MAP kinase kinase kinase

Overview
MAP kinase kinase kinase (or MAP3K or MEKK) is a serine/threonine-specific protein kinase which acts upon MAP kinase kinase.

There are 15 genes:
 * MAP3K1 (aka MEKK1)
 * MAP3K2
 * MAP3K3 (aka MEKK3)
 * MAP3K4
 * MAP3K5
 * MAP3K6
 * MAP3K7 (aka MEKK7)
 * MAP3K8
 * MAP3K9
 * MAP3K10
 * MAP3K11 (aka MEKK11)
 * MAP3K12
 * MAP3K13
 * MAP3K14
 * MAP3K15

MEKK1 activates MAPK8/JNK by phosphorylation of its activator SEK1(MAP2K4). MAP3K3 directly regulates the MAPK8/JNK and extracellular signal-regulated protein kinase (ERK) pathways by activating SEK and MEK1/2 respectively; it does not regulate the p38 pathway. MAP3K7(TAK1)participate in regulation of transcription by transforming growth factor-beta (TGF-beta).