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Three-Dimensional Visualization of Transcription Sites and Their Association with Splicing Factor–Rich Nuclear Speckles
Transcription sites are detected by labeling nascent transcripts with BrUTP in permeabilized 3T3 mouse fibroblasts followed by laser scanning confocal microscopy. Inhibition and enzyme digestion studies confirm that the labeled sites are from RNA transcripts and that RNA polymerase I (RP I) and II (...
Autores principales: | , , , |
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Formato: | Texto |
Lenguaje: | English |
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The Rockefeller University Press
1999
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2150559/ https://www.ncbi.nlm.nih.gov/pubmed/10444064 |
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author | Wei, Xiangyun Somanathan, Suryanarayan Samarabandu, Jagath Berezney, Ronald |
author_facet | Wei, Xiangyun Somanathan, Suryanarayan Samarabandu, Jagath Berezney, Ronald |
author_sort | Wei, Xiangyun |
collection | PubMed |
description | Transcription sites are detected by labeling nascent transcripts with BrUTP in permeabilized 3T3 mouse fibroblasts followed by laser scanning confocal microscopy. Inhibition and enzyme digestion studies confirm that the labeled sites are from RNA transcripts and that RNA polymerase I (RP I) and II (RP II) are responsible for nucleolar and extranucleolar transcription, respectively. An average of 2,000 sites are detected per nucleus with over 90% in the extranucleolar compartment where they are arranged in clusters and three-dimensional networklike arrays. The number of transcription sites, their three-dimensional organization and arrangement into functional zones (Wei et al. 1998) is strikingly maintained after extraction for nuclear matrix. Significant levels of total RP II mediated transcription sites (45%) were associated with splicing factor–rich nuclear speckles even though the speckles occupied <10% of the total extranucleolar space. Moreover, the vast majority of nuclear speckles (>90%) had moderate to high levels of associated transcription activity. Transcription sites were found along the periphery as well as inside the speckles themselves. These spatial relations were confirmed in optical sections through individual speckles and after in vivo labeling of nascent transcripts. Our results demonstrate that nuclear speckles and their surrounding regions are major sites of RP II-mediated transcription in the cell nucleus, and support the view that both speckle- and nonspeckle-associated regions of the nucleus contain sites for the coordination of transcription and splicing processes. |
format | Text |
id | pubmed-2150559 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 1999 |
publisher | The Rockefeller University Press |
record_format | MEDLINE/PubMed |
spelling | pubmed-21505592008-05-01 Three-Dimensional Visualization of Transcription Sites and Their Association with Splicing Factor–Rich Nuclear Speckles Wei, Xiangyun Somanathan, Suryanarayan Samarabandu, Jagath Berezney, Ronald J Cell Biol Original Article Transcription sites are detected by labeling nascent transcripts with BrUTP in permeabilized 3T3 mouse fibroblasts followed by laser scanning confocal microscopy. Inhibition and enzyme digestion studies confirm that the labeled sites are from RNA transcripts and that RNA polymerase I (RP I) and II (RP II) are responsible for nucleolar and extranucleolar transcription, respectively. An average of 2,000 sites are detected per nucleus with over 90% in the extranucleolar compartment where they are arranged in clusters and three-dimensional networklike arrays. The number of transcription sites, their three-dimensional organization and arrangement into functional zones (Wei et al. 1998) is strikingly maintained after extraction for nuclear matrix. Significant levels of total RP II mediated transcription sites (45%) were associated with splicing factor–rich nuclear speckles even though the speckles occupied <10% of the total extranucleolar space. Moreover, the vast majority of nuclear speckles (>90%) had moderate to high levels of associated transcription activity. Transcription sites were found along the periphery as well as inside the speckles themselves. These spatial relations were confirmed in optical sections through individual speckles and after in vivo labeling of nascent transcripts. Our results demonstrate that nuclear speckles and their surrounding regions are major sites of RP II-mediated transcription in the cell nucleus, and support the view that both speckle- and nonspeckle-associated regions of the nucleus contain sites for the coordination of transcription and splicing processes. The Rockefeller University Press 1999-08-09 /pmc/articles/PMC2150559/ /pubmed/10444064 Text en © 1999 The Rockefeller University Press This article is distributed under the terms of an Attribution–Noncommercial–Share Alike–No Mirror Sites license for the first six months after the publication date (see http://www.rupress.org/terms). After six months it is available under a Creative Commons License (Attribution–Noncommercial–Share Alike 4.0 Unported license, as described at http://creativecommons.org/licenses/by-nc-sa/4.0/). |
spellingShingle | Original Article Wei, Xiangyun Somanathan, Suryanarayan Samarabandu, Jagath Berezney, Ronald Three-Dimensional Visualization of Transcription Sites and Their Association with Splicing Factor–Rich Nuclear Speckles |
title | Three-Dimensional Visualization of Transcription Sites and Their Association with Splicing Factor–Rich Nuclear Speckles |
title_full | Three-Dimensional Visualization of Transcription Sites and Their Association with Splicing Factor–Rich Nuclear Speckles |
title_fullStr | Three-Dimensional Visualization of Transcription Sites and Their Association with Splicing Factor–Rich Nuclear Speckles |
title_full_unstemmed | Three-Dimensional Visualization of Transcription Sites and Their Association with Splicing Factor–Rich Nuclear Speckles |
title_short | Three-Dimensional Visualization of Transcription Sites and Their Association with Splicing Factor–Rich Nuclear Speckles |
title_sort | three-dimensional visualization of transcription sites and their association with splicing factor–rich nuclear speckles |
topic | Original Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2150559/ https://www.ncbi.nlm.nih.gov/pubmed/10444064 |
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