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

Abstract

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.

• Authors: Leslie L Woo, Kazunobu Futami, Akira Shimamoto, Yasuhiro Furuichi, Karen M Frank
• Journal: Experimental cell research (Exp Cell Res) Vol. 312 Issue 17 Pg. 3443-57 (Oct 15 2006) ISSN: 0014-4827 [Print] United States
• PMID: 16949575 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)

Chemical References

• 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

Topics

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