The processing of Holliday junctions by BLM and WRN helicases is regulated by p53
The processing of Holliday junctions by BLM and WRN helicases is regulated by p53
复制标题
DOI：
10.1074/jbc.m204111200
复制
发表时间：
2002-08-30
影响因子：
4.8
通讯作者：
Harris, CC
中科院分区：
文献类型：
--
作者：
Yang, Q;Zhang, R;Harris, CC
BLM、WRN和p53参与同源DNA重组途径。DNA结构特异性解旋酶，BLM和WRN，解开霍利迪连接（HJ），一种可以抑制DNA复制过程中不适当的同源重组的活性。在这里，我们表明，纯化，重组p53结合BLM和WRN解旋酶，并减弱其能力，在体外解旋合成HJ。p53 248 W突变体降低了两者结合HJ和抑制解旋酶活性的能力，而p53 273 H突变体丧失了这些能力。此外，全长p53和C-末端多肽（残基373-383）抑制BLM和WRN解旋酶活性，但Ser（376）或Ser（378）的磷酸化完全消除了这种抑制作用。阻断DNA复制后，Ser（15）磷酸化p53、BLM和RAD 51共定位于细胞核中可能含有DNA复制中间体的位点。我们的研究结果与p53介导的DNA重组修复调控的新机制一致，该机制涉及p53翻译后修饰和与BLM和WRN DNA解旋酶的功能性蛋白-蛋白相互作用。
BLM, WRN, and p53 are involved in the homologous DNA recombination pathway. The DNA structure-specific helicases, BLM and WRN, unwind Holliday junctions (HJ), an activity that could suppress inappropriate homologous recombination during DNA replication. Here, we show that purified, recombinant p53 binds to BLM and WRN helicases and attenuates their ability to unwind synthetic HJ in vitro. The p53 248W mutant reduces abilities of both to bind HJ and inhibit helicase activities, whereas the p53 273H mutant loses these abilities. Moreover, full-length p53 and a C-terminal polypeptide (residues 373-383) inhibit the BLM and WRN helicase activities, but phosphorylation at Ser(376) or Ser(378) completely abolishes this inhibition. Following blockage of DNA replication, Ser(15) phospho-p53, BLM, and RAD51 colocalize in nuclear foci at sites likely to contain DNA replication intermediates in cells. Our results are consistent with a novel mechanism for p53-mediated regulation of DNA recombinational repair that involves p53 post-translational modifications and functional protein-protein interactions with BLM and WRN DNA helicases.