RRC ID 55979
著者 Kajimoto T, Mohamed NNI, Badawy SMM, Matovelo SA, Hirase M, Nakamura S, Yoshida D, Okada T, Ijuin T, Nakamura SI.
タイトル Involvement of Gβγ subunits of Gi protein coupled with S1P receptor on multivesicular endosomes in F-actin formation and cargo sorting into exosomes.
ジャーナル J Biol Chem
Abstract Exosomes play a critical role in cell-to-cell communication by delivering cargo molecules to recipient cells. However, the mechanism underlying the generation of the exosomal multivesicular endosome (MVE) is one of the mysteries in the field of endosome research. Although sphingolipid metabolites such as ceramide and sphingosine 1-phosphate (S1P) are known to play important roles in MVE formation and maturation, the detailed molecular mechanisms are still unclear. Here, we show that Rho family GTPases, including Cdc42 and Rac1, are constitutively activated on exosomal MVEs and are regulated by S1P signaling as measured by fluorescence resonance energy transfer (FRET)-based conformational changes. Moreover, we detected S1P signaling-induced filamentous actin (F-actin) formation. A selective inhibitor of Gβγ subunits, M119, strongly inhibited both F-actin formation on MVEs and cargo sorting into exosomal intralumenal vesicles of MVEs, both of which were fully rescued by the simultaneous expression of constitutively active Cdc42 and Rac1. Our results shed light on the mechanism underlying exosomal MVE maturation and inform the understanding of the physiological relevance of continuous activation of the S1P receptor and subsequent downstream G protein signaling to Gβγ subunits/Rho family GTPases-regulated F-actin formation on MVEs for cargo sorting into exosomal intralumenal vesicles.
巻・号 293(1)
ページ 245-253
公開日 2018-1-5
DOI 10.1074/jbc.M117.808733
PII S0021-9258(20)31926-8
PMID 29133526
PMC PMC5766922
MeSH Actin Cytoskeleton / metabolism Actins / metabolism* Cell Movement / physiology Endosomes / metabolism Exosomes / metabolism Fluorescence Resonance Energy Transfer / methods GTP-Binding Protein alpha Subunits, Gi-Go / metabolism* GTP-Binding Protein beta Subunits / metabolism* GTP-Binding Protein gamma Subunits / metabolism* HeLa Cells Humans Lysophospholipids / metabolism Multivesicular Bodies / metabolism Protein Transport Receptors, Lysosphingolipid / metabolism* Signal Transduction Sphingosine / analogs & derivatives Sphingosine / metabolism cdc42 GTP-Binding Protein / metabolism rac1 GTP-Binding Protein / metabolism rho GTP-Binding Proteins / metabolism
IF 4.106
引用数 23
リソース情報
ヒト・動物細胞 HeLa