| Popis: |
The Saccharomyces cerevisiae Rad9 checkpoint protein contains only one set of known domains - the BRCT domains. Originally identified in the C-terminus of the human breast cancer susceptibility gene BRCAl, these domains occur frequently in proteins involved in recognizing and/or repairing DNA damage. To better understand the role of the two C-terminal BRCT domains in Rad9, various deletion constructs were created and either overexpressed or endogenously expressed in rad9 strains. These strains were assayed for their ability to repair different forms of DNA damage and for their ability to arrest in response to such damage. Other indicators, such as downstream phosphorylation of Rad53, were also analyzed as signs of activation of the rad9 deletion constructs. Our results show that the BRCT domains are essential for Rad9's checkpoint functions. These domains act to increase the local concentration of Rad9 both by stabilizing the protein and by dimerizing the protein. |
