Living Cells Employ Ubiquitin-Proteasomal System and Nucleotide Excision Repair Pathways to Remove Reactive Oxygen...

Area of Science:

• Molecular Biology
• Biochemistry
• Genetics

Background:

• Oxidative DNA damage from reactive oxygen species (ROS) drives aging and diseases.
• ROS-induced DNA-protein crosslinks (DPCs) are toxic but poorly characterized.
• Understanding ROS-DPC formation and repair is crucial for cellular health.

Purpose of the Study:

• To characterize ROS-induced DPCs in human cells.
• To elucidate the mechanisms of ROS-DPC removal.
• To explore therapeutic strategies for preventing ROS-DPC formation.

Main Methods:

• Hydrogen peroxide (H2O2) treatment of human fibrosarcoma (HT1080) cells.
• Mass spectrometry-based proteomics to identify proteins in DPC formation.
• Analysis of DNA replication and transcription roles in DPC detection and repair.

Main Results:

• Over 100 cellular proteins involved in ROS-DPC formation were identified, many linked to DNA metabolism.
• DNA replication and transcription facilitate ROS-DPC detection.
• The ubiquitin-proteasomal system (UPS), SPRTN metalloprotease, and nucleotide excision repair (NER) are key to ROS-DPC removal.
• A glutathione (GSH) analog (ψ-GSH) blocked ROS-DPC formation.

Conclusions:

• Living cells possess mechanisms to recognize and remove ROS-induced DPCs.
• SPRTN and NER play critical roles in repairing these lesions.
• Glutathione analogs show potential for preventing ROS-DPC-associated diseases.