TOLLIP Antibody from MyBioSource.com

Description: 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 (1-3). TLRs recognize conserved motifs found in various pathogens and mediate defense responses. Triggering of the TLR pathway leads to the activation of NF-kappaB and subsequent regulation of immune and inflammatory genes. 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. Upon activation, TLRs associate with a number of cytoplasmic adaptor proteins containing TIR domains, including myeloid differentiation factor 88 (MyD88), MyD88-adaptor-like/TIR-associated protein (MAL/TIRAP), Toll-receptor-associated activator of interferon (TRIF), and Toll-receptor-associated molecule (TRAM). This association leads to the recruitment and activation of IRAK1 and IRAK4, which form a complex with TRAF6 to activate TAK1 and IKK. Activation of IKK leads to the degradation of IkappaB, which normally maintains NF-kappaB in an inactive state by sequestering it in the cytoplasm. Tollip (Toll interacting protein) is an adaptor protein discovered to be associated with the IRAK complex and recruited to IL1-R following IL-1 stimulation (4). Overexpression of Tollip results in impaired NF-kappaB signaling (4). Tollip also associates directly with TLR2 and TLR4 and inhibits TLR-mediated signaling through inhibition of IRAK (5). Studies of Tollip deficient mice suggest that it plays a role in the regulation of inflammatory cytokines in response to IL-1 and LPS (6).
Function: Component of the signaling pathway of IL-1 and Toll-like receptors. Inhibits cell activation by microbial products. Recruits IRAK1 to the IL-1 receptor complex. Inhibits IRAK1 phosphorylation and kinase activity (PubMed:11751856). Connects the ubiquitin pathway to autophagy by functioning as a ubiquitin-ATG8 family adapter and thus mediating autophagic clearance of ubiquitin conjugates. The TOLLIP-dependent selective autophagy pathway plays an important role in clearance of cytotoxic polyQ proteins aggregates (PubMed:25042851).
Subunit Structure: Oligomerizes. Binds to TLR2 and the TLR4-MD2 complex via its C-terminus. Exists as complex with IRAK1 in unstimulated cells. Upon IL-1 signaling, Tollip binds to the activated IL-1 receptor complex containing IL-1RI, IL-1RacP and the adapter protein MyD88, where it interacts with the TIR domain of IL-1RacP. MyD88 then triggers IRAK1 autophosphorylation, which in turn leads to the dissociation of IRAK1 from Tollip and IL-1RAcP. Interacts with TOM1L2. Interacts with ATG8 family proteins (via AIM motifs), and ubiquitin (via CUE domain).
Post-translational Modifications: Phosphorylated by IRAK1 upon stimulation by IL-1 or microbial products.
Similarity: Both ATG8-interaction motifs (AIM1 and AIM2) are required for the association with ATG8 family proteins. Belongs to the tollip family