The Rothmund-Thomson gene product RECQL4 localizes to the nucleolus in response to oxidative stress

Exp Cell Res. 2006 Oct 15;312(17):3443-57. doi: 10.1016/j.yexcr.2006.07.023. Epub 2006 Aug 2.


Mutations in the RECQL4 helicase gene have been linked to Rothmund-Thomson syndrome (RTS), which is characterized by poikiloderma, growth deficiency, and a predisposition to cancer. Examination of RECQL4 subcellular localization in live cells demonstrated a nucleoplasmic pattern and, to a lesser degree, staining in nucleoli. Analysis of RECQL4-GFP deletion mutants revealed two nuclear localization regions in the N-terminal region of RECQL4 and a nucleolar localization signal at amino acids 376-386. RECQL4 localization did not change after treatment with the DNA-damaging agents bleomycin, etoposide, UV irradiation and gamma irradiation, in contrast to the Bloom and Werner syndrome helicases that relocate to distinct nuclear foci after damage. However, in a significant number of cells exposed to hydrogen peroxide or streptonigrin, RECQL4 accumulated in nucleoli. Using a T7 phage display screen, we determined that RECQL4 interacts with poly(ADP-ribose) polymerase-1 (PARP-1), a nuclear enzyme that promotes genomic integrity through its involvement in DNA repair and signaling pathways. The RECQL4 nucleolar localization was inhibited by pretreatment with a PARP-1 inhibitor. The C-terminal portion of RECQL4 was found to be an in vitro substrate for PARP-1. These results demonstrate changes in the intracellular localization of RECQL4 in response to oxidative stress and identify an interaction between RECQL4 and PARP-1.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine Triphosphatases / chemistry
  • Adenosine Triphosphatases / genetics*
  • Adenosine Triphosphatases / metabolism*
  • Cell Line
  • Cell Nucleolus / metabolism*
  • Cell Nucleus / chemistry
  • DNA Helicases / chemistry
  • DNA Helicases / genetics*
  • DNA Helicases / metabolism*
  • Green Fluorescent Proteins / genetics
  • HeLa Cells
  • Humans
  • Oxidative Stress*
  • Poly (ADP-Ribose) Polymerase-1
  • Poly(ADP-ribose) Polymerases / metabolism
  • RecQ Helicases


  • enhanced green fluorescent protein
  • Green Fluorescent Proteins
  • PARP1 protein, human
  • Poly (ADP-Ribose) Polymerase-1
  • Poly(ADP-ribose) Polymerases
  • Adenosine Triphosphatases
  • RECQL4 protein, human
  • DNA Helicases
  • RecQ Helicases