Dnmt3a-CD is less susceptible to bulky benzo[a]pyrene diol epoxide-derived DNA lesions than prokaryotic DNA methyltransferases.
Dnmt3a-CD is less susceptible to bulky benzo[a]pyrene diol epoxide-derived DNA lesions than prokaryotic DNA methyltransferases.
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DOI：
10.1021/bi101717b
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发表时间：
2011-02-08
期刊：
影响因子：
2.9
通讯作者：
Gromova ES
中科院分区：
文献类型：
--
作者：
Lukashevich OV;Baskunov VB;Darii MV;Kolbanovskiy A;Baykov AA;Gromova ES
苯并[a]芘（B[a]P）是一种典型的环境多环芳烃污染物。在活生物体中，B[a]P代谢为遗传毒性抗苯并[a]芘二醇环氧化物，该环氧化物与细胞DNA反应形成立体异构抗B [a]PDE-N2-dG加合物。在这项研究中，我们探讨了加合物的立体化学和双链DNA底物的位置对小鼠从头DNA甲基转移酶Dnmt 3a（Dnmt 3a-CD）的催化结构域的功能特性的影响。制备了许多18-mer双链体，其含有位点特异性掺入的（+）-和（−）-反式-抗B[a]PDE-N2-dG损伤，这些损伤位于靶胞嘧啶残基的3′-和5′-相邻和相对处。与未受损的DNA双链体相比，Dnmt 3a-CD以高达5倍的亲和力与DNA双链体协同结合。甲基化测定显示，受损双链体的甲基化反应速率降低1.7-6.3倍。B[a]PDE修饰刺激非生产性结合，并显著有利于Dnmt 3a-CD的底物抑制，与DNA甲基化状态无关。后者的效果是敏感的B[a]PDE-N2-dG加合物的位置和立体化学。反式-抗B[a]PDE-N2-dG加合物对Dnmt 3a-CD的总体影响比我们先前研究的原核甲基转移酶的情况下的有害性小。
Benzo[a]pyrene (B[a]P) is a well-characterized environmental polycyclic aromatic hydrocarbon pollutant. In living organisms, B[a]P is metabolized to the genotoxic anti-benzo[a]pyrene diol epoxide that reacts with cellular DNA to form stereoisomeric anti-B[a]PDE-N2-dG adducts. In this study, we explored the effects of adduct stereochemistry and position in double-stranded DNA substrates on the functional characteristics of the catalytic domain of murine de novo DNA methyltransferase Dnmt3a (Dnmt3a-CD). A number of 18-mer duplexes containing site-specifically incorporated (+)- and (−)-trans-anti-B[a]PDE-N2-dG lesions located 3′- and 5′-adjacent to and opposite the target cytosine residue were prepared. The Dnmt3a-CD binds cooperatively to the DNA duplexes with an up to 5-fold greater affinity as compared to the undamaged DNA duplexes. Methylation assays showed a 1.7–6.3 fold decrease of the methylation reaction rates for the damaged duplexes. B[a]PDE modifications stimulated a non-productive binding and markedly favoured substrate inhibition of Dnmt3a-CD independently of DNA methylation status. The latter effect was sensitive to the position and stereochemistry of the B[a]PDE-N2-dG adducts. The overall effect of trans-anti-B[a]PDE-N2-dG adducts on Dnmt3a-CD was less detrimental than in the case of the prokaryotic methyltransferases we previously investigated.
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影响因子：
5.9
作者：
CONNEY, AH;CHANG, RL;WEI, SJC
通讯作者：
WEI, SJC
DOI：
10.1016/j.bbrc.2009.07.093
发表时间：
2009-09-25
影响因子：
3.1
作者：
Deng, Tao;Kuang, Ying;Fei, Jian
通讯作者：
Fei, Jian
影响因子：
64.5
作者：
Okano, M;Bell, DW;Li, E
通讯作者：
Li, E
影响因子：
2.9
作者：
Maltseva, Diana V.;Baykov, Alexander A.;Gromova, Elizaveta S.
通讯作者：
Gromova, Elizaveta S.
影响因子：
4.8
作者：
Gowher, H;Jeltsch, A
通讯作者：
Jeltsch, A