title: Elg1, an alternative subunit of the RFC clamp loader, preferentially interacts with SUMOylated PCNA.
abstract: Replication-factor C (RFC) is a protein complex that loads the processivity clamp PCNA onto DNA. Elg1 is a conserved protein with homology to the largest subunit of RFC, but its function remained enigmatic. Here, we show that yeast Elg1 interacts physically and genetically with PCNA, in a manner that depends on PCNA modification, and exhibits preferential affinity for SUMOylated PCNA. This interaction is mediated by three small ubiquitin-like modifier (SUMO)-interacting motifs and a PCNA-interacting protein box close to the N-terminus of Elg1. These motifs are important for the ability of Elg1 to maintain genomic stability. SUMOylated PCNA is known to recruit the helicase Srs2, and in the absence of Elg1, Srs2 and SUMOylated PCNA accumulate on chromatin. Strains carrying mutations in both ELG1 and SRS2 exhibit a synthetic fitness defect that depends on PCNA modification. Our results underscore the importance of Elg1, Srs2 and SUMOylated PCNA in the maintenance of genomic stability.
authors.affiliation: Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Ramat Aviv, Israel.
authors.forename: Oren
authors.initials: O
authors.lastname: Parnas
authors.forename: Adi
authors.initials: A
authors.lastname: Zipin-Roitman
authors.forename: Boris
authors.initials: B
authors.lastname: Pfander
authors.forename: Batia
authors.initials: B
authors.lastname: Liefshitz
authors.forename: Yuval
authors.initials: Y
authors.lastname: Mazor
authors.forename: Shay
authors.initials: S
authors.lastname: Ben-Aroya
authors.forename: Stefan
authors.initials: S
authors.lastname: Jentsch
authors.forename: Martin
authors.initials: M
authors.lastname: Kupiec
mesh_terms: D000595:Amino Acid Sequence; D034961:Antigens, Nuclear / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D004265:DNA Helicases / Q000235:genetics / Q000378:metabolism; D017353:Gene Deletion; D042822:Genomic Instability; D008969:Molecular Sequence Data; D018809:Proliferating Cell Nuclear Antigen; D011485:Protein Binding; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D016415:Sequence Alignment; D025841:Small Ubiquitin-Related Modifier Proteins / Q000737:chemistry / Q000378:metabolism*; D054875:Ubiquitination
chemical_list: D034961:Antigens, Nuclear; D002352:Carrier Proteins; C477609:Elg1 protein, S cerevisiae; C546594:POL30 protein, S cerevisiae; D018809:Proliferating Cell Nuclear Antigen; D029701:Saccharomyces cerevisiae Proteins; D025841:Small Ubiquitin-Related Modifier Proteins; C061376:SRS2 protein, S cerevisiae; D004265:DNA Helicases