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© The Rockefeller University Press,
0021-9525/2000//265 $5.00
The Journal of Cell Biology, Volume 150, Number 1,
, 2000 265-274
Brief Report |
Creb-Binding Protein (Cbp/P300) and RNA Polymerase II Colocalize in Transcriptionally Active Domains in the Nucleus
phemmer{at}imb-jena.de
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.
Key Words: transcription • coactivators • nuclear body • RNA polymerase II • promyelocytic leukemia
© 2000 The Rockefeller University Press
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Promyelocytic leukemia (PML) protein–containing nuclear bodies (PML oncogenic domains; PODs, nuclear domain 10; ND10, or Kr bodies) also have been functionally linked to transcription, e.g., of viral genes (Maul 1998), and other nuclear processes such as RNA processing, transport, and RNP assembly (Doucas and Evans 1996; Sternsdorf et al. 1997; Maul 1998; Matera 1999). PML bodies appear as 5–30 discrete punctate regions distinct from speckles after immunofluorescence staining (Brasch and Ochs 1992). Direct evidence for a role of PML bodies in transcription comes from the demonstration of nascent pol II transcripts within this nuclear body (LaMorte et al. 1998). In contrast, other groups detected nascent RNA in the periphery, indicating that the surroundings of the PML nuclear bodies are the sites of transcriptional activity (Grande et al. 1996; Boisvert et al. 2000). Thus, it remains controversial, whether transcription is occurring in or near PML bodies.
CREB-binding protein (CBP) and p300 are structurally and functionally related transcriptional coactivator proteins that operate at the end points of a variety of signal transduction pathways, thereby modulating specific gene expression programs involved in cell growth, differentiation, homeostasis, and viral pathogenesis (for review see Janknecht and Hunter 1996; Shikama et al. 1997). The ability of CBP and p300 to interact with multiple, signal-dependent transcription factors suggested that these coactivators function as signal integrators by coordinating complex signal transduction events at the transcriptional level (Chrivia et al. 1993; Arany et al. 1994; Arias et al. 1994; Kwok et al. 1994; Eckner et al. 1994; Lundblad et al. 1995). CBP and p300 have been proposed to mediate transcription induction via intrinsic and associated histone-acetylase activities, which may facilitate binding of nuclear factors to their target sites by destabilizing promoter-bound nucleosomes (Bannister and Kouzarides 1996; Ogryzko et al. 1996; Yang et al. 1996). Additionally, CBP/p300 may also mediate target gene activation through association with active pol II complexes, thereby bridging upstream transcription factors with the general transcription machinery (Kee et al. 1996; Nakajima et al. 1997a,Nakajima et al. 1997b; Neish et al. 1998; Cho et al. 1998).
To investigate step(s) in gene activity modulation in which CBP/p300 operate, we have compared the spatial distribution and the characteristics of the association of the coactivators with RNA polymerase II and active transcription in mammalian nuclei.
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-Amanitin (-am; 10 µg/ml working concentration; Sigma-Aldrich) for 8 h.
Antibodies
Polyclonal rabbit antibodies CBP-C20, CBP-A22 (both from Santa Cruz Biotechnology, Inc.), CBP-5614, CBP-5729, and CBP-254-256 have been described previously (Arias et al. 1994; Kee et al. 1996; Bex et al. 1998; Doucas et al. 1999). Antibody 254-256 is directed against aa 634–648 of CBP (Arias et al. 1994), and was affinity purified from a peptide column for immunohistochemistry and immunoblots. mAb p300-CT (clone RW128; Upstate Biotechnology) has been described previously (Bex et al. 1998). Polyclonal rabbit antibodies p300-N15 and p300-C20 were purchased from Santa Cruz Biotechnology, Inc. To detect pol II, monoclonal antibodies mara3 (Patturajan et al. 1998; kindly donated by Bart Sefton, Salk Institute, La Jolla, CA), and 8WG16 (Thompson et al. 1989; kindly provided by Nancy Thompson, University of Madison, WI), were used. PML bodies were visualized in immunofluorescence studies with rat antibodies directed against the PML protein or the SP100 protein (kindly provided by Thomas Sternsdorf, Heinrich-Pette-Institute, Hamburg, Germany). The nuclear mitotic apparatus protein NuMa, coiled bodies, nucleoli, and centromeres were stained with human autoimmune sera obtained from the reference serum bank of the W.M. Keck Autoimmune Disease Center, The Scripps Research Institute.
