title: The histone chaperone facilitates chromatin transcription (FACT) protein maintains normal replication fork rates.
abstract: Ordered nucleosome disassembly and reassembly are required for eukaryotic DNA replication. The facilitates chromatin transcription (FACT) complex, a histone chaperone comprising Spt16 and SSRP1, is involved in DNA replication as well as transcription. FACT associates with the MCM helicase, which is involved in DNA replication initiation and elongation. Although the FACT-MCM complex is reported to regulate DNA replication initiation, its functional role in DNA replication elongation remains elusive. To elucidate the functional role of FACT in replication fork progression during DNA elongation in the cells, we generated and analyzed conditional SSRP1 gene knock-out chicken (Gallus gallus) DT40 cells. SSRP1-depleted cells ceased to grow and exhibited a delay in S-phase cell cycle progression, although SSRP1 depletion did not affect the level of chromatin-bound DNA polymerase α or nucleosome reassembly on daughter strands. The tracking length of newly synthesized DNA, but not origin firing, was reduced in SSRP1-depleted cells, suggesting that the S-phase cell cycle delay is mainly due to the inhibition of replication fork progression rather than to defects in the initiation of DNA replication in these cells. We discuss the mechanisms of how FACT promotes replication fork progression in the cells.
authors.affiliation: Molecular Cell Biology Laboratory, Graduate School of Pharmaceutical Sciences, Tohoku University, Miyagi 980-8578.
authors.forename: Takuya
authors.initials: T
authors.lastname: Abe
authors.affiliation: Department of Life Science, Graduate School of Bioresources, Mie University, Mie 514-8507; Department of Biochemistry and Proteomics, Graduate School of Medicine, Mie University, Mie 514-8507.
authors.forename: Kazuto
authors.initials: K
authors.lastname: Sugimura
authors.affiliation: Molecular Cell Biology Laboratory, Graduate School of Pharmaceutical Sciences, Tohoku University, Miyagi 980-8578.
authors.forename: Yoshifumi
authors.initials: Y
authors.lastname: Hosono
authors.affiliation: Department of Medical Sciences, Section of Biochemistry and Molecular Biology, Miyazaki Medical College, University of Miyazaki, Miyazaki 889-1692.
authors.forename: Yasunari
authors.initials: Y
authors.lastname: Takami
authors.affiliation: Molecular Cell Biology Laboratory, Graduate School of Pharmaceutical Sciences, Tohoku University, Miyagi 980-8578.
authors.forename: Motomu
authors.initials: M
authors.lastname: Akita
authors.affiliation: Molecular Cell Biology Laboratory, Graduate School of Pharmaceutical Sciences, Tohoku University, Miyagi 980-8578; Research Institute of Pharmaceutical Sciences, Faculty of Pharmacy, Musashino University, Tokyo 202-8585.
authors.forename: Akari
authors.initials: A
authors.lastname: Yoshimura
authors.affiliation: Molecular Cell Biology Laboratory, Graduate School of Pharmaceutical Sciences, Tohoku University, Miyagi 980-8578.
authors.forename: Shusuke
authors.initials: S
authors.lastname: Tada
authors.affiliation: Department of Medical Sciences, Section of Biochemistry and Molecular Biology, Miyazaki Medical College, University of Miyazaki, Miyazaki 889-1692.
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Nakayama
authors.affiliation: Department of Applied Molecular Biosciences, Graduate School of Medicine, Yamaguchi University, Yamaguchi 753-8512.
authors.forename: Hiromu
authors.initials: H
authors.lastname: Murofushi
authors.affiliation: Department of Life Science, Graduate School of Bioresources, Mie University, Mie 514-8507.
authors.forename: Katsuzumi
authors.initials: K
authors.lastname: Okumura
authors.affiliation: Department of Radiation Genetics, Faculty of Medicine, Kyoto University, Koyoto 606-8501.
authors.forename: Shunichi
authors.initials: S
authors.lastname: Takeda
authors.affiliation: Laboratory of Developmental Biology, Institute of Molecular and Cellular Biosciences, The University of Tokyo, Tokyo 111-0032, Japan. Electronic address: horikosh@am.iu-tokyo.ac.jp.
authors.forename: Masami
authors.initials: M
authors.lastname: Horikoshi
authors.affiliation: Molecular Cell Biology Laboratory, Graduate School of Pharmaceutical Sciences, Tohoku University, Miyagi 980-8578. Electronic address: seki@mail.pharm.tohoku.ac.jp.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Seki
authors.affiliation: Molecular Cell Biology Laboratory, Graduate School of Pharmaceutical Sciences, Tohoku University, Miyagi 980-8578; Research Institute of Pharmaceutical Sciences, Faculty of Pharmacy, Musashino University, Tokyo 202-8585. Electronic address: t_eno@musashino-u.ac.jp.
authors.forename: Takemi
authors.initials: T
authors.lastname: Enomoto
mesh_terms: D000818:Animals; D002453:Cell Cycle; D002645:Chickens; D002843:Chromatin / Q000737:chemistry*; D004261:DNA Replication; D004268:DNA-Binding Proteins / Q000378:metabolism*; D044127:Epigenesis, Genetic; D005434:Flow Cytometry / Q000379:methods; D006609:High Mobility Group Proteins / Q000378:metabolism*; D056488:Histone Chaperones / Q000737:chemistry*; D006657:Histones / Q000737:chemistry; D006801:Humans; D018832:Molecular Chaperones / Q000378:metabolism; D009707:Nucleosomes / Q000378:metabolism; D016196:S Phase; D014158:Transcription, Genetic; D035602:Transcriptional Elongation Factors / Q000378:metabolism*
chemical_list: D002843:Chromatin; D004268:DNA-Binding Proteins; D006609:High Mobility Group Proteins; D056488:Histone Chaperones; D006657:Histones; D018832:Molecular Chaperones; D009707:Nucleosomes; C073537:SSRP1 protein, human; D035602:Transcriptional Elongation Factors