HUMAN DNA-REPAIR EXCISION NUCLEASE - ANALYSIS OF THE ROLES OF THE SUBUNITS INVOLVED IN DUAL INCISIONS BY USING ANTI-XPG AND ANTI-ERCC1 ANTIBODIES
HUMAN DNA-REPAIR EXCISION NUCLEASE - ANALYSIS OF THE ROLES OF THE SUBUNITS INVOLVED IN DUAL INCISIONS BY USING ANTI-XPG AND ANTI-ERCC1 ANTIBODIES
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DOI：
10.1074/jbc.270.35.20862
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发表时间：
1995-09-01
影响因子：
4.8
通讯作者：
SANCAR, A
中科院分区：
文献类型：
--
作者：
MATSUNAGA, T;MU, D;SANCAR, A
人DNA修复切除核酸酶通过以精确的方式在损伤的两侧切割来去除DNA损伤。该活性需要16-17个多肽的参与。其中，XPF。基于对重组蛋白及其酵母同源物的研究，预测ERCC 1复合物和XPG携带核酸酶活性位点。此外，最近的工作与模型（未受损）基板已导致预测的作用，这些蛋白质切割5'或3'的病变。我们使用受损的DNA底物和XPG和ERCC 1的抗体来测试这些预测。我们的研究结果表明，抗XPG抗体改变3'切口的位点，并且在高浓度下抑制3'切口而不显著影响5'切口，表明XPG形成3'切口，并且进一步表明在这种情况下5'切口可以在没有3'切口的情况下发生。相反，抗ERCC 1抗体抑制3'和5'切口。使用一个明确的切除修复系统，我们还证明了3'切口可以在没有5'切口的情况下发生，这使我们得出结论，在某些条件下，两个切口可以独立发生。
Human DNA repair excision nuclease removes DNA damage by incising on both sides of the lesion in a precise manner. The activity requires participation of 16-17 polypeptides. Of these, the XPF . ERCC1 complex and XPG were predicted to carry the nuclease active sites based on studies with the recombinant proteins and the yeast homologs of these proteins. Furthermore, recent work with model (undamaged) substrates have led to predictions of the roles of these proteins in incising 5' or 3' to the lesion. We have used damaged DNA substrates and antibodies to XPG and ERCC1 to test these predictions. Our results reveal that anti-XPG antibodies change the site of 3' incision and at high concentration inhibit the 3' incision without significantly affecting the 5' incision, indicating that XPG makes the 3' incision and further that under this condition 5' incision can occur without 3' incision. In contrast, anti-ERCC1 antibodies inhibit both the 3' and 5' incisions. Using a defined system for excision repair we also demonstrate that the 3' incision can occur without the 5' incision, leading us to conclude that under certain conditions the two incisions can occur independently.