Immunocytochemistry
Cells grown on coverslips were fixed by treatment with methanol at –20°C for 5 min followed by acetone (prechilled to –20°C) for 2 min, or by incubation in 2% paraformaldehyde for 20 min at room temperature followed by acetone treatment (prechilled to –20°C) for 2 min. Immunofluorescence was performed as previously described (von Mikecz et al. 1997). For dual or triple immunofluorescence staining, primary antibodies from different sources (mouse, rabbit, human, or rat) were used simultaneously and detected with species-specific secondary antibodies linked to fluorescein, rhodamine, or Cy5 (Jackson ImmunoResearch Laboratories).
Confocal Microscopy and Scatter Diagrams
Samples were scanned with a Zeiss LSM 510 laser scanning confocal device attached to an Axioplan 2 microscope using a 63x Plan-Apochromat oil objective (Carl Zeiss, Inc.), or on a Fluoview laser scanning system from Olympus. Fluorescein, rhodamine, or Cy5 dyes were excited by laser light at a 488-, 543-, or 633-nm wavelength, respectively. To avoid bleed-through effects in double or triple staining experiments, each dye was scanned independently using the multitracking function of the LSM 510 unit. Single optical sections were selected either by eye-scanning the sample in z axis for optimal fluorescence signals, or taken from stack projections. Images were electronically merged using the LSM 510 (Carl Zeiss, Inc.) software and stored as TIFF files. Figures were assembled from the TIFF files using Adobe Photoshop software. Colocalization scatter diagrams were generated with the LSM 510 software. A scatter diagram represents a comparison of pixel coincidence between two images (i.e., red and green). All pixels having the same position in both images are considered a pair. Of every pair of pixels (P1, P2) from the two source images, the brightness level of pixel P1 is interpreted as the x coordinate, and that of pixel P2 as the y coordinate of the scatter diagram. The value of the pixel thus addressed is increased by one every time, up to the maximum number of pixels used. This way, each pixel of the scatter diagram is a value that shows how often a particular pair of pixels has occurred. Two completely overlapping images would result in a straight, diagonal line from bottom left to top right of the scatter diagram. Accordingly, two proteins displaying a high degree of colocalization would produce diagonal club-like patterns from bottom right to top left.
In Situ Immunolabeling of Nascent RNA Transcripts
Bromouridine triphosphate (BrU) was used for detecting ongoing RNA synthesis in permeabilized HEp-2 cells by immunodetection with antibody against bromodeoxyuridine (Boehringer) as previously described (Zhang et al. 1999), according to protocols developed by Jackson et al. 1993 and Wansink et al. 1993.
Immunoprecipitation and Immunoblotting
Immunoprecipitations were performed with HEp-2 whole cell lysates according to protocols described by Kee et al. 1996. A rabbit anti–mouse bridging antibody (Jackson ImmunoResearch Laboratories) was added in precipitations using mAbs. Immunoprecipitates were resuspended in SDS loading buffer and analyzed by SDS-PAGE. For immunoblotting, gels were transferred onto nitrocellulose and specific proteins were visualized using enhanced chemiluminescence according to the manufacturer's instructions (Amersham Pharmacia Biotech).
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250 kD corresponding to the molecular weight of CBP and p300 (Chrivia et al. 1993; Eckner et al. 1994).
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3–10 bright dot-like foci in >50% of HEp-2 cells (Fig. 1, micrograph, bottom row, 8WG16 and inset). Immunoblot analyses confirmed the specificity of the anti–pol II antibodies. Mara3 preferentially reacted with the hyperphosphorylated form of pol II (IIo), whereas 8WG16 predominantly recognized hypophosphorylated forms of pol II (IIa) (Fig. 1, immunoblot, bottom).
