Enterovirus-A71 exploits Rab11 to recruit chaperones for virus morphogenesis

Abstract

Enterovirus 71 (EV-A71) causes Hand, Foot and Mouth Disease (HFMD) in children and has been associated with neurological complications. A siRNA screen in EV-A71 infected-motor neurons identified small GTPase Rab11a as a pro-viral host factor. Rab11a and Rab11b isoforms were interchangeably exploited by strains from major EV-A71 genogroups and Coxsackievirus 16, another major causative agent of HFMD. We showed that Rab11 did not play a role in viral entry, IRES-mediated protein translation, or viral genome replication, although it co-localized with replication organelles. GTPase-defective Rab11 mutants had no effect on EV-A71 replication, ruling out Rab11 involvement in intracellular trafficking of viral or host components. Instead, reduced VP2:VP0 ratio in siRab11-treated cells supported a role in provirion maturation. Co-immunoprecipitation and mass spectrometry revealed chaperones as Rab11 top interacting partners during infection. Among which, CCT8 subunit of the chaperone complex TRiC/CCT was found to interact with viral structural proteins specifically. Together, this study describes a novel, unconventional role for Rab11 during viral infection, where it participates in the complex process of virus morphogenesis by recruiting essential chaperone proteins.