The group I alphabaculovirus-specific protein, AC5, is a novel component of the occlusion body but is not associated with ODVS or the PIF complex

Xi Wang, Cheng Chen, Nan Zhang, Jiang Li, Fei Deng, Hualin Wang, Just M. Vlak, Zhihong Hu*, Manli Wang

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

10 Citations (Scopus)

Abstract

Autographa californica nucleopolyhedrovirus (AcMNPV) orf5 (ac5) is a group I alphabaculovirus-specific gene of unknown function, although the protein (AC5) was previously reported to be associated with the per os infectivity factor (PIF) complex. The purpose of this study was to study the dynamics of AC5 during AcMNPV infection and to verify whether it is indeed a component of the PIF complex. Transcription and expression analyses suggested that ac5 is a late viral gene. An ac5-deleted recombinant AcMNPV was generated by homologous recombination. A one-step growth curve assay indicated that ac5 was not required for budded virus (BV) production in Sf9 cells. Scanning electron microscopy and transmission electron microscopy demonstrated that the deletion of ac5 did not affect occlusion body (OB) morphology, and nor did it affect the insertion of occlusion-derived virus (ODV) into OBs. Partially denaturing SDS-PAGE and a co-immunoprecipitation assay clearly showed that AC5 was not a component of the PIF complex, while the deletion of ac5 did not affect the formation and presence of the PIF complex. Further analyses showed, however, that AC5 was an OB-specific protein, but it was not detected as a component of BVs or ODVs. Bioassay experiments showed that the oral infectivity of ac5-deleted AcMNPV to third instar Spodoptera exigua larvae was not significantly different from that of the ac5-repaired virus. In conclusion, AC5 is an intrinsic protein of OBs, instead of being a component of the PIF complex, and is not essential for either BV or ODV infection. AC5 is awaiting the assignment of another hitherto unknown function.
Original languageEnglish
Pages (from-to)585-595
JournalJournal of General Virology
Volume99
Issue number4
DOIs
Publication statusPublished - 1 Apr 2018

Keywords

  • Ac5
  • Baculovirus
  • Function
  • Group I alphabaculovirus
  • Occlusion body
  • PIF complex

Fingerprint

Dive into the research topics of 'The group I alphabaculovirus-specific protein, AC5, is a novel component of the occlusion body but is not associated with ODVS or the PIF complex'. Together they form a unique fingerprint.

Cite this