TAK1

TAK1 (transforming growth factor-β-activated kinase 1) is a MAPKKK activated by TGF-β, or the pro-inflammatory cytokines TNF (tumour necrosis factor) and IL-1 (interleukin-1), or bacterial LPS (lipopolysaccha­ride). It plays a key role in switching on several pro-inflammatory signaling pathways, including those that activate the MAPKs (mitogenactivated protein kinases), termed p38α MAPK, JNK1/2 (c-Jun N-terminal kinase 1/2) and ERK1/2 (extracellular-signal-regulated kinase 1/2), as well as the transcription factor NFκB (nuclear factor κB). TAB1 (TAK1-binding protein 1) is one of the regulatory subunits of TAK1 and plays a role as an activator of TAK1 in response to stimulation of ΤGF-β. TAB-1 can also mediate MKKindependent p38 kinase. Recently, induction of p38 autophosphorylation and consequent kinase activation by TAB1 expression in cultured neonatal cardiomyocytes have been reported.