Poxvirus-encoded decapping enzymes promote selective translation of viral mRNAs

Autor: Zhilong Yang, Shuai Cao, Candy Hernandez, Joshua Spradlin, Pragyesh Dhungel, Fernando Cantu
Rok vydání: 2020
Předmět:
viruses
Gene Expression
Virus Replication
Pathology and Laboratory Medicine
Biochemistry
chemistry.chemical_compound
Gene expression
Medicine and Health Sciences
Biology (General)
0303 health sciences
Chemistry
Messenger RNA
030302 biochemistry & molecular biology
virus diseases
Translation (biology)
Poxviruses
Cell biology
Enzymes
Nucleic acids
Medical Microbiology
Viral Pathogens
Viruses
293T cells
RNA
Viral
Cell lines
Pathogens
Cellular Structures and Organelles
Oxidoreductases
Biological cultures
Luciferase
Research Article
DNA Replication
RNA Caps
QH301-705.5
RNase P
Immunology
Vaccinia virus
Transfection
Research and Analysis Methods
Microbiology
Cell Line
03 medical and health sciences
Viral Proteins
Virology
Genetics
Humans
Molecular Biology Techniques
Microbial Pathogens
Molecular Biology
030304 developmental biology
Biology and life sciences
Poxviridae
Wild type
Organisms
RNA
Proteins
Cell Biology
RC581-607
Protein kinase R
Polyribosomes
DNA
Viral
Enzymology
Parasitology
Protein Translation
Immunologic diseases. Allergy
DNA viruses
Ribosomes
DNA
Zdroj: PLoS Pathogens
PLoS Pathogens, Vol 16, Iss 10, p e1008926 (2020)
ISSN: 1553-7374
Popis: Cellular decapping enzymes negatively regulate gene expression by removing the methylguanosine cap at the 5’ end of eukaryotic mRNA, rendering mRNA susceptible to degradation and repressing mRNA translation. Vaccinia virus (VACV), the prototype poxvirus, encodes two decapping enzymes, D9 and D10, that induce the degradation of both cellular and viral mRNAs. Using a genome-wide survey of translation efficiency, we analyzed vaccinia virus mRNAs in cells infected with wild type VACV and mutant VACVs with inactivated decapping enzymes. We found that VACV decapping enzymes are required for selective translation of viral post-replicative mRNAs (transcribed after viral DNA replication) independent of PKR- and RNase L-mediated translation repression. Further molecular characterization demonstrated that VACV decapping enzymes are necessary for efficient translation of mRNA with a 5'-poly(A) leader, which are present in all viral post-replicative mRNAs. Inactivation of D10 alone in VACV significantly impairs poly(A)-leader-mediated translation. Remarkably, D10 stimulates mRNA translation in the absence of VACV infection with a preference for RNA containing a 5’-poly(A) leader. We further revealed that VACV decapping enzymes are needed for 5’-poly(A) leader-mediated cap-independent translation enhancement during infection. Our findings identified a mechanism by which VACV mRNAs are selectively translated through subverting viral decapping enzymes to stimulate 5’-poly(A) leader-mediated translation.
Author summary Decapping enzymes are encoded in eukaryotic cells and some viruses. Previous studies indicated that decapping enzymes are negative gene expression regulators by accelerating mRNA degradation and repressing translation. Surprisingly however, in this study we found that vaccinia virus (VACV) encoded-decapping enzymes, D9 and D10, are required to promote selective synthesis of viral proteins, although they are known to promote both cellular and viral mRNA degradation. We further showed that the unusual 5'-UTR of VACV mRNA, the 5'-poly(A) leader, confers an advantage to mRNA translation promoted by the decapping enzymes during vaccinia virus infection. Moreover, D9 and D10 are necessary for stimulating poly(A)-leader-mediated cap-independent translation enhancement during VACV infection. In the absence of VACV infection, D10 alone stimulates mRNA translation in a decapping activity-dependent manner, with a preference for mRNA that contains a poly(A) leader. The stimulation of mRNA translation by D10 is unique among decapping enzymes. Therefore, we identified a new mechanism to selectively synthesize VACV proteins through a coordination of viral mRNA 5’-UTR and virus-encoded decapping enzymes.
Databáze: OpenAIRE
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