Charge as a selection criterion for translocation through the nuclear pore complex.
Lucy J Colwell1, Michael P Brenner, Katharina Ribbeck
1School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts, United States of America.
Plos Computational Biology
|April 28, 2010
Summary
Nuclear pore complexes (NPCs) act as selective filters. Our study reveals that negatively charged transport receptors efficiently pass through NPCs due to favorable electrostatic interactions with the NPC
Area of Science:
- Cellular biology
- Molecular mechanisms of transport
- Biophysics of molecular interactions
Background:
- Nuclear pore complexes (NPCs) regulate molecular traffic between the nucleus and cytoplasm.
- The precise principles governing NPC selectivity remain incompletely understood.
- Previous research linked rapid NPC translocation to protein hydrophobicity.
Purpose of the Study:
- To investigate the role of charge in selective nuclear transport.
- To determine if electrostatic interactions influence the translocation rate of transport receptors through NPCs.
- To elucidate the criteria for selective passage via NPCs.
Main Methods:
- Analysis of surface properties of transport receptors and NPC components.
- Estimation of electrostatic interaction energy between transport receptors and the NPC.
- Comparison of translocation rates based on charge and hydrophobicity.
Main Results:
- Transport receptors and their complexes exhibit significant negative surface charge.
- NPC components forming the permeability barrier are positively charged.
- Electrostatic interactions provide a substantial energy gain (several k(B)T) for transport receptors.
- This energy gain facilitates faster translocation compared to other proteins.
Conclusions:
- Negative surface charge is a key factor for selective translocation through NPCs.
- Electrostatic interactions significantly enhance the transport rate of specific molecules.
- Charge, in conjunction with hydrophobicity, dictates selective nuclear transport.
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