Genetic and physical interactions between Schizosaccharomyces pombe Mcl1 and Rad2, Dna2 and DNA polymerase alpha: evidence for a multifunctional role of Mcl1 in DNA replication and repair.
Schizosaccharomyces pombe rad2 is involved in Okazaki fragments processing during lagging-strand DNA replication. Previous studies identified several slr mutants that are co-lethal with rad2Delta and sensitive to methyl methanesulfonate as single mutants. One of these mutants, slr3-1, is characterized here. Complementation and sequence analyses show that slr3-1 (mcl1-101) is allelic to mcl1(+), which is required for chromosome replication, cohesion and segregation. mcl1-101 is temperature-sensitive for growth and is highly sensitive to DNA damage. mcl1 cells arrest with 2C DNA content and chromosomal DNA double-strand breaks accumulate at the restrictive temperature. Mcl1p, which belongs to the Ctf4p/SepBp family, interacts both genetically and physically with DNA polymerase alpha. Mutations in rhp51 and dna2 enhance the growth defect of the mcl1-101 mutant. These results strongly suggest that Mcl1p is a functional homologue of Saccharomyces cerevisiae Ctf4p and plays a role in lagging-strand synthesis and Okazaki fragment processing, in addition to DNA repair.
Tsutsui
Yasuhiro
Y
Research Institute for Microbial Diseases, Osaka University, Suita, Osaka 565-0871, Japan. ytsutsui@lab.nig.ac.jp
Morishita
Takashi
T
Natsume
Toyoaki
T
Yamashita
Kentaro
K
Iwasaki
Hiroshi
H
Yamao
Fumiaki
F
Shinagawa
Hideo
H
D003001:Cloning, Molecular; D004247:DNA; D004249:DNA Damage; D004256:DNA Polymerase I / Q000235:genetics* / Q000378:metabolism; D004260:DNA Repair / Q000502:physiology*; D004261:DNA Replication / Q000502:physiology*; D016521:Electrophoresis, Gel, Pulsed-Field; D004706:Endodeoxyribonucleases / Q000235:genetics* / Q000378:metabolism; D045585:Flap Endonucleases / Q000235:genetics* / Q000502:physiology; D009154:Mutation; D064549:Myeloid Cell Leukemia Sequence 1 Protein; D009363:Neoplasm Proteins / Q000235:genetics* / Q000378:metabolism; D010957:Plasmids; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics* / Q000378:metabolism; D012568:Schizosaccharomyces / Q000235:genetics* / Q000378:metabolism; D029702:Schizosaccharomyces pombe Proteins / Q000235:genetics; D020798:Two-Hybrid System Techniques
D064549:Myeloid Cell Leukemia Sequence 1 Protein; D009363:Neoplasm Proteins; C022262:Okazaki fragments; D019253:Proto-Oncogene Proteins c-bcl-2; D029702:Schizosaccharomyces pombe Proteins; D004247:DNA; D004256:DNA Polymerase I; C493531:Dna2 protein, S pombe; D004706:Endodeoxyribonucleases; D045585:Flap Endonucleases; C445562:Rad2 protein, S pombe