PT - JOURNAL ARTICLE AU - Bahnisikha Barman AU - Jie Ping AU - Evan Krystofiak AU - Ryan Allen AU - Nripesh Prasad AU - Kasey Vickers AU - James G. Patton AU - Qi Liu AU - Alissa M. Weaver TI - Biogenesis of RNA-containing extracellular vesicles at endoplasmic reticulum membrane contact sites AID - 10.1101/2020.12.04.412379 DP - 2020 Jan 01 TA - bioRxiv PG - 2020.12.04.412379 4099 - http://biorxiv.org/content/early/2020/12/05/2020.12.04.412379.short 4100 - http://biorxiv.org/content/early/2020/12/05/2020.12.04.412379.full AB - RNA transferred via extracellular vesicles (EVs) can influence cell and tissue phenotypes; however, the biogenesis of RNA-containing EVs is poorly understood and even controversial. Here, we identify the conserved endoplasmic reticulum membrane contact site (MCS) linker protein VAP-A as a major regulator of the RNA and RNA-binding protein content of small and large EVs. We also identify a unique subpopulation of secreted small EVs that is highly enriched in RNA and regulated by VAP-A. Functional experiments revealed that VAP-A-regulated EVs are critical for the transfer of miR-100 between cells and for in vivo tumor formation. Lipid analysis of VAP-A-knockdown EVs revealed large alterations in lipids known to regulate EV biogenesis, including ceramides and cholesterol. Knockdown of VAP-A-binding ceramide and cholesterol transfer proteins CERT and ORP1L led to similar defects in biogenesis of RNA-containing EVs. We propose that lipid transfer at VAP-A-positive MCS drives biogenesis of a select RNA-containing EV population.Competing Interest StatementThe authors have declared no competing interest.