CBP/p300 Are Targeted to Active Sites of Transcription
Since CBP/p300 are believed to function as bridging molecules between transcription factors and the basal transcription machinery, we investigated the spatial relationship of the coactivators with the largest subunit of pol II and active sites of transcription. The staining patterns of pol IIo and pol IIa were compared with nucleoplasmic CBP distribution in double-labeling experiments, followed by confocal microscopy (Fig. 2, a and b). The overlay images show that the nucleoplasmic meshwork staining patterns of CBP partially overlapped with pol IIo and pol IIa (Fig. 2, a and b). CBP and pol II did not occupy the same discrete domains, rather they appeared to be present in individual irregularly shaped nucleoplasmic structures that partially overlapped (Fig. 2; see magnified areas in insets). The merged images also revealed multiple regions and dot-like structures of CBP and pol II that did not colocalize, indicating the existence of nuclear domains of exclusive localization of either CBP or pol II. We also analyzed the nuclear distribution of CBP with respect to transcription sites by in situ transcriptional run-on experiments (Fig. 2 c). Nascent transcripts in HEp-2 nuclei were labeled with BrU and detected with anti-bromodeoxyuridine antibodies. Double labeling revealed partial overlap between CBP staining and sites of transcription (Fig. 2 c). However, many domains exclusively contain CBP and no or little nascent RNA, and vice versa. Similar results were obtained when p300 labeling was compared with pol II staining or BrU incorporation (data not shown). No colocalization could be detected between CBP or p300 and NuMa, a 200-kD transcription-unrelated nuclear protein (Cleveland 1995) that served as a control (Fig. 2 d and data not shown, respectively), indicating that the regions of overlap between CBP/p300 and pol II, or transcription, are not fortuitous.
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To test whether the colocalization between CBP/p300 and pol II correlates with in vivo complex formation of these proteins we performed coimmunoprecipitation studies on protein lysates from HEp-2 cell nuclei. This analysis revealed that pol IIo is not present in immunoprecipitates from CBP or p300 antibodies (Fig. 2 g, row 1, lanes 3 and 4). In contrast, 10–20% of pol IIa was recovered from CBP or p300 immunoprecipitates (Fig. 2 g, row 2, compare lane 2 with lanes 3 and 4, respectively). A similar fraction of endogenous CBP or p300 was recovered from pol IIa immunoprecipitates (Fig. 2 g, rows 3 and 4). As a control, anti-NuMa immunoprecipitation complexes did not contain pol II, CBP, or p300 protein (Fig. 2 g, rows 1–4, lane 5). NuMa was not detected in immunoprecipitates of pol IIa, CBP, or p300 (Fig. 2 g, row 5, lanes 2–4). Taken together, these results suggest that a subpopulation of CBP and p300 is in close vicinity to sites of mRNA transcription and in tight association with hypo-, but not hyperphosphorylated pol II. Thus, although CBP/p300 colocalized with pol IIo and pol IIa in situ, the coactivators appear to participate only in pol II a–containing complexes in vivo.
Dynamic Relocation of CBP/p300 into Speckles
In transcriptionally inhibited cells, factors involved in mRNA biogenesis including pol II redistribute to a classical speckle distribution pattern (Spector 1993; Bregman et al. 1995). A speckled pattern of pol II localization has been shown to be characteristic of poorly transcribing or transcriptionally inactive cells because they fail to show incorporation of BrU into nascent mRNA in nuclear run-on experiments (Zeng et al. 1997). -am, a compound that completely blocks pol II–mediated transcription (Lindell et al. 1970), was used to experimentally induce the redistribution of pol II into speckle domains (Fig. 3). In HEp-2 cells treated with -am (10 µg/ml), CBP (detected by antibody 254-256) redistributed into speckle structures where it strongly colocalized with pol IIo and splicing factor SC35 (Fig. 3, top and middle). A subpopulation of p300 exhibited a similar redistribution into pol II–containing speckles in transcriptionally inhibited cells (Fig. 3, bottom). However, it should be noted that CBP and p300 were not detected in all pol II–containing speckles and vice versa, thus indicating a heterogeneity of the molecular composition of speckles with respect to the coactivators. Pol II could not be detected in speckle structures of transcriptionally inhibited cells using antibody 8WG16 (Fig. 4 h). This result indicates that speckle-bound pol II is hyperphosphorylated, which is in agreement with prior observations (Bregman et al. 1995). Taken together, these results suggest that a fraction of CBP and p300 is dynamically redistributed together with pol IIo into speckled domains in transcriptionally inactive cells.
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The spatial relationship of PML bodies and pol II was also analyzed in double-labeling experiments. Cells exhibiting the broad nucleoplasmic meshwork staining of pol IIo overlaid with sites of preferred localization produced by mara3 did not reveal any colocalizing structures (Fig. 4 c). In contrast, some of the dot structures labeled by antibody 8WG16 colocalized with PML protein–containing nuclear bodies (Fig. 4 d). However, some PML bodies do not contain pol IIa and some of the pol IIa–containing dot structures do not contain PML protein (Fig. 4 d, insets). Pol-IIa–containing nuclear dots, as detected with mAB 8WG16, also colocalized with some of the p300 dot-shaped foci (data not shown). The finding that only a subset of PML bodies colocalized with CBP/p300 or pol IIa raised the question whether the same nuclear bodies contain both the coactivators and the enzyme. We addressed this question by performing triple-labeling immunofluorescence experiments. This analysis demonstrated that CBP, pol IIa, and the PML protein can be detected in the same nuclear bodies (Fig. 4 e). Taken together these results show that the CBP/p300 coactivators are associated with pol IIa and PML protein in a subset of nuclear bodies and suggest that they may function as modulators of active transcription in or near these structures.
