Related Experiment Video
Updated: May 7, 2026
18:25
Live Imaging Assay for Assessing the Roles of Ca2+ and Sphingomyelinase in the Repair of Pore-forming Toxin Wounds
Published on: August 25, 2013
Caveolae internalization repairs wounded cells and muscle fibers
Matthias Corrotte1, Patricia E Almeida, Christina Tam
1Department of Cell Biology and Molecular Genetics , University of Maryland , College Park , United States.
Elife
|September 21, 2013
Summary
Cell membrane repair involves calcium-triggered lysosome release and lesion removal by caveolar endocytosis. This process is crucial for maintaining muscle fiber integrity and preventing muscular dystrophy.
Area of Science:
- Cell Biology
- Membrane Biology
- Muscle Physiology
Background:
- Plasma membrane wound repair is essential for cell survival.
- Defective sarcolemma resealing in muscle fibers leads to muscular dystrophy.
- Caveolae, caveolin, and cavin proteins are implicated in muscle pathology, but the mechanism is unclear.
Purpose of the Study:
- To elucidate the mechanism of plasma membrane wound repair.
- To investigate the role of caveolae in membrane repair and muscle integrity.
- To explain the muscle pathology associated with mutations in caveolae proteins.
Main Methods:
- Studied Ca(2+)-triggered exocytosis of lysosomes.
- Investigated the release of acid sphingomyelinase.
- Analyzed lesion removal by caveolar endocytosis using toxin SLO and caveolin depletion.
Main Results:
- Membrane wounding triggers Ca(2+)-dependent lysosome exocytosis and acid sphingomyelinase release.
- Caveolar endocytosis mediates rapid removal of membrane lesions.
- Depletion of caveolin impairs plasma membrane resealing and promotes toxin entry via caveolar vesicles.
Conclusions:
- Caveolar endocytosis is a key mechanism for removing membrane lesions and maintaining plasma membrane integrity.
- This pathway is critical for muscle fiber integrity, and its dysfunction explains muscular dystrophy linked to caveolae protein mutations.
Related Concept Videos
01:15Receptor Downregulation in MVBs
Multivesicular bodies (MVBs) are mature endosomes that sort ubiquitinated proteins and then fuse with lysosomes to degrade the sorted proteins. Epidermal growth factor (EGF) and its receptor (EGFR) form a complex that can be internalized through endocytosis, sorted into an MVB, and later degraded.
The EGFR can initiate signaling pathways that lead to cell proliferation, migration, and differentiation. Overexpression of EGFR stimulates cells to proliferate. Excessive EGFR activation may...
The EGFR can initiate signaling pathways that lead to cell proliferation, migration, and differentiation. Overexpression of EGFR stimulates cells to proliferate. Excessive EGFR activation may...
01:38Intralumenal Vesicles and Multivesicular Bodies
Intraluminal vesicles (ILVs) are small vesicles 50-80 nm in diameter formed during the maturation of early endosomes. A specialized endosome containing numerous ILVs is called a multivesicular body (MVB). ILVs contain internalized molecules such as antigens, nucleic acids, proteins, and metabolites. Some of these molecules are released from the MVBs inside exosomes and are transported to other cells. Other MVBs contain molecules that are retained in the ILVs and are later degraded within the...
01:22Enlargement of the Plasma Membrane
Cell division and enlargement are processes that require precise control. The control ensures that cell division cannot proceed unless the cell has grown to a specific size. A spherical, dividing cell requires an approximately 1.6X increase in its surface area to double its volume. The secretory pathway also has a significant role in cell membrane enlargement. Secretory vesicles that bud off from the Golgi apparatus and later fuse with the plasma membrane during exocytosis are a major source of...
01:16Cell Motility through Blebbing
Blebs are a type of membrane protrusion formed by the internal hydrostatic pressure of the cytoplasm. Blebs are observed in several cell types, including fibroblasts, immune cells, and single-celled organisms like the amoeba. The primary function of blebs is cell locomotion and apoptosis, but they are also found during necrosis and cell division. The life cycle of a bleb comprises an initiation phase followed by the expansion and retraction phases.
Blebbing Through the Matrix
In multicellular...
Blebbing Through the Matrix
In multicellular...
01:12Clathrin Coated Vesicles
Clathrin-coated vesicles use endocytosis to transport receptors and lysosomal hydrolases from the Golgi to the lysosome in the late secretory pathway. Clathrin-mediated endocytosis was the first described endocytic process, and Clathrin-coated vesicles remain one of the most well-studied transport vesicles. The molecular machinery that generates clathrin-coated vesicles comprises over 50 proteins that precisely coordinate vesicle formation. Cell surface receptors concentrated in indented sites...
01:45Vesicular Tubular Clusters
After budding out from the ER membrane, some COPII vesicles lose their coat and fuse with one another to form larger vesicles and interconnected tubules called vesicular tubular clusters or VTCs. These clusters constitute a compartment at the ER-Golgi interface known as ERGIC (Endoplasmic Reticulum Golgi Intermediate Compartment). The ERGIC is a mobile membrane-bound cargo transport system that sorts proteins secreted from ER and delivers them to the Golgi.
With the help of motor proteins such...
With the help of motor proteins such...