Abstract
Baculoviruses are arthropod-specific large DNA viruses that orally infect the larvae of lepidopteran, hymenopteran and dipteran insect species. These larvae become infected when they eat a food source that is contaminated with viral occlusion bodies (OBs). These OBs contain occlusion-derived viruses (ODVs), which are released upon ingestion of the OBs and infect the endothelial midgut cells. At least nine different ODV envelope proteins are essential for this oral infectivity and these are denoted per os infectivity factors (PIFs). Seven of these PIFs form a complex, consisting of PIF1, 2, 3 and 4 that form a stable core complex and PIF0 (P74), PIF6 and PIF8 (P95) that associate with this complex with lower affinity than the core components. The existence of a PIF complex and the fact that the pif genes are conserved in baculovirus genomes suggests that PIF-proteins cooperatively mediate oral infectivity rather than as individual functional entities. This review therefore discusses the knowledge obtained for individual PIFs in light of their relationship with other members of the PIF complex.
Highlights
The Baculoviridae form a family of arthropod-specific large double stranded DNA viruses that infect insect larvae
Viruses classified in the genera Alphabaculovirus and Betabaculoviruses infect the larvae of lepidopteran insect species
occlusion-derived viruses (ODVs) bind to the microvilli of midgut columnar cells and the viral envelope fuses with the cell membrane, releasing nucleocapsids into the cell. This process of virus entry is mediated by a specific set of proteins in the ODV-envelope, the so-called per os infectivity factors (PIFs)
Summary
The Baculoviridae form a family of arthropod-specific large double stranded DNA viruses that infect insect larvae. Each BV consists of a single nucleocapsid surrounded by an envelope derived from the plasma membrane of a host cell These BVs display a fusion protein to allow cell entry (either GP64 or F protein). ODVs bind to the microvilli of midgut columnar cells and the viral envelope fuses with the cell membrane, releasing nucleocapsids into the cell This process of virus entry is mediated by a specific set of proteins in the ODV-envelope, the so-called per os infectivity factors (PIFs). For Autographa californica multiple nucleopolyhedrovirus (AcMNPV), Peng and co-workers showed that PIFs form a large protein complex, suggesting that these proteins mediate midgut entry of baculovirus ODVs in a cooperative manner [4,5]. We summarize current knowledge of PIF-protein structure and function
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.