Related Experiment Video
Updated: Jul 28, 2025
09:13
Using Reverse Genetics to Manipulate the NSs Gene of the Rift Valley Fever Virus MP-12 Strain to Improve Vaccine Safety and Efficacy
Published on: November 1, 2011
17.5K
Mutations in the non-structural protein coding region regulate gene expression from replicon RNAs derived from
Guibin Lin1,2,3,4, Yuan Zhang5,6,7,8
1School of Biomedical Sciences and Engineering, South China University of Technology, Guangzhou International Campus, Guangzhou, 511442, Guangdong, China.
Biotechnology Letters
|June 2, 2023
Summary
Mutant Venezuelan equine encephalitis virus (VEE) replicons with specific nsP1-4 mutations enhance gene expression by reducing innate immune responses. These modified VEE repRNA vectors show promise for advanced gene therapies.
Area of Science:
- Molecular Biology
- Virology
- Gene Therapy
Background:
- Self-replicating RNA (repRNA) from Venezuelan equine encephalitis (VEE) virus offers prolonged gene expression for gene therapy.
- However, VEE repRNA exhibits suboptimal transgene expression due to innate immune responses that inhibit translation.
Purpose of the Study:
- To enhance transgene expression of VEE repRNA vectors.
- To achieve this, point mutations were introduced into the non-structural protein 1-4 (nsP1-4) coding region of VEE replicons.
Main Methods:
- Engineered VEE replicons with mutations in the nsP1-4 region.
- Inflammatory cytokines were used as genes of interest and cloned into wild-type and mutant replicon vectors.
- Transfection of mammalian cells was performed to evaluate vector performance.
Main Results:
- VEE replicons with nsP1GGAC-nsP2T or nsP1GGAC-nsP2AT mutations significantly reduced type I interferon production, indicating decreased innate immune recognition.
- These mutant vectors demonstrated enhanced transgene expression in host cells compared to wild-type VEE replicons.
Conclusions:
- Mutant VEE replicon vectors with specific nsP1-4 modifications effectively reduce innate immune sensing.
- These improved VEE-derived repRNA vectors represent promising platforms for advancing VEE repRNA-based gene therapies.
Related Concept Videos
02:28Leaky Scanning
5.2K
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...
5.2K
01:29Viruses with RNA Genomes
60
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...
60
00:36Viral Mutations
32.6K
A mutation is a change in the sequence of bases of DNA or RNA in a genome. Some mutations occur during replication of the genome due to errors made by the polymerase enzymes that replicate DNA or RNA. Unlike DNA polymerase, RNA polymerase is prone to errors because it is not capable of “proofreading” its work. Viruses with RNA-based genomes, like HIV, therefore accrue mutations faster than viruses with DNA-based genomes. Because mutation and recombination provide the raw material...
32.6K
01:36What is Gene Expression?
8.6K
A gene is a stretch of DNA that serves as the blueprint for functional RNAs and proteins. Since DNA is comprised of nucleotides and proteins are comprised of amino acids, a mediator is required to convert the information encoded in DNA into proteins. This mediator is the messenger RNA (mRNA). mRNA copies the blueprint from DNA by a process called transcription. In eukaryotes, transcription occurs in the nucleus by complementary base-pairing with the DNA template. The mRNA is then...
8.6K
01:32RNA Splicing
56.5K
Splicing is the process by which eukaryotic RNA is edited before its translation into protein. The RNA strand transcribed from eukaryotic DNA is called the primary transcript. The primary transcripts that become mRNAs are called precursor messenger RNAs (pre-mRNAs). Eukaryotic pre-mRNA contains alternating sequences of exons and introns. Exons are nucleotide sequences that code for proteins, whereas introns are the non-coding regions. In RNA splicing, introns are removed and exons are bonded...
56.5K
01:23Regulation of Expression at Multiple Steps
954
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...
954