title: Techniques to study specific cell-surface receptor-mediated cellular vitamin A uptake.
abstract: STRA6 is a multitransmembrane domain protein that was recently identified as the cell-surface receptor for plasma retinol-binding protein (RBP), the vitamin A carrier protein in the blood. STRA6 binds to RBP with high affinity and mediates cellular uptake of vitamin A from RBP. It is not homologous to any known receptors, transporters, and channels, and it represents a new class of membrane transport protein. Consistent with the diverse physiological functions of vitamin A, STRA6 is widely expressed in diverse adult organs and throughout embryonic development. Mutations in human STRA6 that abolish its vitamin A uptake activity cause severe pathological phenotypes in many human organs including the eye, brain, lung, and heart. This chapter describes functional assays for STRA6 in live cells and on cellular membranes. These assays can be employed to study the mechanism of this new membrane transport mechanism and its roles in the physiology and pathology of many organs.
authors.affiliation: Department of Physiology, Jules Stein Eye Institute, and Brain Research Institute, David Geffen School of Medicine, University of California, Los Angeles, CA 90095-1751, USA.
authors.forename: Riki
authors.initials: R
authors.lastname: Kawaguchi
authors.forename: Hui
authors.initials: H
authors.lastname: Sun
mesh_terms: D000818:Animals; D001059:Apoproteins / Q000096:biosynthesis / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D001692:Biological Transport; D019556:COS Cells; D002462:Cell Membrane / Q000378:metabolism; D002470:Cell Survival; D002474:Cell-Free System / Q000378:metabolism; D002522:Chlorocebus aethiops; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004952:Esters; D006801:Humans; D008565:Membrane Proteins / Q000737:chemistry / Q000378:metabolism*; D057054:Molecular Imaging; D020673:Protein Renaturation; D011956:Receptors, Cell Surface / Q000737:chemistry / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D012177:Retinol-Binding Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D012995:Solubility; D014316:Tritium / Q000737:chemistry; D014801:Vitamin A / Q000378:metabolism*
chemical_list: D001059:Apoproteins; D004952:Esters; D008565:Membrane Proteins; D011956:Receptors, Cell Surface; D011993:Recombinant Fusion Proteins; D012177:Retinol-Binding Proteins; C519685:STRA6 protein, human; D014316:Tritium; D014801:Vitamin A