title: The intracellular interactome of tetraspanin-enriched microdomains reveals their function as sorting machineries toward exosomes.
abstract: Extracellular vesicles are emerging as a potent mechanism of intercellular communication because they can systemically exchange genetic and protein material between cells. Tetraspanin molecules are commonly used as protein markers of extracellular vesicles, although their role in the unexplored mechanisms of cargo selection into exosomes has not been addressed. For that purpose, we have characterized the intracellular tetraspanin-enriched microdomain (TEM) interactome by high throughput mass spectrometry, in both human lymphoblasts and their derived exosomes, revealing a clear pattern of interaction networks. Proteins interacting with TEM receptors cytoplasmic regions presented a considerable degree of overlap, although some highly specific CD81 tetraspanin ligands, such as Rac GTPase, were detected. Quantitative proteomics showed that TEM ligands account for a great proportion of the exosome proteome and that a selective repertoire of CD81-associated molecules, including Rac, is not correctly routed to exosomes in cells from CD81-deficient animals. Our data provide evidence that insertion into TEM may be necessary for protein inclusion into the exosome structure.
authors: Laboratory of Protein Chemistry and Proteomics, Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Cientificas-Universidad Autónoma de Madrid, E-28049 Madrid, Spain.
authors: Daniel
authors: D
authors: Perez-Hernandez
authors: Cristina
authors: C
authors: Gutiérrez-Vázquez
authors: Inmaculada
authors: I
authors: Jorge
authors: Soraya
authors: S
authors: López-Martín
authors: Angeles
authors: A
authors: Ursa
authors: Francisco
authors: F
authors: Sánchez-Madrid
authors: Jesús
authors: J
authors: Vázquez
authors: María
authors: M
authors: Yáñez-Mó
mesh_terms: D000818:Animals; D002460:Cell Line; D055354:Exosomes; D006801:Humans; D008214:Lymphocytes / Q000378:metabolism*; D051379:Mice; D018345:Mice, Knockout; D017434:Protein Structure, Tertiary; D020543:Proteome / Q000235:genetics / Q000378:metabolism; D060225:Tetraspanin 28 / Q000235:genetics / Q000378:metabolism*; D020744:rac GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: C554798:CD81 protein, human; D020543:Proteome; D060225:Tetraspanin 28; D020744:rac GTP-Binding Proteins