Double-strand breaks (DSBs) of chromosomal DNA trigger the cellular response that activates the pathways for DNA repair and cell-cycle checkpoints, and sometimes the pathways leading to cell death if the damage is too severe to be tolerated. Evidence indicates that, upon generation of DNA DSBs, many nuclear proteins that are involved in DNA repair and checkpoints are recruited to chromatin around the DNA lesions. In the present study we used a proteomics approach to identify DNA-damage-induced chromatin-binding proteins in a systematic way. Two-dimensional gel analysis for protein extracts of chromatin from DNA-damage-induced and control HeLa cells identified four proteins as the candidates for DNA-damage-induced chromatin-binding proteins. MALDI–TOF (matrix-assisted laser-desorption ionization–time-of-flight) MS analysis identified these proteins to be NPM (nucleophosmin), hnRNP (heterogeneous nuclear ribonucleoprotein) C1, hnRNP C2 and 37-kDa laminin-receptor precursor, and the identity of these proteins was further confirmed by immunoblot analysis with specific antibodies. We then demonstrated with chromatin-binding assays that NPM and hnRNP C1/C2, the abundant nuclear proteins with pleiotropic functions, indeed bind to chromatin in a DNA-damage-dependent manner, implicating these proteins in DNA repair and/or damage response. Immunofluorescence experiments showed that NPM, normally present in the nucleoli, is mobilized into the nucleoplasm after DNA damage, and that neither NPM nor hnRNP C1/C2 is actively recruited to the sites of DNA breaks. These results suggest that NPM and hnRNP C1/C2 may function at the levels of the global context of chromatin, rather than by specifically targeting the broken DNA.
Skip Nav Destination
Article navigation
May 2005
-
Cover Image
Cover Image
- PDF Icon PDF LinkFront Matter
- PDF Icon PDF LinkTable of Contents
- PDF Icon PDF LinkEditorial Board
Research Article|
May 10 2005
A proteomics approach for the identification of nucleophosmin and heterogeneous nuclear ribonucleoprotein C1/C2 as chromatin-binding proteins in response to DNA double-strand breaks
Seung Yun LEE;
Seung Yun LEE
1
1Division of Molecular Life Sciences and Center for Cell Signaling Research, Ewha Womans University, Seoul, Korea 120-750
Search for other works by this author on:
Ji-Hye PARK;
Ji-Hye PARK
1
1Division of Molecular Life Sciences and Center for Cell Signaling Research, Ewha Womans University, Seoul, Korea 120-750
Search for other works by this author on:
Sungsu KIM;
Sungsu KIM
1Division of Molecular Life Sciences and Center for Cell Signaling Research, Ewha Womans University, Seoul, Korea 120-750
Search for other works by this author on:
Eun-Jung PARK;
Eun-Jung PARK
1Division of Molecular Life Sciences and Center for Cell Signaling Research, Ewha Womans University, Seoul, Korea 120-750
Search for other works by this author on:
Yungdae YUN;
Yungdae YUN
1Division of Molecular Life Sciences and Center for Cell Signaling Research, Ewha Womans University, Seoul, Korea 120-750
Search for other works by this author on:
Jongbum KWON
Jongbum KWON
2
1Division of Molecular Life Sciences and Center for Cell Signaling Research, Ewha Womans University, Seoul, Korea 120-750
2To whom correspondence should be addressed (email jongkwon@ewha.ac.kr).
Search for other works by this author on:
Publisher: Portland Press Ltd
Received:
December 08 2004
Revision Received:
February 09 2005
Accepted:
March 01 2005
Accepted Manuscript online:
March 01 2005
Online ISSN: 1470-8728
Print ISSN: 0264-6021
The Biochemical Society, London
2005
Biochem J (2005) 388 (1): 7–15.
Article history
Received:
December 08 2004
Revision Received:
February 09 2005
Accepted:
March 01 2005
Accepted Manuscript online:
March 01 2005
Citation
Seung Yun LEE, Ji-Hye PARK, Sungsu KIM, Eun-Jung PARK, Yungdae YUN, Jongbum KWON; A proteomics approach for the identification of nucleophosmin and heterogeneous nuclear ribonucleoprotein C1/C2 as chromatin-binding proteins in response to DNA double-strand breaks. Biochem J 15 May 2005; 388 (1): 7–15. doi: https://doi.org/10.1042/BJ20042033
Download citation file:
Sign in
Don't already have an account? Register
Sign in to your personal account
You could not be signed in. Please check your email address / username and password and try again.
Could not validate captcha. Please try again.