Theinterleukin-23 receptor is atype I cytokine receptor. It is encoded in human by theIL23R gene.[5] In complex with the interleukin-12 receptor β1 subunit (IL-12Rβ1), it is activated by the cytokineinterleukin 23 (IL-23).[6] TheIL23R mRNA is 2.8 kilobases in length and includes 12 exons. The translated protein contains 629 amino acids; it is a type I penetrating protein and includes asignal peptide, anN-terminalfibronectin III-like domain and an intracellular part that contains three potential tyrosine phosphorylation domains.[6] There are 24IL23R splice variants in mitogen-activated lymphocytes.[7]IL23R includes somesingle-nucleotide polymorphisms in the region encoding the domain that binds IL-23, which may lead to differences between people inTh17 activation.[8] There is also a variant of IL-23R that consists of just the extracellular part and is known as soluble IL-23R. This form can compete with the membrane-bound form to bind IL-23, modulating the Th17 immune response and regulation of inflammation and immune function.[9]
The protein encoded by this gene is a subunit of the receptor forIL-23. This protein pairs with the receptor molecule IL-12Rβ1 (IL12RB1), together forming the IL-23 receptor complex, and both are required for IL-23 signaling. This protein associates constitutively with Janus kinase 2 (JAK2) and also binds to transcription activatorSTAT3 in a ligand-dependent manner.[5]
Three variants in theIL23R gene have been shown to protect againstCrohn's disease andulcerative colitis.[10][11][12]The effect of IL-23R variations present in the population have been studied with an in vitro expression model system.[13]
^de Paus RA, van de Wetering D, van Dissel JT, van de Vosse E (September 2008). "IL-23 and IL-12 responses in activated human T cells retrovirally transduced with IL-23 receptor variants".Molecular Immunology.45 (15):3889–95.doi:10.1016/j.molimm.2008.06.029.PMID18675459.
Zhang XY, Zhang HJ, Zhang Y, Fu YJ, He J, Zhu LP, Wang SH, Liu L (Jan 2006). "Identification and expression analysis of alternatively spliced isoforms of human interleukin-23 receptor gene in normal lymphoid cells and selected tumor cells".Immunogenetics.57 (12):934–43.doi:10.1007/s00251-005-0067-0.PMID16372191.S2CID35668044.
Orozco G, Rueda B, Robledo G, García A, Martín J (Aug 2007). "Investigation of the IL23R gene in a Spanish rheumatoid arthritis cohort".Human Immunology.68 (8):681–4.doi:10.1016/j.humimm.2007.05.008.PMID17678723.
Oliver J, Rueda B, López-Nevot MA, Gómez-García M, Martín J (Aug 2007). "Replication of an association between IL23R gene polymorphism with inflammatory bowel disease".Clinical Gastroenterology and Hepatology.5 (8):977–81, 981.e1–2.doi:10.1016/j.cgh.2007.05.002.hdl:10261/75893.PMID17678845.
