MYD88 Human

MYD88 is a cytoplasmic adaptor protein that plays a central role in both the innate and adaptive immune responses. It functions as a vital signal transducer in the interleukin-1 (IL-1) and Toll-like receptor (TLR) signaling pathways . The protein is composed of 296 amino acids and has a modular structure with three main domains encoded by five exons .

MYD88 acts as an adapter, connecting proteins that receive signals from outside the cell to those that relay signals inside the cell. In the context of innate immunity, MYD88 is pivotal for immune cell activation through TLRs, which are pattern recognition receptors (PRRs) that detect pathogen-associated molecular patterns (PAMPs) and damage-associated molecular patterns (DAMPs) .

Upon ligand binding, all TLRs, except TLR3, interact with MYD88. This interaction leads to the activation of transcription factors such as NF-κB, which is responsible for the expression of various inflammatory cytokines, chemokines, and adhesion molecules, triggering acute inflammation and stimulating adaptive immunity .

Recombinant human MYD88 protein is often used in research to study its role in immune signaling pathways. This recombinant protein is typically expressed in E. coli and can be fused to tags such as His-tag at the N-terminus for purification purposes . It has been shown to increase IL-8 transcription and is involved in the IL-18-mediated signaling pathway .

Given its central role in immune signaling, MYD88 has been recognized as a potential drug target. Dysregulation of MYD88 can lead to a wide range of inflammation-associated syndromes and diseases . Small molecule inhibitors targeting the TIR domain of MYD88 have shown promising therapeutic efficacy in experimental models by blocking TIR–TIR domain homo-dimerization, thereby attenuating MYD88-mediated inflammatory responses and enhancing antiviral type I IFN responses .