O-GlcNAcylation Affects the Pathway Choice of DNA Double-Strand Break Repair.
Sera AverbekBurkhard JakobMarco DuranteNicole B AverbeckPublished in: International journal of molecular sciences (2021)
Exposing cells to DNA damaging agents, such as ionizing radiation (IR) or cytotoxic chemicals, can cause DNA double-strand breaks (DSBs), which are crucial to repair to maintain genetic integrity. O-linked β-N-acetylglucosaminylation (O-GlcNAcylation) is a post-translational modification (PTM), which has been reported to be involved in the DNA damage response (DDR) and chromatin remodeling. Here, we investigated the impact of O-GlcNAcylation on the DDR, DSB repair and chromatin status in more detail. We also applied charged particle irradiation to analyze differences of O-GlcNAcylation and its impact on DSB repair in respect of spatial dose deposition and radiation quality. Various techniques were used, such as the γH2AX foci assay, live cell microscopy and Fluorescence Lifetime Microscopy (FLIM) to detect DSB rejoining, protein accumulation and chromatin states after treating the cells with O-GlcNAc transferase (OGT) or O-GlcNAcase (OGA) inhibitors. We confirmed that O-GlcNAcylation of MDC1 is increased upon irradiation and identified additional repair factors related to Homologous Recombination (HR), CtIP and BRCA1, which were increasingly O-GlcNAcyated upon irradiation. This is consistent with our findings that the function of HR is affected by OGT inhibition. Besides, we found that OGT and OGA activity modulate chromatin compaction states, providing a potential additional level of DNA-repair regulation.
Keyphrases
- dna repair
- dna damage
- single molecule
- dna damage response
- induced apoptosis
- genome wide
- gene expression
- transcription factor
- circulating tumor
- oxidative stress
- cell free
- high throughput
- cell cycle arrest
- high resolution
- radiation induced
- dna methylation
- optical coherence tomography
- endoplasmic reticulum stress
- risk assessment
- mass spectrometry
- small molecule
- human health
- copy number
- radiation therapy