Specific functional receptor for IL17C, signaling through the NF-kappa-B and MAPK pathways. Requires TRAF3IP2 /ACT1 for signaling. Crucial regulator in innate immunity to bacterial pathogens, such as Citrobacter rodentium. Isoform 4 and isoform 5 may be either cytoplasmic inactive or dominant active forms. Isoform 2 and isoform 3 may act as soluble decoy receptors. Forms heterodimers with IL17RA; the heterodimer binds IL17C. Predominantly expressed in mucosal tissues, including trachea, lung, kidney and stomach. Highly expressed in colon epithelial cells. Also expressed in testis. Low expression, if any, in heart, liver, spleen, or brain. Among CD4 T-helper cells, expressed at high levels in Th17 cells. Expression starts at 10.5 dpc and reaches a plateau of expression at 12.5 dpc. Up-regulated by its own ligand IL17C. Also up-regulated by IL6 and TNF acting synergically. This induction can be further increased by IL23. Mutant animals are born normally at the expected Mendelian frequency. They exhibit much lower expression of genes encoding antibacterial molecules, much greater bacterial burdens and total mortality after infection with Citrobacter rodentium.