Related Experiment Video
Updated: Oct 2, 2025
08:58
In Vitro Transcribed RNA-based Luciferase Reporter Assay to Study Translation Regulation in Poxvirus-infected Cells
Published on: May 1, 2019
15.2K
Modulation of mRNA 3'-End Processing and Transcription Termination in Virus-Infected Cells
Aarthi Vijayakumar1, Annsea Park2, Joan A Steitz1
1Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, United States.
Frontiers in Immunology
|February 28, 2022
Summary
Viruses disrupt eukaryotic mRNA 3´-end processing, affecting gene expression and host antiviral responses. This viral interference leads to altered transcript levels and host shutoff, impacting cellular machinery.
Area of Science:
- Molecular Biology
- Virology
- Gene Expression Regulation
Background:
- Eukaryotic mRNA 3´-end processing involves pre-mRNA cleavage and polyadenylation, crucial for gene expression.
- Disruption of this process affects mature mRNA levels and is implicated in viral infections.
- Viral proteins can interfere with 3´-end processing machinery, leading to altered transcript levels and host shutoff.
Purpose of the Study:
- To investigate the role of viral interference with eukaryotic mRNA 3´-end processing.
- To understand how viruses modulate host gene expression and antiviral responses through 3´-end processing disruption.
- To explore the mechanisms by which viruses utilize read-through transcripts.
Main Methods:
- Analysis of viral protein interactions with host 3´-end processing factors.
- Quantification of mature mRNA levels and read-through transcripts in infected cells.
- Assessment of host shutoff and antiviral response suppression.
Main Results:
- Viral proteins inhibit pre-mRNA cleavage and polyadenylation, causing read-through transcription.
- Disrupted 3´-end processing leads to decreased mature mRNA levels and suppressed antiviral responses.
- Read-through transcripts exhibit decreased polyadenylation, nuclear retention, and reduced translation.
Conclusions:
- Viral modulation of host 3´-end processing is a key mechanism for viral pathogenesis and host immune evasion.
- Viruses exploit read-through transcripts to manipulate host protein production and cellular functions.
- Understanding these viral strategies is crucial for developing antiviral therapies.
Related Concept Videos
01:23Regulation of Expression at Multiple Steps
1.1K
The gene expression in cells is regulated at different stages: (i) transcription, (ii) RNA processing, (iii) RNA localization, and (iv) translation. Transcriptional regulation is mediated by regulatory proteins such as transcription factors, activators, or repressors—these control gene expression by initiating or inhibiting the transcription of genes. Once a precursor or pre-mRNA is produced, it undergoes post-transcriptional modification, including 5' capping, splicing, and the...
1.1K
02:28Leaky Scanning
5.3K
During most eukaryotic translation processes, the small 40S ribosome subunit scans an mRNA from its 5' end until it encounters the first start AUG codon. The large 60S ribosomal subunit then joins the smaller one to initiate protein synthesis. The location of the translation initiation is largely determined by the nucleotides near the start codon as there may be multiple translation initiation sites present on the mRNA. Marilyn Kozak discovered that the sequence RCCAUGG (where R...
5.3K
01:29Viruses with RNA Genomes
187
RNA viruses are categorized into positive-strand, negative-strand, or double-stranded groups based on their genomic structure and replication mechanisms. This classification dictates how they exploit host cellular machinery for protein synthesis and replication. Some RNA viruses also utilize reverse transcription as part of their life cycle, further diversifying their replication strategies.Positive-Strand RNA VirusesPositive-strand RNA viruses have genomes that function directly as messenger...
187
01:35Pre-mRNA Processing: Modification of pre-mRNA Ends
10.7K
In eukaryotic cells, transcripts made by RNA polymerase are modified and processed before exiting the nucleus. Unprocessed RNA is called precursor mRNA or pre-mRNA to distinguish it from mature mRNA.
Once about 20-40 ribonucleotides have been joined together by RNA polymerase, a group of enzymes adds a cap to the 5' end of the growing transcript. In this process, a 5' phosphate is replaced by modified guanosine that has a methyl group attached (7-methyl guanosine). This 5' cap helps...
Once about 20-40 ribonucleotides have been joined together by RNA polymerase, a group of enzymes adds a cap to the 5' end of the growing transcript. In this process, a 5' phosphate is replaced by modified guanosine that has a methyl group attached (7-methyl guanosine). This 5' cap helps...
10.7K
02:30siRNA - Small Interfering RNAs
17.1K
Small interfering RNAs, or siRNAs, are short regulatory RNA molecules that can silence genes post-transcriptionally, as well as the transcriptional level in some cases. siRNAs are important for protecting cells against viral infections and silencing transposable genetic elements.
In the cytoplasm, siRNA is processed from a double-stranded RNA, which comes from either endogenous DNA transcription or exogenous sources like a virus. This double-stranded RNA is then cleaved by the...
In the cytoplasm, siRNA is processed from a double-stranded RNA, which comes from either endogenous DNA transcription or exogenous sources like a virus. This double-stranded RNA is then cleaved by the...
17.1K
02:24Regulation of Expression Occurs at Multiple Steps
23.6K
Gene expression can be regulated at almost every step from gene to protein. Transcription is the step that is most commonly regulated. This involves the binding of proteins to short regulatory sequences on the DNA. This association can either promote or inhibit the transcription of a gene associated with the respective sequence.
Transcription results in the generation of precursor (pre-mRNA) that consists of both exons and introns, which needs further processing before being translated to a...
Transcription results in the generation of precursor (pre-mRNA) that consists of both exons and introns, which needs further processing before being translated to a...
23.6K