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DeutschPotocytosis
Potocytosis is a type of receptor-mediated endocytosis in which small molecules are transported across the plasma membrane of a cell. The molecules are transported by caveolae (rather than clathrin-coated vesicles) and are deposited directly into the cytosol.[1]
Like other types of receptor-mediated endocytosis, potocytosis typically begins when an extracellular ligand binds to a receptor protein on the surface of a cell, thus beginning the formation of an endocytotic vesicle. The ligand is usually of low molecular mass (e.g. vitamins), but some larger molecules (such as lipids) can also act as ligands.[1][2]
Mechanism
[edit]Lipid rafts in the plasma membrane act as membrane microdomains. They are enriched in cholesterol and sphingolipids and are involved potocytosis as the lateral compartmentalization of molecules. Caveolae are caveolin-1-enriched smooth invaginations found on these lipid rafts that contribute to transportation of molecules.[3] Potocytosis works by taking up material into caveolae at the surface of the cell. Glycosylphosphatidylinositol-anchored class of membrane proteins generate high concentrations of molecules. This may either be by releasing a receptor bound molecule, by converting molecules enzymatically or by releasing them from a carrier protein.[4]
References
[edit]- ^ a b Widmaier, Eric P.; Hershel Raff; Kevin T. Strang (2008). Vander's Human Physiology, 11th Ed. McGraw-Hill. pp. 114. ISBN 978-0-07-304962-5.
- ^ Mineo, C.; Anderson, R.G. (August 2001). "Potocytosis. Robert Feulgen Lecture". Histochem Cell Biology. 116 (2): 109–18. doi:10.1007/s004180100289. PMID 11685539.
- ^ Lajoie, Patrick; Nabi, Ivan R. (2010). "Lipid rafts, caveolae, and their endocytosis". International Review of Cell and Molecular Biology. 282: 135–163. doi:10.1016/S1937-6448(10)82003-9. ISBN 9780123812568. ISSN 1937-6448. PMID 20630468.
- ^ Anderson, R. G. (March 1993). "Potocytosis of small molecules and ions by caveolae". Trends in Cell Biology. 3 (3): 69–72. doi:10.1016/0962-8924(93)90065-9. ISSN 0962-8924. PMID 14731772.