CREB-Binding Protein (CBP)/p300 and RNA Polymerase II Colocalize in Transcriptionally Active Domains in the Nucleus

The spatial organization of transcription-associated proteins is an important control mechanism of eukaryotic gene expression. Here we analyzed the nuclear distribution of the transcriptional coactivators CREB-binding protein (CBP)/p300 in situ by confocal laser scanning microscopy, and in vivo comp...

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Bibliographic Details
Published in:The Journal of cell biology 2000-07, Vol.150 (1), p.265-273
Main Authors: von Mikecz, Anna, Zhang, Suisheng, Montminy, Marc, Tan, Eng M., Hemmerich, Peter
Format: Article
Language:English
Subjects:
Acetyltransferases - metabolism
Antibodies
CBP/p300 protein
Cell Cycle Proteins - metabolism
Cell Line
Cell lines
Cell nucleus
Cell Nucleus - genetics
Cell Nucleus - metabolism
Cell Nucleus - ultrastructure
Cells
CREB-Binding Protein
Genes
Histone Acetyltransferases
Humans
Immunohistochemistry
Leukemia
Microscopy, Fluorescence
Nuclear Proteins - metabolism
p300-CBP Transcription Factors
Pixels
Precipitin Tests
promyelocytic leukemia
Proteins
Ribonucleic acid
RNA
RNA Polymerase II - metabolism
Scatter diagrams
Splicing
Trans-Activators - metabolism
Transcription Factors
Transcription, Genetic - genetics
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Summary:The spatial organization of transcription-associated proteins is an important control mechanism of eukaryotic gene expression. Here we analyzed the nuclear distribution of the transcriptional coactivators CREB-binding protein (CBP)/p300 in situ by confocal laser scanning microscopy, and in vivo complex formation by coimmunoprecipitation. A subpopulation of CBP and p300 is targeted to active sites of transcription and partially colocalizes with hyper- and hypophosphorylated RNA polymerase II (pol II) in discrete regions of variable size throughout the nucleus. However, the coactivators were found in tight association with hypophosphorylated, but not hyperphosphorylated pol II. Transcriptional inhibition induced a relocation of CBP/p300 and pol II into speckles. Moreover, double and triple immunofluorescence analyses revealed the presence of CBP, p300, and pol II in a subset of promyelocytic leukemia (PML) bodies. Our results provide evidence for a dynamic spacial link between coactivators of transcription and the basal transcription machinery in discrete nuclear domains dependent upon the transcriptional activity of the cell. The identification of pol II in CBP/PML-containing nuclear bodies supports the idea that transcription takes place at PML bodies.
ISSN:0021-9525
1540-8140
DOI:10.1083/jcb.150.1.265