extracellular exosome

Definition

Target type: cellularcomponent

A vesicle that is released into the extracellular region by fusion of the limiting endosomal membrane of a multivesicular body with the plasma membrane. Extracellular exosomes, also simply called exosomes, have a diameter of about 40-100 nm. [GOC:BHF, GOC:mah, GOC:vesicles, PMID:15908444, PMID:17641064, PMID:19442504, PMID:19498381, PMID:22418571, PMID:24009894]

Extracellular exosomes are nanoscale vesicles released by cells into the extracellular environment. Their cellular component is a complex structure consisting of a lipid bilayer membrane encasing a variety of molecular cargo, including proteins, lipids, nucleic acids (DNA, RNA), and metabolites. The lipid bilayer membrane, similar to the plasma membrane of the cell, is composed of phospholipids, cholesterol, and glycosphingolipids. These lipids provide structural integrity and create a barrier to the external environment. The membrane is also studded with various transmembrane proteins, including tetraspanins (CD9, CD63, CD81), integrins, and heat shock proteins, which contribute to exosome biogenesis, trafficking, and interactions with target cells. The interior of the exosome, known as the lumen, houses the molecular cargo. This cargo can be derived from the cell's cytoplasm, endoplasmic reticulum, or Golgi apparatus. The specific composition of the cargo varies depending on the cell of origin and its physiological state. Exosomes can be internalized by recipient cells, delivering their cargo and influencing the recipient's cellular processes. The diverse molecular composition and dynamic interactions with target cells make extracellular exosomes crucial mediators of intercellular communication and play a vital role in various biological processes, including immune modulation, cell-cell signaling, and disease progression.'
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Proteins (555)

Compounds (7,069)