When transcription was arrested by -am (10 µg/ml), PML protein dissociated into numerous smaller domains scattered throughout the nucleoplasm (Fig. 4, f–h). Dual labeling of such cells revealed that CBP, as detected with antibody A22, colocalized with these domains (Fig. 4 f ). In drug-treated cells, speckle-associated RNA polymerase, as stained with mara3, did not colocalize with the scattered PML domains, although a few speckles can be seen to overlap with PML protein-containing domains (Fig. 4 g). In contrast, a large number of PML foci appeared to contain pol IIa, as revealed with antibody 8WG16 (Fig. 4 h). These observations confirm the association of CBP, pol IIa, and PML protein in discrete nuclear domains and suggest that a subfraction of CBP and pol IIa is dynamically reorganized into many small PML protein–containing nuclear foci in transcriptionally inactive cells.
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Here, we show by confocal microscopy that the nuclear distribution of CBP/p300 partially coincides with that of hyper- and hypophosphorylated pol II and active sites of transcription. The pattern and degree of colocalization between CBP/p300 and pol II throughout the nucleoplasm was very similar to the colocalization characteristics of CBP/p300 and sites of transcription. Colocalization studies of transcription factors with sites of BrU incorporation or pol II domains frequently reveal a partial overlap (van Steensel et al. 1995; Grande et al. 1997; Schul et al. 1998b; Stenoien et al. 1998). Obviously, CBP/p300 coactivators share this property with some of these transcription factors (Grande et al. 1997), and also other chromatin remodeling coactivator complexes, such as human SWI/SNF (Reyes et al. 1997). There is a high degree of colocalization between hyper- and hypophosphorylated pol II with sites of nascent RNA, indicating that both forms of RNA polymerases are in close vicinity to ongoing transcription (Grande et al. 1997; Zeng et al. 1997; Schul et al. 1998b). These observations and the finding that CBP/p300 (and other transcription-related factors) are associated with only a limited number of BrU foci (and/or pol II domains) suggest that the coactivators are dynamically recruited to a subfraction of nuclear sites with transcriptional activity at a given time. In such subfractions of nuclear sites, CBP/p300 might also associate with specific transcription-related factors. For example, BRCA1, a tumor suppressor protein with properties of a transcription factor, associates functionally and colocalizes partially with p300 in interphase nuclei of HeLa cells (Pao et al. 2000). Moreover, a subfraction of BRCA1 has been found to copurify with pol II in immunoprecipitation analyses (Scully et al. 1997). CBP/p300 domains that are not spatially related to active transcription may serve as storage, or supply sites, or be involved in other transcription-related events such as initiation complex regeneration.
It is believed that pol IIa participates in initiation-competent forms of pol II complexes and pol IIo in elongation-competent forms (Payne et al. 1989; Dahmus 1995). Although both pol IIo and pol IIa colocalized with CBP/p300 in the nucleoplasm, only pol IIa was found in complex with the coactivators in vivo (Fig. 2). This observation confirms the finding that p300 specifically interacts with the nonphosphorylated form of purified pol II complexes (Cho et al. 1998), and that CBP copurifies with pol II complexes precipitated with anti–pol IIa antibody (Kee et al. 1996). Taken together, CBP may serve as a bridging/coactivating/chromatin-remodeling factor during transcriptional initiation, but may be separated from phosphorylated pol II during elongation. In vivo, the interaction between CBP/p300 and pol IIa seems to be mediated either by RNA helicase A (Nakajima et al. 1997a,Nakajima et al. 1997b), or by direct binding of the COOH-terminal half of CBP/p300 (Cho et al. 1998). The recent identification of "zinc bundles" as putative protein–protein interaction modules in the COOH-terminal CH3 domain of CBP/p300 (Newton et al. 2000) suggests that this domain may contribute to the interaction between the coactivators and pol IIa.
