Published online 7 June 2005
Article |
Analysis of nuclear transport signals in the human apurinic/apyrimidinic endonuclease (APE1/Ref1)
Department of Human Biological Chemistry & Genetics, Sealy Center for Molecular Science, University of Texas Medical Branch Galveston, TX 77551-1079, USA 1Department of Otorhinolaryngology, Stanely S. Scott Cancer Center, Louisiana State University Health Sciences Center 533 Bolivar, New Orleans, LA 70112, USA
*To whom correspondence should be addressed. Tel: +1 504 568 4785; Fax: +1 504 568 4460; Email: tizumi{at}lsuhsc.edu
Received April 19, 2005. Revised May 19, 2005. Accepted May 19, 2005.
The mammalian abasic-endonuclease1/redox-factor1 (APE1/Ref1) is an essential protein whose subcellular distribution depends on the cellular physiological status. However, its nuclear localization signals have not been studied in detail. We examined nuclear translocation of APE1, by monitoring enhanced green fluorescent protein (EGFP) fused to APE1. APE1's nuclear localization was significantly decreased by deleting 20 amino acid residues from its N-terminus. Fusion of APE1's N-terminal 20 residues directed nuclear localization of EGFP. An APE1 mutant lacking the seven N-terminal residues (ND7 APE1) showed nearly normal nuclear localization, which was drastically reduced when the deletion was combined with the E12A/D13A double mutation. On the other hand, nearly normal nuclear localization of the full-length E12A/D13A mutant suggests that the first 7 residues and residues 8–13 can independently promote nuclear import. Both far-western analyses and immuno-pull-down assays indicate interaction of APE1 with karyopherin alpha 1 and 2, which requires the 20 N-terminal residues and implicates nuclear importins in APE1's nuclear translocation. Nuclear accumulation of the ND7 APE1(E12A/D13A) mutant after treatment with the nuclear export inhibitor leptomycin B suggests the presence of a previously unidentified nuclear export signal, and the subcellular distribution of APE1 may be regulated by both nuclear import and export.
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  Y. Liu, R. Prasad, W. A. Beard, P. S. Kedar, E. W. Hou, D. D. Shock, and S. H. Wilson Coordination of Steps in Single-nucleotide Base Excision Repair Mediated by Apurinic/Apyrimidinic Endonuclease 1 and DNA Polymerase beta J. Biol. Chem., May 4, 2007; 282(18): 13532 - 13541. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. Qu, G.-H. Liu, B. Huang, and C. Chen Nitric oxide controls nuclear export of APE1/Ref-1 through S-nitrosation of Cysteines 93 and 310 Nucleic Acids Res., April 3, 2007; 35(8): 2522 - 2532. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. Chattopadhyay, L. Wiederhold, B. Szczesny, I. Boldogh, T. K. Hazra, T. Izumi, and S. Mitra Identification and characterization of mitochondrial abasic (AP)-endonuclease in mammalian cells. Nucleic Acids Res., January 1, 2006; 34(7): 2067 - 2076. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Pines, L. Perrone, N. Bivi, M. Romanello, G. Damante, M. Gulisano, M. R. Kelley, F. Quadrifoglio, and G. Tell Activation of APE1/Ref-1 is dependent on reactive oxygen species generated after purinergic receptor stimulation by ATP Nucleic Acids Res., August 2, 2005; 33(14): 4379 - 4394. [Abstract] [Full Text] [PDF]
|
|