Related Experiment Video
Updated: Nov 3, 2025
09:52
A Fluorescence-based Assay of Phospholipid Scramblase Activity
Published on: September 20, 2016
14.2K
TMEM41B and VMP1 are phospholipid scramblases
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.
Autophagy
|June 2, 2021
Summary
TMEM41B and VMP1 proteins are crucial for lipid droplet formation and distribution. These endoplasmic reticulum proteins exhibit scramblase activity, clarifying their roles in autophagy and viral infection.
Area of Science:
- Cell Biology
- Molecular Biology
- Biochemistry
Background:
- TMEM41B and VMP1 are endoplasmic reticulum (ER)-resident transmembrane proteins with known roles in lipid droplet (LD) formation, autophagy, and viral infection.
- The precise biochemical functions of TMEM41B and VMP1 remain largely uncharacterized.
Purpose of the Study:
- To elucidate the biochemical mechanisms underlying the functions of TMEM41B and VMP1.
- To investigate the role of TMEM41B and VMP1 in lipid distribution and membrane dynamics.
Main Methods:
- Lipid distribution screening assays were employed to assess the impact of TMEM41B and VMP1 on cellular lipid content.
- Biochemical analyses were performed to determine the enzymatic activity of TMEM41B and VMP1.
Main Results:
- A lipid distribution screen identified TMEM41B and VMP1 as critical for the proper distribution of cholesterol and phosphatidylserine.
- Biochemical assays revealed that TMEM41B and VMP1 possess scramblase activity, facilitating the movement of lipids across membranes.
Conclusions:
- TMEM41B and VMP1 function as lipid scramblases, providing a mechanistic link to their roles in LD formation, lipid distribution, and autophagy.
- These findings offer new insights into the regulation of membrane lipid asymmetry by ER-resident proteins and their implications in cellular processes and viral pathogenesis.
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