Rad23 links DNA repair to the ubiquitin/proteasome pathway.
Rad23 is an evolutionarily conserved protein that is important for nucleotide excision repair. A regulatory role has been proposed for Rad23 because rad23 mutants are sensitive to ultraviolet light but are still capable of incising damaged DNA. Here we show that Rad23 interacts with the 26S proteasome through an amino-terminal ubiquitin-like domain (UbL[R23]). The carboxy terminus of Rad23 binds to the Rad4 DNA repair protein and creates a link between the DNA repair and proteasome pathways. The ultraviolet sensitivity caused by deletion of the UbL(R23) domain may therefore arise from its inability to interact with the proteasome. The fusion proteins glutathione S-transferase (GST)-Rad23 and Rad4-haemagglutinin (HA), and the proteasome subunits Cim3 and Cim5, cofractionate through consecutive chromatography steps. The ubiquitin-like domain of human Rad23 (UbL[HRB]) also interacts with the human proteasome. These results demonstrate that ubiquitin-like domains (UbLs) represent a new class of proteasome-interacting motifs.
Schauber
C
C
Department of Biochemistry, Robert Wood Johnson Medical School, University of Medicine and Dentistry of New Jersey, Piscataway 08854, USA.
Chen
L
L
Tongaonkar
P
P
Vega
I
I
Lambertson
D
D
Potts
W
W
Madura
K
K
D000251:Adenosine Triphosphatases / Q000378:metabolism; D001665:Binding Sites; D004260:DNA Repair; D045643:DNA Repair Enzymes; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism; D005982:Glutathione Transferase / Q000235:genetics; D006801:Humans; D010447:Peptide Hydrolases / Q000378:metabolism*; D046988:Proteasome Endopeptidase Complex; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D012097:Repressor Proteins / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins; D029702:Schizosaccharomyces pombe Proteins; D011503:Transglutaminases; D014452:Ubiquitins / Q000378:metabolism*
D004268:DNA-Binding Proteins; D005656:Fungal Proteins; C082463:RAD4 protein, S pombe; D011993:Recombinant Fusion Proteins; D012097:Repressor Proteins; D029701:Saccharomyces cerevisiae Proteins; D029702:Schizosaccharomyces pombe Proteins; D014452:Ubiquitins; C086985:RAD23A protein, human; D011503:Transglutaminases; D005982:Glutathione Transferase; D010447:Peptide Hydrolases; D046988:Proteasome Endopeptidase Complex; C061553:ATP dependent 26S protease; D000251:Adenosine Triphosphatases; C084493:RPT1 protein, S cerevisiae; C069670:RPT6 protein, S cerevisiae; D045643:DNA Repair Enzymes