Leucine-rich repeat-containing G-protein coupled receptor 4 (LGR4)

Receptor for R-spondins that potentiates the canonical Wnt signaling pathway and is involved in the formation of various organs. Upon binding to R-spondins (RSPO1, RSPO2, RSPO3 or RSPO4), associates with phosphorylated LRP6 and frizzled receptors that are activated by extracellular Wnt receptors, triggering the canonical Wnt signaling pathway to improve expression of target genes.

In contrast to classical G-protein coupled receptors, doesn't activate heterotrimeric G-proteins to transduce the signal. Its function as activator of the Wnt signaling pathway is necessary for the growth of different organs, including liver, kidney, intestine, bone, reproductive tract and eye.