MAP3K9An oncogene on chromosome 14q24.3-q31 that encodes a MAPK kinase kinase belonging to a protein kinase signal transduction cascade. MAP3K9 acts as an upstream activator of the JNK signal transduction cascade by phosphorylating MAP2K4/MKK4 and MAP2K7/MKK7; the JNK signalling pathway regulates stress response via activator protein-1 (JUN) and GATA4 transcription factors. MAP3K9 also plays a role in mitochondrial death signalling pathway, including cytochrome c release, which triggers apoptosis.
Each mitogen-activated protein kinase (MAPK) pathway is a conserved cascade of three protein kinases: an activated MAPK kinase kinase (MAPKKK) phosphorylates and activates a specific MAPK kinase (MAPKK), which in turn activates a specific MAPK.
MAP3K9 may play a role in oesophageal cancer susceptibility and/or pathogenesis.