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Updated: Aug 7, 2026
Establishment of Viral Infection and Analysis of Host-Virus Interaction in Drosophila Melanogaster
Published on: March 14, 2019
Characterization of cricket paralysis virus-induced polypeptides in Drosophila cells
N F Moore1, A Kearns, J S Pullin
1Natural Environment Research Council, Unit of Invertebrate Virology, Oxford OX1 3UB, United Kingdom.
Abstract:
Cricket paralysis virus purified from Galleria mellonella larvae was shown to be similar to virus purified from Drosophila melanogaster cells. Cricket paralysis virus contained three major structural polypeptides of similar molecular weight (around 30,000), had a buoyant density of 1.344 g/ml, and had a capsid diameter of 27 nm. Twenty virus-induced polypeptides could be detected in CrPV-infected Drosophila cells. Two major polypeptides found in the infected cells corresponded to two structural viral polypeptides (VP1 and VP3), whereas the third major intracellular polypeptide was the apparent precursor of the third viral structural polypeptide (VP2). Three of the primary virus-induced polypeptides had molecular weights of 144,000, 124,000, and 115,000. These and other polypeptides were chased into lower-molecular-weight proteins when excess cold methionine was added after a short [(35)S]methionine pulse. Although cricket paralysis virus has a number of characteristics in common with the mammalian enteroviruses, the extremely fast processing of high-molecular-weight polypeptides into viral proteins seems atypical. Also, no VP4 (8,000 to 10,000 molecular weight) has been found in the virus particles.
Insights
Cricket paralysis virus (CrPV) shares structural similarities with viruses from other species. Its rapid processing of viral proteins from high-molecular-weight precursors is unusual for enteroviruses.
Area of Science:
- Virology
- Molecular Biology
- Insect Pathology
Background:
- Cricket paralysis virus (CrPV) is an insect-specific virus.
- Understanding CrPV replication provides insights into viral protein processing.
- Comparison with mammalian enteroviruses highlights unique viral mechanisms.
Purpose of the Study:
- To characterize Cricket paralysis virus (CrPV) purified from Galleria mellonella.
- To investigate the synthesis and processing of viral proteins in infected Drosophila cells.
- To compare CrPV characteristics with mammalian enteroviruses.
Main Methods:
- Purification of CrPV from insect larvae and cell cultures.
- Analysis of viral structural polypeptides using molecular weight determination.
- Buoyant density and capsid diameter measurements.
- Pulse-chase experiments to study protein processing in infected cells.
Main Results:
- CrPV purified from different sources showed similar structural polypeptides (around 30,000 MW).
- Buoyant density was 1.344 g/ml and capsid diameter was 27 nm.
- Twenty virus-induced polypeptides were detected in infected Drosophila cells, with three primary polypeptides at 144,000, 124,000, and 115,000 MW.
- High-molecular-weight polypeptides were rapidly processed into viral proteins, a process atypical for enteroviruses.
- No VP4 polypeptide (8-10,000 MW) was detected in purified virus particles.
Conclusions:
- CrPV exhibits conserved structural properties across different purification methods.
- The rapid processing of viral polypeptides in CrPV-infected cells is a distinctive feature.
- CrPV's unique protein processing mechanism warrants further investigation, especially in comparison to enteroviruses.
