title: A transcription-dependent micrococcal nuclease-resistant fragment of the urokinase-type plasminogen activator promoter interacts with the enhancer.
abstract: We show the interaction between the enhancer and the minimal promoter of urokinase-type plasminogen activator gene during active transcription by coupling micrococcal nuclease digestion of cross-linked, sonicated chromatin, and chromatin immunoprecipitation. This approach allowed the precise identification of the interacting genomic fragments, one of which is resistant to micrococcal nuclease cleavage. The interacting fragments form a single transcriptional control unit, as indicated by their common protein content. Furthermore, we show that the enhancer-MP interaction persists during the early stages of transcription and is lost upon alpha-amanitin treatment, indicating the requirement for active transcription. Our results support a looping model of interaction between the enhancer and the MP of the urokinase-type plasminogen activator gene.
authors.affiliation: Laboratory of Molecular Genetics, S. Raffaele Scientific Institute, Università Vita-Salute S. Raffaele, Via Olgettina 58, 20132 Milano, Italy.
authors.forename: Carmelo
authors.initials: C
authors.lastname: Ferrai
authors.forename: Davide
authors.initials: D
authors.lastname: Munari
authors.forename: Paolo
authors.initials: P
authors.lastname: Luraghi
authors.forename: Lorenza
authors.initials: L
authors.lastname: Pecciarini
authors.forename: Maria Giulia
authors.initials: MG
authors.lastname: Cangi
authors.forename: Claudio
authors.initials: C
authors.lastname: Doglioni
authors.forename: Francesco
authors.initials: F
authors.lastname: Blasi
authors.forename: Massimo P
authors.initials: MP
authors.lastname: Crippa
mesh_terms: D000818:Animals; D002843:Chromatin / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D047369:Chromatin Immunoprecipitation; D004742:Enhancer Elements, Genetic; D008836:Micrococcal Nuclease / Q000737:chemistry; D008957:Models, Genetic; D011401:Promoter Regions, Genetic; D051381:Rats; D014158:Transcription, Genetic; D014568:Urokinase-Type Plasminogen Activator / Q000096:biosynthesis* / Q000235:genetics
chemical_list: D002843:Chromatin; D008836:Micrococcal Nuclease; D014568:Urokinase-Type Plasminogen Activator