MAP3K 

MAP3Ks (Mitogen-activated protein kinase kinase kinases), the top components of MAPK cascades, provide specificity for stimulus-dependent activation of MAP2K-MAPK pathways through unique protein-protein interactions and phosphorylation of signaling effectors. The MAP3Ks are highly divergent in gene numbers and structure, including TAK1, ASK1, A-Raf and C-Raf.

MAPK system is a three-step sequential phosphorylation cascade which is composed of MAPK, MAP2K, and MAP3K. ERK, p38 MAPK, and JNK, which are known to be activated by mechanical stimuli, belong to the MAPK family. MAP3Ks function as “platforms to integrate MAPK signaling, and activation of multiple MAP3Ks provides the spatiotemporal regulation of the MAPK pathways, which induces a wide range of physiological responses required for determining cell fate, such as cytokine production, survival, differentiation and apoptosis”.