Please use this identifier to cite or link to this item: https://scholarbank.nus.edu.sg/handle/10635/111931
Title: Implication of localization of human DNA repair enzyme O6- methylguanine-DNA methyltransferase at active transcription sites in transcription-repair coupling of the mutagenic O6-methylguanine lesion
Authors: Ali, R.B.
Teo, A.K.-C. 
Oh, H.-K.
Chuang, L.S.-H. 
Ayi, T.-C. 
Li, B.F.L. 
Issue Date: Mar-1998
Citation: Ali, R.B.,Teo, A.K.-C.,Oh, H.-K.,Chuang, L.S.-H.,Ayi, T.-C.,Li, B.F.L. (1998-03). Implication of localization of human DNA repair enzyme O6- methylguanine-DNA methyltransferase at active transcription sites in transcription-repair coupling of the mutagenic O6-methylguanine lesion. Molecular and Cellular Biology 18 (3) : 1660-1669. ScholarBank@NUS Repository.
Abstract: DNA lesions that halt RNA polymerase during transcription are preferentially repaired by the nucleotide excision repair pathway. This transcription-coupled repair is initiated by the arrested RNA polymerase at the DNA lesion. However, the mutagenic O6-methylguanine (6MG) lesion which is bypassed by RNA polymerase is also preferentially repaired at the transcriptionally active DNA. We report here a plausible explanation for this observation: the human 6MG repair enzyme O6-methylguanine-DNA methyltransferase (MGMT) is present as speckles concentrated at active transcription sites (as revealed by polyclonal antibodies specific for its N and C termini). Upon treatment of cells with low dosages of N- methylnitrosourea, which produces 6MG lesions in the DNA, these speckles rapidly disappear, accompanied by the formation of active-site methylated MGMT (the repair product of 6MG by MGMT). The ability of MGMT to target itself to active transcription sites, thus providing an effective means of repairing 6MG lesions, possibly at transcriptionally active DNA, indicates its crucial role in human cancer and chemotherapy by alkylating agents.
Source Title: Molecular and Cellular Biology
URI: http://scholarbank.nus.edu.sg/handle/10635/111931
ISSN: 02707306
Appears in Collections:Staff Publications

Show full item record
Files in This Item:
There are no files associated with this item.

Page view(s)

72
checked on Jul 19, 2019

Google ScholarTM

Check


Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.