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Analysis of Group IV Viral SSHHPS Using In Vitro and In Silico Methods
Published on: December 21, 2019
Cell entry-associated conformational changes in reovirus particles are controlled by host protease activity
Jillann A Madren1, Payel Sarkar, Pranav Danthi
1Department of Biology, Indiana University, Bloomington, Indiana, USA. pdanthi@indiana.edu
Journal of Virology
|January 27, 2012
Summary
Reovirus cell entry involves intermediates like infectious subvirion particles (ISVPs) and ISVP*s. Low chymotrypsin (CHT) concentrations lead to core formation via ISVP*-like particles, distinct from ISVPs.
Area of Science:
- Virology
- Molecular Biology
- Cell Biology
Background:
- Reovirus cell entry requires sequential formation of infectious subvirion particles (ISVPs) and ISVP*s.
- Outer capsid proteolysis by chymotrypsin (CHT) generates these intermediates.
Purpose of the Study:
- Investigate the inverse relationship between CHT concentration and reovirus outer capsid protease susceptibility.
- Clarify the mechanism of core formation under low CHT conditions.
Main Methods:
- In vitro digestion of reovirus virions with varying chymotrypsin concentrations.
- Biochemical analysis of viral particle intermediates.
- Assessment of viral genetic requirements for particle formation.
Main Results:
- Low CHT concentration digestion forms particles with protease-sensitive μ1C protein, characteristic of ISVP*s.
- ISVP* formation and low CHT-induced core formation share biochemical features and genetic requirements.
- Intermediates from low CHT digestion are distinct from ISVPs and readily convert to ISVP*-like particles.
Conclusions:
- Reovirus core formation under low CHT conditions proceeds through an ISVP*-like particle intermediate.
- Host protease activity influencing ISVP formation can impact the subsequent ISVP-to-ISVP* conversion step in reovirus cell entry.
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