DNA repair and genomic (in)stability

Arne Klungland

E-mail: arne.klungland@labmed.uio.no Telefon: 23074072 (Mobil: 47840305)

PhD University of Oslo / The Norwegian Cancer Society 1994
Post doctoral work: ICRF, Clare Hall, London
Senior Scientist, The Norwegian Cancer Society
Director of Research: Prof. Erling Seeberg

The National Hospital in Oslo

Institute of Medical Microbiology, Section for Molecular Biology, is localised in the new National Hospital at Gaustad, Oslo. Four different research group are colocalised, concentrating on DNA-repair studies, brain development, microbiology and biocomputing. Prof. Erling Seeberg has been the director of research since 1995. He also has a long and outstanding record for DNA repair studies, including charaterication of the uvrABC repairosome of E.coli and cloning of several procaryotic and eucaryotic genes for DNA glycosylases. We have a very close collaboration to Erling Seeberg's group for purification and biochemical characterization of DNA repair enzymes (Seeberg and Bjørås), biocomputing (Rognes) and for characterization of knockout mice (Seeberg and Falnes). We also collaborate with excellent research groups in Germany, France, Holland, UK and USA.

Currently we have MSc ("hovedfag") and PhD students from The Agricultural University, University of Oslo and University of Trondheim ("Siv. Ing."), in addition to medical students.

Our research is supported by:

• Norwegian Cancer Society
• Norwegian Advanced Research Program
• Norwegian Research Council
• The National Hospital
• EU

Projects: Mechanisms for DNA repair and genomic (in)stability

Background

Repair of DNA damage is essential for protection against cancer and other age related diseases. DNA damage generated by ionizing radiation, simple alcylating agents or endogenously hydrolytic and oxidative processes is corrected by the base excision repair (BER) pathway(s).

Previous work include:

i) Overexpression of DNA glycosylases in mammalian cells. DNA glycosylases initiate the base excision repair pathway by removing the damaged base, and was shown to be a limiting factor for cell survival following induced DNA damage.

ii) Reconstituting the pathway(s) for base excision repair, in vitro, with purified human proteins. This work also lead to the identification of a human enzyme, XPG, stimulating the BER pathway. XPG is one of the genes causing the severe syndrome Xeroderma Pigmentosum, and is required for the repair of UV-induced DNA damage.

iii) Recent work includes the construction and analysis of a mice deficient for the OGG1 gene. This gene is the major enzyme for removal of the mutagenic oxidized lesion, 8oxoGua. Consequently, the OGG1 KO mice have an increased G to T transvertion mutation frequency and accumulate 8-oxoG in nuclear and mitochondria DNA. However, no obvious phenotype was observed. Interestingly, mouse embryo fibroblasts from the OGG1 KO mouse can still, efficiently, remove 8-oxoG from transcribed sequences.

Future projects

Currently two different approaches are used for identification of new genefunctions for DNA repair.

i) The publication of the human DNA sequence revealed several open reading frames with possible DNA repair domains. Cloning and overexpression of candidate repair enzymes have recently resulted in the characterization of a human DNA damage specific endonuclease.

ii) Sensitive E.coli mutants have been very valuable for the cloning of homologues gene functions from eucaryotic cells by functional complementation. We have produced human cDNA libraries for expression in S.cerevisiae. Several defined S.cerevisiae mutants for genomic instability exist, and complementation of this defect should allow us to identify homologues genefunction with human origin.

iii) Finally, genes involved in maintenance of genomic stability are deleted from the mouse genome by homologous recombination (e.g. generation of knockout mice).

Goals

Identify and characterize genfunctions required for genomic stability and for protection against cancer. Targeted mutations of DNA repair genes in mice.

Illustration of the 5'-endonuclease activity of the FEN-1 enzyme (Five ENdonuclease-1)

Selected publications

A Klungland, L Fairbairn, AJ Watson, GP Margison and E Seeberg (1992) Expression of the E. coli 3-methyladenine DNA glycosylase I gene in mammalian cells reduces the toxic and mutagenic effects of methylating agents. EMBO journal 11, 4439-44.

A Klungland and T Lindahl (1997) Second pathway for completion of human DNA base excision-repair: reconstitution with purified proteins and requirement for DNase IV (FEN1). EMBO journal 16, 3341-48.

A Klungland, M Höss, D Gunz, A Constantinou, SG Clarkson, P Bolton, P Doetsch, RD Wood and T Lindahl (1999) Base excision-repair of oxidative DNA damage activated by XPG protein. Molecular Cell, 3, 33-42.

A Klungland, I Rosewell, S Hollenbach, E Larsen, G Daly, B Epe, E Seeberg, T Lindahl and DE Barnes (1999) Accumulation of pre-mutagenic lesions in the DNA of mice defective in the removal of oxidative DNA base damage. Proc. Nat. Acad. Sci., USA, 96, 13300-05.

F Le Page, A Klungland, DE Barnes, A Sarasin, and S Boiteux (2000) Transcription coupled repair of 8-oxoguanine in murine cells. Proc. Nat. Acad. Sci., USA, 97, 8397-402.

NC de Souza-Pint, L Eide, BA Hogue, T Stevnsner, T Thybo, E Seeberg, A Klungland and VA Bohr (2001) Repair of 8-oxoGua lesions in mitochondrial DNA depends on the OGG1 gene and 8-oxoGua accumulates in the mitochondrial DNA of OGG1 defective mice. Canc. Res., 61, 5378-81.

M Osterod, E Larsen, F Le Page, JG Hengstler, G TJ van der Horst, S Boiteux, A Klungland and B Epe (2002) A global DNA repair meshanism involving the Cockayne syndrome B (CSB) gene product can prevent the in vivo accumulation of endogenous oxidative DNA base damage. Oncogene., 21, 8232-39.

A. Moe, J. Ringvold, L.M. Nordstrand, L. Eide, M. Bjørås, E. Seeberg, T. Rognes and A. Klungland (2003) Incision at hypoxanthine residues in DNA by a mammalian homologue of the E.coli antimutator enzyme endonuclease V. Nucleic Acids Research, 31, 3893-3900

E. Larsen, C. Gran, B. Johnsen, E. Seeberg and A. Klungland (2003) Proliferation failure and gamma-radiation sensitivity of Fen1 null mutant mice at the blastocyst stage. Molecular and Cellular Biology, 23, 5346-5353

E. Seeberg and A. Klungland (2003) Better late than never for repair of miscoding lesions within a transcribed template. Molecular Cell, 12, 799-800 Preview

Current group members

• Arne Klungland, group leader
• Trine Johansen Meza, post doc
• Ane Moe, PhD student
• Elisabeth Larsen, PhD student
• Jeanette Ringvold, PhD student
• Line Mari Nordstrand, PhD student
• Elisabeth K. Aasebø, MSc student
• Liv Kleppa, MSc student
• Christine Gran, technician
• Gaute Nesse, technician
• Karen O. Stenersen, technician
• Kirsten Skaug, technician
• Therese Irene Corneliussen, MSc student
• Lene Uldal, MSc student

Links

Centre for Molecular Biology and Neuroscience; http://www.cmbn.no

Last updated 17 November, 2003 .