Nucleotide excision repair machinery (NER)

The Nucleotide Excision Repair (NER) machinery is a sophisticated multi-protein system essential for maintaining genomic integrity by removing bulky DNA lesions, such as UV-induced pyrimidine dimers and chemical adducts (Schärer, 2013, Cold Spring Harb Perspect Biol). The pathway functions through two distinct recognition mechanisms: Global Genomic NER (GG-NER), which monitors the entire genome, and Transcription-Coupled NER (TC-NER), which specifically repairs lesions that stall RNA polymerase II (Marteijn et al., 2014, Nat Rev Mol Cell Biol). Key components of this machinery include the TFIIH complex (containing XPB and XPD helicases), XPA, and the ERCC1-XPF endonuclease (UniProt). In clinical practice, NER activity is a major factor in tumor resistance to platinum-based chemotherapy, as the machinery repairs the DNA cross-links these drugs create (Bowden, 2004, Nat Rev Cancer). Therapeutic strategies currently explore the inhibition of NER proteins, such as using Spironolactone to target XPB, to overcome drug resistance and enhance the efficacy of DNA-damaging treatments (Aleixo et al., 2015, Chem Biol). Conversely, genetic deficiencies in NER components lead to disorders like Xeroderma pigmentosum, characterized by extreme UV sensitivity and a high incidence of skin cancer (NIH).

Other names

NER pathwayDNA nucleotide excision repair complexNucleotide excision repair systemNER machinery

Inhibition of specific NER components (e.g., XPB, XPA, or ERCC1) to prevent the removal of bulky DNA lesions, thereby sensitizing cancer cells to DNA-damaging agents or inducing apoptosis in repair-deficient tumors (Schärer, 2013; Aleixo et al., 2015).