Werner syndrome protein phosphorylation by Abl tyrosine kinase regulates its activity and distribution
Werner syndrome protein phosphorylation by Abl tyrosine kinase regulates its activity and distribution
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DOI：
10.1128/mcb.23.18.6385-6395.2003
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发表时间：
2003-09-01
影响因子：
5.3
通讯作者：
Bohr, VA
中科院分区：
文献类型：
--
作者：
Cheng, WH;von Kobbe, C;Bohr, VA
Werner综合征蛋白(WRN)是人类基因组的管理者，而Abl激酶是DNA损伤反应的调节因子。DNA修复的异常与癌症的发生有关。在此，我们在体外通过WRN的N端和中心区以及c-Abl的Src同源结构域3鉴定了WRN与c-Abl之间的直接结合。经博莱霉素处理后，WRN和c-Abl被解离，随后Abl依赖的WRN重新定位到核质中。WRN是c-Abl的体外和体内底物。WRN被博莱霉素处理的HeLa细胞瞬时或在慢性髓系白血病(CML)患者的细胞中结构性地被酪氨酸磷酸化，而这些磷酸化可被Abl激酶抑制剂STI-571阻止。WRN的酪氨酸磷酸化导致WRN外切酶和解旋酶活性的抑制。此外，经STI-571处理的CML细胞的抗WRN免疫沉淀物显示3‘-->；5’外切酶活性增加。这些发现提示了一条新的信号通路，c-Abl通过该通路介导WRN对DNA损伤的核定位和催化活性。
The Werner syndrome protein (WRN) is a caretaker of the human genome, and the Abl kinase is a regulator of the DNA damage response. Aberrant DNA repair has been linked to the development of cancer. Here, we have identified a direct binding between WRN and c-Abl in vitro via the N-terminal and central regions of WRN and the Src homology domain 3 of c-Abl. After bleomycin treatment in culture, WRN and c-Abl are dissociated and followed by an Abl kinase-dependent WRN relocalization to the nucleoplasm. WRN is a substrate of c-Abl in vitro and in vivo. WRN is tyrosine phosphorylated either transiently by treatment of HeLa cells with bleomycin or constitutively in cells from chronic myeloid leukemia (CML) patients, and these phosphorylations are prevented by treatment with the Abl kinase inhibitor STI-571. Tyrosine phosphorylation of WRN results in inhibition of both WRN exonuclease and helicase activities. Furthermore, anti-WRN immunoprecipitates from CML cells treated with STI-571 show increased 3'-->5' exonuclease activity. These findings suggest a novel signaling pathway by which c-Abl mediates WRN nuclear localization and catalytic activities in response to DNA damage.