A membrane receptor for retinol binding protein mediates cellular uptake of vitamin A.
Vitamin A has diverse biological functions. It is transported in the blood as a complex with retinol binding protein (RBP), but the molecular mechanism by which vitamin A is absorbed by cells from the vitamin A-RBP complex is not clearly understood. We identified in bovine retinal pigment epithelium cells STRA6, a multitransmembrane domain protein, as a specific membrane receptor for RBP. STRA6 binds to RBP with high affinity and has robust vitamin A uptake activity from the vitamin A-RBP complex. It is widely expressed in embryonic development and in adult organ systems. The RBP receptor represents a major physiological mediator of cellular vitamin A uptake.
Kawaguchi
Riki
R
Department of Physiology, David Geffen School of Medicine at UCLA, 650 Charles E. Young Drive South, Los Angeles, CA 90095, USA.
Yu
Jiamei
J
Honda
Jane
J
Hu
Jane
J
Whitelegge
Julian
J
Ping
Peipei
P
Wiita
Patrick
P
Bok
Dean
D
Sun
Hui
H
D000217:Acyltransferases / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D001813:Blood-Retinal Barrier; D019556:COS Cells; D002417:Cattle; D002460:Cell Line; D045744:Cell Line, Tumor; D002462:Cell Membrane / Q000378:metabolism; D002522:Chlorocebus aethiops; D047108:Embryonic Development; D004705:Endocytosis; D006801:Humans; D008969:Molecular Sequence Data; D020125:Mutation, Missense; D010857:Pigment Epithelium of Eye / Q000378:metabolism*; D010920:Placenta / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000378:metabolism*; D012171:Retinal Vessels / Q000378:metabolism; D012177:Retinol-Binding Proteins / Q000378:metabolism*; D013154:Spleen / Q000378:metabolism; D014162:Transfection; D014801:Vitamin A / Q000378:metabolism*
D011956:Receptors, Cell Surface; D012177:Retinol-Binding Proteins; C027928:retinol binding protein receptor; D014801:Vitamin A; D000217:Acyltransferases; C056942:lecithin-retinol acyltransferase