Reference - PMID:15155581 - Chk1 activation requires Rad9 S/TQ-site phosphorylation to promote association with C-terminal BRCT domains of Rad4TOPBP1.
Reference summary
- PubMed ID
- PMID:15155581
- Title
- Chk1 activation requires Rad9 S/TQ-site phosphorylation to promote association with C-terminal BRCT domains of Rad4TOPBP1.
- Authors
- Furuya K, Poitelea M, Guo L, Caspari T, Carr AM
- Citation
- Genes Dev 2004 May 15;18(10):1154-64
- Publication year
- 2004
- Abstract
- To gain insight into the function and organization of proteins assembled on the DNA in response to genotoxic insult we investigated the phosphorylation of the Schizosaccharomyces pombe PCNA-like checkpoint protein Rad9. C-terminal T412/S423 phosphorylation of Rad9 by Rad3(ATR) occurs in S phase without replication stress. Rad3(ATR) and Tel1(ATM) phosphorylate these same residues, plus additional ones, in response to DNA damage. In S phase and after damage, only Rad9 phosphorylated on T412/S423, but not unphosphorylated Rad9, associates with a two-BRCT-domain region of the essential Rad4(TOPBP1) protein. Rad9-Rad4(TOPBP1) interaction is required to activate the Chk1 damage checkpoint but not the Cds1 replication checkpoint. When the Rad9-T412/S423 are phosphorylated, Rad4(TOPBP1) coprecipitates with Rad3(ATR), suggesting that phosphorylation coordinates formation of an active checkpoint complex.
