Vitamin A Research Today is a free monthly online journal that collates and summarizes the latest research about Vitamin A, including details on retinol, benefits, dosage, supplements, deficiency, information.

A membrane receptor for retinol binding protein mediates cellular uptake of vitamin A.

Kawaguchi R, Yu J, Honda J, Hu J, Whitelegge J, Ping P, Wiita P, Bok D, Sun H

Department of Physiology, David Geffen School of Medicine at UCLA, 650 Charles E. Young Drive South, Los Angeles, CA 90095, USA.

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.

Published 9 February 2007 in Science, 315(5813): 820-5.
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