Recombinant Human LIF Rα

Leukemia inhibitory factor receptor alpha (LIF Rα), also known as CD118, is a subunit of the receptor for leukemia inhibitory factor LIF, which is a pleiotropic cytokine affecting the differentiation, survival and proliferation of a wide variety of cells in the adult and the embryo (1). LIF action is mediated through a high-affinity heterodimeric receptor complex consisting of two membrane glycoproteins: LIF Rα that binds LIF with low affinity and the gp130 subunit that does not bind LIF by itself, but is required for high-affinity binding of LIF by the complex. The gp130 subunit was first described as the signal transducing subunit of the high-affinity IL-6 receptor complex (2). Signaling for the LIF complex is achieved through activation of the JAK-STAT pathway. The LIF complex also mediates the activities of oncostatin M (OSM) (3), cardiotropin-1 and ciliary neurotrophic factor (CNTF) (4). Soluble LIF Rα has been shown to bind LIF and has LIF antagonistic activities. Defects in LIF Rα are the cause of Stueve-Wiedemann syndrome (SWS), a severe autosomal recessive condition and belongs to the group of the bent-bone dysplasias (5).