Related Experiment Video
Updated: Aug 11, 2026
12:13
Single-Molecule Imaging of Nuclear Transport
Published on: June 10, 2010
Virtual gating and nuclear transport: the hole picture
Michael P Rout1, John D Aitchison, Marcelo O Magnasco
1The Rockefeller University, New York, NY 10021, USA. rout@rockefeller.edu
Trends in Cell Biology
|November 20, 2003
Summary
Nuclear pore complexes (NPCs) control transport between the nucleus and cytoplasm. We propose a
Area of Science:
- Cell Biology
- Molecular Biology
- Biophysics
Background:
- The eukaryotic nucleus is enclosed by a nuclear envelope.
- Nuclear pore complexes (NPCs) are essential channels within the nuclear envelope.
- NPCs regulate the passage of molecules between the nucleus and cytoplasm.
Purpose of the Study:
- To elucidate the mechanism of selective macromolecular trafficking through NPCs.
- To propose a novel model explaining NPC transport dynamics.
- To understand how NPCs differentiate between small molecules and large macromolecules.
Main Methods:
- The abstract does not specify methods, focusing on a proposed model.
- Theoretical modeling of molecular transport.
- Analysis of NPC structure and function.
Main Results:
- Small molecules traverse NPCs without hindrance.
- Large macromolecules require transport factors for nuclear-cytoplasmic exchange.
- A 'virtual gating' model is proposed to explain selective macromolecular trafficking.
Conclusions:
- The 'virtual gating' model provides a framework for understanding NPC selectivity.
- This model explains the rapid and selective transport of macromolecules.
- Further research is needed to experimentally validate the 'virtual gating' mechanism.
Related Concept Videos
01:34Nuclear 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...
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...
01:42Nuclear 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...
NES are of three types- the canonical 10-residue long leucine-rich signal and other...
01:42Directionality of Nuclear Transport
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...
01:45Regulation 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...
01:24Non-gated Ion Channels
Ion channels are specialized proteins on the plasma membrane that allow charged ions to pass down their electrochemical gradient. Their main function is to maintain the membrane potential which is critical for cell viability. These channels are either gated or non-gated and can transport more than a thousand ions within milliseconds for the cellular event to occur.
Compared to the gated ion channels, the non-gated channels, also known as leakage or passive channels, have no gating mechanism.
Compared to the gated ion channels, the non-gated channels, also known as leakage or passive channels, have no gating mechanism.
01:24Non-gated Ion Channels
Ion channels are specialized proteins on the plasma membrane that allow charged ions to pass down their electrochemical gradient. Their main function is to maintain the membrane potential which is critical for cell viability. These channels are either gated or non-gated and can transport more than a thousand ions within milliseconds for the cellular event to occur.
Compared to the gated ion channels, the non-gated channels, also known as leakage or passive channels, have no gating mechanism.
Compared to the gated ion channels, the non-gated channels, also known as leakage or passive channels, have no gating mechanism.