Retinol-binding protein 1 (Cellular retinol-binding protein I) (CRBP1)

Retinol-binding protein 1 (CRBP1) is a low-molecular-weight cytoplasmic carrier protein that plays a fundamental role in the intracellular metabolism and homeostasis of vitamin A (retinol). It belongs to the fatty acid-binding protein (FABP) family and functions as a chaperone, sequestering retinol to protect it from non-specific oxidation while facilitating its delivery to specific enzymes, such as retinol dehydrogenases (RDHs) for retinoic acid synthesis or lecithin:retinol acyltransferase (LRAT) for storage as retinyl esters (UniProt P09455; NIH). By regulating the bioavailability of retinol, CRBP1 indirectly controls the activation of retinoic acid receptors (RARs), which are essential for maintaining cell differentiation and suppressing oncogenic pathways like Wnt/beta-catenin (MDPI; NIH). In many human malignancies, including breast, ovarian, and hepatocellular cancers, CRBP1 is frequently silenced through epigenetic promoter hypermethylation, a loss that contributes to tumor progression and altered sensitivity to retinoid-based therapies (Frontiers; MDPI). Beyond oncology, CRBP1 is involved in metabolic health, heart remodeling, and vision, making it a significant target for therapeutic restoration or modulation in various disease contexts (NIH; ResearchGate).

Other names

RBP1CRBPCRBP1CRBPIRBPChCRBP1Cellular retinol-binding protein 1

CRBP1 acts as an intracellular chaperone that binds all-trans-retinol with high affinity, facilitating its uptake from the membrane receptor STRA6 and channeling it to specific metabolic enzymes (RDH and LRAT) to regulate the production of retinoic acid and the storage of retinyl esters.