When transcription was arrested by specific inhibitors, CBP/p300 redistributed to pol IIo–containing minimal domains corresponding to speckles (Fig. 4). Speckles are characterized by an accumulation of factors involved in mRNA biogenesis, mainly splicing factors (Spector 1993). Our results and other studies indeed revealed colocalization of CBP with splicing factor Sm and SC-35 in speckle structures, but not in the more diffusely stained compartment of the nucleoplasm (Bex et al. 1998; Fig. 3, and data not shown, respectively). However, we were not able to detect Sm protein or other splicing factors in immunoprecipitates of CBP, suggesting that there is no functional relationship between splicing and CBP (von Mikecz, A., and M. Montminy, unpublished results). It has been proposed that speckles may function as storage places supplying active gene loci with factors needed for mRNA biogenesis (Antoniou et al. 1993; Gui et al. 1994; Misteli et al. 1997; Zeng et al. 1997; Lamond and Earnshaw 1998; Misteli and Spector 1998). If speckles serve as depots for CBP/p300 in transcriptionally inactive cells, it is conceivable that the "stored" coactivators are dynamically recruited together with pol II from speckles to active loci of transcription (or other sites) throughout the nucleoplasm in transcriptionally active cells.
We also demonstrated that CBP/p300 colocalize with pol IIa in a subset of PML bodies. Although a variety of nuclear processes have been suggested to take place at or near PML bodies, the function of these structures is unknown (Doucas and Evans 1996; Sternsdorf et al. 1997; Maul 1998; Matera 1999). They do not seem to be major sites of splicing factor localization (Grande et al. 1996); instead, proteins associated with these nuclear domains show properties of transcriptional modulators (Doucas and Evans 1996; Bloch et al. 1999; Doucas et al. 1999). Most importantly, LaMorte et al. have identified nascent RNA within nuclear bodies, including PML bodies, by in vivo nucleic acid labeling (1998). However, it was shown by analytical transmission microscopy that PML nuclear bodies do not accumulate RNA (Boisvert et al. 2000), but that newly synthesized RNA is associated with the periphery of the PML bodies (Grande et al. 1996; Boisvert et al. 2000). The contradictory results might be due to (a) usage of different techniques and (b) different cell lines, since PML body number, structure, composition, and thus function can vary considerably depending on the cell type (Maul 1998). The presence of PML protein, CBP, and pol IIa in the same PML bodies (Fig. 4) suggests that they may serve as supply or recycling sites of preformed initiation complexes for transcription of gene loci that are localized adjacent to PML bodies. Such complexes may be recruited from the core to PML body–associated genes to facilitate and regulate the expression of these genes. A similar model has recently been proposed for coiled bodies (Schul et al. 1998b).
Several viral transforming factors, including the adenoviral E1A protein, the SV40 T antigen, and Tax from HTLV-1 interact with CBP/p300 to modulate transcriptional activity of target genes (for review see Shikama et al. 1997). Some of these proteins target PML bodies, causing a dramatic redistribution of PML body proteins, including PML itself, to transcription sites scattered throughout the nucleoplasm (Doucas et al. 1996; Maul 1998). Viral proteins may disrupt transcription of PML body–specific genes and/or target transcription (initiation) complexes containing PML, CBP/p300, and pol II within the PML bodies in order to recruit such complexes to genes whose expression is important for efficient virus propagation. We are confident that identification of the genes expressed at PML bodies will provide further insight into PML nuclear body function and molecular mechanisms of virus propagation and evasion of the host immune defense as well.
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Acknowledgments |
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Submitted: 19 October 1999
Revised: 18 May 2000
Accepted: 26 May 2000
Abbreviations used in this paper:
-am, -Amanitin; BrU, Bromouridine triphosphate, CBP, CREB-binding protein; pol II, RNA polymerase II; PML, promyelocytic leukemia.
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References |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
Antoniou M. Carmo-Fonseca M. Ferreira J. Lamond A.I. Nuclear organization of splicing snRNPs during differentiation of murine erythroleukemia cells in vitro, J. Cell Biol, 123, 1993, 1055–1068.
Arany Z. Sellers W.R. Livingston D.M. Eckner R.. E1A-associated p300 and CREB-associated CBP belong to a conserved family of coactivators, Cell., 77, 1994, 799–800.[Medline]
Arias J. Alberts A.S. Brindle P. Claret F.X. Smeal T. Karin M. Feramisco J. Montminy M.. Activation of cAMP and mitogen responsive genes relies on a common nuclear factor, Nature., 370, 1994, 226–229.[Medline]
Bannister A.J. Kouzarides T.. The CBP coactivator is a histone acetyltransferase, Nature., 384, 1996, 641–643.[Medline]
Bex F. Yin M.J. Burny A. Gaynor R.B.. Differential transcriptional activation by human T-cell leukemia virus type 1 Tax mutants is mediated by distinct interactions with CREB binding protein and p300, Mol. Cell. Biol, 18, 1998, 2392–2405.
