Sci. STKE, 6 April 2004
CHECKPOINTS Complex Response to DNA Damage
Cells avoid the disastrous effects of DNA damage by activating a checkpoint mechanism to prevent proliferation of cells that contain damaged DNA. The protein kinase ATM is an important component of this signaling mechanism, but precisely how its activity is regulated has not been clear. The protein Nbs1, which is mutated in the human disorder Nijmegen breakage syndrome, forms MRN complexes with two other proteins that participate in DNA repair, Mre11 and Rad50 (Mre11-Rad50-Nbs1, hence, MRN). Nbs is also a substrate for ATM. But now, Lee and Paull suggest that the interaction between Nbs1 and ATM is more complicated. MRN complexes directly activate enzymatic activity of ATM, possibly by causing a conformational change in ATM that alters the affinity of the kinase toward its substrates.
Citation: Complex Response to DNA Damage. Sci. STKE 2004, tw128 (2004).
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