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Differential inhibition of host cell RNA synthesis in several picornavirus-infected cell lines
Abstract:
Patterns of cellular RNA synthesis during poliovirus (types 1,2 and 3) and mengovirus infections in HeLa, HEp-2, Vero and L-cells were investigated by means of high-resolution autoradiography, kinetics of 3H-uridine incorporation, and sucrose gradient centrifugation. Only mengovirus-infected L-cells showed an early and exponential inhibition of hnRNA and rRNA synthesis. The other cell lines tested, whether infected with polio- or mengovirus, exhibited a slowly and linearly decreasing cellular RNA synthesis, with hnRNA production suppressed completely, although somewhat later than in L-cells, and rRNA synthesis continuing at a gradually reduced rate during the entire viral growth cycle. Locations of cleavage steps of rRNA precursor molecules are discussed.
Insights
Poliovirus and mengovirus infections differentially affect cellular RNA synthesis. While mengovirus rapidly inhibits RNA synthesis in L-cells, other cell types show a slower decline, with complete suppression of hnRNA and reduced rRNA synthesis.
Area of Science:
- Virology
- Molecular Biology
- Cell Biology
Background:
- Poliovirus and mengovirus are RNA viruses that infect mammalian cells.
- Cellular RNA synthesis is crucial for cell function and viral replication.
Purpose of the Study:
- To investigate the impact of poliovirus and mengovirus infections on cellular RNA synthesis patterns.
- To compare the effects of different viruses and cell lines on RNA synthesis kinetics and inhibition.
Main Methods:
- High-resolution autoradiography
- Kinetics of 3H-uridine incorporation
- Sucrose gradient centrifugation
Main Results:
- Mengovirus infection in L-cells caused early, exponential inhibition of heterogeneous nuclear RNA (hnRNA) and ribosomal RNA (rRNA) synthesis.
- Infection with poliovirus or mengovirus in HeLa, HEp-2, and Vero cells resulted in a slow, linear decrease in total cellular RNA synthesis.
- hnRNA production was completely suppressed in these cell lines, while rRNA synthesis gradually decreased throughout the viral growth cycle.
Conclusions:
- Viral infections exhibit distinct patterns of cellular RNA synthesis inhibition depending on the virus and host cell type.
- hnRNA synthesis is a primary target for suppression by these viruses.
- Further investigation into the cleavage sites of rRNA precursor molecules during viral infections is warranted.