MKK4/MAP2K4

null MKK4, also called SEK1 or JNKK1, is encoded by MAP2K4 and belongs to the STE7 group of dual-specificity kinases. Uniquely among its relatives, it activates both the JNK and p38 branches: it phosphorylates the threonine residue within the TPY motif of JNK1/2/3 and can also act on p38 isoforms, integrating signals from TNF receptor family members, osmotic and genotoxic stress, and MAP3Ks such as the MEKK and MLK families. MKK4 influences apoptosis, embryonic liver development, and stress responses, and reduced expression or inactivating changes have been reported in several cancers, supporting a context-dependent tumor-suppressor role that distinguishes it from its paralog MKK7.