Lgr4/GPR48 Proteins and Enzymes

Lgr4, also called GPR48, is a 7TM receptor that forms complexes with R-Spondins, Frizzled Wnt receptors and LRP Wnt co-receptors. It enhances Wnt-dependent LRP phosphorylation, internalization of LRPs, and accumulation of beta-catenin. Rodent Lgr4 is widely expressed in both embryo and adult. Lgr4 deletion inhibits fetal liver definitive erythropoiesis, arrests germ cell meiosis, induces loss of intestinal crypts, and leads to hyperactive inflammatory responses. Lgr4 may be overexpressed in carcinomas and may promote invasiveness and metastasis by downregulating p27Kip1 expression.