Rouse John, Jackson Stephen P
Wellcome Trust and Cancer Research UK, Institute of Cancer and Developmental Biology, University of Cambridge, Cambridge CB2 1QR, United Kingdom.
Mol Cell. 2002 Apr;9(4):857-69. doi: 10.1016/s1097-2765(02)00507-5.
The Lcd1p/Mec1p complex is crucial for normal S phase progression and for signaling DNA damage. We show that Lcd1p/Ddc2p and Mec1p in cell extracts bind to DNA ends. Although Lcd1p binds DNA independently of Mec1p, recruitment of Mec1p to DNA requires Lcd1p. DNA binding by Lcd1p is also independent of Rad9p, Rad17p, and Rad24p. Recombinant Lcd1p binds DNA, and this is impaired by Lcd1p mutations that abrogate its in vivo functions. Furthermore, Mec1p is recruited to cdc13-induced DNA damage and HO endonuclease-induced double-strand breaks in vivo. This requires Lcd1p, and recruitment of Lcd1p/Mec1p to cdc13-induced damage is abolished by Lcd1p mutations that abrogate its in vivo functions. Recruitment of Lcd1p to these lesions is independent of Mec1p and Rad9p/Rad24p. Thus, recruitment of Mec1p to DNA lesions by Lcd1p is crucial for the DNA damage response.
Lcd1p/Mec1p复合物对于正常的S期进程以及DNA损伤信号传导至关重要。我们发现，细胞提取物中的Lcd1p/Ddc2p和Mec1p能与DNA末端结合。尽管Lcd1p可独立于Mec1p结合DNA，但Mec1p募集至DNA需要Lcd1p。Lcd1p与DNA的结合也不依赖于Rad9p、Rad17p和Rad24p。重组Lcd1p能结合DNA，而那些消除其体内功能的Lcd1p突变会损害这种结合。此外，在体内，Mec1p被募集至cdc13诱导的DNA损伤处以及HO核酸内切酶诱导的双链断裂处。这需要Lcd1p，而那些消除其体内功能的Lcd1p突变会消除Lcd1p/Mec1p募集至cdc13诱导的损伤处的现象。Lcd1p募集至这些损伤处不依赖于Mec1p以及Rad9p/Rad24p。因此，Lcd1p将Mec1p募集至DNA损伤处对于DNA损伤反应至关重要。
