title: Sap1 is a replication-initiation factor essential for the assembly of pre-replicative complex in the fission yeastSchizosaccharomyces pombe.
abstract: A central step in the initiation of chromosomal DNA replication in eukaryotes is the assembly of pre-replicative complex (pre-RC) at late M and early G1phase of the cell cycles. Since 1973, four proteins or protein complexes, including cell division control protein 6 (Cdc6)/Cdc18, minichromosome maintenance protein complex, origin recognition complex (ORC), and Cdt1, are known components of the pre-RC. Previously, we reported that a non-ORC protein binds to the essential element Δ9 of theSchizosaccharomyces pombeDNA-replication origin ARS3001. In this study, we identified that the non-ORC protein is Sap1. Like ORC, Sap1 binds to DNA origins during cell growth cycles. But unlike ORC, which binds to asymmetric AT-rich sequences through its nine AT-hook motifs, Sap1 preferentially binds to a DNA sequence of 5'-(A/T)n(C/G)(A/T)9-10(G/C)(A/T)n-3' (n≥ 1). We also found that Sap1 and ORC physically interact. We further demonstrated that Sap1 is required for the assembly of the pre-RC because of its essential role in recruiting Cdc18 to DNA origins. Thus, we conclude that Sap1 is a replication-initiation factor that directly participates in the assembly of the pre-RC. DNA-replication origins in fission yeast are defined by possessing two essential elements with one bound by ORC and the other by Sap1.
authors.affiliation: From the Peking-Tsinghua Center for Life Sciences, National Laboratory of Protein and Plant Gene Research, College of Life Sciences.
authors.forename: Ling
authors.initials: L
authors.lastname: Guan
authors.affiliation: From the Peking-Tsinghua Center for Life Sciences, National Laboratory of Protein and Plant Gene Research, College of Life Sciences.
authors.forename: Peng
authors.initials: P
authors.lastname: He
authors.affiliation: From the Peking-Tsinghua Center for Life Sciences, National Laboratory of Protein and Plant Gene Research, College of Life Sciences.
authors.forename: Fang
authors.initials: F
authors.lastname: Yang
authors.affiliation: From the Peking-Tsinghua Center for Life Sciences, National Laboratory of Protein and Plant Gene Research, College of Life Sciences.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: the Beijing Nuclear Magnetic Resonance Center.|the College of Chemistry and Molecular Engineering, and.
authors.forename: Yunfei
authors.initials: Y
authors.lastname: Hu
authors.affiliation: the Beijing Nuclear Magnetic Resonance Center.
authors.forename: Jienv
authors.initials: J
authors.lastname: Ding
authors.affiliation: From the Peking-Tsinghua Center for Life Sciences, National Laboratory of Protein and Plant Gene Research, College of Life Sciences.
authors.forename: Yu
authors.initials: Y
authors.lastname: Hua
authors.affiliation: the Beijing Nuclear Magnetic Resonance Center.
authors.forename: Yi
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: From the Peking-Tsinghua Center for Life Sciences, National Laboratory of Protein and Plant Gene Research, College of Life Sciences.
authors.forename: Qiong
authors.initials: Q
authors.lastname: Ye
authors.affiliation: From the Peking-Tsinghua Center for Life Sciences, National Laboratory of Protein and Plant Gene Research, College of Life Sciences.
authors.forename: Jiazhi
authors.initials: J
authors.lastname: Hu
authors.affiliation: the Department of Biology, South University of Science and Technology of China, 1088 Xueyuan Road, Nanshan District, Shenzhen 518055, Guangdong, China wangtao@sustc.edu.cn.
authors.forename: Tao
authors.initials: T
authors.lastname: Wang
authors.affiliation: the Beijing Nuclear Magnetic Resonance Center, changwen@pku.edu.cn.|the College of Chemistry and Molecular Engineering, and.|the Beijing National Laboratory for Molecular Sciences, Peking University, Beijing 100871 and.
authors.forename: Changwen
authors.initials: C
authors.lastname: Jin
authors.affiliation: From the Peking-Tsinghua Center for Life Sciences, National Laboratory of Protein and Plant Gene Research, College of Life Sciences, kongdc@pku.edu.cn.
authors.forename: Daochun
authors.initials: D
authors.lastname: Kong
mesh_terms: D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism; D004261:DNA Replication / Q000502:physiology*; D004271:DNA, Fungal / Q000096:biosynthesis* / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D059372:Nucleotide Motifs / Q000502:physiology*; D018741:Replication Origin / Q000502:physiology*; D012568:Schizosaccharomyces / Q000235:genetics / Q000378:metabolism*; D029702:Schizosaccharomyces pombe Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D018797:Cell Cycle Proteins; D004271:DNA, Fungal; D004268:DNA-Binding Proteins; C085981:Sap1 protein, S pombe; D029702:Schizosaccharomyces pombe Proteins; C082462:cdc18 protein, S pombe; C491233:cdc6 protein, S pombe
keywords: Cdc18; DNA; DNA binding protein; DNA origin; DNA replication; DNA replication initiation; DNA synthesis; DNA-protein interaction; Sap1; pre-RC