RT Journal Article
SR Electronic
T1 Reduced protein expression in a virus attenuated by codon deoptimization
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 106799
DO 10.1101/106799
A1 Benjamin R. Jack
A1 Daniel R. Boutz
A1 Matthew L. Paff
A1 Bartram L. Smith
A1 James J. Bull
A1 Claus O. Wilke
YR 2017
UL http://biorxiv.org/content/early/2017/02/07/106799.abstract
AB The engineering of hundreds of synonymous codon changes into a viral genome appears to provide a general means of achieving attenuation. The mechanistic underpinnings of this approach remain enignmatic, however. Using quantitative proteomics and RNA sequencing, we explore the molecular basis of attenuation in a strain of bacteriophage T7 whose major capsid gene was engineered to carry 182 suboptimal codons. As expected, there was no evident effect of the recoding on transcription. Proteomic observations revealed that translation is halved for the recoded major capsid gene, and a smaller reduction applies to a few genes downstream, potentially caused by translational coupling. Viral burst size is also approximately halved, and the fitness drop accompanying attenuation is compatible with the reduced burst size. Overall, the fitness effect and molecular basis of attenuation by codon deoptimization are compatible with a relatively simple model of reduced translation of a few genes and a consequent diminished virion assembly. This mechanism is simpler than that operating in eukaryotic viruses.