title: Potentiation of RNA polymerase II transcription by Gal4-VP16 during but not after DNA replication and chromatin assembly.
abstract: Purified, reconstituted chromatin templates containing regular, physiological nucleosome spacing were transcribed in vitro by RNA polymerase II along with the Gal4-VP16 activator. When Gal4-VP16 was prebound to DNA before reconstitution of either H1-deficient or H1-containing chromatin, the resulting templates were transcribed with a similar efficiency. Under such conditions, we observed long-range (1000 bp) activation of transcription in vitro with H1-containing chromatin, but not naked DNA templates. When Gal4-VP16 was added to preassembled chromatin, the H1-deficient chromatin was transcriptionally active, whereas the H1-containing chromatin, which possessed properties similar to native chromatin, was transcriptionally inert. We then mimicked DNA replication and chromatin assembly at a replication fork and found that Gal4-VP16 could potentiate transcription during, but not after, replication and assembly of histone H1-containing chromatin. These experiments provide biochemical data that support a DNA replication-dependent mechanism for reconfiguration of chromatin structure and activation of transcription by Gal4-VP16.
authors.affiliation: Department of Biology, University of California, San Diego, La Jolla 92093-0347.
authors.forename: R T
authors.initials: RT
authors.lastname: Kamakaka
authors.forename: M
authors.initials: M
authors.lastname: Bulger
authors.forename: J T
authors.initials: JT
authors.lastname: Kadonaga
mesh_terms: D000818:Animals; D002843:Chromatin / Q000378:metabolism* / Q000648:ultrastructure; D004261:DNA Replication; D004330:Drosophila / Q000196:embryology / Q000235:genetics; D005656:Fungal Proteins / Q000378:metabolism*; D006657:Histones / Q000378:metabolism; D012319:RNA Polymerase II / Q000235:genetics*; D015534:Trans-Activators / Q000378:metabolism*; D014158:Transcription, Genetic
chemical_list: D002843:Chromatin; D005656:Fungal Proteins; C070633:Gal-VP16; D006657:Histones; D015534:Trans-Activators; D012319:RNA Polymerase II