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The poliovirus 135S particle is infectious
1Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115, USA.
Journal of Virology
|October 1, 1996
Summary
Poliovirus converts to a 135S particle that can infect cells independently of receptors. The N terminus of VP1 is crucial for this viral entry mechanism.
Area of Science:
- Virology
- Molecular Biology
- Cell Biology
Background:
- The cell entry mechanism of unenveloped viruses, like poliovirus, remains incompletely understood.
- Picornaviruses, including poliovirus, transform into a 135S particle upon receptor interaction at 37°C, a step considered essential for infection.
Purpose of the Study:
- To investigate the precise role of the 135S particle in poliovirus cell entry.
- To determine the receptor-dependence and protein requirements of 135S particle infectivity.
Main Methods:
- Infecting receptor-lacking Chinese hamster ovary (CHO) and murine L cells with poliovirus 135S particles.
- Assessing 135S particle infectivity using RNase and proteolytic treatments.
- Analyzing the effect of proteolysis on the N terminus of viral protein 1 (VP1).
Main Results:
- Poliovirus 135S particles infected CHO and murine L cells, indicating receptor-independent entry.
- 135S particle infectivity was resistant to RNase but significantly reduced by proteolysis.
- Proteolytic treatment removed the N terminus of VP1, a region involved in lipid membrane interactions.
Conclusions:
- The 135S particle can mediate poliovirus entry independently of cellular receptors.
- Viral protein VP1's N terminus is critical for the infectivity of the 135S particle.
- Findings support the 135S particle's role as an intermediate in poliovirus cell entry.