Structures of Nbs1 domains alone [161,168, 169] and bound to a CTP1 peptide  or Mre11 [167, 170] have illuminated our knowledge of the eukaryotic-specific components.
Limbo et al., "Nbs1 flexibly tethers Ctp1 and Mre11-Rad50 to coordinate DNA double-strand break processing and repair," Cell, vol.
Clapperton et al, "A supramodular FHA/BRCT-repeat architecture mediates Nbs1 adaptor function in response to DNA damage," Cell, vol.
Electron microscopy has revealed that ATM binds to DNA in monomeric form and upon exposure to ionizing radiation ATM phosphorylates many proteins, including Chk2, p53, NBS1, and BRCA1 (Cortez et al., 1999).
ATM-dependent phosphorylation of BRCA1, NBS1 and two additional players in the NBS1 branch of the pathway the SMC1, a chromosomal structural maintenance protein and FANCD2, a Fanconi anemia complementation group D2 protein, both are needed for an intact intra-S phase checkpoint (Shiloh et al., 2003; Andrea et al., 2003).
The majority of HR repair is mediated by Rad52 epistasis group that includes the Rad51, Rad52, Rad54, Rad55, Rad57, MRE11 and NBS1 function in the initial sensor of the broken DNA ends (Sonoda et al., 2001).
A functional link between SIRT1 deacetylase and NBS1
in DNA damage response.
Huang, "The phosphorylation status of PAS-B distinguishes HIF-1alpha from HIF-2alpha in NBS1
repression," The EMBO Journal, vol.
Initiation and maintenance of the SASP requires the DDR proteins ATM, NBS1
, and CHK2, but not p53 and pRb.
In A549 cells, [H.sub.2][O.sub.2] activates DDR through the Mre11 (MRN) complex of proteins (Mre11, Rad50, and Nbs1
), which are essential for activation of telangiectasia mutated protein kinase (ATM), checkpoint kinase 2 (Chk2), and H2AX ([gamma]H2AX).
Rzeszowska-Wolny, "The influence of XPD, APE1, XRCC1, and NBS1
polymorphic variants on DNA repair in cells exposed to X-rays," Mutation Research--Genetic Toxicology and Environmental Mutagenesis, vol.