title: Identification of Apolipoprotein A-I as a Retinoic Acid-binding Protein in the Eye.
abstract: All-trans-retinoic acid may be an important molecular signal in the postnatal control of eye size. The goal of this study was to identify retinoic acid-binding proteins secreted by the choroid and sclera during visually guided ocular growth. Following photoaffinity labeling with all-trans-[11,12-(3)H]retinoic acid, the most abundant labeled protein detected in the conditioned medium of choroid or sclera had an apparent Mr of 27,000 Da. Following purification and mass spectrometry, the Mr 27,000 band was identified as apolipoprotein A-I. Affinity capture of the radioactive Mr 27,000 band by anti-chick apolipoprotein A-I antibodies confirmed its identity as apolipoprotein A-I. Photoaffinity labeling and fluorescence quenching experiments demonstrated that binding of retinoic acid to apolipoprotein A-I is 1) concentration-dependent, 2) selective for all-trans-retinoic acid, and 3) requires the presence of apolipoprotein A-I-associated lipids for retinoid binding. Expression of apolipoprotein A-I mRNA and protein synthesis were markedly up-regulated in choroids of chick eyes during the recovery from induced myopia, and apolipoprotein A-I mRNA was significantly increased in choroids following retinoic acid treatment. Together, these data suggest that apolipoprotein A-I may participate in a regulatory feedback mechanism with retinoic acid to control the action of retinoic acid on ocular targets during postnatal ocular growth.
authors.affiliation: From the Departments of Cell Biology and jody-summers@ouhsc.edu.
authors.forename: Jody A
authors.initials: JA
authors.lastname: Summers
authors.affiliation: From the Departments of Cell Biology and.
authors.forename: Angelica R
authors.initials: AR
authors.lastname: Harper
authors.affiliation: Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104, Thermo Fisher Scientific, West Palm Beach, Florida 33407.
authors.forename: Christa L
authors.initials: CL
authors.lastname: Feasley
authors.affiliation: Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104, Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia, 30602, and.
authors.forename: Hanke
authors.initials: H
authors.lastname: Van-Der-Wel
authors.affiliation: Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104.
authors.forename: Jennifer N
authors.initials: JN
authors.lastname: Byrum
authors.affiliation: Department of Medical Biochemistry, Medical University of Vienna, Max F. Perutz Laboratories, Dr. Bohr Gasse 9/2, 1030 Vienna, Austria.
authors.forename: Marcela
authors.identifier: 0000-0003-2298-4269
authors.initials: M
authors.lastname: Hermann
authors.affiliation: Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104, Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia, 30602, and.
authors.forename: Christopher M
authors.initials: CM
authors.lastname: West
mesh_terms: D000818:Animals; D016632:Apolipoprotein A-I / Q000096:biosynthesis* / Q000737:chemistry; D030161:Avian Proteins / Q000096:biosynthesis* / Q000737:chemistry; D002645:Chickens; D002829:Choroid / Q000737:chemistry / Q000378:metabolism*; D005136:Eye Proteins / Q000096:biosynthesis* / Q000737:chemistry; D005786:Gene Expression Regulation / Q000187:drug effects*; D018168:Receptors, Retinoic Acid / Q000096:biosynthesis* / Q000737:chemistry; D014212:Tretinoin / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D016632:Apolipoprotein A-I; D030161:Avian Proteins; D005136:Eye Proteins; D018168:Receptors, Retinoic Acid; D014212:Tretinoin
keywords: apolipoprotein; eye; retinoic acid; retinoid-binding protein; vision