title: The link between 20S proteasome activity and post-replication DNA repair in Saccharomyces cerevisiae.
abstract: We have shown previously that deletion of the Saccharomyces cerevisiae UMP1 gene encoding the 20S proteasome maturase causes sensitivity to UV radiation. In the current report, we have extended this finding to show that mutations specifically compromising chymotrypsin-like or trypsin-like activity of 20S proteasome peptidases also result in increased UV sensitivity. We have also established that mutations affecting proteasome activity, namely ump1Delta, pre2-K108R and pup1-T20A, result in spontaneous and UV-induced mutator phenotypes. To elucidate the origin of these DNA repair phenotypes of the proteasomal mutants, we performed epistasis analysis, with respect to UV sensitivity, using yeast strains with the UMP1 deletion in different DNA repair backgrounds. We show that UMP1 is not epistatic to RAD23 and RAD2, which are involved in the nucleotide excision repair (NER) pathway. Instead, our results indicate that UMP1 as well as PUP1 and PRE2 (encoding catalytic subunits of 20S proteasome) belong to an epistatic group of genes functioning in post-replication DNA repair (PRR) and are hypostatic to RAD18, which, in complex with RAD6, plays a central role in PRR. We also show that UMP1 is epistatic to REV3 and RAD30, although the relationship of UMP1 with these genes is different.
authors.affiliation: Institute of Biochemistry and Biophysics, Polish Academy of Sciences, ul. Pawinskiego 5A, 02-106 Warsaw, Poland.
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Podlaska
authors.forename: Justyna
authors.initials: J
authors.lastname: McIntyre
authors.forename: Adrianna
authors.initials: A
authors.lastname: Skoneczna
authors.forename: Ewa
authors.initials: E
authors.lastname: Sledziewska-Gojska
mesh_terms: D002172:Canavanine / Q000494:pharmacology; D015825:Chromosomes, Fungal / Q000378:metabolism; D015169:Colony Count, Microbial; D003546:Cysteine Endopeptidases / Q000235:genetics / Q000502:physiology*; D004260:DNA Repair; D004261:DNA Replication; D004268:DNA-Binding Proteins / Q000235:genetics / Q000502:physiology; D004706:Endodeoxyribonucleases / Q000235:genetics / Q000502:physiology; D004843:Epistasis, Genetic; D005656:Fungal Proteins / Q000235:genetics / Q000502:physiology; D017353:Gene Deletion; D005800:Genes, Fungal; D018832:Molecular Chaperones / Q000235:genetics; D009097:Multienzyme Complexes / Q000235:genetics / Q000502:physiology*; D009154:Mutation; D046988:Proteasome Endopeptidase Complex; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000254:growth & development / Q000528:radiation effects; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000502:physiology; D044763:Ubiquitin-Conjugating Enzymes / Q000502:physiology; D014466:Ultraviolet Rays
chemical_list: D004268:DNA-Binding Proteins; D005656:Fungal Proteins; D018832:Molecular Chaperones; D009097:Multienzyme Complexes; C490846:RAD23 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; C110856:proteasome maturation protein; C073998:RAD2 protein, S cerevisiae; D002172:Canavanine; C471606:RAD6 protein, S cerevisiae; D044763:Ubiquitin-Conjugating Enzymes; D004706:Endodeoxyribonucleases; D003546:Cysteine Endopeptidases; C080044:PRE2 protein, S cerevisiae; D046988:Proteasome Endopeptidase Complex; C479563:Pup1 protein, S cerevisiae