Endosome

Endosomes (Gr. Endo = "inside" and soma = "body") are vesicles of animal and plant cells that arise during endocytosis . They are among the organelles of the cell. Endosomes are viewed as a pre-lysosomal intermediate stage , a distinction being made between early and late endosomes. A retromer- mediated sorting of membrane proteins takes place . Early endosomes are located on the cell periphery, late endosomes are more in the area of ​​the nucleus . Acidification by special proton pumps causes the molecules bound in the endosomes to detach from the respective membrane receptors . These receptors can be discharged and transported back to the cell membrane in order to be available for a further endocytotic process.

Endolysosomes are created by the fusion of an endosome with a lysosome , a vesicle that contains degrading enzymes. Proteins are broken down in the endolysosomes ; they represent a late compartment of the endocytotic pathway.

literature

• Daniel Boujard, Bruno Anselme, Christophe Cullin, Céline Raguénès-Nicol: An overview of cell and molecular biology . Springer, Berlin / Heidelberg 2014, ISBN 978-3-642-41761-0 , Chapter 8: Vesicular transport , doi : 10.1007 / 978-3-642-41761-0_8 .
• A. Haas: When phagocytes have digestive disorders - unusual phagosome biogenesis in macrophages. In: BIOspectrum. Volume 8, No. 3, 2002, pp. 243-247 ( PDF ).