TY - JOUR
T1 - Arrest of human mitochondrial RNA polymerase transcription by the biological aldehyde adduct of DNA, M 1dG
AU - Cline, Susan D.
AU - Lodeiro, M. Fernanda
AU - Marnett, Lawrence J.
AU - Cameron, Craig E.
AU - Arnold, Jamie J.
N1 - Funding Information:
The National Institutes of Health (GM087681 to S.D.C. and CA087819 to L.J.M); Mercer University Seed Grant (to S.D.C.); Berg Endowment of the Eberly College of Science (to C.E.C.). Funding for open access charge: National Institutes of Health and National Institute of General Medical Sciences (grant GM087681).
PY - 2010/11
Y1 - 2010/11
N2 - The biological aldehydes, malondialdehyde and base propenal, react with DNA to form a prevalent guanine adduct, M1dG. The exocyclic ring of M1dG opens to the acyclic N 2-OPdG structure when paired with C but remains closed in single-stranded DNA or when mispaired with T. M1dG is a target of nucleotide excision repair (NER); however, NER is absent in mitochondria. An in vitro transcription system with purified human mitochondrial RNA polymerase (POLRMT) and transcription factors, mtTFA and mtTFB2, was used to determine the effect of M1dG on POLRMT elongation. DNA templates contained a single adduct opposite either C or T downstream of either the light-strand (LSP) or heavy-strand (HSP1) promoter for POLRMT. M1dG in the transcribed strand arrested 60-90 POLRMT elongation complexes with greater arrest by the adduct when opposite T. POLRMT was more sensitive to N 2-OPdG and M1dG after initiation at LSP, which suggests promoter-specific differences in the function of POLRMT complexes. A closed-ring analog of M1dG, PdG, blocked 95 of transcripts originating from either promoter regardless of base pairing, and the transcripts remained associated with POLRMT complexes after stalling at the adduct. This work suggests that persistent M1dG adducts in mitochondrial DNA hinder the transcription of mitochondrial genes.
AB - The biological aldehydes, malondialdehyde and base propenal, react with DNA to form a prevalent guanine adduct, M1dG. The exocyclic ring of M1dG opens to the acyclic N 2-OPdG structure when paired with C but remains closed in single-stranded DNA or when mispaired with T. M1dG is a target of nucleotide excision repair (NER); however, NER is absent in mitochondria. An in vitro transcription system with purified human mitochondrial RNA polymerase (POLRMT) and transcription factors, mtTFA and mtTFB2, was used to determine the effect of M1dG on POLRMT elongation. DNA templates contained a single adduct opposite either C or T downstream of either the light-strand (LSP) or heavy-strand (HSP1) promoter for POLRMT. M1dG in the transcribed strand arrested 60-90 POLRMT elongation complexes with greater arrest by the adduct when opposite T. POLRMT was more sensitive to N 2-OPdG and M1dG after initiation at LSP, which suggests promoter-specific differences in the function of POLRMT complexes. A closed-ring analog of M1dG, PdG, blocked 95 of transcripts originating from either promoter regardless of base pairing, and the transcripts remained associated with POLRMT complexes after stalling at the adduct. This work suggests that persistent M1dG adducts in mitochondrial DNA hinder the transcription of mitochondrial genes.
UR - http://www.scopus.com/inward/record.url?scp=78649839856&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=78649839856&partnerID=8YFLogxK
U2 - 10.1093/nar/gkq656
DO - 10.1093/nar/gkq656
M3 - Article
C2 - 20671026
AN - SCOPUS:78649839856
SN - 0305-1048
VL - 38
SP - 7546
EP - 7557
JO - Nucleic acids research
JF - Nucleic acids research
IS - 21
ER -