Associates with OSMR to form the interleukin-31 receptor which activates STAT3 and to a lower extent STAT1 and STAT5. May function in skin immunity (PubMed:15184896). Mediates IL31-induced itch, probably in a manner dependent on cation channels TRPA1 and TRPV1 (PubMed:24373353). Positively regulates numbers and cycling status of immature subsets of myeloid progenitor cells in bone marrow in vivo and enhances myeloid progenitor cell survival in vitro (PubMed:17379091). Heterodimer with OSMR. Interacts with JAK1 and STAT3. Expressed in a subset of dorsal root ganglia neurons (PubMed:16926070, PubMed:24373353, PubMed:25381841). Expressed in spinal cord and trigeminal ganglion (at protein level) (PubMed:25381841). Expressed in skin, testis, bone marrow and thymus (PubMed:15184896). Primarily expressed at postnatal day 10 in the dorsal root ganglia where expression gradually increases as the development proceed. Up-regulated in the diseased tissues of a mouse models of allergic asthma and airway hypersensitivity (PubMed:15184896, PubMed:25847241). Up-regulated by IL31 in dorsal root ganglia (PubMed:25381841). Up-regulated by Th2 cytokines IL4 and IL13 in macrophages (PubMed:25847241). N-glycosylated. Mice do not develop dermatitis upon Il31 overexpression (PubMed:15184896). Decreased levels of immature myeloid progenitor cells in bone marrow and spleen but normal numbers of circulating blood cells (PubMed:17379091). Belongs to the type I cytokine receptor family. Type 2 subfamily.