ASGARD ESCRT-III AND VPS4 REVEAL EVOLUTIONARY CONSERVED CHROMATIN BINDING PROPERTIES OF THE ESCRT MACHINERY

The archaeal Asgard superphylum currently stands as the most promising prokaryotic candidate from which eukaryotic cells emerged. This unique superphylum encodes for eukaryotic signature proteins (ESP) that could shed light on the origin of eukaryotes, but the properties and function of these proteins is largely unresolved. Here, we set to understand the function of an Asgard archaeal protein family that is conserved across all domains of life and executes basic cellular eukaryotic functions, such as cell division, namely the ESCRT machinery. We find that Asgard ESCRT proteins express and interact with one another inside mammalian cells. Unexpectedly, Asgard ESCRT proteins were found to associate with chromatin, recruit their counterparts to organize in discrete foci inside the mammalian nucleus, and directly bind DNA. Similar properties were also observed for human ESCRT proteins and were driven by a domain conserved in both human and Asgard homologs. Therefore, ESCRT proteins hold chromatin binding properties that were highly preserved through the billion years of evolution separating Asgard archaea and humans. The evolutionary conserved chromatin binding properties reported here for the ESCRT membrane remodeling machinery, may shed light on the origin of eukaryogenesis