POGZ promotes homology‐directed DNA repair in an HP1‐dependent manner

Abstract

The heterochromatin protein HP1 plays a central role in the maintenance of genome stability but little is known about how HP1 is controlled. Here, we show that the zinc finger protein POGZ promotes the presence of HP1 at DNA double-strand breaks (DSBs) in human cells. POGZ depletion delays the resolution of DSBs and sensitizes cells to different DNA-damaging agents, including cisplatin and talazoparib. Mechanistically, POGZ promotes homology-directed DNA repair by retaining the BRCA1/BARD1 complex at DSBs in an HP1-dependent manner. In vivo CRISPR inactivation of Pogz is embryonically lethal. Pogz haploinsufficiency (Pogz + /delta) results in developmental delay, impaired intellectual abilities, hyperactive behaviour and a compromised humoral immune response in mice, recapitulating the main clinical features of the White Sutton syndrome (WHSUS). Pogz + /delta mice are further radiosensitive and accumulate DSBs in diverse tissues, including the spleen and brain. Altogether, our findings identify POGZ as an important player in homology-directed DNA repair both in vitro and in vivo.

CHAMP1 binds to REV7/FANCV and promotes homologous recombination repair

“…To confirm and extend these studies, we next evaluated the POGZ subunit of this complex. A recent report indicated that POGZ also functions in HR repair ( Heath et al, 2021 ). Consistent with this report, knockdown of POGZ, like knockout of CHAMP1, resulted in decreased DSB end resection, decreased RAD51 foci, and increased PARPi sensitivity, consistent with a decrease in HR activity ( Figures 7A – 7C , S7A , and S7B ).…”

C1orf112 is a novel regulator of interstrand crosslink that decreases FIGNL1-RAD51 interaction

“…Analysis of MS data was conducted as described before with minor modifications 55 . Briefly, samples were injected into an Orbitrap Fusion (Thermo Fisher), and raw files were analyzed with the Comet, XTandem!…”

“…Analyses of Annexin-V and PI signals were done on at least 30 000 events acquired on a BD Fortessa (Becton Dickinson). Data were analyzed using the FlowJo software as previously described 55 .…”

“…mturboID sample preparation for mass spectrometry HEK293 Flp-In tm cells expressing mTurboID-tagged protein or mTurbo tag alone were seeded in 150 mm plates in technical duplicates. Induction of fusion protein and proximity biotinylation were conducted as previously described 14,55 . Briefly, induction of mturboID-tagged protein expression was done by adding 1 µM tetracycline to the media for 24 h. Then, the medium was supplemented with 50 µM biotin for 1 hr and incubated for an additional 3hrs with 100 ng/mL neocarzinostatin (NCS).…”

“…Analysis of MS data was conducted as described before with minor modifications 55 (A) Chemogenomic profiling using the NormZ-score from the CRISPR screens performed in RPE1 hTERT Cas9 p53 -/cells with the indicated DNA damaging agents as detailed in 28 .…”