Related Experiment Video
Updated: Jan 14, 2026
06:40
Temporal Analysis of the Nuclear-to-cytoplasmic Translocation of a Herpes Simplex Virus 1 Protein by Immunofluorescent Confocal Microscopy
Published on: November 4, 2018
6.6K
Nuclear transport factor IPO4 modifies localization by PCV2 and facilitates viral replication.
Cui Lin1, Chengcheng Wu1, Fanfan Zhang1
1Institute of Animal Husbandry and Veterinary Medicine, Jiangxi Academy of Agricultural Sciences, Nanchang, Jiangxi 330200, China; Jiangxi Provincial Key Laboratory of Green and Healthy Breeding of Livestock and Poultry, Nanchang, Jiangxi 330200, China.
Veterinary Microbiology
|October 25, 2025
Summary
Porcine circovirus type 2 (PCV2) capsid protein interacts with importin 4 (IPO4), a nuclear transport receptor. This interaction facilitates viral replication by enabling IPO4
Area of Science:
- Virology
- Molecular Biology
- Cell Biology
Background:
- Nuclear transport receptors (NTRs) are essential for cellular processes but are often exploited by viruses.
- Porcine circovirus type 2 (PCV2) relies on host cell machinery for its replication cycle.
Purpose of the Study:
- To investigate the interaction between PCV2 capsid protein (Cap) and nuclear transport receptors.
- To elucidate the role of importin 4 (IPO4) in PCV2 replication.
Main Methods:
- Mass spectrometry
- Co-immunoprecipitation
- Glutathione-S-transferase (GST) pull-down assays
- RNA interference (RNAi) for gene knockdown
Main Results:
- Direct interaction confirmed between PCV2 Cap and importin 4 (IPO4).
- The N-terminal domain (residues 1-100) of Cap is crucial for IPO4 binding.
- PCV2 Cap binding induces IPO4 nuclear translocation without affecting its import function or Cap degradation.
- IPO4 knockdown significantly reduces PCV2 Cap levels and inhibits viral replication.
Conclusions:
- PCV2 Cap interacts with IPO4, mediating its nuclear translocation.
- IPO4 plays a critical role in facilitating PCV2 replication.
- Targeting the Cap-IPO4 interaction could be a strategy against PCV2 infection.
Related Concept Videos
01:45Regulation of Nuclear Protein Sorting
3.2K
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...
3.2K
01:34Nuclear Protein Sorting
6.2K
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...
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...
6.2K
01:46Nuclear Localization Signals and Import
7.6K
Proteins targeted to the nucleus carry short stretches of amino acid sequences called the nuclear localization signal or NLS. Classical nuclear localization signals are of two types: monopartite and bipartite NLS. Monopartite classical NLS (cNLS) consists of a single cluster of 4-8 amino acids. Bipartite cNLS consists of two clusters of 2-3 amino acids and a 9-12 residue long proline-rich linker bridging the two clusters. Signal clusters are rich in positively charged amino acids such as...
7.6K
01:42Directionality of Nuclear Transport
4.5K
Ras-related nuclear protein or Ran is a small G protein that cycles between its GTP and GDP bound states. Ran specific regulators, a Ran GTPase Activating Protein or RanGAP present in the cytosol and a Ran guanine nucleotide exchange factor or RanGEF present inside the nucleus regulate GTP/GDP exchange. A high concentration of GTP inside the cells, in addition to this asymmetric distribution of Ran-specific regulators, leads to a higher RanGTP concentration inside the nucleus. This...
4.5K
02:22Regulated mRNA Transport
6.9K
In eukaryotes, transcription and translation are compartmentalized; an mRNA is first synthesized in the nucleus and then selectively transported to the cytoplasm for protein synthesis. Before transport, a pre-mRNA undergoes several steps of post-transcriptional modifications including splicing, 5' capping, and the addition of a poly-adenine tail. Various proteins bind to the pre-mRNA during these modifications. The mRNA transport takes place with the help of multiple proteins playing...
6.9K
01:42Nuclear Export
4.8K
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...
NES are of three types- the canonical 10-residue long leucine-rich signal and other...
4.8K