Identification of a novel GR-ARID1a-P53BP1 protein complex involved in DNA damage repair and cell cycle regulation.
Felicity E StubbsBenjamin P FlynnCaroline A RiversMatthew T BirnieAndrew HermanErin E SwinsteadSongjoon BaekHai FangJillian TempleJason S CarrollGordon L HagerStafford Louis LightmanBecky L Conway-CampbellPublished in: Oncogene (2022)
ARID1a (BAF250), a component of human SWI/SNF chromatin remodeling complexes, is frequently mutated across numerous cancers, and its loss of function has been putatively linked to glucocorticoid resistance. Here, we interrogate the impact of siRNA knockdown of ARID1a compared to a functional interference approach in the HeLa human cervical cancer cell line. We report that ARID1a knockdown resulted in a significant global decrease in chromatin accessibility in ATAC-Seq analysis, as well as affecting a subset of genome-wide GR binding sites determined by analyzing GR ChIP-Seq data. Interestingly, the specific effects on gene expression were limited to a relatively small subset of glucocorticoid-regulated genes, notably those involved in cell cycle regulation and DNA repair. The vast majority of glucocorticoid-regulated genes were largely unaffected by ARID1a knockdown or functional interference, consistent with a more specific role for ARID1a in glucocorticoid function than previously speculated. Using liquid chromatography-mass spectrometry, we have identified a chromatin-associated protein complex comprising GR, ARID1a, and several DNA damage repair proteins including P53 binding protein 1 (P53BP1), Poly(ADP-Ribose) Polymerase 1 (PARP1), DNA damage-binding protein 1 (DDB1), DNA mismatch repair protein MSH6 and splicing factor proline and glutamine-rich protein (SFPQ), as well as the histone acetyltransferase KAT7, an epigenetic regulator of steroid-dependent transcription, DNA damage repair and cell cycle regulation. Not only was this protein complex ablated with both ARID1a knockdown and functional interference, but spontaneously arising DNA damage was also found to accumulate in a manner consistent with impaired DNA damage repair mechanisms. Recovery from dexamethasone-dependent cell cycle arrest was also significantly impaired. Taken together, our data demonstrate that although glucocorticoids can still promote cell cycle arrest in the absence of ARID1a, the purpose of this arrest to allow time for DNA damage repair is hindered.
Keyphrases
- dna damage
- cell cycle
- dna repair
- genome wide
- binding protein
- cell cycle arrest
- cell proliferation
- dna methylation
- gene expression
- oxidative stress
- mass spectrometry
- liquid chromatography
- transcription factor
- endothelial cells
- pi k akt
- dna damage response
- protein protein
- electronic health record
- low dose
- amino acid
- artificial intelligence
- single cell
- single molecule
- cancer therapy
- deep learning
- ms ms
- induced pluripotent stem cells
- machine learning
- circulating tumor