The baculovirus occlusion-derived virion (ODV) is required to spread virus infection among insect hosts via the route. The multicapsid nucleopolyhedrovirus P74 protein is an ODV envelope protein that is essential for ODVs to be infectious. P74 is anchored in the ODV envelope by a C-terminal transmembrane anchor domain and is N-terminally exposed on the ODV surface. In the present study, a series of N-terminal and C-terminal truncation mutants of P74 were evaluated for their ability to rescue infectivity of the P74-null virus, AcLP4. It was discovered that a P74 truncation mutant lacking the C-terminal transmembrane anchor domain of P74 was able to rescue infection. This result shows that a soluble form of P74 retains infectivity factor function and suggests that P74 may be complexed with other proteins in the ODV envelope.


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  1. Braunagel, S. C. & Summers, M. D.(1994).Autographa californica nuclear polyhedrosis virus, PDV, and ECV viral envelopes and nucleocapsids: structural proteins, antigens, lipid and fatty acid profiles. Virology 202, 315–328.[CrossRef] [Google Scholar]
  2. Cocchi, F., Fusco, D., Menotti, L., Gianni, T., Eisenberg, R. J., Cohen, G. H. & Campadelli-Fiume, G.(2004). The soluble ectodomain of herpes simplex virus gD contains a membrane-proximal pro-fusion domain and suffices to mediate virus entry. Proc Natl Acad Sci U S A 101, 7445–7450.[CrossRef] [Google Scholar]
  3. Faulkner, P., Kuzio, J., Williams, G. V. & Wilson, J. A.(1997). Analysis of p74, a PDV envelope protein of Autographa californica nucleopolyhedrovirus required for occlusion body infectivity in vivo. J Gen Virol 78, 3091–3100. [Google Scholar]
  4. Gianni, T., Amasio, M. & Campadelli-Fiume, G.(2009). Herpes simplex virus gD forms distinct complexes with fusion executors gB and gH/gL in part through the C-terminal profusion domain. J Biol Chem 284, 17370–17382.[CrossRef] [Google Scholar]
  5. Granados, R. R.(1978). Early events in the infection of Heliothis zea midgut cells by a baculovirus. Virology 90, 170–174.[CrossRef] [Google Scholar]
  6. Haas-Stapleton, E. J., Washburn, J. O. & Volkman, L. E.(2004). P74 mediates specific binding of Autographa californica M nucleopolyhedrovirus occlusion-derived virus to primary cellular targets in the midgut epithelia of Heliothis virescens larvae. J Virol 78, 6786–6791.[CrossRef] [Google Scholar]
  7. Horton, H. M. & Burand, J. P.(1993). Saturable attachment sites for polyhedron-derived baculovirus on insect cells and evidence for entry via direct membrane fusion. J Virol 67, 1860–1868. [Google Scholar]
  8. Kikhno, I., Gutierrez, S., Croizier, L., Croizier, G. & Ferber, M. L.(2002). Characterization of pif, a gene required for the per os infectivity of Spodoptera littoralis nucleopolyhedrovirus. J Gen Virol 83, 3013–3022. [Google Scholar]
  9. Krogh, A., Larsson, B., von Heijne, G. & Sonnhammer, E. L.(2001). Predicting transmembrane protein topology with a hidden Markov model: application to complete genomes. J Mol Biol 305, 567–580.[CrossRef] [Google Scholar]
  10. Kuzio, J., Jaques, R. & Faulkner, P.(1989). Identification of p74, a gene essential for virulence of baculovirus occlusion bodies. Virology 173, 759–763.[CrossRef] [Google Scholar]
  11. Ohkawa, T., Washburn, J. O., Sitapara, R., Sid, E. & Volkman, L. E.(2005). Specific binding of Autographa californica M nucleopolyhedrovirus occlusion-derived virus to midgut cells of Heliothis virescens larvae is mediated by products of pif genes Ac119 and Ac022 but not by Ac115. J Virol 79, 15258–15264.[CrossRef] [Google Scholar]
  12. Pijlman, G. P., Pruijssers, A. J. & Vlak, J. M.(2003). Identification of pif-2, a third conserved baculovirus gene required for per os infection of insects. J Gen Virol 84, 2041–2049.[CrossRef] [Google Scholar]
  13. Slack, J. M. & Arif, B.(2007).Per os infectivity of baculoviruses and the structure of occlusion-derived virus. Adv Virus Res 69, 99–165. [Google Scholar]
  14. Slack, J. M. & Lawrence, S. D.(2005). Evidence for proteolytic cleavage of the baculovirus occlusion-derived virion envelope protein P74. J Gen Virol 86, 1637–1643.[CrossRef] [Google Scholar]
  15. Slack, J. M., Dougherty, E. M. & Lawrence, S. D.(2001). A study of the Autographa californica multiple nucleopolyhedrovirus ODV envelope protein p74 using a GFP tag. J Gen Virol 82, 2279–2287. [Google Scholar]
  16. Slack, J. M., Lawrence, S. D., Krell, P. J. & Arif, B. M.(2008). Trypsin cleavage of the baculovirus occlusion-derived virus attachment protein P74 is required for function in per os infection. J Gen Virol 89, 2388–2397.[CrossRef] [Google Scholar]
  17. Wang, L., Salem, T. Z., Campbell, D. J., Turney, C. M., Kumar, C. M. & Cheng, X. W.(2009). Characterization of a virion occlusion-defective Autographa californica multiple nucleopolyhedrovirus mutant lacking the p26, p10 and p74 genes. J Gen Virol 90, 1641–1648.[CrossRef] [Google Scholar]
  18. Yao, L., Zhou, W., Xu, H., Zheng, Y. & Qi, Y.(2004). The Heliothis armigera single nucleocapsid nucleopolyhedrovirus envelope protein P74 is required for infection of the host midgut. Virus Res 104, 111–121.[CrossRef] [Google Scholar]

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