VAP-A and its binding partner CERT drive biogenesis of RNA-containing extracellular vesicles at ER membrane contact sites

Dev Cell. 2022 Apr 25;57(8):974-994.e8. doi: 10.1016/j.devcel.2022.03.012. Epub 2022 Apr 13.

Abstract

RNA transfer via extracellular vesicles (EVs) influences cell phenotypes; however, lack of information regarding biogenesis of RNA-containing EVs has limited progress in the field. Here, we identify endoplasmic reticulum membrane contact sites (ER MCSs) as platforms for the generation of RNA-containing EVs. We identify a subpopulation of small EVs that is highly enriched in RNA and regulated by the ER MCS linker protein VAP-A. Functionally, VAP-A-regulated EVs are critical for miR-100 transfer between cells and in vivo tumor formation. Lipid analysis of VAP-A-knockdown EVs revealed reductions in the EV biogenesis lipid ceramide. Knockdown of the VAP-A-binding ceramide transfer protein CERT led to similar defects in EV RNA content. Imaging experiments revealed that VAP-A promotes luminal filling of multivesicular bodies (MVBs), CERT localizes to MVBs, and the ceramide-generating enzyme neutral sphingomyelinase 2 colocalizes with VAP-A-positive ER. We propose that ceramide transfer via VAP-A-CERT linkages drives the biogenesis of a select RNA-containing EV population.

Keywords: ER membrane contact sites; RNA-binding proteins; VAP-A; ceramide; colon cancer; exosomes; extracellular RNA; extracellular vesicles; miRNA.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Ceramides / metabolism
  • Endoplasmic Reticulum / metabolism
  • Extracellular Vesicles* / metabolism
  • Golgi Apparatus* / metabolism
  • Protein Serine-Threonine Kinases
  • RNA / metabolism

Substances

  • Ceramides
  • RNA
  • Protein Serine-Threonine Kinases