ECSIT: Proteins and Enzymes

Activation of NF-kB as a result of Toll-like receptor (TLR) and IL-1 receptor signaling is a major component of innate immune responses (reviewed in 1). Signals from these receptors are relayed by a number of adapter molecules such as TRIF, TIRAP, and MyD88 (2) to kinases such as IRAK (3) and other intermediates such as TNF receptor associated factor (TRAF)-6 (4). ECSIT (evolutionarily conserved signaling intermediate in Toll pathways) was initially identified as a cytoplasmic protein interacting specifically with TNF receptor associated factor (TRAF)-6 in the TLR pathway (5). Recently however, ECSIT has also been shown to be required for bone morphogenetic protein (Bmp) signaling and mesoderm formation during mouse embryogenesis (6), indicating the possibility of cross-talk between the TLR/IL-B and Bmp signaling pathways.