title: Rotavirus core shell subdomains involved in polymerase encapsidation into virus-like particles.
abstract: The triple-layered rotavirus virion encases an 11-segmented, dsRNA genome and 11-12 copies of the viral polymerase (VP1). VP1 transcribes and replicates the genome while tethered beneath the VP2 core shell. Genome replication (i.e. minus-strand RNA synthesis) by VP1 occurs in association with core assembly. During this process, VP2 directly engages VP1, thereby (i) packaging the polymerase into a nascent core and (ii) triggering the enzyme to initiate minus-strand RNA synthesis on bound plus-strand RNA templates. Recent work has shed light on VP2 regions important for VP1 enzymic activity. In the current study, we sought to investigate VP2 subdomains involved in the encapsidation of VP1 into recombinant virus-like particles (VLPs), which are formed of VP2 and the middle layer virion protein (VP6). We showed that strain SA11 VLPs efficiently encapsidated SA11 VP1, but not the genetically divergent Bristol VP1. VLPs made with an SA11 VP2 mutant lacking residues 1-10 of the amino-terminal domain (NTD) were still able to encapsidate VP1; however, removal of the entire NTD (residues 1-102) completely abolished polymerase packaging. We also showed that a chimeric VP2 protein containing the NTD and dimer-forming subdomain of strain Bristol VP2 can efficiently encapsidate SA11 VP1. These results suggest that the VP2 NTD and dimer-forming subdomain play important, albeit non-specific, roles in both VP1 packaging and activation. When combined with previous work, the results of this study support the notion that the same VP2 regions that engage VP1 during activation are also involved in packaging the enzyme into the core.
authors.affiliation: Virginia Tech Carilion Research Institute, Roanoke, VA, USA.
authors.forename: Crystal E
authors.initials: CE
authors.lastname: Boudreaux
authors.affiliation: Virginia Tech Carilion School of Medicine, Roanoke, VA, USA.|Virginia Tech Carilion Research Institute, Roanoke, VA, USA.
authors.forename: Donald C
authors.initials: DC
authors.lastname: Vile
authors.affiliation: Virginia Tech Carilion Research Institute, Roanoke, VA, USA.
authors.forename: Brian L
authors.initials: BL
authors.lastname: Gilmore
authors.affiliation: Virginia Tech Carilion Research Institute, Roanoke, VA, USA.
authors.forename: Justin R
authors.initials: JR
authors.lastname: Tanner
authors.affiliation: Department of Biological Sciences, Virginia Tech, Blacksburg, VA, USA.|Virginia Tech Carilion School of Medicine, Roanoke, VA, USA.|Virginia Tech Carilion Research Institute, Roanoke, VA, USA.
authors.forename: Deborah F
authors.initials: DF
authors.lastname: Kelly
authors.affiliation: Department of Biomedical Sciences and Pathobiology, Virginia-Maryland Regional College of Veterinary Medicine, Blacksburg, VA, USA.|Virginia Tech Carilion School of Medicine, Roanoke, VA, USA.|Virginia Tech Carilion Research Institute, Roanoke, VA, USA.
authors.forename: Sarah M
authors.initials: SM
authors.lastname: McDonald
mesh_terms: D036022:Capsid Proteins / Q000235:genetics / Q000378:metabolism*; D004252:DNA Mutational Analysis; D006801:Humans; D009154:Mutation; D054730:Protein Interaction Domains and Motifs; D012401:Rotavirus / Q000502:physiology*; D017384:Sequence Deletion; D014758:Viral Core Proteins / Q000235:genetics / Q000378:metabolism*; D019065:Virus Assembly
chemical_list: D036022:Capsid Proteins; C069187:VP1 protein, Rotavirus; C442545:VP2 protein, Rotavirus; D014758:Viral Core Proteins