title: Association of p107 with Sp1: genetically separable regions of p107 are involved in regulation of E2F- and Sp1-dependent transcription.
abstract: The retinoblastoma-related protein p107 has been shown to be a regulator of the transcription factor E2F. p107 associates with E2F via its pocket region and represses E2F-dependent transcription. In this study, we provide evidence for a novel interaction between p107 and the transcription factor Sp1. We show that p107 can be found endogenously associated with Sp1 in the extracts of several different cell lines. Moreover, in transient transfection assays, expression of p107 represses Sp1-dependent transcription. This repression of Sp1-dependent transcription does not require the DNA-binding domain of Sp1. Transcription driven by a chimeric protein containing the Ga14 DNA-binding domain and the Sp1 activation domains is inhibited by p107. Interestingly, unlike the repression of E2F-dependent transcription, the repression of Sp1-dependent transcription does not depend on an intact pocket region. We show that distinct regions of p107 are involved in the control of Sp1 and E2F.
authors.affiliation: Center for Molecular Biology of Oral Diseases, College of Dentistry, University of Illinois at Chicago 60612, USA.
authors.forename: P K
authors.initials: PK
authors.lastname: Datta
authors.forename: P
authors.initials: P
authors.lastname: Raychaudhuri
authors.forename: S
authors.initials: S
authors.lastname: Bagchi
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal; D001483:Base Sequence; D002352:Carrier Proteins; D018797:Cell Cycle Proteins; D003429:Cross Reactions; D004247:DNA / Q000378:metabolism; D004268:DNA-Binding Proteins; D050684:E2F Transcription Factors; D007739:L Cells; D051379:Mice; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D010446:Peptide Fragments; D011233:Precipitin Tests; D011401:Promoter Regions, Genetic / Q000235:genetics; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000378:metabolism; D012097:Repressor Proteins / Q000378:metabolism*; D056465:Retinoblastoma-Binding Protein 1; D050720:Retinoblastoma-Like Protein p107; D016329:Sp1 Transcription Factor / Q000235:genetics / Q000378:metabolism*; D050680:Transcription Factor DP1; D014157:Transcription Factors / Q000502:physiology*; D014158:Transcription, Genetic / Q000502:physiology
chemical_list: D000911:Antibodies, Monoclonal; C533431:Arid4a protein, mouse; D002352:Carrier Proteins; D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; D050684:E2F Transcription Factors; D009687:Nuclear Proteins; D010446:Peptide Fragments; C489485:Rbl1 protein, mouse; D011993:Recombinant Fusion Proteins; D012097:Repressor Proteins; D056465:Retinoblastoma-Binding Protein 1; D050720:Retinoblastoma-Like Protein p107; D016329:Sp1 Transcription Factor; D050680:Transcription Factor DP1; D014157:Transcription Factors; D004247:DNA