The human Rothmund-Thomson syndrome gene product, RECQL4, localizes to distinct nuclear foci that coincide with proteins involved in the maintenance of genome stability
The human Rothmund-Thomson syndrome gene product, RECQL4, localizes to distinct nuclear foci that coincide with proteins involved in the maintenance of genome stability
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DOI：
10.1242/jcs.02556
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发表时间：
2005-09-15
影响因子：
4
通讯作者：
Stagljar, I
中科院分区：
文献类型：
--
作者：
Petkovic, M;Dietschy, T;Stagljar, I
罗斯蒙德-汤姆森综合征（RTS）是一种人类遗传性疾病，其特征是基因组不稳定、癌症易感性和过早衰老。 RTS 病例子集中的缺陷基因 RECQL4 编码 DNA 解旋酶 RecQ 家族的成员。为了更好地定义 RECQL4 蛋白的功能，我们确定了其亚细胞定位。我们已经制备了针对 RECQL4 N 端和 C 端部分的抗体，并且可以证明在各种人类细胞中，内源性 RECQL4 形成与早幼粒细胞白血病蛋白 (PML) 共定位的离散核灶。在诱导不同类型的 DNA 损伤后，病灶数量及其与 PML 的共定位并没有显着变化。通过 siRNA 沉默 RECQL4 表达会导致 RECQL4 核灶形成显着减少。此外，我们证明 RECQL4 焦点与人类 Rad51 和诱导 DNA 双链断裂后的单链 DNA 区域形成的焦点一致。与此一致，我们还展示了 RECQL4 和 Rad51。在人体细胞中形成复合物。我们的研究结果表明 RECQL4 在通过同源重组修复 DNA 双链断裂中发挥作用，并为 RECQL4 在人类细胞中的功能提供了新的线索。
Rothmund-Thomson syndrome (RTS) is a human genetic disorder characterized by genome instability, cancer susceptibility and premature aging. The gene defective in a subset of RTS cases, RECQL4, encodes a member of the RecQ family of DNA helicases. To better define the function of the RECQL4 protein, we have determined its subcellular localization. We have raised antibodies against the N- and C-terminal parts of RECQL4 and could show that in various human cells endogenous RECQL4 forms discrete nuclear foci that colocalize with promyelotic leukaemia protein (PML). The number of foci and their colocalization with PML does not significantly change after induction of different types of DNA damages. Silencing of RECQL4 expression by siRNA causes a significant reduction in RECQL4 nuclear foci formation. Furthermore, we demonstrate that RECQL4 foci coincide with foci formed by human Rad51 and regions of single-stranded DNA after induction of DNA double-strand breaks. In agreement with this, we also show that RECQL4 and Rad51. form a complex in human cells. Our findings suggest a role for RECQL4 in the repair of DNA double-strand breaks by homologous recombination and shed new light onto RECQL4's function in human cells.