Leucine Rich Repeat Containing G Protein Coupled Receptor 4 (LGR4)

G protein-coupled receptors (GPCRs) play key roles in a variety of physiologic functions. Members of the leucine-rich GPCR (LGR) family, such as GPR48, have multiple N-terminal leucine-rich repeats (LRRs) and a 7-transmembrane domain.

The predicted 951-amino acid rat Lgr4 protein contains a signal peptide; N- and C-flanking cysteine-rich sequences separated by 17 LRRs; 5 potential N-glycosylation sites; a transmembrane region; and a 145-residue cytoplasmic tail with multiple phosphorylation sites and a conserved potential protein kinase A phosphorylation site. Northern blot analysis of human tissues detected a 5.5-kb LGR4 transcript in multiple steroidogenic tissues and in a number of other tissues.