A network of multi-tasking proteins at the DNA replication fork preserves genome stability.
To elucidate the network that maintains high fidelity genome replication, we have introduced two conditional mutant alleles of DNA2, an essential DNA replication gene, into each of the approximately 4,700 viable yeast deletion mutants and determined the fitness of the double mutants. Fifty-six DNA2-interacting genes were identified. Clustering analysis of genomic synthetic lethality profiles of each of 43 of the DNA2-interacting genes defines a network (consisting of 322 genes and 876 interactions) whose topology provides clues as to how replication proteins coordinate regulation and repair to protect genome integrity. The results also shed new light on the functions of the query gene DNA2, which, despite many years of study, remain controversial, especially its proposed role in Okazaki fragment processing and the nature of its in vivo substrates. Because of the multifunctional nature of virtually all proteins at the replication fork, the meaning of any single genetic interaction is inherently ambiguous. The multiplexing nature of the current studies, however, combined with follow-up supporting experiments, reveals most if not all of the unique pathways requiring Dna2p. These include not only Okazaki fragment processing and DNA repair but also chromatin dynamics.
Budd
Martin E
ME
Braun Laboratories, California Institute of Technology, Pasadena, California, USA.
Tong
Amy Hin Yan
AH
Polaczek
Piotr
P
Peng
Xiao
X
Boone
Charles
C
Campbell
Judith L
JL
D000251:Adenosine Triphosphatases / Q000235:genetics*; D002843:Chromatin / Q000737:chemistry; D002874:Chromosome Mapping; D016000:Cluster Analysis; D004249:DNA Damage; D004265:DNA Helicases / Q000235:genetics*; D004260:DNA Repair; D004261:DNA Replication; D004275:DNA, Ribosomal / Q000235:genetics; D016681:Genome, Fungal; D006657:Histones / Q000737:chemistry; D006801:Humans; D018384:Oxidative Stress; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics*; D012854:Sister Chromatid Exchange
D002843:Chromatin; D004275:DNA, Ribosomal; D006657:Histones; D029701:Saccharomyces cerevisiae Proteins; D000251:Adenosine Triphosphatases; D004265:DNA Helicases; C410222:DNA2 protein, S cerevisiae