Nuclear coiled bodies and the nucleolus

1994 ◽  
Vol 52 ◽  
pp. 20-21
Author(s):  
K. Brasch ◽  
J. Williams ◽  
D. Gallo ◽  
T. Lee ◽  
R. L. Ochs
Keyword(s):  
Mouse Liver ◽  
Nuclear Body ◽  
Nuclear Bodies ◽  
Model Systems ◽  
Coiled Body ◽  
Rrna Processing ◽  
Malignant Cells ◽  
Sm Proteins ◽  
Coiled Bodies ◽  
Unique Protein

Though first described in 1903 by Ramon-y-Cajal as silver-staining “accessory bodies” to nucleoli, nuclear bodies were subsequently rediscovered by electron microscopy about 30 years ago. Nuclear bodies are ubiquitous, but seem most abundant in hyperactive and malignant cells. The best studied type of nuclear body is the coiled body (CB), so termed due to characteristic morphology and content of a unique protein, p80-coilin (Fig.1). While no specific functions have as yet been assigned to CBs, they contain spliceosome snRNAs and proteins, and also the nucleolar protein fibrillarin. In addition, there is mounting evidence that CBs arise from or are generated near the nucleolus and then migrate into the nucleoplasm. This suggests that as yet undefined links may exist, between nucleolar pre-rRNA processing events and the spliceosome-associated Sm proteins in CBs.We are examining CB and nucleolar changes in three diverse model systems: (1) estrogen stimulated chick liver, (2) normal and neoplastic cells, and (3) polyploid mouse liver.

scholarly journals M Phase Phosphoprotein 10 Is a Human U3 Small Nucleolar Ribonucleoprotein Component

1998 ◽  
Vol 9 (2) ◽  
pp. 437-449 ◽  
Author(s):  
Joanne M. Westendorf ◽  
Konstantin N. Konstantinov ◽  
Steven Wormsley ◽  
Mei-Di Shu ◽  
Naoko Matsumoto-Taniura ◽  
...  
Keyword(s):  
Coiled Body ◽  
Cell Fractionation ◽  
Rrna Processing ◽  
Novel Proteins ◽  
Nucleolar Proteins ◽  
Coiled Bodies ◽  
Interphase Cells ◽  
M Phase ◽  
Almost All ◽  
Nucleolar Rna

We have previously developed a novel technique for isolation of cDNAs encoding M phase phosphoproteins (MPPs). In the work described herein, we further characterize MPP10, one of 10 novel proteins that we identified, with regard to its potential nucleolar function. We show that by cell fractionation, almost all MPP10 was found in isolated nucleoli. By immunofluorescence, MPP10 colocalized with nucleolar fibrillarin and other known nucleolar proteins in interphase cells but was not detected in the coiled bodies stained for either fibrillarin or p80 coilin, a protein found only in the coiled body. When nucleoli were separated into fibrillar and granular domains by treatment with actinomycin D, almost all the MPP10 was found in the fibrillar caps, which contain proteins involved in rRNA processing. In early to middle M phase of the cell cycle, MPP10 colocalized with fibrillarin to chromosome surfaces. At telophase, MPP10 was found in cellular structures that resembled nucleolus-derived bodies and prenucleolar bodies. Some of these bodies lacked fibrillarin, a previously described component of nucleolus-derived bodies and prenucleolar bodies, however, and the bulk of MPP10 arrived at the nucleolus later than fibrillarin. To further examine the properties of MPP10, we immunoprecipitated it from cell sonicates. The resulting precipitates contained U3 small nucleolar RNA (snoRNA) but no significant amounts of other box C/D snoRNAs. This association of MPP10 with U3 snoRNA was stable to 400 mM salt and suggested that MPP10 is a component of the human U3 small nucleolar ribonucleoprotein.

scholarly journals Coiled bodies without coilin.

