Alphavirus Particles Can Assemble with an Alternate Triangulation Number
Jason T Kaelber1, David Chmielewski2,3, Wah Chiu2,3,4
1Institute for Quantitative Biomedicine, Rutgers University, Piscataway, NJ 08854, USA.
Viruses
|December 23, 2022
Summary
Researchers discovered a new T=3 icosahedral structure in Eastern equine encephalitis virus (EEEV) particles, revealing an alternate alphavirus assembly. This finding expands our understanding of viral architecture and potential applications.
Area of Science:
- Virology
- Structural Biology
- Molecular Biology
Background:
- Alphaviruses are enveloped RNA viruses transmitted by mosquitoes, causing arthritogenic and neurotropic diseases.
- Alphaviruses exhibit pleomorphism, incorporating structural defects that may be functionally significant.
- Previous studies noted frequent defects in alphavirus particles, unlike typical icosahedral viruses.
Purpose of the Study:
- To investigate the structural diversity and assembly mechanisms of alphaviruses.
- To characterize the alternate architecture of Eastern equine encephalitis virus (EEEV) particles.
- To explore the functional implications of structural variations in alphavirus particles.
Main Methods:
- Analysis of live viral particles to confirm genus-wide pleomorphism.
- Structural characterization of Eastern equine encephalitis virus (EEEV) particles.
- Comparative analysis of T=3 and T=4 icosahedral architectures.
Main Results:
- Confirmed pleomorphism across the alphavirus genus in live viral particles.
- Discovered an alternate T=3 icosahedral architecture for EEEV particles, distinct from the typical T=4 structure.
- Observed looser apposition of fusion spike glycoproteins and altered capsid protein lattice in the T=3 form.
Conclusions:
- Alphavirus assembly allows for alternate architectures, such as the T=3 icosahedral form in EEEV.
- Structural variations in alphaviruses, including the T=3 architecture, may have functional roles.
- The identified alternate architecture offers potential for engineering alphavirus-based delivery systems.
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