Bloch D.B. Chiche J.D. Orth D. de la Monte S.M. Rosenzweig A. Bloch K.D.. Structural and functional heterogeneity of nuclear bodies, Mol. Cell. Biol, 19, 1999, 4423–4430.
Boisvert F.-M. Hendzel M.J. Bazett-Jones D.P.. Promyelocytic leukemia (PML) nuclear bodies are protein structures that do not accumulate RNA, J. Cell Biol., 148, 2000, 283–292.
Brasch K. Ochs R.L.. Nuclear bodies (NBs)a newly "rediscovered" organelle, Exp. Cell Res, 202, 1992, 211–223.[Medline]
Bregman D.B. Du L. van der Zee S. Warren S.L.. Transcription-dependent redistribution of the large subunit of RNA polymerase II to discrete nuclear domains, J. Cell Biol, 129, 1995, 287–298.
Cho H. Orphanides G. Sun X. Ogryzko V. Lees E. Nakatani Y. Reinberg D.. A human RNA polymerase II complex containing factors that modify chromatin structure, Mol. Cell. Biol., 18, 1998, 5355–5362.
Chrivia J.C. Kwok R.P. Lamb N. Hagiwara M. Montminy M.R. Goodman R.H.. Phosphorylated CREB binds specifically to the nuclear protein CBP, Nature., 365, 1993, 855–859.[Medline]
Cleveland D.W.. NuMaa protein involved in nuclear structure, spindle assembly, and nuclear reformation, Trends Cell Biol, 5, 1995, 60–64.[Medline]
Dahmus M.E.. Phosphorylation of the C-terminal domain of RNA polymerase II, Biochim. Biophys. Acta., 1261, 1995, 171–182.[Medline]
Doucas V. Evans R.M.. The PML nuclear compartment and cancer, Biochim. Biophys. Acta., 1288, 1996, 25–29.
Doucas V. Ishov A.M. Romo A. Juguilon H. Weitzmann M.D. Evans R.M. Maul G.G.. Adenovirus replication is coupled with the dynamic properties of the PML nuclear structure, Genes Dev, 10, 1996, 196–207.
Doucas V. Tini M. Egan D.A. Evans R.M.. Modulation of CREB binding protein function by the promyelocytic (PML) oncoprotein suggests a role for nuclear bodies in hormone signaling, Proc. Natl. Acad. Sci. USA, 96, 1999, 2627–2632.
Eckner R. Ewen M.E. Newsome D. Gerdes M. DeCaprio J.A. Lawrence J.B. Livingston D.M.. Molecular cloning and functional analysis of the adenovirus E1A-associated 300-kD protein (p300) reveals a protein with properties of a transcriptional adaptor, Genes Dev, 8, 1994, 869–884.
Fu X.D. Maniatis T.. Factor required for mammalian spliceosome assembly is localized to discrete regions in the nucleus, Nature., 343, 1990, 437–441.[Medline]
Grande M.A. van der Kraan I. van Steensel B. Schul W. de The H. van der Voort H.T. de Jong L. van Driel R.. PML-containing nuclear bodiestheir spatial distribution in relation to other nuclear components, J. Cell. Biochem, 63, 1996, 280–291.[Medline]
Grande M.A. van der Kraan I. de Jong J. van Driel R.. Nuclear distribution of transcription factors in relation to sites of transcription and RNA polymerase II, J. Cell Sci, 110, 1997, 1781–1791.[Abstract]
Gui J.F. Lane W.S. Fu X.D.. A serine kinase regulates intracellular localization of splicing factors in the cell cycle, Nature., 369, 1994, 678–682.[Medline]
Iborra F.J. Pombo A. Jackson D.A. Cook P.R.. Active RNA polymerases are localized within discrete transcription "factories" in human nuclei, J. Cell Sci., 109, 1996, 1427–1436.[Abstract]
Jackson D.A. Hassan A.B. Errington R.J. Cook P.R.. Visualization of focal sites of transcription within human nuclei, EMBO (Eur. Mol. Biol. Organ.) J., 12, 1993, 1059–1065.[Medline]
Janknecht R. Hunter T.. Transcription. A growing coactivator network, Nature., 383, 1996, 22–23.[Medline]
Kee B.L. Arias J. Montminy M.R.. Adaptor-mediated recruitment of RNA polymerase II to a signal-dependent activator, J. Biol. Chem, 271, 1996, 2373–2375.
