Chapter 8: RNA processing Flashcards
What is the purpose of adding a modified nucleotide to the 5′ end of an mRNA, known as “capping”
Ensures efficient translation, protects the mRNA from exonucleases, and prevents activation of antiviral responses
How does the addition of poly(A) to the 3′ end of an mRNA impact
Enhances translation and mRNA stability.
Who mediates viral mRNA splicing?
Mediated by host cell components.
How do alternative splicing and editing of viral pre-mRNAs contribute to viral gene expression?
Expand coding capacity and can regulate viral gene expression
What mediates the export of viral mRNAs, and how does it compare to the export of cellular RNAs?
Mediated by the host cell machinery; in most cases, it is indistinguishable from the export of analogous cellular RNAs.
Why is the production of unspliced or partially spliced mRNAs necessary for some viruses?
Reproduction of some viruses requires it; viral sequences or virus-encoded proteins allow the nuclear export of these molecules.
What role do viral proteins encoded in the genomes of some viruses play in RNA-processing reactions
They regulate one or more RNA-processing reactions; important for temporal regulation of viral gene expression or inhibition of the production of cellular mRNAs.
How can cellular micro-RNAs and long noncoding RNAs affect the reproduction of viruses?
They may inhibit or facilitate the reproduction of a variety of viruses.
