SIGIRR Proteins

Protein Information

SIGIRR (single Ig IL-1R-related molecule) is a novel member of the interleukin 1 receptor (IL-1R) superfamily. Although it shows the typical conserved motifs that characterize the IL-1R and Toll superfamily, it is structurally and functionally distinct from both. SIGIRR has only one Ig domain in its extracellular portion whereas the IL-1R family contains three Ig folds. An unusually long cytoplasmic domain is reminiscent of the structure of drosophila Toll, yet the SIGIRR peptide sequence is more closely related to IL-1RI. A chimera, in which the SIGIRR intracellular domain was fused to the IL-1R extracellular domain, did not activate NFkappaB unlike similar fusion proteins of other IL-1R related molecules. Phylogenetic data that suggest that the plasma membrane protein SIGIRR is a close functional relative of MyD88 in mammals.

Synonyms

AI256711; IL-1R8; MGC110992; Sigirr; single Ig and TIR domain containing; single Ig IL-1 receptor related protein; single Ig IL-1-related receptor; Single Ig IL-1R-related molecule; single Ig IL-1R-related protein; single immunoglobulin and toll-interleukin 1 receptor (TIR) domain; single immunoglobulin domain IL1R1 related; single immunoglobulin domain-containing IL1R-related protein; TIR8; Toll/interleukin-1 receptor 8; UNQ301/PRO342