This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Supplemental material
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Vijayakumar, S.
Right arrow Articles by Tomkinson, A. E.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Vijayakumar, S.
Right arrow Articles by Tomkinson, A. E.

 Previous Article  |  Next Article 

Molecular and Cellular Biology, April 2009, p. 2042-2052, Vol. 29, No. 8
0270-7306/09/$08.00+0     doi:10.1128/MCB.01732-08
Copyright © 2009, American Society for Microbiology. All Rights Reserved.

Phosphorylation of Human DNA Ligase I Regulates Its Interaction with Replication Factor C and Its Participation in DNA Replication and DNA Repair{triangledown} ,{dagger}

Sangeetha Vijayakumar,1,2,{ddagger},§ Barbara Dziegielewska,1,{ddagger} David S. Levin,2,¶ Wei Song,1,|| Jinhu Yin,1 Austin Yang,3 Yoshihiro Matsumoto,4 Vladimir P. Bermudez,5 Jerard Hurwitz,5 and Alan E. Tomkinson1*

Radiation Oncology Research Laboratory, Department of Radiation Oncology and Marlene and Stewart Greenebaum Cancer Center, University of Maryland School of Medicine, Baltimore, Maryland 21201-1509,1 Department of Molecular Medicine, Institute of Biotechnology, University of Texas Health Science Center at San Antonio, San Antonio, Texas 78245,2 Department of Anatomy and Neurobiology and Marlene and Stewart Greenebaum Cancer Center, University of Maryland School of Medicine, Baltimore, Maryland 21201-1509,3 Medical Science Division, Fox Chase Cancer Center, Philadelphia, Pennsylvania 19111,4 Program in Molecular Biology, Sloan-Kettering Institute, Memorial Sloan-Kettering Cancer Center, New York, New York 100215

Received 11 November 2008/ Returned for modification 15 December 2008/ Accepted 3 February 2009

Human DNA ligase I (hLigI) participates in DNA replication and excision repair via an interaction with proliferating cell nuclear antigen (PCNA), a DNA sliding clamp. In addition, hLigI interacts with and is inhibited by replication factor C (RFC), the clamp loader complex that loads PCNA onto DNA. Here we show that a mutant version of hLigI, which mimics the hyperphosphorylated M-phase form of hLigI, does not interact with and is not inhibited by RFC, demonstrating that inhibition of ligation is dependent upon the interaction between hLigI and RFC. To examine the biological relevance of hLigI phosphorylation, we isolated derivatives of the hLigI-deficient cell line 46BR.1G1 that stably express mutant versions of hLigI in which four serine residues phosphorylated in vivo were replaced with either alanine or aspartic acid. The cell lines expressing the phosphorylation site mutants of hLigI exhibited a dramatic reduction in proliferation and DNA synthesis and were also hypersensitive to DNA damage. The dominant-negative effects of the hLigI phosphomutants on replication and repair are due to the activation of cellular senescence, presumably because of DNA damage arising from replication abnormalities. Thus, appropriate phosphorylation of hLigI is critical for its participation in DNA replication and repair.

* Corresponding author. Mailing address: Radiation Oncology Research Laboratory, Department of Radiation Oncology and Marlene and Stewart Greenebaum Cancer Center, University of Maryland School of Medicine, Baltimore, MD 21201-1509. Phone: (410) 706-2365. Fax: (410) 706-6666. E-mail: atomkinson{at}som.umaryland.edu

{triangledown} Published ahead of print on 17 February 2009.

{dagger} Supplemental material for this article may be found at http://mcb.asm.org/.

{ddagger} These authors contributed equally.

§ Present address: Department of Pathology and NYU Cancer Institute, NYU School of Medicine, 522 First Avenue, Smilow Research Building, 1104, New York, NY 10016.

Present address: Eisai, Inc., Teaneck, NJ 07666.

|| Present address: Department of Molecular Genetics, Duke University Medical Center, Durham NC 27710.

Molecular and Cellular Biology, April 2009, p. 2042-2052, Vol. 29, No. 8
0270-7306/09/$08.00+0     doi:10.1128/MCB.01732-08
Copyright © 2009, American Society for Microbiology. All Rights Reserved.



This article has been cited by other articles:

  • Lopez Castel, A., Tomkinson, A. E., Pearson, C. E. (2009). CTG/CAG Repeat Instability Is Modulated by the Levels of Human DNA Ligase I and Its Interaction with Proliferating Cell Nuclear Antigen: A DISTINCTION BETWEEN REPLICATION AND SLIPPED-DNA REPAIR. J. Biol. Chem. 284: 26631-26645 [Abstract] [Full Text]  
  • Karanja, K. K., Livingston, D. M. (2009). C-Terminal Flap Endonuclease (rad27) Mutations: Lethal Interactions With a DNA Ligase I Mutation (cdc9-p) and Suppression by Proliferating Cell Nuclear Antigen (POL30) in Saccharomyces cerevisiae. Genetics 183: 63-78 [Abstract] [Full Text]  


Copyright © 2009 by the American Society for Microbiology.   For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»