title: c-ETS transcription factors play an essential role in the licensing of human MCM4 origin of replication.
abstract: In metazoans, DNA replication is a highly regulated and ordered process that occurs during the S phase of cell cycle. It begins with the licensing of origins of replication usually found in close proximity of actively transcribing genes owing perhaps to a profound influence of transcription factors on the epigenetic signatures and architecture of chromatin. Here we show that ETS transcription factors are novel regulators of MCM4 origin, whose binding sites are localized between two divergently transcribing MCM4 and PRKDC genes. c-ETS1 and c-ETS2 were recruited to the MCM4 origin respectively during the S and G1 phases of cell cycle. c-ETS2 binding was facilitated by an active chromatin distinguished by acetylated histone H3 orchestrated by histone acetyl transferase GCN5 and followed by HBO1 mediated histone H4 acetylation. Interestingly, c-ETS2 overexpression led to increased BrdU incorporation in the S phase cells while its down-regulation by RNA interference compromised the loading of pre-replicative complex at the origin. Conversely, the recruitment of c-ETS1 at the origin coincided with histone H3 methylation signature characteristic of closed chromatin conformation. As expected, enforced expression of c-ETS1 severely compromised DNA replication whereas its down-regulation enhanced DNA replication as evident from increased BrdU incorporation. Thus, c-ETS transcription factors appear to be key regulators of MCM4 origin where c-ETS2 seems to promote DNA replication whereas c-ETS1 functions as a negative regulator.
authors.affiliation: Virology Group, International Center for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi 110067, India.
authors.forename: Kaveri
authors.initials: K
authors.lastname: Sidhu
authors.affiliation: Virology Group, International Center for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi 110067, India. Electronic address: vijay@icgeb.res.in.
authors.forename: Vijay
authors.initials: V
authors.lastname: Kumar
mesh_terms: D004261:DNA Replication / Q000502:physiology*; D051747:DNA-Activated Protein Kinase / Q000096:biosynthesis / Q000235:genetics; D016193:G1 Phase / Q000502:physiology*; D057809:HEK293 Cells; D006657:Histones / Q000235:genetics / Q000378:metabolism; D006801:Humans; D008745:Methylation; D064148:Minichromosome Maintenance Complex Component 4 / Q000096:biosynthesis / Q000235:genetics; D009687:Nuclear Proteins / Q000096:biosynthesis / Q000235:genetics; D050784:Proto-Oncogene Protein c-ets-1 / Q000235:genetics / Q000378:metabolism*; D050787:Proto-Oncogene Protein c-ets-2 / Q000235:genetics / Q000378:metabolism*; D018741:Replication Origin / Q000502:physiology*; D016196:S Phase / Q000502:physiology*
chemical_list: C494069:ETS2 protein, human; D006657:Histones; D009687:Nuclear Proteins; D050784:Proto-Oncogene Protein c-ets-1; D050787:Proto-Oncogene Protein c-ets-2; D051747:DNA-Activated Protein Kinase; C497263:PRKDC protein, human; C099243:MCM4 protein, human; D064148:Minichromosome Maintenance Complex Component 4
keywords: ChIP assay; DNA replication; Epigenetic modifications; MCM4 origin of replication; c-ETS transcription factor