Heterologous expression of the modified coat protein of Cowpea chlorotic mottle bromovirus results in the assembly of protein cages with altered architectures and function

• DOI: 10.1099/vir.0.19688-0
• Publication Date: 2004-03-23T19:42:56Z
• Authors: Susan Brumfield; Deborah Willits; Liang Tang; John E. Johnson; Trevor Douglas; Mark Young
• Keywords: Microscopy, Electron; 0303 health sciences; 03 medical and health sciences; Virus Assembly; Mutagenesis, Site-Directed; Capsid Proteins; Bromovirus; Pichia; Recombinant Proteins; 3. Good health

We have developed methods for producing viral-based protein cages in high yield that are amenable to genetic modification. Expression of the structural protein ofCowpea chlorotic mottle bromovirus(CCMV) using the yeast-basedPichia pastorisheterologous expression system resulted in the assembly of particles that were visibly indistinguishable from virus particles produced in the natural host. We have shown that a collection of non-infectious CCMV coat protein mutants expressed in theP. pastorissystem assemble into viral protein cages with altered architectures and function. This provides an alternative to other heterologous expression systems for production of viral structural proteins in which expression has resulted in unassembled cages. Heterologous expression inP. pastorisfurther enhances the development of viral-based protein cages as biotemplates for nanotechnology and for future studies examining details of icosahedral virus assembly.