1997 ◽  
Vol 8 (1) ◽  
pp. 73-82 ◽  
Author(s):  
D W Bauer ◽  
J G Gall
Keyword(s):  
Rna Processing ◽  
Coiled Body ◽  
Sm Proteins ◽  
Light Microscope Level ◽  
Xenopus Egg Extract ◽  
Coiled Bodies ◽  
Egg Extract ◽  
Processing Pathways ◽  
Xenopus Egg

Nuclei assembled in vitro in Xenopus egg extract contain coiled bodies that have components from three different RNA processing pathways: pre-mRNA splicing, pre-rRNA processing, and histone pre-mRNA 3'-end formation. In addition, they contain SPH-1, the Xenopus homologue of p80-coilin, a protein characteristic of coiled bodies. To determine whether coilin is an essential structural component of the coiled body, we removed it from the egg extract by immunoprecipitation. We showed that nuclei with bodies morphologically identical to coiled bodies (at the light microscope level) formed in such coilin-depleted extract. As expected, these bodies did not stain with antibodies against coilin. Moreover, they failed to stain with an antibody against the Sm proteins, although Sm proteins associated with snRNAs were still present in the extract. Staining of the coilin- and Sm-depleted coiled bodies was normal with antibodies against two nucleolar proteins, fibrillarin and nucleolin. Similar results were observed when Sm proteins were depleted from egg extract: staining of the coiled bodies with antibodies against the Sm proteins and coilin was markedly reduced but bright nucleolin and fibrillarin staining remained. These immunodepletion experiments demonstrate an interdependence between coilin and Sm snRNPs and suggest that neither is essential for assembly of nucleolar components in coiled bodies. We propose that coiled bodies are structurally heterogeneous organelles in which the components of the three RNA processing pathways may occur in separate compartments.

Use of human autoantibodies and immunoelectron microscopy to study structure and function of the nucleolus and nuclear bodies

1992 ◽  
Vol 50 (1) ◽  
pp. 506-507
Author(s):  
Robert L. Ochs
Keyword(s):  
Electron Microscopy ◽  
Structure And Function ◽  
Nuclear Bodies ◽  
Nuclear Interior ◽  
Coiled Bodies ◽  
Interchromatin Granules ◽  
And Function ◽  
Conventional Electron Microscopy ◽  
Perichromatin Granules ◽  
Perichromatin Fibrils

By conventional electron microscopy, the formed elements of the nuclear interior include the nucleolus, chromatin, interchromatin granules, perichromatin granules, perichromatin fibrils, and various types of nuclear bodies (Figs. 1a-c). Of these structures, all have been reasonably well characterized structurally and functionally except for nuclear bodies. The most common types of nuclear bodies are simple nuclear bodies and coiled bodies (Figs. 1a,c). Since nuclear bodies are small in size (0.2-1.0 μm in diameter) and infrequent in number, they are often overlooked or simply not observed in any random thin section. The rat liver hepatocyte in Fig. 1b is a case in point. Historically, nuclear bodies are more prominent in hyperactive cells, they often occur in proximity to nucleoli (Fig. 1c), and sometimes they are observed to “bud off” from the nucleolar surface.

scholarly journals Nuclear body phase separation drives telomere clustering in ALT cancer cells

2020 ◽  
Vol 31 (18) ◽  
pp. 2048-2056 ◽  
Author(s):  
Huaiying Zhang ◽  
Rongwei Zhao ◽  
Jason Tones ◽  
Michel Liu ◽  
Robert L. Dilley ◽  
...  
Keyword(s):  
Dna Repair ◽  
Phase Separation ◽  
Cancer Cells ◽  
Nuclear Body ◽  
Promyelocytic Leukemia ◽  
Nuclear Bodies ◽  
Telomere Elongation ◽  
Alternative Lengthening ◽  
Induce Phase Separation ◽  
Induce Phase

A chemical dimerization approach is developed to induce phase separation of APB nuclear bodies involved in telomere elongation in alternative lengthening of telomeres (ALT) cancer cells. It reveals that ALT telomere-associated promyelocytic leukemia nuclear body (APB) fusion leads to telomere clustering to provide templates for homology-directed telomere synthesis, an ability that is decoupled from APB function in enriching DNA repair factors.

scholarly journals EBNA3C Coactivation with EBNA2 Requires a SUMO Homology Domain

2004 ◽  
Vol 78 (1) ◽  
pp. 367-377 ◽  
Author(s):  
Adam Rosendorff ◽  
Diego Illanes ◽  
Gregory David ◽  
Jeffrey Lin ◽  
Elliott Kieff ◽  
...  
Keyword(s):  
Amino Acids ◽  
Gene Activation ◽  
Point Mutations ◽  
Nuclear Body ◽  
Nuclear Bodies ◽  
Nuclear Antigen ◽  
Barr Virus ◽  
Epstein Barr ◽  
Necessary And Sufficient ◽  
Regulated Promoters

