Werner syndrome protein is regulated and phosphorylated by DNA-dependent protein kinase.
Werner syndrome protein is regulated and phosphorylated by DNA-dependent protein kinase.
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DOI：
10.1074/jbc.m101913200
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发表时间：
2001-10
期刊：
影响因子：
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通讯作者：
S. Yannone;Sashwati Roy;D. Chan;Michael B. Murphy;Shurong Huang;J. Campisi;David J. Chen
中科院分区：
文献类型：
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作者：
S. Yannone;Sashwati Roy;D. Chan;Michael B. Murphy;Shurong Huang;J. Campisi;David J. Chen
DNA 双链断裂 (DSB) 是一种高度诱变且可能致命的损伤，发生在所有生物体中。哺乳动物细胞通过同源重组和非同源末端连接修复 DSB，后者需要 DNA 依赖性蛋白激酶 (DNA-PK)。 Werner 综合征是一种以基因组不稳定、衰老病理和缺陷 WRN（一种具有核酸外切酶活性的 RecQ 样解旋酶）为特征的疾病。我们发现 WRN 直接与 DNA-PK (DNA-PK(CS)) 催化亚基相互作用，从而抑制 WRN 的解旋酶和核酸外切酶活性。此外，我们还发现 WRN 与 DNA-PK(CS) 和 DNA 结合亚基 Ku 在 DNA 上形成稳定的复合物。该组装逆转了 WRN 酶抑制。最后，我们发现 WRN 在体外被 DNA-PK 磷酸化，并且需要 DNA-PK 在体内磷酸化，并且 WRN 缺陷的细胞对电离辐射轻度敏感。这些数据表明 DNA-PK 和 WRN 可能在 DNA 代谢中共同发挥作用，并暗示 WRN 在非同源末端连接中发挥作用。
DNA double-strand breaks (DSBs) are a highly mutagenic and potentially lethal damage that occurs in all organisms. Mammalian cells repair DSBs by homologous recombination and non-homologous end joining, the latter requiring DNA-dependent protein kinase (DNA-PK). Werner syndrome is a disorder characterized by genomic instability, aging pathologies and defective WRN, a RecQ-like helicase with exonuclease activity. We show that WRN interacts directly with the catalytic subunit of DNA-PK (DNA-PK(CS)), which inhibits both the helicase and exonuclease activities of WRN. In addition we show that WRN forms a stable complex on DNA with DNA-PK(CS) and the DNA binding subunit Ku. This assembly reverses WRN enzymatic inhibition. Finally, we show that WRN is phosphorylated in vitro by DNA-PK and requires DNA-PK for phosphorylation in vivo, and that cells deficient in WRN are mildly sensitive to ionizing radiation. These data suggest that DNA-PK and WRN may function together in DNA metabolism and implicate WRN function in non-homologous end joining.