Molecular Basis for Recognition and Nuclear Import of Non-classical NLS Cargos

Summary

Principal Investigator: Gino Cingolani
Affiliation: Thomas Jefferson University
Country: USA
Abstract: [unreadable] DESCRIPTION (provided by applicant): Proteins bearing a classical nuclear localization signal (cNLS) are imported into the nucleus of eukaryotic cells by the heterodimer importin a/b (also known as karyopherin a/b). This import pathway, often referred as classical, also requires the small GTPase Ran, which exists mainly bound to GTP in the nucleoplasm and to GDP in the cytoplasm. RanGTP allows movement of the import complex through the Nuclear Pore Complex, by releasing importin b from high affinity binding sites as well as releasing the import cargo into the nucleoplasm. In the past ten years a wealth of cellular, biochemical, and structural data has dramatically increased our understanding of nuclear transport. It has become evident that, in addition to the classical importin a/b- dependent nuclear import pathway, eukaryotic cells have developed a remarkable variety of alternative import pathways. Whereas we do not fully understand the need of such transport "redundancy", alternative import pathways often rely on distinct non-classical transport signals, and use diverse mechanisms of import. In this proposal we intend to investigate the molecular basis for the recognition and nuclear import of three non-classical cargos, which include the adaptor snurportin, HIV-1 Rev protein, and the transcription factor STAT1. Our research is aimed at understanding how non-classical NLSs are recognized by importin a and b and how their nuclear import is regulated, both in terms of energy requirement and kinetic of accumulation in the nucleus. Specific Aims of our work include: 1. Determining the molecular basis for the Ran and energy independent nuclear import of snurportin 2. Carry out a quantitative structural and functional analysis of HIV-1 Rev-NLS 3. Define the molecular basis for the recognition of STAT1 "dinner-specific" NLS by importin a-5. [unreadable] [unreadable] [unreadable]
Funding Period: 2006-04-01 - 2011-03-31
more information: NIH RePORT

Top Publications

  1. doi Molecular basis for the recognition of snurportin 1 by importin beta
    Gregory Mitrousis
    Department of Biochemistry and Molecular Biology, State University of New York SUNY Upstate Medical University, Syracuse, New York 13210, USA
    J Biol Chem 283:7877-84. 2008
  2. pmc Atomic structure of dual-specificity phosphatase 26, a novel p53 phosphatase
    Ravi Kumar Lokareddy
    Department of Biochemistry and Molecular Biology, Thomas Jefferson University, 233 South 10th Street, Philadelphia, Pennsylvania 19107, United States
    Biochemistry 52:938-48. 2013
  3. pmc Nucleoporin Nup50 stabilizes closed conformation of armadillo repeat 10 in importin α5
    Ruth A Pumroy
    Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, USA
    J Biol Chem 287:2022-31. 2012
  4. pmc A minimal nuclear localization signal (NLS) in human phospholipid scramblase 4 that binds only the minor NLS-binding site of importin alpha1
    Kaylen Lott
    Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, USA
    J Biol Chem 286:28160-9. 2011
  5. pmc Dimerization of Vaccinia virus VH1 is essential for dephosphorylation of STAT1 at tyrosine 701
    Adem C Koksal
    Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, USA
    J Biol Chem 286:14373-82. 2011
  6. pmc The importin β binding domain as a master regulator of nucleocytoplasmic transport
    Kaylen Lott
    Department of Biochemistry and Molecular Biology, Thomas Jefferson University, 233 South 10th Street, Philadelphia, PA 19107, USA
    Biochim Biophys Acta 1813:1578-92. 2011
  7. pmc Molecular basis for the recognition of phosphorylated STAT1 by importin alpha5
    Jonathan Nardozzi
    Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, 750 East Adams Street, Syracuse, NY 13210, USA
    J Mol Biol 402:83-100. 2010
  8. ncbi Conformational selection in the recognition of the snurportin importin beta binding domain by importin beta
    Anshul Bhardwaj
    Department of Biochemistry and Molecular Biology, Thomas Jefferson University, 233 South 10th Street, Philadelphia, Pennsylvania 19107, USA
    Biochemistry 49:5042-7. 2010
  9. pmc The importin beta binding domain modulates the avidity of importin beta for the nuclear pore complex
    Kaylen Lott
    Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, USA
    J Biol Chem 285:13769-80. 2010
  10. pmc Dimeric quaternary structure of the prototypical dual specificity phosphatase VH1
    Adem C Koksal
    Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, New York 13210, USA
    J Biol Chem 284:10129-37. 2009

