Extracellular vesicle formation in <i>Euryarchaeota</i> is driven by a small GTPase

Abstract

Since their discovery, extracellular vesicles (EVs) have changed our view on how organisms interact with their extracellular world. EVs are able to traffic a diverse array of molecules across different species and even domains, facilitating numerous functions. In this study, we investigate EV production in <i>Euryarchaeota,</i> using the model organism <i>Haloferax volcanii</i>. We uncover that EVs enclose RNA, with specific transcripts preferentially enriched, including those with regulatory potential, and conclude that EVs can act as an RNA communication system between haloarchaea. We demonstrate the key role of an EV-associated small GTPase for EV formation in <i>H. volcanii</i> that is also present across other diverse evolutionary branches of Archaea. We propose the name, ArvA, for the identified family of archaeal vesiculating GTPases. Additionally, we show that two genes in the same operon with <i>arvA</i> (<i>arvB</i> and <i>arvC</i>) are also involved in EV formation. Both, <i>arvB</i> and <i>arvC</i>, are closely associated with <i>arvA</i> in the majority of other archaea encoding ArvA. Our work demonstrates that small GTPases involved in membrane deformation and vesiculation, ubiquitous in Eukaryotes, are also present in Archaea and are widely distributed across diverse archaeal phyla.