Kornberg R.D.. Eukaryotic transcriptional control, Trends Cell Biol., 9, 1999, M46–M49.[Medline]
Kwok R.P. Lundblad J.R. Chrivia J.C. Richards J.P. Bachinger H.P. Brennan R.G. Roberts S.G. Green M.R. Goodman R.H.. Nuclear protein CBP is a coactivator for the transcription factor CREB, Nature., 370, 1994, 223–226.[Medline]
Lamond A.I. Earnshaw W.C.. Structure and function in the nucleus, Science., 280, 1998, 547–553.
LaMorte V.J. Dyck J.A. Ochs R.L. Evans R.M.. Localization of nascent RNA and CREB binding protein with the PML-containing nuclear body, Proc. Natl. Acad. Sci. USA., 95, 1998, 4991–4996.
Lindell T.J. Weinberg F. Morris P.W. Roeder R.G. Rutter W.J.. Specific inhibition of nuclear RNA polymerase II by alpha-amanitin, Science., 170, 1970, 447–449.
Lundblad J.R. Kwok R.P. Laurance M.E. Harter M.L. Goodman R.H.. Adenoviral E1A-associated protein p300 as a functional homologue of the transcriptional coactivator CBP, Nature., 374, 1995, 85–88.[Medline]
Matera A.G.. Nuclear bodiesmultifaceted subdomains of the interchromatin space, Trends Cell Biol., 9, 1999, 302–309.[Medline]
Maul G.G.. Nuclear domain 10, the site of DNA virus transcription and replication, Bioessays., 20, 1998, 660–667.[Medline]
Newton A.L. Sharpe B.K. Kwan A. Mackay J.P. Crossley M.. The transactivation domain within cysteine/histidine-rich region 1 of CBP comprises two novel zinc-binding modules, J. Biol. Chem, 275, 2000, 15128–15134.
Misteli T. Spector D.L.. The cellular organization of gene expression, Curr. Opin. Cell Biol, 10, 1998, 323–331.[Medline]
Misteli T. Caceres J.F. Spector D.L.. The dynamics of a pre-mRNA splicing factor in living cells, Nature., 387, 1997, 523–527.[Medline]
Montminy M.R.. Something new to hang your HAT on, Nature., 387, 1997, 654–655.[Medline]
Nakajima T. Uchida C. Anderson S.F. Lee C.G. Hurwitz J. Parvin J.D. Montminy M.R.. RNA helicase A mediates association of CBP with RNA polymerase II, Cell., 90, 1997, 1107–1112a.[Medline]
Nakajima T. Uchida C. Anderson S.F. Parvin J.D. Montminy M.R.. Analysis of a cAMP-responsive activator reveals a two-component mechanism for transcriptional induction via signal-dependent factors, Genes Dev, 11, 1997, 738–747b.
Neish A.S. Anderson S.F. Schlegel B.P. Wei W. Parvin J.D.. Factors associated with the mammalian RNA polymerase II holoenzyme, Nucleic Acids Res, 26, 1998, 847–853.
Neugebauer K.M. Roth M.B.. Transcription units as RNA processing units, Genes Dev, 11, 1997, 3279–3285.
Ogryzko V.V. Schiltz R.L. Russanova V. Howard B.H. Nakatani Y.. The transcriptional coactivators p300 and CBP are histone acetyltransferases, Cell., 87, 1996, 953–959.[Medline]
Pao G.M. Janknecht R. Ruffner H. Hunter T. Verma I.M.. CBP/p300 interact with and function as transcriptional coactivators of BRCA1, Proc. Natl. Acad. Sci. USA, 97, 2000, 1020–1025.
Parvin J.D. Young R.A.. Regulatory targets in the RNA polymerase II holoenzyme, Curr. Opin. Genet. Dev., 8, 1998, 565–570.[Medline]
Patturajan M. Schulte R.J. Sefton B.M. Berezney R. Vincent M. Bensaude O. Warren S.L. Corden J.L.. Growth-related changes in phosphorylation of yeast RNA polymerase II, J. Biol. Chem, 273, 1998, 4689–4694.
