The nucleus is the central organelle of eukaryotic cells. The molecular transport between the nucleus and the cytoplasm is mediated only through the nuclear pore complex (NPC), which perforates the double membraned nuclear envelope that defines the nuclear compartment. Our long-term objective is to obtain real-time information about individual channel-gating and protein-translocation events in the single NPC. The information about the nucleocytoplasmic transport through the nanometer-sized protein machine, which does not presently exist, will facilitate our comprehensive understanding of many biological processes and diseases, and will accelerate future pharmaceutical regulation of gene expression. To achieve the goal, we will establish a novel experimental approach for single channel recording of the NPC by improving spatial and time resolutions of scanning electrochemical microscope (SECM) to nanometer and microsecond ranges. While SECM is a well-established method for non-invasive and quantitative measurements of membrane permeability, improvement of the spatial resolution by nanofabricated SECM probes will enable us to measure the single NPC permeability. Real-time information about the individual channel events can be obtained by monitoring their effects on the single NPC permeability with high time resolution. The time-resolved information will allow us to evaluate the transport models whose validity can not be checked by currently-available experimental data, leading to more comprehensive understanding of this important transport process.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM073439-04
Application #
7676009
Study Section
Enabling Bioanalytical and Biophysical Technologies Study Section (EBT)
Program Officer
Shapiro, Bert I
Project Start
2006-09-25
Project End
2011-08-31
Budget Start
2009-09-01
Budget End
2010-08-31
Support Year
4
Fiscal Year
2009
Total Cost
$259,548
Indirect Cost
Name
University of Pittsburgh
Department
Chemistry
Type
Schools of Arts and Sciences
DUNS #
004514360
City
Pittsburgh
State
PA
Country
United States
Zip Code
15213
Kim, Jiyeon; Izadyar, Anahita; Shen, Mei et al. (2014) Ion permeability of the nuclear pore complex and ion-induced macromolecular permeation as studied by scanning electrochemical and fluorescence microscopy. Anal Chem 86:2090-8
Kim, Jiyeon; Izadyar, Anahita; Nioradze, Nikoloz et al. (2013) Nanoscale mechanism of molecular transport through the nuclear pore complex as studied by scanning electrochemical microscopy. J Am Chem Soc 135:2321-9
Amemiya, Shigeru; Kim, Jiyeon; Izadyar, Anahita et al. (2013) Electrochemical Sensing and Imaging Based on Ion Transfer at Liquid/Liquid Interfaces. Electrochim Acta 110:
Nioradze, Nikoloz; Chen, Ran; Kim, Jiyeon et al. (2013) Origins of nanoscale damage to glass-sealed platinum electrodes with submicrometer and nanometer size. Anal Chem 85:6198-202
Kim, Jiyeon; Shen, Mei; Nioradze, Nikoloz et al. (2012) Stabilizing nanometer scale tip-to-substrate gaps in scanning electrochemical microscopy using an isothermal chamber for thermal drift suppression. Anal Chem 84:3489-92
Shen, Mei; Ishimatsu, Ryoichi; Kim, Jiyeon et al. (2012) Quantitative imaging of ion transport through single nanopores by high-resolution scanning electrochemical microscopy. J Am Chem Soc 134:9856-9
Nioradze, Nikoloz; Kim, Jiyeon; Amemiya, Shigeru (2011) Quasi-steady-state voltammetry of rapid electron transfer reactions at the macroscopic substrate of the scanning electrochemical microscope. Anal Chem 83:828-35
Kim, Jiyeon; Xiong, Hui; Hofmann, Mario et al. (2010) Scanning electrochemical microscopy of individual single-walled carbon nanotubes. Anal Chem 82:1605-7
Ishimatsu, Ryoichi; Kim, Jiyeon; Jing, Ping et al. (2010) Ion-selective permeability of an ultrathin nanoporous silicon membrane as probed by scanning electrochemical microscopy using micropipet-supported ITIES tips. Anal Chem 82:7127-34
Kim, Eunkyoung; Kim, Jiyeon; Amemiya, Shigeru (2009) Spatially resolved detection of a nanometer-scale gap by scanning electrochemical microscopy. Anal Chem 81:4788-91

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