Alphavirus Particles Can Assemble with an Alternate Triangulation Number.
Jason T Kaelber, David Chmielewski, Wah Chiu, Albert J Auguste
Author Information
Jason T Kaelber: Institute for Quantitative Biomedicine, Rutgers University, Piscataway, NJ 08854, USA. ORCID
David Chmielewski: Biophysics Graduate Program, Department of Bioengineering, Stanford University, Stanford, CA 94305, USA.
Wah Chiu: Biophysics Graduate Program, Department of Bioengineering, Stanford University, Stanford, CA 94305, USA.
Albert J Auguste: Department of Entomology, College of Agriculture and Life Sciences, Fralin Life Science Institute, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA. ORCID
Alphaviruses are spherical, enveloped RNA viruses primarily transmitted by mosquitoes, and cause significant arthritogenic and neurotropic disease in humans and livestock. Previous reports have shown that-in contrast to prototypical icosahedral viruses-alphaviruses incorporate frequent defects, and these may serve important functions in the viral life cycle. We confirm the genus-wide pleomorphism in live viral particles and extend our understanding of alphavirus assembly through the discovery of an alternate architecture of Eastern equine encephalitis virus (EEEV) particles. The alternate = 3 icosahedral architecture differs in triangulation number from the classic = 4 icosahedral organization that typifies alphaviruses, but the alternate architecture maintains the quasi-equivalence relationship of asymmetric units. The fusion spike glycoproteins are more loosely apposed in the = 3 form with corresponding changes in the underlying capsid protein lattice. This alternate architecture could potentially be exploited in engineering alphavirus-based particles for delivery of alphaviral or other RNA.
