FBS Colloquia No.265Human Cell Biology Group

Functional analysis of CSA ubiquitin ligase complex in transcription-coupled nucleotide excision repair

DNA lesion that is on the transcribed strand of genes and inhibits transcription elongation is removed by "transcription-coupled nucleotide excision repair (TC-NER)". It is known that the arrest of RNA polymerase progression by the lesions triggers the recruitment of repair factors, but the molecular mechanism of how DNA lesions are removed and transcription is resumed is not yet clear. CSA, one of the TC-NER factors, has seven WD40 repeat motifs and forms Cullin 4-RING ubiquitin ligase complex (CRL4). In this colloquium, I will present analyses on complex formation and repair ability using CSA mutants and also consider the involvement of the CSA complex in the ubiquitination of RNA polymerase II after UV irradiation.