OSM

Functions as a cytokine that uses both type I OSM receptor (heterodimers composed of LIFR and IL6ST) and type II OSM receptor (heterodimers composed of OSMR and IL6ST). Functionally, regulates many processes including cell proliferation, cell differentiation, cytokine production. Mechanistically, low affinity ligand binding to IL6ST/gp130, induces heterodimerization with LIFR or OSMR, activating JAK tyrosine kinases (JAK1 or JAK2 and to a lesser extent TYK2) bound to their intracellular domains. These kinases subsequently phosphorylate IL6ST/gp130 and LIFR or OSMR. The tyrosine phosphorylated signaling receptors serve in turn as docking sites for recruitment and activation of STAT3. The type II OSM complex receptor is also able in addition to STAT3 to recruit STAT5B. Moreover, the type II OSM complex receptor recruits SHC1 through OSMR in a JAK1 mediated phosphotyrosine-dependent manner, leading to SHC1 association with GRB2 and downstream activation of the Ras/Raf/MAPK pathway..

Function from UniProtKB (P13725), read 2026-09-23. CC BY 4.0.