Phosphorylation and rapid relocalization of 53BP1 to nuclear foci upon DNA damage.
53BP1 is a human BRCT protein that was originally identified as a p53-interacting protein by the Saccharomyces cerevisiae two-hybrid screen. Although the carboxyl-terminal BRCT domain shows similarity to Crb2, a DNA damage checkpoint protein in fission yeast, there is no evidence so far that implicates 53BP1 in the checkpoint. We have identified a Xenopus homologue of 53BP1 (XL53BP1). XL53BP1 is associated with chromatin and, in some cells, localized to a few large foci under normal conditions. Gamma-ray irradiation induces increased numbers of the nuclear foci in a dose-dependent manner. The damage-induced 53BP1 foci appear rapidly (in 30 min) after irradiation, and de novo protein synthesis is not required for this response. In human cells, 53BP1 foci colocalize with Mrel1 foci at later stages of the postirradiation period. XL53BP1 is hyperphosphorylated after X-ray irradiation, and inhibitors of ATM-related kinases delay the relocalization and reduce the phosphorylation of XL53BP1 in response to X-irradiation. In AT cells, which lack ATM kinase, the irradiation-induced responses of 53BP1 are similarly affected. These results suggest a role for 53BP1 in the DNA damage response and/or checkpoint control which may involve signaling of damage to p53.
Anderson
L
L
The Wellcome Trust Centre for Cell Biology, Institute of Cell & Molecular Biology, University of Edinburgh, Edinburgh EH9 3JR, United Kingdom.
Henderson
C
C
Adachi
Y
Y
D000730:Androstadienes / Q000494:pharmacology; D000818:Animals; D064007:Ataxia Telangiectasia Mutated Proteins; D002110:Caffeine / Q000494:pharmacology; D002352:Carrier Proteins / Q000737:chemistry* / Q000378:metabolism; D018797:Cell Cycle Proteins; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism*; D003001:Cloning, Molecular; D004249:DNA Damage / Q000528:radiation effects; D004307:Dose-Response Relationship, Radiation; D004706:Endodeoxyribonucleases; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005090:Exodeoxyribonucleases; D005656:Fungal Proteins / Q000378:metabolism; D005720:Gamma Rays; D006367:HeLa Cells; D006801:Humans; D015151:Immunoblotting; D047908:Intracellular Signaling Peptides and Proteins; D008856:Microscopy, Fluorescence; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology; D010750:Phosphoproteins; D010766:Phosphorylation; D010957:Plasmids / Q000378:metabolism; D011233:Precipitin Tests; D011485:Protein Binding; D014176:Protein Biosynthesis / Q000528:radiation effects; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D017434:Protein Structure, Tertiary; D029701:Saccharomyces cerevisiae Proteins; D015398:Signal Transduction; D013997:Time Factors; D014158:Transcription, Genetic / Q000528:radiation effects; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*; D000071857:Tumor Suppressor p53-Binding Protein 1; D000077191:Wortmannin; D014965:X-Rays; D014981:Xenopus; D029867:Xenopus Proteins
D000730:Androstadienes; D002352:Carrier Proteins; D018797:Cell Cycle Proteins; D004791:Enzyme Inhibitors; D005656:Fungal Proteins; D047908:Intracellular Signaling Peptides and Proteins; D010726:Phosphodiesterase Inhibitors; D010750:Phosphoproteins; D029701:Saccharomyces cerevisiae Proteins; C498301:TP53BP1 protein, human; D016159:Tumor Suppressor Protein p53; D000071857:Tumor Suppressor p53-Binding Protein 1; D029867:Xenopus Proteins; D002110:Caffeine; C576898:Atr protein, Xenopus; C576897:Atr protein, mouse; C576597:ATR protein, human; D064007:Ataxia Telangiectasia Mutated Proteins; D017346:Protein Serine-Threonine Kinases; D004706:Endodeoxyribonucleases; D005090:Exodeoxyribonucleases; C094191:MRE11 protein, S cerevisiae; D000077191:Wortmannin