Activation of NF-kappaB as a consequence of signaling through the Toll and IL-1 receptors is a major element of innate immune responses. ECSIT plays an important role in signalling to NF-kappaB, functioning as the intermediate in the signaling pathways between TRAF-6 and MEKK-1 [1]. It is part of the MCIA ((mitochondrial complex I intermediate assembly) complex, involved in the assembly of mitochondrial complex I [2]. This is the N-terminal helical domain of ECSIT which adopts a TPR-like structure.

1: ECSIT is an evolutionarily conserved intermediate in the Toll/IL-1 signal transduction pathway. Kopp E, Medzhitov R, Carothers J, Xiao C, Douglas I, Janeway CA, Ghosh S; Genes Dev 1999;13:2059-2071. PMID:10465784

2: Dissecting the Roles of Mitochondrial Complex I Intermediate Assembly Complex Factors in the Biogenesis of Complex I. Formosa LE, Muellner-Wong L, Reljic B, Sharpe AJ, Jackson TD, Beilharz TH, Stojanovski D, Lazarou M, Stroud DA, Ryan MT; Cell Rep. 2020;31:107541. PMID:32320651