title: The histone methyltransferase SET8 is required for S-phase progression.
abstract: Chromatin structure and function is influenced by histone posttranslational modifications. SET8 (also known as PR-Set7 and SETD8) is a histone methyltransferase that monomethylates histonfe H4-K20. However, a function for SET8 in mammalian cell proliferation has not been determined. We show that small interfering RNA inhibition of SET8 expression leads to decreased cell proliferation and accumulation of cells in S phase. This is accompanied by DNA double-strand break (DSB) induction and recruitment of the DNA repair proteins replication protein A, Rad51, and 53BP1 to damaged regions. SET8 depletion causes DNA damage specifically during replication, which induces a Chk1-mediated S-phase checkpoint. Furthermore, we find that SET8 interacts with proliferating cell nuclear antigen through a conserved motif, and SET8 is required for DNA replication fork progression. Finally, codepletion of Rad51, an important homologous recombination repair protein, abrogates the DNA damage after SET8 depletion. Overall, we show that SET8 is essential for genomic stability in mammalian cells and that decreased expression of SET8 results in DNA damage and Chk1-dependent S-phase arrest.
authors.affiliation: Biotech Research and Innovation Centre and 2Centre for Epigenetics, University of Copenhagen, 2200 Copenhagen N, Denmark.
authors.forename: Stine
authors.initials: S
authors.lastname: Jørgensen
authors.forename: Ingegerd
authors.initials: I
authors.lastname: Elvers
authors.forename: Morten Beck
authors.initials: MB
authors.lastname: Trelle
authors.forename: Tobias
authors.initials: T
authors.lastname: Menzel
authors.forename: Morten
authors.initials: M
authors.lastname: Eskildsen
authors.forename: Ole Nørregaard
authors.initials: ON
authors.lastname: Jensen
authors.forename: Thomas
authors.initials: T
authors.lastname: Helleday
authors.forename: Kristian
authors.initials: K
authors.lastname: Helin
authors.forename: Claus Storgaard
authors.initials: CS
authors.lastname: Sørensen
mesh_terms: D020816:Amino Acid Motifs / Q000235:genetics; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism*; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D000071877:Checkpoint Kinase 1; D004249:DNA Damage / Q000235:genetics*; D004260:DNA Repair / Q000235:genetics; D004261:DNA Replication / Q000235:genetics; D015536:Down-Regulation / Q000235:genetics*; D042822:Genomic Instability / Q000235:genetics*; D011495:Histone-Lysine N-Methyltransferase / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D018809:Proliferating Cell Nuclear Antigen / Q000737:chemistry / Q000378:metabolism; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism; D034622:RNA Interference / Q000502:physiology; D051135:Rad51 Recombinase / Q000235:genetics / Q000378:metabolism; D016196:S Phase / Q000235:genetics*
chemical_list: D018797:Cell Cycle Proteins; D018809:Proliferating Cell Nuclear Antigen; D011495:Histone-Lysine N-Methyltransferase; C470730:KMT5A protein, human; D011494:Protein Kinases; C000605867:CHEK1 protein, human; D000071877:Checkpoint Kinase 1; D051135:Rad51 Recombinase