Molecular mechanism of the recruitment of NBS1/hMRE11/hRAD50 complex to DNA double-strand breaks:: NBS1 binds to γ-H2AX through FHA/BRCT domain
Molecular mechanism of the recruitment of NBS1/hMRE11/hRAD50 complex to DNA double-strand breaks:: NBS1 binds to γ-H2AX through FHA/BRCT domain
复制标题
DOI：
10.1269/jrr.45.473
复制
发表时间：
2004-12-01
影响因子：
2
通讯作者：
Kobayashi, J
中科院分区：
文献类型：
--
作者：
Kobayashi, J
DNA双链断裂代表了对基因组的最潜在的严重损伤，因此，许多修复蛋白被招募到DNA损伤位点的传感器机制尚未充分表征。我们阐明了NBSI与γ-H2 AX物理相互作用，在DNA损伤位点形成核灶。NBSI的叉头相关结构域（FHA）和BRCA 1 C末端结构域（BRCT）对于NBSI响应DNA损伤的物理相互作用和焦点形成至关重要。通过将抗-γ-H2 AX抗体引入细胞来抑制这种相互作用消除了响应于DNA损伤的NBS 1病灶形成。因此，FHA/BRCT结构域可能对与组蛋白的结合以及将NBS 1/hMRE 11/hRAD 50复合物重新定位到DNA损伤附近具有关键作用。此外，含有BRCT结构域的DNA修复相关蛋白（如BRCA 1）的灶形成需要与γ-H2 AX相互作用以响应DNA损伤。这些发现表明，γ-H2 AX和DNA修复相关蛋白之间的物理相互作用对于这些蛋白的募集是不可或缺的。此外，最近有报道称，NBS 1/hMRE 11/hRAD 50复合物对于ATM向DNA损伤位点的募集和随后的ATM活化都具有关键作用。因此，γ-H2 AX和NBS 1/hMRE 11/hRAD 50复合物都可能在DNA损伤的初始识别中起作用。
DNA double-strand breaks represent the most potentially serious damage to a genome, and hence, many repair proteins are recruited to DNA damage sites by as yet poorly characterized sensor mechanisms. We clarified that NBSI physically interacts with gamma-H2AX to form nuclear foci at DNA damage sites. The fork-head associated (FHA) and the BRCA1 C-terminal domains (BRCT) of NBSI are essential for this physical interaction and focus formation of NBSI in response to DNA damage. The inhibition of this interaction by introduction of anti-gamma-H2AX antibody into cells abolishes NBS1 foci formation in response to DNA damage. Consequently, the FHA/BRCT domain is likely to have a crucial role for both binding to histone and for re-localization of the NBS1/hMRE11/hRAD50 complex to the vicinity of DNA damage. Moreover, the foci formation of DNA repair-related proteins containing BRCT domain, such as BRCA1, requires the interaction with gamma-H2AX in response to DNA damage. These findings indicate that the physical interaction between gamma-H2AX and DNA repair-related proteins is indispensable for the recruitment of these proteins. Further, it was recently reported that the NBS1/hMRE11/hRAD50 complex has a crucial role for both the recruitment of ATM to DNA damage sites and the subsequent activation of ATM. Therefore, both gamma-H2AX and the NBS1/hMRE11/hRAD50 complex might function for the initial recognition of DNA damage.