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Visualization of Protein-protein Interaction in Nuclear and Cytoplasmic Fractions by Co-immunoprecipitation and In Situ Proximity Ligation Assay
Published on: January 16, 2017
Ran-binding protein 3 is a cofactor for Crm1-mediated nuclear protein export
M E Lindsay1, J M Holaska, K Welch
1Center for Cell Signaling, University of Virginia School of Medicine, Charlottesville, Virginia 22098, USA. mel3f@virginia.edu
The Journal of Cell Biology
|June 27, 2001
Summary
Ran-binding protein 3 (RanBP3) acts as a cofactor for Crm1-mediated nuclear export. This protein enhances the Crm1-Ran:GTP-cargo complex, facilitating nuclear transport and cellular function.
Area of Science:
- Cell Biology
- Molecular Biology
- Biochemistry
Background:
- Crm1 (chromosome region maintenance 1) is a key nuclear export receptor.
- It mediates the transport of proteins out of the nucleus by forming complexes with cargo and Ran-GTP.
- The precise role of its interacting partners, like yeast Yrb2p, remains unclear.
Purpose of the Study:
- To elucidate the function of the human orthologue of Yrb2p, Ran-binding protein 3 (RanBP3).
- To investigate RanBP3's role as a cofactor in Crm1-mediated nuclear export.
- To characterize the interaction between RanBP3, Crm1, and cargo.
Main Methods:
- Utilized a permeabilized cell assay to study Crm1-mediated export.
- Investigated direct binding between RanBP3 and Crm1.
- Analyzed the effect of RanBP3 on the affinity of the Crm1 complex for Ran:GTP and cargo.
- Tracked RanBP3's subcellular localization and interaction with nucleoporins.
Main Results:
- RanBP3 functions as a cofactor for Crm1-mediated nuclear export.
- RanBP3 binds directly to Crm1, enhancing its affinity for Ran:GTP and cargo.
- The Crm1-RanBP3 complex efficiently associates with nucleoporins.
- RanBP3 shuttles between the nucleus and cytoplasm via a Crm1-dependent pathway.
Conclusions:
- RanBP3 is a crucial cofactor that enhances Crm1-mediated nuclear export.
- The Crm1-RanBP3 complex facilitates nuclear pore translocation.
- RanBP3 plays a vital role in regulating nucleocytoplasmic transport pathways.
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