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Series GSE133805 Query DataSets for GSE133805
Status Public on Oct 22, 2019
Title 53BP1 Enforces Distinct Pre- and Post-resection Blocks on Homologous Recombination (ChIP-seq)
Organism Mus musculus
Experiment type Genome binding/occupancy profiling by high throughput sequencing
Summary 53BP1 activity drives genome instability and embryonic lethality in BRCA1-deficient cells by inhibiting homologous recombination (HR).53BP1’s anti-recombinogenic functions require phosphorylation-dependent interactions with two effector complexes, PTIP and RIF1/Shieldin. While RIF1/Shieldin is thought to block 5’-3’ nucleolytic processing of DNA ends, it remains unclear how PTIP antagonizes HR. Here we show that mutation of the PTIP interaction site in 53BP1 (S25A) increases Shieldin association with DNA damage. Despite excessive Shieldin “end-blocking” activity, the mutant protein allows end resection sufficient to rescue the lethality of BRCA1D11 mice. End resection in BRCA1D1153BP1S25A mice is rewired in a manner driven by DNA2 since Shieldin blocks EXO1-mediated nucleolytic processing. Despite ample resection, mutant cells fail to complete HR, as 53BP1/Shieldin also inhibits RNF168-mediated loading of PALB2/RAD51 onto ssDNA post-resection. As a result, BRCA1D1153BP1S25A mice exhibit hallmark features of HR insufficiency, including increased developmental neuronal apoptosis, premature aging and hypersensitivity to PARP inhibitors. Disruption of Shieldin or forced targeting of PALB2 to ssDNA in BRCA1D1153BP1S25A cells restores RNF168 recruitment, RAD51 nucleofilament formation, and PARPi resistance. Our study supports a model in which RIF1/Shieldin and PTIP associate independently with 53BP1 to regulate distinct end-resection pathways, and reveals a critical function of 53BP1/Shieldin post-resection that limits RNF168-mediated loading of RAD51.
Overall design RPA ChIP-seq in WT, 53BP1-/-, BRCA1-/- MEFs at DSB sites upon induction of AsiSI. Rad51 ChIP-seq profile in WT, BRCA1-/- and BRCA1-/- 53BP1_S25A MEFs with or without FHA-PALB2 at AsiSI-induced DSB sites
Contributor(s) Callen E, Zong D, Wu W, Wong N, Stanlie A, Dumitrache LC, Byrum AK, Mendez-Dorantes C, Martinez P, Canela A, Maman Y, Day A, Kruhlak MJ, Blasco MA, Stark JM, Mosammaparast N, McKinnon PJ, Nussenzweig A
Citation(s) 31653568
Submission date Jul 03, 2019
Last update date Jan 21, 2020
Contact name Wei Wu
Organization name National Cancer Institute
Department Center for Cancer Research
Lab Laboratory of Genome Integrity
Street address 9000 Rockville Pike
City Bethesda
State/province MD
ZIP/Postal code 20892
Country USA
Platforms (1)
GPL21626 NextSeq 550 (Mus musculus)
Samples (9)
GSM3927546 WT AsiSI MEFS RPA ChIP-seq
GSM3927547 BRCA1-/- AsiSI MEFS RPA ChIP-seq
GSM3927548 53BP1-/- AsiSI MEFS RPA ChIP-seq
This SubSeries is part of SuperSeries:
GSE133808 53BP1 Enforces Distinct Pre- and Post-resection Blocks on Homologous Recombination
BioProject PRJNA552569
SRA SRP212930

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Supplementary file Size Download File type/resource
GSE133805_RAW.tar 412.5 Mb (http)(custom) TAR (of BW)
SRA Run SelectorHelp
Raw data are available in SRA
Processed data provided as supplementary file

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