Host cell reactivation of plasmids containing oxidative DNA lesions is defective in Cockayne syndrome but normal in UV-sensitive syndrome fibroblasts

摘要: Abstract UV-sensitive syndrome (UV S S) is a human DNA repair-deficient disease with mild clinical manifestations. No neurological or developmental abnormalities predisposition to cancer have been reported. In contrast, Cockayne (CS) patients exhibit severe and defects, in addition photosensitivity. The cellular biochemical responses of UV CS cells are indistinguishable, result from defective transcription-coupled repair (TCR) photoproducts expressed genes. We propose that develop normally because they proficient oxidative base damage. Consistent our model, we show complementation groups A B (CS-A, CS-B) more sensitive treatment hydrogen peroxide than wild type cells. Using host cell reactivation assay plasmids containing UV-induced photoproducts, find expression the plasmid-encoded lacZ gene reduced TCR-deficient CS-B When contain lesion thymine glycol, recovery expression, whereas levels similar those 8-oxoguanine similarly CS-A cells; abasic sites single strand breaks cause decreases all lines examined. Repair glycols was measured extracted transfected removal lesions efficient without bias tested.