MAP3K1

MAP3K1 (MEKK1) is a STE11-group MAP kinase kinase kinase that phosphorylates and activates the MAP2Ks MKK4 and MKK7, coupling diverse stimuli to JNK and, more weakly, to ERK and p38 cascades. An N-terminal PB1-like domain mediates oligomerization and interaction with scaffold proteins, while additional regulatory surfaces integrate signals from TNF-family receptors, cytoskeletal stress and DNA damage. MAP3K1 promotes apoptosis and stress responses and contributes to development of the lens and other tissues. Truncating and missense mutations in MAP3K1 are recurrent in invasive lobular breast carcinoma, where altered MEKK1 signaling perturbs ER-dependent transcriptional programs.