Related Experiment Video
Updated: Jul 14, 2026

Real-time Analyses of Retinol Transport by the Membrane Receptor of Plasma Retinol Binding Protein
Published on: January 28, 2013
Molecular mechanism of alpha-tocopheryl-phosphate transport across the cell membrane
Yesim Negis1, Mohsen Meydani, Jean-Marc Zingg
1Vascular Biology Laboratory, The Jean Mayer USDA Human Nutrition Center at Tufts University, Boston, MA 02111, USA.
Abstract:
alpha-Tocopheryl-phosphate (alpha-TP) is synthesized and hydrolyzed in animal cells and tissues where it modulates several functions. alpha-TP is more potent than alpha-T in inhibiting cell proliferation, down-regulating CD36 transcription, inhibiting atherosclerotic plaque formation. Administration of alpha-TP to cells or animals requires its transfer through membranes, via a transporter. We show here that alpha-TP is passing the plasma membrane via a system that is inhibited by glibenclamide and probenecid, inhibitors of a number of transporters. Glibenclamide and probenecid prevent dose-dependently alpha-TP inhibition of cell proliferation. The two inhibitors act on ATP binding cassette (ABC) and organic anion transporters (OAT). Since ABC transporters function to export solutes and alpha-TP is transported into cells, it may be concluded that alpha-TP transport may occur via an OAT family member. Due to the protection by glibenclamide and probenecid on the alpha-TP induced cell growth inhibition it appears that alpha-TP acts after its uptake inside cells.
More Related Videos
12:25Isolation of Physiologically Active Thylakoids and Their Use in Energy-Dependent Protein Transport Assays
Published on: September 28, 2018
05:03Quantitative Analysis of Dietary Vitamin A Metabolites in Murine Ocular and Non-Ocular Tissues Using High-Performance Liquid Chromatography
Published on: December 27, 2024
Related Concept Videos
Drug Absorption Mechanism: Carrier-Mediated Membrane Transport
Facilitated diffusion is a passive process that utilizes human Solute Carrier (SLC) transporters. These transporters bind to the drug, undergo structural...
Cellular Membranes and Drug Transport
Phospholipids arrange themselves into a bilayer, with hydrophilic heads oriented outward and hydrophobic tails facing inward.
Protein Transport to the Thylakoids
Carrier-Mediated Transport
Active transport involves two types of membrane-spanning transporters: uptake and efflux. Uptake transporters are expressed in the small...
Facilitated Diffusion
In this process, substrates such as organic compounds and ions interact with a transporter on one side, triggering conformational changes in proteins that enable...
Drug Absorption Mechanism: Passive Membrane Transport