RAL-1 controls multivesicular body biogenesis and exosome secretion

• DOI: 10.1083/jcb.201504136
• Publication Date: 2015-10-12T20:39:02Z
• Authors: Vincent Hyenne; Ahmet Apaydin; David Rodriguez; Coralie Spiegelha...; Sarah Hoff-Yoessle; Maxime Diem; Saurabh Tak; Olivier Lefebvre; Yannick Schwab; Jacky G. Goetz; Michel Labouesse
• Keywords: Exocyst; Exosome; Vesicular Transport Proteins; Secretory Vesicle

Exosomes are secreted vesicles arising from the fusion of multivesicular bodies (MVBs) with plasma membrane. Despite their importance in various processes, molecular mechanisms controlling formation and release remain unclear. Using nematodes mammary tumor cells, we show that Ral GTPases involved exosome biogenesis. In Caenorhabditis elegans, RAL-1 localizes at surface secretory MVBs. A quantitative electron microscopy analysis RAL-1–deficient animals revealed is both MVB These functions do not involve exocyst complex, a common guanosine triphosphatase (GTPase) effector. Furthermore, target membrane SNARE protein SYX-5 colocalizes constitutively active form membrane, MVBs accumulate under when absent. mammals, RalA RalB required for secretion exosome-like cultured cells. Therefore, represent new regulators release.