Leucine Rich Repeats And Immunoglobulin Like Domains Protein 3 (LRIG3)

The deduced 1,119-amino acid protein contains a signal peptide; 15 tandem leucine-rich repeats with cysteine-rich N- and C-flanking domains; 3 C2-type immunoglobulin-like domains; a transmembrane domain; and a cytoplasmic tail. LRIG3 shares 46.8% and 54.0% amino acid identity with LRIG1 and LRIG2, respectively, with highest conservation in the extracellular, transmembrane, and membrane-proximal sequences. mouse Lrig3 shares 85.5% amino acid identity with human LRIG3. Northern blot analysis detected a 5.1-kb LRIG3 transcript in all tissues analyzed. Quantitative RT-PCR detected highest expression in stomach and lowest expression in blood. Quantitative RT-PCR of mouse tissues revealed ubiquitous expression, but the pattern of expression differed from that in human tissues.