Detail Information

Publications10

  1. doi Molecular basis for the recognition of snurportin 1 by importin beta
    Gregory Mitrousis
    Department of Biochemistry and Molecular Biology, State University of New York SUNY Upstate Medical University, Syracuse, New York 13210, USA
    J Biol Chem 283:7877-84. 2008
    ..We propose that in vivo the synergy of Nup153 and nuclear RanGTP promotes translocation of uridine-rich ribonucleoproteins into the nucleus...
  2. pmc Atomic structure of dual-specificity phosphatase 26, a novel p53 phosphatase
    Ravi Kumar Lokareddy
    Department of Biochemistry and Molecular Biology, Thomas Jefferson University, 233 South 10th Street, Philadelphia, Pennsylvania 19107, United States
    Biochemistry 52:938-48. 2013
    ..The structural characterization of DUSP26 presented in this paper provides the first atomic insight into this disease-associated phosphatase...
  3. pmc Nucleoporin Nup50 stabilizes closed conformation of armadillo repeat 10 in importin α5
    Ruth A Pumroy
    Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, USA
    J Biol Chem 287:2022-31. 2012
    ..This is the first evidence for a nucleoporin modulating the import reaction by directly altering the three-dimensional structure of an import adaptor...
  4. pmc A minimal nuclear localization signal (NLS) in human phospholipid scramblase 4 that binds only the minor NLS-binding site of importin alpha1
    Kaylen Lott
    Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, USA
    J Biol Chem 286:28160-9. 2011
    ..These data provide the first structural and functional evidence of a novel NLS-binding mode in importin α1 that uses only the minor groove as the exclusive site for nuclear import of nonclassical cargos...
  5. pmc Dimerization of Vaccinia virus VH1 is essential for dephosphorylation of STAT1 at tyrosine 701
    Adem C Koksal
    Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, USA
    J Biol Chem 286:14373-82. 2011
    ..We propose that dimerization may represent a common mechanism to regulate the activity and substrate recognition of DSPs, often assumed to function as monomers...
  6. pmc The importin β binding domain as a master regulator of nucleocytoplasmic transport
    Kaylen Lott
    Department of Biochemistry and Molecular Biology, Thomas Jefferson University, 233 South 10th Street, Philadelphia, PA 19107, USA
    Biochim Biophys Acta 1813:1578-92. 2011
    ..This article is part of a Special Issue entitled: Regulation of Signaling and Cellular Fate through Modulation of Nuclear Protein Import...
  7. pmc Molecular basis for the recognition of phosphorylated STAT1 by importin alpha5
    Jonathan Nardozzi
    Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, 750 East Adams Street, Syracuse, NY 13210, USA
    J Mol Biol 402:83-100. 2010
    ....
  8. ncbi Conformational selection in the recognition of the snurportin importin beta binding domain by importin beta
    Anshul Bhardwaj
    Department of Biochemistry and Molecular Biology, Thomas Jefferson University, 233 South 10th Street, Philadelphia, Pennsylvania 19107, USA
    Biochemistry 49:5042-7. 2010
    ..We propose the population selection may be a general mechanism used by beta-karyopherins to recognize transport substrates...
  9. pmc The importin beta binding domain modulates the avidity of importin beta for the nuclear pore complex
    Kaylen Lott
    Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, USA
    J Biol Chem 285:13769-80. 2010
    ..We propose that by controlling the degree of strain in the tertiary structure of importin beta, the IBB domain modulates the affinity of the import complex for nucleoporins, thus dictating its persistence inside the NPC...
  10. pmc Dimeric quaternary structure of the prototypical dual specificity phosphatase VH1
    Adem C Koksal
    Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, New York 13210, USA
    J Biol Chem 284:10129-37. 2009
    ..We propose that the dimeric quaternary structure of VH1 is essential for specific recognition of activated STAT1, which prevents its nuclear translocation, thus blocking interferon-gamma signal transduction and antiviral response...