SARM1 (D2M5I) Rabbit mAb #13022

Members of the Toll-like receptor (TLR) family, named for the closely related Toll receptor in Drosophila, play a pivotal role in innate immune responses (1-4). TLRs recognize conserved motifs found in various pathogens and mediate defense responses (5-7). Triggering of the TLR pathway leads to the activation of NF-κB and subsequent regulation of immune and inflammatory genes (4). The TLRs and members of the IL-1 receptor family share a conserved stretch of approximately 200 amino acids known as the Toll/Interleukin-1 receptor (TIR) domain (1). Upon activation, TLRs associate with a number of cytoplasmic adapter proteins containing TIR domains, including myeloid differentiation factor 88 (MyD88), MyD88-adapter-like/TIR-associated protein (MAL/TIRAP), TIR domain-containing adapter-inducing IFN-β (TRIF), and Toll-receptor-associated molecule (TRAM) (8-10). This association leads to the recruitment and activation of IRAK1 and IRAK4, which form a complex with TRAF6 to activate TAK1 and IKK (8,11-14). Activation of IKK leads to the degradation of IκB, which normally maintains NF-κB in an inactive state by sequestering it in the cytoplasm.

Sterile alpha and TIR motif-containing protein 1 (SARM1) is a TIR domain-containing adaptor protein that contains two sterile alpha motif (SAM) domains (15). SARM1 is the only known TIR domain-containing adaptor that does not activate NF-κB, but instead negatively regulates toll-like receptor signaling (16). Research studies suggest that SARM1 inhibits signaling by TLR3 and TLR4 through direct interaction with the TIR domain-containing adapter TRIF, which is required for TLR3 and MyD88-independent TLR4 signaling (16-18). Additional research indicates that SARM1 can mediate injury-induced axon death, neuronal cell death in response to infection with the encephalitis-causing La Crosse virus, and T cell death following an immune response to infection (19-21).