Transcription-coupled repair in yeast is independent from ubiquitylation of RNA pol II: implications for Cockayne's syndrome.

Cockayne's syndrome cells lack transcription-coupled nucleotide excision repair (TCR) and ubiquitylation of RNA polymerase II large subunit (RNA pol II LS), suggesting that ubiquitylation of RNA pol II LS may be necessary for TCR in eukaryotes. Rsp5 is the sole yeast ubiquitin-protein ligase that ubiquitylates RNA pol II LS in cells exposed to DNA-damaging agents. In yeast lacking functional Rsp5, there is no ubiquitylation of RNA pol II LS. We show here that removal, repression, or over-expression of Rsp5 has no effect on TCR, demonstrating that ubiquitylation of the RNA pol II LS is not required for TCR. We infer that the lack of ubiquitylation of RNA pol II LS in Cockayne's syndrome cells does not cause their defect in TCR.