Payne J. Laybourne P. Dahmus M.. The transition of RNA polymerase II from initiation to elongation is associated with phosphorylation of the carboxyl-terminal domain of subunit IIa, J. Biol. Chem., 264, 1989, 19621–19629.
Reyes J.C. Muchardt C. Yaniv M.. Components of the human SWI/SNF complex are enriched in active chromatin and are associated with the nuclear matrix, J. Cell Biol., 137, 1997, 263–274.
Schul W. de Jong L. van Driel R.. Nuclear neighboursthe spatial and functional organization of genes and nuclear domains, J. Cell. Biochem, 70, 1998, 159–171a.[Medline]
Schul W. van Driel R. de Jong L.. Coiled bodies and U2 snRNA genes adjacent to coiled bodies are enriched in factors required for snRNA transcription, Mol. Biol. Cell., 5, 1998, 1025–1036b.
Scully R. Anderson S.F. Chao D.M. Wei W. Ye L. Young R.A. Livingston D.M. Parvin J.D.. BRCA1 is a component of the RNA polymerase II holoenzyme, Proc. Natl. Acad. Sci. USA., 94, 1997, 5605–5610.
Shikama N. Lyon J. La Thangue N.. The p300/CBP familyintegrating signals with transcription factors and chromatin, Trends Cell. Biol, 7, 1997, 230–236.[Medline]
Singer R.H. Green M.R.. Compartmentalization of eukaryotic gene expressioncauses and effects, Cell., 91, 1997, 291–294.[Medline]
Spector D.L.. Macromolecular domains within the cell nucleus, Annu. Rev. Cell Biol, 9, 1993, 265–315.
Stenoien D. Sharp Z.D. Smith C.L. Mancini M.A.. Functional subnuclear partitioning of transcription factors, J. Cell. Biochem, 70, 1998, 213–221.[Medline]
Sternsdorf T. Grotzinger T. Jensen K. Will H.. Nuclear dotsactors on many stages, Immunobiology., 198, 1997, 307–331.[Medline]
Thompson N.E. Steinberg T.H. Aranson D.B. Burgess R.B.. Inhibition of in vivo and in vitro transcription by monoclonal antibodies prepared against wheat germ RNA polymerase II that react with the heptapeptide repeat of eukaryotic RNA polymerase II, J. Biol. Chem, 264, 1989, 4350–4354.
Torchia J. Glass C. Rosenfeld M.G.. Co-activators and co-repressors in the integration of transcriptional responses, Curr. Opin. Cell Biol., 10, 1998, 373–383.[Medline]
van Steensel B. Brink M. van der Meulen K. van Binnendijk E.P. Wansink D.G. de Jong L. de Kloet E.R. van Driel R.. Localization of the glucocorticoid receptor in discrete clusters in the cell nucleus, J. Cell Sci, 108, 1995, 3003–3011.[Abstract]
von Mikecz A. Konstantinov K. Buchwald D. Gerace L. Tan E.M.. High frequency of autoantibodies to insoluble cellular antigens in patients with chronic fatigue syndrome, Arthritis Rheum., 40, 1997, 295–305.[Medline]
Wansink D.G. Schul W. van der Kraan I. van Steensel B. van Driel R. de Jong L.. Fluorescent labeling of nascent RNA reveals transcription by RNA polymerase II in domains scattered throughout the nucleus, J. Cell Biol, 122, 1993, 283–293.
Xing Y. Johnson C.V. Dobner P.R. Lawrence J.B.. Higher level organization of individual gene transcription and RNA splicing, Science., 259, 1993, 1326–1330.
Yang X.J. Ogryzko V.V. Nishikawa J. Howard B.H. Nakatani Y.. A p300/CBP-associated factor that competes with the adenoviral oncoprotein E1A, Nature., 382, 1996, 319–324.[Medline]
Zeng C. Kim E. S.L.Warren Berget S.M.. Dynamic relocation of transcription and splicing factors dependent upon transcriptional activity, EMBO (Eur. Mol. Biol. Organ.) J., 16, 1997, 1401–1412.[Medline]
Zhang G. Taneja K.L. Singer R.H. Green M.R.. Localization of pre-mRNA splicing in mammalian nuclei, Nature., 372, 1994, 809–812.[Medline]
Zhang S. Herrman C. Grosse F.. Nucleolar localization of murine nuclear DNA helicase II (RNA helicase II), J. Cell Sci., 112, 1999, 2693–2703.[Abstract]
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