1t3g
From Proteopedia
Crystal structure of the Toll/interleukin-1 receptor (TIR) domain of human IL-1RAPL
Structural highlights
Disease[IRPL1_HUMAN] Defects in IL1RAPL1 are the cause of mental retardation X-linked type 21 (MRX21) [MIM:300143]. Mental retardation is a mental disorder characterized by significantly sub-average general intellectual functioning associated with impairments in adaptative behavior and manifested during the developmental period. Non-syndromic mental retardation patients do not manifest other clinical signs.[1] [2] Function[IRPL1_HUMAN] May regulate secretion and presynaptic differentiation through inhibition of the activity of N-type voltage-gated calcium channel. May activate the MAP kinase JNK. Plays a role in presynaptic and postsynaptic differentiation and dendritic spine formation in neurons.[3] [4] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedThe Toll/interleukin-1 receptor (TIR) domain is conserved in the intracellular regions of Toll-like receptors (TLRs) and interleukin-1 receptors (IL-1Rs) as well as in several cytoplasmic adapter molecules. This domain has crucial roles in signal transduction by these receptors for host immune response. Here we report the crystal structure at 2.3-A resolution of the TIR domain of human IL-1RAPL, the first structure of a TIR domain of the IL-1R superfamily. There are large structural differences between this TIR domain and that of TLR1 and TLR2. Helix alphaD in IL-1RAPL is almost perpendicular to its equivalent in TLR1 or TLR2. The BB loop contains a hydrogen bond unique to IL-1RAPL between Thr residues at the 8th and 10th positions. The structural and sequence diversity among these domains may be important for specificity in the signal transduction by these receptors. A dimer of the TIR domain of IL-1RAPL is observed in the crystal, although this domain is monomeric in solution. Residues in the dimer interface are mostly unique to IL-1RAPL, which is consistent with the distinct functional roles of this receptor. Our functional studies show IL-1RAPL can activate JNK but not the ERK or the p38 MAP kinases, whereas its close homolog, TIGIRR, cannot activate JNK. Deletion mutagenesis studies show that the activation of JNK by IL-1RAPL does not depend on the integrity of its TIR domain, suggesting a distinct mechanism of signaling through this receptor. Crystal structure of the Toll/interleukin-1 receptor domain of human IL-1RAPL.,Khan JA, Brint EK, O'Neill LA, Tong L J Biol Chem. 2004 Jul 23;279(30):31664-70. Epub 2004 Apr 30. PMID:15123616[5] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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Categories: Human | Khan, J A | Tong, L | Il-1r | Il-1rapl | Membrane protein | Tir | Tlr
