The 19S regulatory complex of the proteasome functions independently of proteolysis in nucleotide excision repair

Steven Jon Russell, Simon H. Reed, Wenya Huang, Errol C. Friedberg, Stephen Albert Johnston

Research output: Contribution to journalArticle

165 Scopus citations


The 26S proteasome degrades proteins targeted by the ubiquitin pathway, a function thought to explain its role in cellular processes. The proteasome interacts with the ubiquitin-like N terminus of Rad23, a nucleotide excision repair (NER) protein, in Saccharomyces cerevisiae. Deletion of the ubiquitin- like domain causes UV radiation sensitivity. Here, we show that the ubiquitin-like domain of Rad23 is required for optimal activity of an in vitro NER system. Inhibition of proteasomal ATPases diminishes NER activity in vitro and increases UV sensitivity in vivo. Surprisingly, blockage of protein degradation by the proteasome has no effect on the efficiency of NER. This establishes that the regulatory complex of the proteasome has a function independent of protein degradation.

Original languageEnglish (US)
Pages (from-to)687-695
Number of pages9
JournalMolecular Cell
Issue number6
Publication statusPublished - Jun 1999


ASJC Scopus subject areas

  • Molecular Biology

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