title: Genome-wide location analysis and expression studies reveal a role for p110 CUX1 in the activation of DNA replication genes.
abstract: Proteolytic processing of the CUX1 transcription factor generates an isoform, p110 that accelerates entry into S phase. To identify targets of p110 CUX1 that are involved in cell cycle progression, we performed genome-wide location analysis using a promoter microarray. Since there are no antibodies that specifically recognize p110, but not the full-length protein, we expressed physiological levels of a p110 isoform with two tags and purified chromatin by tandem affinity purification (ChAP). Conventional ChIP performed on synchronized populations of cells confirmed that p110 CUX1 is recruited to the promoter of cell cycle-related targets preferentially during S phase. Multiple approaches including silencing RNA (siRNA), transient infection with retroviral vectors, constitutive expression and reporter assays demonstrated that most cell cycle targets are activated whereas a few are repressed or not affected by p110 CUX1. Functional classes that were over-represented among targets included DNA replication initiation. Consistent with this finding, constitutive expression of p110 CUX1 led to a premature and more robust induction of replication genes during cell cycle progression, and stimulated the long-term replication of a plasmid bearing the oriP replicator of Epstein Barr virus (EBV).
authors.affiliation: Molecular Oncology Group, McGill University Health Center, Montreal, Canada.
authors.forename: Ryoko
authors.initials: R
authors.lastname: Harada
authors.forename: Charles
authors.initials: C
authors.lastname: Vadnais
authors.forename: Laurent
authors.initials: L
authors.lastname: Sansregret
authors.forename: Lam
authors.initials: L
authors.lastname: Leduy
authors.forename: Ginette
authors.initials: G
authors.lastname: Bérubé
authors.forename: François
authors.initials: F
authors.lastname: Robert
authors.forename: Alain
authors.initials: A
authors.lastname: Nepveu
mesh_terms: D000818:Animals; D002460:Cell Line; D002843:Chromatin / Q000302:isolation & purification; D002846:Chromatography, Affinity; D004261:DNA Replication / Q000235:genetics*; D018816:Genes, cdc; D023281:Genomics; D018398:Homeodomain Proteins / Q000502:physiology*; D006801:Humans; D051379:Mice; D009687:Nuclear Proteins / Q000502:physiology*; D020411:Oligonucleotide Array Sequence Analysis; D011401:Promoter Regions, Genetic; D012097:Repressor Proteins / Q000502:physiology*; D016196:S Phase / Q000235:genetics; D017422:Sequence Analysis, DNA; D014157:Transcription Factors; D015533:Transcriptional Activation
chemical_list: C080632:CUX1 protein, human; D002843:Chromatin; D018398:Homeodomain Proteins; D009687:Nuclear Proteins; D012097:Repressor Proteins; D014157:Transcription Factors