Mechanistic insights on the inhibition of c5 DNA methyltransferases by zebularine.
Mechanistic insights on the inhibition of c5 DNA methyltransferases by zebularine.
复制标题
DOI：
10.1371/journal.pone.0012388
复制
发表时间：
2010-08-24
期刊：
影响因子：
3.7
通讯作者：
Guieysse-Peugeot AL
中科院分区：
文献类型：
--
作者：
Champion C;Guianvarc'h D;Sénamaud-Beaufort C;Jurkowska RZ;Jeltsch A;Ponger L;Arimondo PB;Guieysse-Peugeot AL
在哺乳动物中，DNA甲基化发生在CpG环境中胞嘧啶的第5位，并调节基因的表达。它在疾病中扮演着重要的角色，DNA甲基转移酶(DNMT)的抑制剂-负责DNA甲基化的酶-被用于癌症治疗的临床。最有效的抑制剂是5-氮杂胞苷和5-氮杂脱氧胞苷。ZeBularine(1-(β-D-riboFuranosyl)-2(1H)-mididinone)是另一种胞苷类似物，被描述为一种有效的抑制剂，当与DNMT结合时，它通过与DNMT形成共价复合体来发挥作用。在这里，我们带来了额外的实验来解释它的作用机制。首先，我们观察到，与脱氧胞苷和5-氟脱氧胞苷相比，当ZeBularine与DNA结合时，DNA结合增加，同时解离速率显著降低。其次，我们通过变性凝胶分析表明，酶与DNA之间的中间共价复合体是可逆的，因此不同于5-氟脱氧胞苷。第三，当DNA中存在ZeBularine时，不会发生甲基化反应。我们证实，Zebuarine通过稳定DNMT与DNA的结合，阻止甲基化，减少解离，从而捕获酶，甚至在其他位置阻止周转，从而发挥其去甲基化活性。
In mammals DNA methylation occurs at position 5 of cytosine in a CpG context and regulates gene expression. It plays an important role in diseases and inhibitors of DNA methyltransferases (DNMTs)—the enzymes responsible for DNA methylation—are used in clinics for cancer therapy. The most potent inhibitors are 5-azacytidine and 5-azadeoxycytidine. Zebularine (1-(β-D-ribofuranosyl)-2(1H)- pyrimidinone) is another cytidine analog described as a potent inhibitor that acts by forming a covalent complex with DNMT when incorporated into DNA. Here we bring additional experiments to explain its mechanism of action. First, we observe an increase in the DNA binding when zebularine is incorporated into the DNA, compared to deoxycytidine and 5-fluorodeoxycytidine, together with a strong decrease in the dissociation rate. Second, we show by denaturing gel analysis that the intermediate covalent complex between the enzyme and the DNA is reversible, differing thus from 5-fluorodeoxycytidine. Third, no methylation reaction occurs when zebularine is present in the DNA. We confirm that zebularine exerts its demethylation activity by stabilizing the binding of DNMTs to DNA, hindering the methylation and decreasing the dissociation, thereby trapping the enzyme and preventing turnover even at other sites.
登录
查看更多内容
影响因子：
3.7
作者：
Jeltsch, Albert
通讯作者：
Jeltsch, Albert
影响因子：
5.7
作者：
Balch, C;Yan, P;Nephew, KP
通讯作者：
Nephew, KP
影响因子：
4.8
作者：
Gowher, H;Jeltsch, A
通讯作者：
Jeltsch, A
影响因子：
3.8
作者：
Lee, G;Wolff, E;Miller, JH
通讯作者：
Miller, JH
DOI：
10.1016/j.bbapap.2009.07.016
发表时间：
2009-11-01
影响因子：
3.2
作者：
Darii, Maria V.;Cherepanova, Natalia A.;Gromova, Elizaveta S.
通讯作者：
Gromova, Elizaveta S.