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bioRxiv · 10.1101/2020.12.04.412379

Biogenesis of RNA-containing extracellular vesicles at endoplasmic reticulum membrane contact sites

Barman, B.·Ping, J.·Krystofiak, E.·Allen, R.·Prasad, N.·Vickers, K.·Patton, J. G.·Liu, Q.·Weaver, A. M.
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Abstract

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.

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Barman, B., Ping, J., Krystofiak, E., Allen, R., Prasad, N., Vickers, K., Patton, J. G., Liu, Q., Weaver, A. M.. 2020-12-05. Biogenesis of RNA-containing extracellular vesicles at endoplasmic reticulum membrane contact sites. https://doi.org/10.1101/2020.12.04.412379

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