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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
Structural basis of high-affinity nuclear localization signal interactions with importin-α
Mary Marfori1, Thierry G Lonhienne, Jade K Forwood
1School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, QLD, 4072, Australia.
Traffic (Copenhagen, Denmark)
|January 18, 2012
Summary
Classical nuclear localization signals (cNLSs) bind importin-α. This study reveals how cNLSs achieve high affinity through specific interactions, improving understanding of nuclear import specificity.
Area of Science:
- Molecular Biology
- Structural Biology
- Biochemistry
Background:
- Classical nuclear localization signals (cNLSs) mediate nuclear import by binding importin-α.
- The precise determinants governing cNLS specificity remain incompletely understood.
Purpose of the Study:
- To investigate the structural basis of importin-α binding to high-affinity cNLS-like sequences.
- To elucidate the specificity determinants of cNLSs.
Main Methods:
- Structural and interaction analysis of importin-α with designed and natural cNLS-like peptides.
- Analysis of peptide inhibitors (Bimax1, Bimax2) and cap-binding protein 80 cNLS peptides.
Main Results:
- High-affinity binding is achieved by maximizing interactions at the importin-α minor site and utilizing linker region interactions.
- Identified extended binding cavities on importin-α and confirmed the role of longer linker sequences.
- Demonstrated that long-range electrostatic complementarity contributes to cNLS-binding affinity.
Conclusions:
- The study provides a molecular and structural explanation for observed cNLS binding affinities.
- Offers improved understanding of cNLS specificity determinants.
- Has implications for identifying novel cNLSs in proteins.
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