4B18

The crystal structure of human Importin alpha 5 with TERT NLS peptide

Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.52 Å
  • R-Value Free: 0.253 
  • R-Value Work: 0.198 
  • R-Value Observed: 0.201 

wwPDB Validation   3D Report Full Report


This is version 1.4 of the entry. See complete history. 


Literature

Akt-Mediated Phosphorylation Increases the Binding Affinity of Htert for Importin Alpha to Promote Nuclear Translocation.

Jeong, S.A., Kim, K., Lee, J.H., Cha, J.S., Khadka, P., Cho, H., Chung, I.K.

(2015) J Cell Sci 128: 2287

  • DOI: 10.1242/jcs.166132
  • Primary Citation of Related Structures:  
    4B18

  • PubMed Abstract: 

    • Telomeres are essential for chromosome integrity and protection, and their maintenance requires the ribonucleoprotein enzyme telomerase. Previously, we have shown that human telomerase reverse transcriptase (hTERT) contains a bipartite nuclear localization signal (NLS; residues 222-240) that is responsible for nuclear import, and that Akt-mediated phosphorylation of residue S227 is important for efficient nuclear import of hTERT ...

    Telomeres are essential for chromosome integrity and protection, and their maintenance requires the ribonucleoprotein enzyme telomerase. Previously, we have shown that human telomerase reverse transcriptase (hTERT) contains a bipartite nuclear localization signal (NLS; residues 222-240) that is responsible for nuclear import, and that Akt-mediated phosphorylation of residue S227 is important for efficient nuclear import of hTERT. Here, we show that hTERT binds to importin-α proteins through the bipartite NLS and that this heterodimer then forms a complex with importin-β proteins to interact with the nuclear pore complex. Depletion of individual importin-α proteins results in a failure of hTERT nuclear import, and the resulting cytoplasmic hTERT is degraded by ubiquitin-dependent proteolysis. Crystallographic analysis reveals that the bipartite NLS interacts with both the major and minor sites of importin-α proteins. We also show that Akt-mediated phosphorylation of S227 increases the binding affinity for importin-α proteins and promotes nuclear import of hTERT, thereby resulting in increased telomerase activity. These data provide details of a binding mechanism that enables hTERT to interact with the nuclear import receptors and of the control of the dynamic nuclear transport of hTERT through phosphorylation.

    Organizational Affiliation: 

    Department of Integrated Omics for Biomedical Science, Yonsei University, Seoul 120-749, Korea Department of Systems Biology, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749, Korea hscho8@yonsei.ac.kr topoviro@yonsei.ac.kr.



Macromolecules
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(by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
IMPORTIN SUBUNIT ALPHA-1A447Homo sapiensMutation(s): 0 
Gene Names: KPNA1, RCH2
Find proteins for P52294 (Homo sapiens)
Explore P52294 
Go to UniProtKB:  P52294
NIH Common Fund Data Resources
PHAROS:  P52294
GTEx:  ENSG00000114030
Protein Feature View
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  • Reference Sequence
  • Find similar proteins by:  Sequence   |   Structure
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetailsImage
TELOMERASE REVERSE TRANSCRIPTASEB20Homo sapiensMutation(s): 0 
Gene Names: TERT, EST2, TCS1, TRT
EC: 2.7.7.49
Find proteins for O14746 (Homo sapiens)
Explore O14746 
Go to UniProtKB:  O14746
NIH Common Fund Data Resources
PHAROS:  O14746
GTEx:  ENSG00000164362
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.52 Å
  • R-Value Free: 0.253 
  • R-Value Work: 0.198 
  • R-Value Observed: 0.201 
  • Space Group: C 1 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 159.723α = 90
b = 59.916β = 96.29
c = 69.331γ = 90
Software Package:
Software NamePurpose
REFMACrefinement
HKL-2000data reduction
SCALEPACKdata scaling
MOLREPphasing

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2013-09-04
    Type: Initial release
  • Version 1.1: 2015-04-22
    Changes: Database references
  • Version 1.2: 2015-04-29
    Changes: Derived calculations, Source and taxonomy
  • Version 1.3: 2015-06-24
    Changes: Database references
  • Version 1.4: 2015-07-01
    Changes: Database references