title: Alien inhibits E2F1 gene expression and cell proliferation.
abstract: Recently, using a proteomic approach we have identified the corepressor Alien as a novel interacting factor of the cell cycle regulator E2F1. Unclear was whether this interaction influences cell proliferation and endogenous E2F1 target gene expression. Here, we show by chromatin immunoprecipitation (ChIP) that Alien is recruited in vivo to the E2F binding sites present in the E2F1 gene promoter, inhibits the transactivation of E2F1 and represses endogenous E2F1 gene expression. Interestingly, using synchronized cells to assess the expression of Alien profile during cell cycle the levels of endogenous Alien are increased during G1, G1/S and G2 phase. Furthermore, stable transfection of Alien leads to reduction of cell proliferation. Thus, the data suggest that Alien acts as a corepressor for E2F1 and is involved in cell cycle regulation.
authors.affiliation: Molecular Genetics, Institute of Human Genetics and Anthropology, Friedrich-Schiller-University, 07740 Jena, Germany.
authors.forename: Stephan P
authors.initials: SP
authors.lastname: Tenbaum
authors.forename: Maria
authors.initials: M
authors.lastname: Papaioannou
authors.forename: Christina A
authors.initials: CA
authors.lastname: Reeb
authors.forename: Frauke
authors.initials: F
authors.lastname: Goeman
authors.forename: Niko
authors.initials: N
authors.lastname: Escher
authors.forename: Robert
authors.initials: R
authors.lastname: Kob
authors.forename: Ferdinand
authors.initials: F
authors.lastname: von Eggeling
authors.forename: Christian
authors.initials: C
authors.lastname: Melle
authors.forename: Aria
authors.initials: A
authors.lastname: Baniahmad
mesh_terms: D001665:Binding Sites; D000075686:COP9 Signalosome Complex; D002453:Cell Cycle; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D047369:Chromatin Immunoprecipitation; D050687:E2F1 Transcription Factor / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000502:physiology*; D016193:G1 Phase / Q000502:physiology; D016195:G2 Phase / Q000502:physiology; D015870:Gene Expression; D006367:HeLa Cells; D006801:Humans; D008297:Male; D011401:Promoter Regions, Genetic; D011471:Prostatic Neoplasms / Q000473:pathology; D011485:Protein Binding; D012097:Repressor Proteins / Q000502:physiology*; D016196:S Phase / Q000502:physiology; D014158:Transcription, Genetic; D015533:Transcriptional Activation; D014162:Transfection
chemical_list: C402762:COPS2 protein, human; D050687:E2F1 Transcription Factor; C493753:E2F1 protein, human; D012097:Repressor Proteins; D000075686:COP9 Signalosome Complex