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Updated: Jun 28, 2026

The Cell-based L-Glutathione Protection Assays to Study Endocytosis and Recycling of Plasma Membrane Proteins
Published on: December 13, 2013
RLIP76: A novel glutathione-conjugate and multi-drug transporter
Sharad S Singhal1, Sushma Yadav, Cherice Roth
1Department of Molecular Biology and Immunology, University of North Texas Health Science Center, Fort Worth, TX 76107, USA. ssinghal@hsc.unt.edu
Abstract:
RLIP76, a stress-responsive, multi-functional protein with multi-specific transport activity towards glutathione-conjugates (GS-E) and chemotherapeutic agents, is frequently over-expressed in malignant cells. Our recent studies suggest that it plays a prominent anti-apoptotic role selectively in cancer cells. We have previously shown that RLIP76 accounts for up to 80% of the transport of GS-E and blocking the RLIP76-mediated transport of GS-E in cells results in the accumulation of pro-apoptotic endogenous electrophiles and on-set of apoptosis. Here we demonstrate that when RLIP76 mediate transport of GS-E is abrogated either by anti-RLIP76 IgG or accumulation of 4-hydroxynonenal (4-HNE) and its GSH-conjugate (GS-HNE) occurs and a massive apoptosis is observed in cells, indicate that the inhibition of RLIP76 transport activity at the cell surface is sufficient for observed anti-tumor activity. RLIP76 is linked with certain cellular functions including membrane plasticity and movement (as a primary 'effector' in the Ral pathway, perhaps functioning as a GTPase activating protein, or GAP), and as a component of clathrin-coated pit-mediated receptor-ligand endocytosis-a process that mediates movement of membrane vesicles.
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