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LDL Cholesterol Uptake Assay Using Live Cell Imaging Analysis with Cell Health Monitoring
Published on: November 17, 2018
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GRAMD1-mediated accessible cholesterol sensing and transport
Tomoki Naito1, Yasunori Saheki2
1Lee Kong Chian School of Medicine, Nanyang Technological University, 308232, Singapore.
Summary
Cells use GRAMD1 proteins to sense plasma membrane cholesterol levels and transport it to the ER, maintaining cellular cholesterol homeostasis.
Area of Science:
- Cell Biology
- Lipid Metabolism
- Membrane Biology
Background:
- Cholesterol is vital for plasma membrane (PM) structure and signaling.
- Cholesterol regulation occurs in the endoplasmic reticulum (ER).
- ER must monitor PM cholesterol levels.
Purpose of the Study:
- Investigate the role of GRAMD1 proteins in sensing and transporting PM cholesterol to the ER.
- Elucidate the mechanism of cholesterol transport regulation by GRAMD1s.
Main Methods:
- Studied GRAMD1s/Asters (GRAMD1a/1b/1c) function in cholesterol transport.
- Investigated GRAM domain's role in sensing cholesterol and anionic lipids.
- Analyzed GRAMD1s' interaction with PM and ER membranes.
Main Results:
- GRAMD1s form ER-PM contact sites and transport accessible cholesterol to the ER.
- GRAMD1 GRAM domain senses cholesterol and phosphatidylserine in the PM.
- This sensing regulates tethering and cholesterol transport.
Conclusions:
- GRAMD1s act as crucial sensors for PM cholesterol levels.
- Regulated transport of accessible cholesterol by GRAMD1s maintains cellular cholesterol homeostasis.
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