BRCT repeats as phosphopeptide-binding modules involved in protein targeting.
We used a proteomic approach to identify phosphopeptide-binding modules mediating signal transduction events in the DNA damage response pathway. Using a library of partially degenerate phosphopeptides, we identified tandem BRCT (BRCA1 carboxyl-terminal) domains in PTIP (Pax transactivation domain-interacting protein) and in BRCA1 as phosphoserine- or phosphothreonine-specific binding modules that recognize substrates phosphorylated by the kinases ATM (ataxia telangiectasia-mutated) and ATR (ataxia telangiectasia- and RAD3-related) in response to gamma-irradiation. PTIP tandem BRCT domains are responsible for phosphorylation-dependent protein localization into 53BP1- and phospho-H2AX (gamma-H2AX)-containing nuclear foci, a marker of DNA damage. These findings provide a molecular basis for BRCT domain function in the DNA damage response and may help to explain why the BRCA1 BRCT domain mutation Met1775 --> Arg, which fails to bind phosphopeptides, predisposes women to breast and ovarian cancer.
Center for Cancer Research, Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
Isaac A
IA
Manke
Drew M
DM
Lowery
Anhco
A
Nguyen
Michael B
MB
Yaffe
D020816:Amino Acid Motifs; D064007:Ataxia Telangiectasia Mutated Proteins; D019313:BRCA1 Protein / Q000737:chemistry* / Q000378:metabolism*; D002110:Caffeine / Q000494:pharmacology; D002151:Calorimetry; D002352:Carrier Proteins / Q000737:chemistry* / Q000378:metabolism*; D018797:Cell Cycle Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism; D002467:Cell Nucleus / Q000378:metabolism; D003600:Cytosol / Q000378:metabolism; D004249:DNA Damage; D004268:DNA-Binding Proteins; D005720:Gamma Rays; D006801:Humans; D009687:Nuclear Proteins / Q000737:chemistry* / Q000378:metabolism*; D019151:Peptide Library; D010748:Phosphopeptides / Q000378:metabolism*; D010766:Phosphorylation; D010768:Phosphoserine / Q000378:metabolism; D010769:Phosphothreonine / Q000378:metabolism; D011485:Protein Binding; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D017434:Protein Structure, Tertiary; D040901:Proteomics; D015398:Signal Transduction; D014407:Tumor Cells, Cultured; D025521:Tumor Suppressor Proteins
D019313:BRCA1 Protein; D002352:Carrier Proteins; D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; C485876:PAXIP1 protein, human; D019151:Peptide Library; D010748:Phosphopeptides; D025521:Tumor Suppressor Proteins; D010769:Phosphothreonine; D010768:Phosphoserine; D002110:Caffeine; C576897:Atr protein, mouse; C576324:ATM protein, human; C576597:ATR protein, human; D064007:Ataxia Telangiectasia Mutated Proteins; C576325:Atm protein, mouse; D017346:Protein Serine-Threonine Kinases