Rad23 links DNA repair to the ubiquitin/proteasome pathway

Abstract

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.

Energetic determinants of protein binding specificity: Insights into protein interaction networks

“…This fact is in accord with our predictions of their role as hot spots in the interaction with ubiquitin protease ubp2 (YOR124C). The other two predicted modules are located in two hydrophobic patches, the first contains two hot spots (I44,F45) that has been related to endocytosis and proteasome degradation [47], and were predicted to interact with rad23 (YEL037C), a protein involved in DNA repair that interacts with the proteasome [48], while the second one contains a single hot spot (F4), which is mainly involved in internalization [49], and interacts with the deubiquitinating enzyme dsk2 (YMR276W).…”

Biochemical and Structural Domain Analysis of Xeroderma Pigmentosum Complementation Group C Protein

“…3-20 ng of either proteinase K, subtilisn, chymotrypsin, or trypsin (from 1 ng/µl stock solutions) were added to the samples and incubated. 10 µl aliquots were removed from the reaction mix at time points 0, 1,5,10,15,20,30,45,60,90, and 120 min post-addition of the protease and combined with 10 µl of gel loading solution. The gel sample for each time point was heated immediately at 90 °C for 10 min and then placed on ice for the remainder of the experiment until complete analysis by SDS-PAGE.…”

Proteasome inhibitor induced gene expression profiles reveal overexpression of transcriptional regulators ATF3, GADD153 and MAD1

“…Proteins targeted for proteasomal degradation have functions in a wide variety of cellular processes from growth factor response (Bai, 1995) to antigen presentation (Bogyo et al, 1997), cell cycle control (Machiels et al, 1997), DNA repair (Schauber et al, 1998), proliferation (Wang et al, 1998a) and apoptosis (Drexler, 1998).…”