This research investigates the biological paradox of how viruses produce proteins efficiently despite using genetic codes that are poorly adapted to human host cells. Typically, human cells use mRNA circularization to monitor and slow the translation of sequences with rare, non-optimal codons. The study reveals that viral 5′ untranslated regions (UTRs) actively block this looping process, allowing viral RNA to bypass the host's natural quality control mechanisms. By remaining linear, these viral transcripts achieve high-speed protein synthesis regardless of their codon quality. These findings offer a new explanation for the virulence of pathogens like SARS-CoV-2 and suggest novel strategies for improving vaccine design and antiviral therapies. This discovery identifies mRNA shape as a primary regulator of how genetic instructions are converted into functional proteins.

References:

• Liu H, Liu Y. How viral RNAs escape a host mechanism that controls translation[J]. Mol. Syst. Biol, 2009, 5: 311.