Large-scale chromatin decondensation and recondensation regulated by transcription from a natural promoter
Open Access
- 9 July 2001
- journal article
- Published by Rockefeller University Press in The Journal of cell biology
- Vol. 154 (1) , 33-48
- https://doi.org/10.1083/jcb.200011069
Abstract
We have examined the relationship between transcription and chromatin structure using a tandem array of the mouse mammary tumor virus (MMTV) promoter driving a ras reporter. The array was visualized as a distinctive fluorescent structure in live cells stably transformed with a green fluorescent protein (GFP)-tagged glucocorticoid receptor (GR), which localizes to the repeated MMTV elements after steroid hormone treatment. Also found at the array by immunofluorescence were two different steroid receptor coactivators (SRC1 and CBP) with acetyltransferase activity, a chromatin remodeler (BRG1), and two transcription factors (NFI and AP-2). Within 3 h after hormone addition, arrays visualized by GFP-GR or DNA fluorescent in situ hybridization (FISH) decondensed to varying degrees, in the most pronounced cases from a ∼0.5-μm spot to form a fiber 1–10 μm long. Arrays later recondensed by 3–8 h of hormone treatment. The degree of decondensation was proportional to the amount of transcript produced by the array as detected by RNA FISH. Decondensation was blocked by two different drugs that inhibit polymerase II, 5,6-dichloro-1-β-d-ribofuranosylbenzimidazole (DRB) and α-amanitin. These observations demonstrate a role for polymerase in producing and maintaining decondensed chromatin. They also support fiber-packing models of higher order structure and suggest that transcription from a natural promoter may occur at much higher DNA-packing densities than reported previously.Keywords
This publication has 60 references indexed in Scilit:
- The Glucocorticoid Receptor: Rapid Exchange with Regulatory Sites in Living CellsScience, 2000
- Action of α-Amanitin during Pyrophosphorolysis and Elongation by RNA Polymerase IIPublished by Elsevier ,1995
- Transcription Factor Loading on the MMTV Promoter: A Bimodal Mechanism for Promoter ActivationScience, 1992
- GAL4-VP16 is an unusually potent transcriptional activatorNature, 1988
- Packing of a specific gene into higher order structures following repression of RNA synthesis.The Journal of cell biology, 1984
- Characterization of active transcription units in Balbiani rings of chironomus tentansCell, 1979
- The size of the transcription unit in balbiani ring 2 of Chironomus tentans as derived from analysis of the primary transcript and 75 S RNAJournal of Molecular Biology, 1978
- Transcription in polytene chromosomesCell, 1975
- Incorporation of tritiated uridine in nuclei of Triturus oocytes treated with ?-amanitin*1Experimental Cell Research, 1971
- Effects of ?-amanitin on lampbrush chromosomesExperimental Cell Research, 1971