Transports retinoic acid to the nucleus. Regulates the access of retinoic acid to the nuclear retinoic acid receptors (By similarity). Upon ligand binding, a conformation change exposes a nuclear localization motif and the protein is transported into the nucleus. Embryo. Forms a beta-barrel structure that accommodates hydrophobic ligands in its interior. Belongs to the calycin superfamily. Fatty-acid binding protein (FABP) family.