Journal Article

OGG1 protein suppresses G:C→T:A mutation in a shuttle vector containing 8-hydroxyguanine in human cells

Noriaki Sunaga, Takashi Kohno, Kazuya Shinmura, Takayuki Saitoh, Tomonari Matsuda, Ryusei Saito and Jun Yokota

in Carcinogenesis

Volume 22, issue 9, pages 1355-1362
Published in print September 2001 | ISSN: 0143-3334
Published online September 2001 | e-ISSN: 1460-2180 | DOI: http://dx.doi.org/10.1093/carcin/22.9.1355
OGG1 protein suppresses G:C→T:A mutation in a shuttle vector containing 8-hydroxyguanine in human cells

More Like This

Show all results sharing this subject:

  • Clinical Cytogenetics and Molecular Genetics

GO

Show Summary Details

Preview

8-Hydroxyguanine (8-OHG) is an oxidatively damaged mutagenic base which causes G:C→T:A transversions in DNA. OGG1 was cloned as a human gene encoding a DNA glycosylase that specifically excises 8-OHG from DNA in vitro. However, it was not clear whether OGG1 protein suppresses G:C→T:A transversions caused by 8-OHG in human cells in vivo. In the present study we have examined the ability of OGG1 protein to suppress G:C→T:A transversions caused by 8-OHG in human cells by bacterial suppressor tRNA (supF) forward mutation assay using a shuttle vector DNA, pMY189. Introduction of a single 8-OHG residue at position 159 of the supF gene in plasmid pMY189 resulted in a 130-fold increase in mutation frequency compared with untreated plasmid pMY189 after replication in the NCI-H1299 human lung cancer cell line. G:C→T:A transversions at position 159 were detected in >90% of the supF mutants from the 8-OHG-containing plasmid. The mutation frequency of the 8-OHG-containing plasmid was significantly reduced by overexpression of OGG1 protein in NCI-H1299 cells and, in particular, the occurrence of G:C→T:A transversion at position 159 in the supF gene was suppressed. Furthermore, frequencies and spectra of mutations of the untreated pMY189 plasmid did not differ significantly with overexpression of OGG1 protein. These results indicate that OGG1 protein has the ability to suppress G:C→T:A transversions caused by 8-OHG in human cells in vivo.

Keywords: AP, apurinic/apyrimidinic; APEX, AP endonuclease; dG, deoxyguanosine; HPLC–ECD, high performance liquid chromatography with electrochemical detection; IPTG, isopropyl-β-d-thiogalactopyranoside; LB, Luria–Bertani; 8-OHdG, 8-hydroxydeoxyguanosine; 8-OHG, 8-hydroxyguanine; X-gal, 5-bromo-4-chloro-3-indolyl-β-d-galactopyranoside.

Journal Article.  6529 words.  Illustrated.

Subjects: Clinical Cytogenetics and Molecular Genetics

Full text: subscription required

How to subscribe Recommend to my Librarian

Users without a subscription are not able to see the full content. Please, subscribe or login to access all content.