Leucine Rich Repeat Containing G Protein Coupled Receptor 5 (LGR5)

The receptors for glycoprotein hormones such as follicle-stimulating hormone (FSH) and thyroid-stimulating hormone (TSH) are G protein-coupled, 7-transmembrane receptors (GPCRs) with large N-terminal extracellular domains. Leucine-rich repeat (LRR)-containing GPCRs (LGRs) form a subgroup of the GPCR superfamily. The deduced 907-amino acid 7-transmembrane GPR49 protein has an N-terminal signal peptide, 16 LRRs, and is approximately 35% identical to FSH receptor, TSH receptor, and luteinizing hormone (LH) receptor. Functional analysis, however, did not show activation of GPR49 by any ligands of those receptors. Northern blot analysis revealed expression of a 5.0-kb GPR49 transcript in skeletal muscle, spinal cord, and various subregions of brain.