Related Experiment Video

Updated: Jul 28, 2025

Analysis of mRNA Nuclear Export Kinetics in Mammalian Cells by Microinjection
11:32

Analysis of mRNA Nuclear Export Kinetics in Mammalian Cells by Microinjection

Published on: December 4, 2010

15.4K

Nsp14 of SARS-CoV-2 inhibits mRNA processing and nuclear export by targeting the nuclear cap-binding complex

Jun Katahira1, Tatsuya Ohmae1, Mayo Yasugi2

  • 1Laboratory of Cellular Molecular Biology, Graduate School of Veterinary Sciences, Osaka Metropolitan University, 1-58 Rinku-Orai-kita, Izumisano, Osaka 598-8531, Japan.

Nucleic Acids Research
|June 1, 2023
PubMed

Insights

SARS-CoV-2

Area of Science:

  • Virology
  • Molecular Biology
  • Gene Expression Regulation

Background:

  • Viruses disrupt host gene expression for replication.
  • Nuclear export of messenger RNA (mRNA) is a common viral target.
  • Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) inhibits mRNA nuclear export.

Purpose of the Study:

  • Identify novel SARS-CoV-2 inhibitors of mRNA nuclear export.
  • Investigate the mechanism by which SARS-CoV-2 blocks host gene expression.
  • Determine the role of viral protein Nsp14 in mRNA processing and export.

Main Methods:

  • Genome-wide gene expression analysis.
  • Mutation analysis of viral protein Nsp14.
  • Capillary electrophoresis-mass spectrometry (CE-MS) for metabolite detection.
  • Analysis of nuclear cap-binding complex (NCBC) association.

Main Results:

  • Nsp14 identified as a novel inhibitor of mRNA nuclear export.
  • Nsp14 causes nuclear accumulation of poly(A)+ RNA and nuclear speckle disruption.
  • Nsp14 induces global splicing and 3'-end processing defects, particularly in histone mRNAs.
  • Nsp14's guanine-N7-methyltransferase activity produces N7-methyl-GTP, impairing NCBC function.
  • Nsp14 inhibits mRNA cap binding and recruitment of U1 snRNP and SLBP.

Conclusions:

  • SARS-CoV-2 Nsp14 inhibits host mRNA processing and export.
  • Nsp14's N7-methyltransferase activity generates N7-methyl-GTP, compromising NCBC function.
  • This mechanism represents a novel viral strategy to suppress host gene expression.

More Related Videos

Exploring Sequence Space to Identify Binding Sites for Regulatory RNA-Binding Proteins11:34

Exploring Sequence Space to Identify Binding Sites for Regulatory RNA-Binding Proteins

Published on: August 9, 2019

6.7K
In vitro Transcription and Capping of Gaussia Luciferase mRNA Followed by HeLa Cell Transfection08:55

In vitro Transcription and Capping of Gaussia Luciferase mRNA Followed by HeLa Cell Transfection

Published on: March 26, 2012

18.3K

Related Concept Videos

Nuclear Export of mRNA02:31

Nuclear Export of mRNA

Before mRNAs are exported to the cytoplasm, it is crucial to check each mRNA for structural and functional integrity. Eukaryotic cells use several different mechanisms, collectively known as mRNA surveillance, to look for irregularities in mRNAs. Irregular or aberrant mRNA are rapidly degraded by various enzymes. If a defective mRNA escapes the surveillance, it would be translated into a protein which would either be non-functional or not function properly. One of the primary irregularities in...
7.7K
Regulation of Nuclear Protein Sorting01:45

Regulation of Nuclear Protein Sorting

Nuclear protein sorting regulates nucleus composition and gene expression, crucial for determining the fate of a eukaryotic cell. Hence, the entry and exit of molecules across the nuclear envelope is a tightly controlled process. Nuclear protein sorting can be inhibited by one of the following ways: 1) masking cargo signal sequences, 2) modifying the nuclear receptor's affinity for cargo, 3) controlling the nuclear pore size, 4) retaining the cargo during its transit to the cytosol or the...
2.4K
Nuclear Export01:42

Nuclear Export

The nucleus restricts several proteins within and allows others to pass. The restricted proteins possess a nuclear retention sequence or NRS, anchoring them to the nuclear lamins and preventing their transport to the cytosol. The non-restricted proteins, after their synthesis, are transported to their site of action, such as the cytosol or other organelles, with the help of nuclear export signals or NES.
NES are of three types- the canonical 10-residue long leucine-rich signal and other...
3.7K
Nonsense-mediated mRNA Decay02:27

Nonsense-mediated mRNA Decay

The Upf proteins that carry out nonsense-mediated decay (NMD) are found in all eukaryotic organisms, including humans. Each protein has an individual role, but they need to work in collaboration. Upf1 is an ATP-dependent RNA helicase that unwinds the RNA helix. Because Upf1 can unwind any RNA, Upf2 and Upf3 are required to help Upf1 discriminate between nonsense and normal mRNAs.
Usually, Upf3 binds to an Exon Junction Complex (EJC) at mRNA splice sites. If a ribosome fully translates the mRNA,...
10.7K
Chromatin Structure Regulates pre-mRNA Processing02:41

Chromatin Structure Regulates pre-mRNA Processing

In eukaryotic cells, nascent mRNA transcripts need to undergo many post-transcriptional modifications to reach the cell cytoplasm and translate into functional proteins. For a long time, transcription and pre-mRNA processing were considered two independent events that occur sequentially in the cell. However, it has now been well established that transcription and pre-mRNA processing are two simultaneous processes that are precisely regulated inside the cell.
The chromatin structure, especially...
7.1K
Nuclear Protein Sorting01:34

Nuclear Protein Sorting

Nuclear protein sorting is the selective trafficking of histones, polymerases, gene regulatory proteins into the nucleus and exporting RNAs and ribosomes to the cytosol. It is a tightly controlled process that regulates gene expression within a cell.
Proteins targeted to the nucleus carry nuclear localization signals or NLS recognized by import receptors in the cytosol. Similarly, proteins with nuclear export signals are recognized by export receptors. Import and export receptors are...
4.7K