Myddosome signaling complex (Myddosome)

The Myddosome signaling complex is a critical multiprotein assembly that mediates the signal transduction of most Toll-like receptors (TLRs) and Interleukin-1 receptors (IL-1Rs) within the innate immune system (Lin et al., 2010, Nature). It is primarily composed of the adaptor protein MyD88 and kinases from the Interleukin-1 receptor-associated kinase (IRAK) family, specifically IRAK4 and IRAK1 or IRAK2 (Motshwene et al., 2009, J Biol Chem). Upon receptor activation, MyD88 recruits IRAK4 through death domain interactions, forming a helical scaffold that allows IRAK4 to auto-phosphorylate and subsequently activate IRAK1 (Kessler et al., 2013, PNAS). This cascade leads to the activation of the NF-kappaB and MAPK pathways, driving the production of pro-inflammatory cytokines. Dysfunctional Myddosome signaling, particularly through the gain-of-function MYD88 L265P mutation, is a key driver in B-cell malignancies such as Waldenström macroglobulinemia and activated B-cell-like diffuse large B-cell lymphoma (Ngo et al., 2011, Nature). Therapeutic strategies targeting the Myddosome include the development of IRAK4 inhibitors and MyD88-IRAK4 interaction disruptors to treat chronic inflammatory diseases and specific cancers (Cohen, 2014, Nat Rev Drug Discov).

Other names

MyD88-IRAK complexMyD88-IRAK4-IRAK1 complexMyD88-dependent signaling complexMyD88-IRAK4-IRAK2 complex

Inhibition of IRAK4 kinase activity, disruption of MyD88-IRAK4 protein-protein interactions, or targeted degradation of IRAK4 (PROTACs) to prevent downstream NF-kappaB and MAPK signaling.