Cellular retinoic acid-binding proteins (CRABP)

Abstract
Mammalian cell cytoplasm contains at least two proteins which bind retinoic acid (RA): CRABP I and CRABP II. Produced by separate genes, they differ in their affinity for RA, their transcriptional regulation by RA, their tissue distribution, and possibly their function. They intervene, probably at different stages, in the "intracine" metabolic process which controls the amount of biologically active ligand that is available for binding to the nuclear receptors of RA.