IRAK (Pelle) Family Member IRAK-2 and MyD88 as Proximal Mediators of IL-1 Signaling

TLDR

The IL‑1 receptor signaling pathway activates NF‑κB in mammals and is analogous to the Drosophila Toll pathway, with the IL‑1R‑associated kinase (IRAK) homologous to Pelle. The study aimed to determine whether IRAK‑2 and MyD88 serve as additional proximal mediators of IL‑1‑induced NF‑κB activation, suggesting new therapeutic targets. IRAK‑2 and MyD88 were identified as essential proximal mediators that associate with the IL‑1R complex and whose dominant‑negative forms suppress IL‑1‑induced NF‑κB activation.

Abstract

The interleukin-1 receptor (IL-1R) signaling pathway leads to nuclear factor kappa B (NF-kappaB) activation in mammals and is similar to the Toll pathway in Drosophila: the IL-1R-associated kinase (IRAK) is homologous to Pelle. Two additional proximal mediators were identified that are required for IL-1R-induced NF-kappaB activation: IRAK-2, a Pelle family member, and MyD88, a death domain-containing adapter molecule. Both associate with the IL-1R signaling complex. Dominant negative forms of either attenuate IL-1R-mediated NF-kappaB activation. Therefore, IRAK-2 and MyD88 may provide additional therapeutic targets for inhibiting IL-1-induced inflammation.