiation, and oxidative stress. Pathologically, hyperactivation of the JNK1–c-Jun interface is linked to the progression of various cancers, insulin resistance in type 2 diabetes, and neuronal apoptosis in neurodegenerative conditions like Alzheimer's disease (PubMed: 11564670). Therapeutic candidates such as BI-78D3 and the peptide Brimapitide (XG-102) have been developed to disrupt this specific interaction to treat inflammatory and ischemic disorders (Borsello et al., 2003, Nature Medicine). However, challenges remain regarding the metabolic stability of peptide-based inhibitors and the potential for disrupting essential physiological stress signaling.

Other names

JNK1-c-Jun docking siteMAPK8-JUN interaction interfacec-Jun N-terminal kinase 1-c-Jun substrate interfaceJNK-c-Jun PPI

Inhibition of protein-protein interaction by blocking the substrate docking site (D-site) on the kinase, preventing substrate recruitment and phosphorylation.