title: A new retinoid-binding protein with a low molecular weight.
abstract: Cellular retinoid-binding proteins and nuclear receptors may mediate the intracellular transport and the action of retinoids in the control of differentiation and tumorigenesis. We report a new retinoid-binding protein (Ret BP) with a molecular size of 4,000 that binds retinol, retinoic acid, and some of their derivatives. Purification of Ret BP from chick skin cytosol involved DEAE-Sephadex, Sephadex G-100, and Mono Q column chromatography. The Ret BP-retinoid complex eluted at 195 mM NaCl during Mono Q column chromatography using a 0-300 nM NaCl gradient. Superose-12 column chromatography indicated a molecular size of 4,000 for Ret BP. The binding protein showed a pI of 6.8 on electrofocusing in ampholines of pH 3-10. Ret BP may act as an affinant for retinoids in the cell, and may serve to dispense the ligands to their respective functionally active sites.
authors.affiliation: Kettering-Meyer Laboratory, Southern Research Institute, Birmingham, Alabama 35255-5305.
authors.forename: B P
authors.initials: BP
authors.lastname: Sani
authors.forename: L G
authors.initials: LG
authors.lastname: Reddy
authors.forename: R K
authors.initials: RK
authors.lastname: Singh
authors.forename: E A
authors.initials: EA
authors.lastname: Arello
mesh_terms: D000818:Animals; D002642:Chick Embryo; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D007525:Isoelectric Focusing; D008970:Molecular Weight; D012177:Retinol-Binding Proteins / Q000302:isolation & purification / Q000378:metabolism*; D014212:Tretinoin / Q000378:metabolism*; D014801:Vitamin A / Q000378:metabolism*
chemical_list: D012177:Retinol-Binding Proteins; D014801:Vitamin A; D014212:Tretinoin