TMEM41B and VMP1 are phospholipid scramblases
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Updated: Nov 3, 2025

A Fluorescence-based Assay of Phospholipid Scramblase Activity
Published on: September 20, 2016
Tizhong Zhang1, Yang E Li2, Yiqiong Yuan1
1Department of Urology, Institute of Urology (Laboratory of Reconstructive Urology), State Key Laboratory of Biotherapy, West China Hospital, College of Life Sciences, Sichuan University, Chengdu, Sichuan, China.
Abstract:
TMEM41B and VMP1, two endoplasmic reticulum (ER)-resident transmembrane proteins, play important roles in regulating the formation of lipid droplets (LDs), autophagy initiation, and viral infection. However, the biochemical functions of TMEM41B and VMP1 are unclear. A lipids distribution screen suggested TMEM41B and VMP1 are critical to the normal distribution of cholesterol and phosphatidylserine. Biochemical analyses unveiled that TMEM41B and VMP1 have scramblase activity. These findings shed light on the mechanism by which TMEM41B and VMP1 regulate LD formation, lipids distribution, macroautophagy, and viral infection.
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