Enzymatic methylation of DNA and poly(dG—dC) · poly(dG—dC) modified by 4‐acetoxyaminoquinoline‐1‐oxide, the ultimate carcinogen of 4‐nitroquinoline‐1‐oxide

FEBS Letters

Pfohl-Leszkowicz, A.²  Galiegue-Zouitina, S.¹  Bailleul, B.¹  Dirheimer, G.²  Loucheux-Lefebvre, M.H.¹ 

[1] Institut de Recherches sur le Cancer de Lille et U124 INSERM BP 311, 59020 Lille Cedex, France;Institut de Biologie Moléculaire et Cellulaire du CNRS et Faculté de Pharmacie, Université Louis Pasteur, 15 rue René Descartes, 67084 Strasbourg Cedex France

关键词: DNA methylation;    4-Nitroquinoline-oxide;    DNA(cytosine-5-)-methyltransferase;    Brain;    Poly(dG-dC) · poly(dG-dC);    Chemical carcinogen;    4NQO;    4-nitroquinoline-1-oxide;    4HAQO;    4-hydroxyaminoquinoline-1-oxide;    SAM;    S- adenosyl-L-methionine;    Ac-4HAQO;    4-acetoxyamino quinoline-1-oxide;    diAc-4HAQO;    O;    O'-diacetyl-4-hydroxyaminoquinoline-1-oxide;    AAF;    2-acetylaminofluorene;    AAAF;    N-acetoxyacetylaminofluorene;    DNA-AAF;    DNA modified by AAAF;    DNA-NQO;    DNA modified by Ac-4HAQO;    poly(dG-dC)-NQO;    poly(dG-dC)·poly(dG-dC) modified by Ac-4HAQO;   

DOI  :  10.1016/0014-5793(83)81169-7

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Both the initial velocity and the overall methylation of Ac-4HAQO modified DNA by a calf brain DNA (cytosine-5-)-methyltransferase are increased as compared to native DNA. The affinity of the modified DNA for the enzyme decreases as a function of the extent of the modification. Heat-denatured, single-stranded DNA shows exactly the opposite results; the more it is modified, the less it is methylated. The poly(dG—dC) · poly(dG—dC) modified by 4NQO is as well methylated as the non-modified one. The carcinogen may induce a tertiary structure favouring the ‘walking’ of the enzyme along the DNA. The hypermethylation caused by this carcinogen could have a significance in gene activity and cellular differentiation.

【 授权许可】

Unknown