Related Experiment Video
Updated: Jul 18, 2026
10:12
Enrichment of Mammalian Tissues and Xenopus Oocytes with Cholesterol
Published on: March 25, 2020
Membrane cholesterol content modulates ClC-2 gating and sensitivity to oxidative stress
Alexandre Hinzpeter1, Janine Fritsch, Florence Borot
1INSERM, U806, Université Paris-Descartes, Faculté de Médecine René Descartes, F-75015 Paris, France.
The Journal of Biological Chemistry
|November 18, 2006
Summary
Cholesterol regulates the function of the ClC-2 chloride channel. Depleting cholesterol causes ClC-2 to move to detergent-soluble microdomains, speeding up its activation kinetics.
Area of Science:
- Cellular Biology
- Ion Channel Physiology
- Membrane Biophysics
Background:
- ClC-2 is a widely expressed voltage-gated chloride channel.
- The role of membrane lipid environment, particularly cholesterol, in ClC-2 function is not fully understood.
Purpose of the Study:
- To investigate how cholesterol and membrane microdomains affect ClC-2 channel activity.
- To determine the distribution of ClC-2 in different membrane microdomains under various conditions.
Main Methods:
- HEK293 cells stably expressing ClC-2 were used.
- Detergent-resistant and detergent-soluble microdomains were isolated using OptiPrep gradients.
- Patch clamp recordings assessed channel activation kinetics.
- Cholesterol levels were manipulated using methyl-beta-cyclodextrin and enrichment.
Main Results:
- ClC-2 was primarily found in detergent-insoluble membranes under basal conditions.
- Cholesterol depletion induced ClC-2 relocalization to detergent-soluble microdomains (DSM).
- This relocalization accelerated ClC-2 activation kinetics, an effect also observed with oxidative or ATP-depleted stress.
- Cholesterol enrichment prevented this stress-induced activation.
Conclusions:
- Cholesterol levels critically regulate ClC-2 channel activity.
- Increased ClC-2 activity during oxidative or metabolic stress is mediated by its relocation to DSM.
Related Concept Videos
01:29Cholesterol: Significance and Regulation
Although not a source of energy, cholesterol plays a significant role as a foundational structure for bile salts, steroid hormones, and vitamin D, as well as being a crucial component of plasma membranes. Approximately 15% of blood cholesterol is derived from our diet, with the remainder synthesized from acetyl CoA by the liver and intestines. Cholesterol is eliminated from the body through its conversion into bile salts, which are eventually discarded in the feces.
Considering cholesterol and...
Considering cholesterol and...
01:23Membrane Fluidity
Cell membranes are composed of phospholipids, proteins, and carbohydrates loosely attached to one another through chemical interactions. Molecules are generally able to move about in the plane of the membrane, giving the membrane its flexible nature called fluidity. Two other features of the membrane contribute to membrane fluidity: the chemical structure of the phospholipids and the presence of cholesterol in the membrane.Fatty acids tails of phospholipids can be either saturated or...
01:26Membrane Fluidity
Membrane fluidity is explained by the fluid mosaic model of the cell membrane, which describes the plasma membrane structure as a mosaic of components—including phospholipids, cholesterol, proteins, and carbohydrates—that gives the membrane a fluid character.
Mosaic nature of the membrane
The mosaic characteristic of the membrane helps the plasma membrane remain fluid. The integral proteins and lipids exist as separate but loosely-attached molecules in the membrane. The membrane is a relatively...
Mosaic nature of the membrane
The mosaic characteristic of the membrane helps the plasma membrane remain fluid. The integral proteins and lipids exist as separate but loosely-attached molecules in the membrane. The membrane is a relatively...
01:28Assembly of the Lipid Bilayer in the ER
Biological membranes are more than just a barrier separating cell cytoplasm from the outside environment. They are highly dynamic and help maintain the integrity and physiological stability of the cells as well as membrane-bound organelles. Membranes also play vital roles in cell-to-cell and intracellular communication.
A large chunk of any biological membrane is composed of phospholipids. These lipids have a heterogeneous distribution across different subcellular organelles and even between...
A large chunk of any biological membrane is composed of phospholipids. These lipids have a heterogeneous distribution across different subcellular organelles and even between...
01:32Membrane Lipids
Lipids are an essential component of all biological membranes. The average lipid content in mammalian membranes is 50%, though it can be as low as 20% in the inner mitochondrial membrane or as high as 80% in the myelin sheath present around the nerve cells.
Phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, and sphingomyelin are the most common phospholipids present in mammalian membranes. At physiological pH, phosphatidylserine is negatively charged, while the other three...
Phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, and sphingomyelin are the most common phospholipids present in mammalian membranes. At physiological pH, phosphatidylserine is negatively charged, while the other three...
01:45Regulation of Nuclear Protein Sorting
Nuclear protein sorting regulates nucleus composition and gene expression, crucial for determining the fate of a eukaryotic cell. Hence, the entry and exit of molecules across the nuclear envelope is a tightly controlled process. Nuclear protein sorting can be inhibited by one of the following ways: 1) masking cargo signal sequences, 2) modifying the nuclear receptor's affinity for cargo, 3) controlling the nuclear pore size, 4) retaining the cargo during its transit to the cytosol or the...