Excision repair cross-complementation group 3 (XPB) (XPB)

ERCC3 encodes the XPB protein, an essential DNA-dependent ATPase/helicase that unwinds damaged DNA for nucleotide excision repair and forms part of the TFIIH transcription factor complex. XPB/ERCC3 functions in both repair of bulky DNA adducts (from UV or chemicals) and initiation of transcription by RNA polymerase II. Mutations in ERCC3 cause rare genetic diseases characterized by photosensitivity, neurodevelopmental impairment, and increased risk of cancer—including xeroderma pigmentosum, trichothiodystrophy, and Cockayne syndrome. ERCC3 is studied as a potential therapeutic target in oncology and severe genetic disorders, but direct pharmacological targeting remains a challenge due to its essential roles in cellular function.

Other names

basic transcription factor 2 89 kDa subunitBTF2BTF2 p89DNA excision repair protein ERCC-3DNA repair protein complementing XP-B cellsERCC3_HUMANexcision repair cross-complementation group 3GTF2HRAD25TFIIH 89 kDa subunitTFIIH basal transcription factor complex helicase XPB subunitTFIIH p89xeroderma pigmentosum group B-complementing protein

For drugs affecting ERCC3 indirectly: induction of DNA damage that is repaired by the NER pathway, dependent on XPB helicase activity. Cells with defective ERCC3 are hypersensitive to such agents (e.g., UV irradiation, platinum-based drugs). Direct targeting is experimental: inhibition of XPB/ERCC3 helicase activity disrupts DNA repair and transcription, potentially inducing apoptosis in cancer cells.