Retinol Binding Protein 2, Cellular (RBP2)

Cellular retinol-binding protein-2 is an abundant 134-residue protein present in the small intestinal epithelium. It is thought to participate in the uptake and/or intracellular metabolism of vitamin A. Demmer et al. (1987) isolated and sequenced the rat Crbp2 gene. Its 4 exons span 0.65 kb and are interrupted by 3 introns within an aggregate length of 19.5 kb. Southern blot hybridization analysis indicated that the gene is highly conserved in rats, mice, and humans. Crbp2 belongs to a protein family that contains liver fatty acid-binding protein. Demmer et al. (1987) mapped the gene for Crbp2 in mice using recombinant inbred strains and restriction fragment length polymorphisms. They were found to be located on chromosome 9 within 5.3 cM of the phosphoglucomutase-3 locus and closely linked to Crbp, which is highly homologous.