ABSTRACT Epstein-Barr virus (EBV) nuclear antigen 3C (EBNA3C) is critical for EBV immortalization of infected B lymphocytes and can coactivate the EBV LMP1 promoter with EBNA2. EBNA3C amino acids 365 to 545 are necessary and sufficient for coactivation and are required for SUMO-1 and SUMO-3 interaction. We found that EBNA3C but not EBNA3CΔ343-545 colocalized with SUMO-1 in nuclear bodies and was modified by SUMO-2, SUMO-3, and SUMO-1. EBNA3C amino acids 545 to 628 and amino acids 30 to 365 were also required for EBNA3C sumolation and nuclear body localization but were dispensable for coactivation, indicating that EBNA3C sumolation is not required for coactivation. Furthermore, EBNA3C amino acids 476 to 992 potently coactivated with EBNA2 but EBNA3C amino acids 516 to 922 lacked activity, indicating that amino acids 476 to 515 are critical for coactivation. EBNA3C amino acids 476 to 515 include DDDVIEV507-513, which are similar to SUMO-1 EEDVIEV84-90. EBNA3C m1 and m2 point mutations, DDD507-509 mutated to AAA and DVIEVID509-513 mutated to AVIAVIA, respectively, diminished SUMO-1 and SUMO-3 interaction in directed yeast two-hybrid and glutathione S-transferase pulldown assays. Furthermore, EBNA3C m1 and m2 did not coactivate the LMP1 promoter with EBNA2. Overexpression of wild-type SUMO-1, SUMO-3, and the SUMO-conjugating enzyme UBC9 coactivated the LMP1 promoter with EBNA2. Since EBNA2 activation is dependent on p300/CBP, the possible effect of EBNA3C on p300-mediated transcription was assayed. EBNA3C potentiated transcription of p300 fused to a heterologous DNA binding domain, whereas EBNA3C m1 and m2 did not. All of these data are consistent with a model in which EBNA3C upregulates EBNA2-mediated gene activation by binding to a sumolated repressor and inhibiting repressive effects on p300/CBP and other transcription factor(s) at EBNA2-regulated promoters.

scholarly journals Interactions of U2 Gene Loci and Their Nuclear Transcripts with Cajal (Coiled) Bodies: Evidence for PreU2 within Cajal Bodies

2000 ◽  
Vol 11 (9) ◽  
pp. 2987-2998 ◽  
Author(s):  
Kelly P. Smith ◽  
Jeanne Bentley Lawrence
Keyword(s):  
Potential Role ◽  
Coiled Body ◽  
Oligonucleotide Probes ◽  
Primary Transcript ◽  
U2 Snrna ◽  
Rna Foci ◽  
Coiled Bodies ◽  
Snrna Gene

The Cajal (coiled) body (CB) is a structure enriched in proteins involved in mRNA, rRNA, and snRNA metabolism. CBs have been shown to interact with specific histone and snRNA gene loci. To examine the potential role of CBs in U2 snRNA metabolism, we used a variety of genomic and oligonucleotide probes to visualize in situ newly synthesized U2 snRNA relative to U2 loci and CBs. Results demonstrate that long spacer sequences between U2 coding repeats are transcribed, supporting other recent evidence that U2 transcription proceeds past the 3′ box. The presence of bright foci of this U2 locus RNA differed between alleles within the same nucleus; however, this did not correlate with the loci's association with a CB. Experiments with specific oligonucleotide probes revealed signal for preU2 RNA within CBs. PreU2 was also detected in the locus-associated RNA foci, whereas sequences 3′ of preU2 were found only in these foci, not in CBs. This suggests that a longer primary transcript is processed before entry into CBs. Although this work shows that direct contact of a U2 locus with a CB is not simply correlated with RNA at that locus, it provides the first evidence of new preU2 transcripts within CBs. We also show that, in contrast to CBs, SMN gems do not associate with U2 gene loci and do not contain preU2. Because other evidence indicates that preU2 is processed in the cytoplasm before assembly into snRNPs, results point to an involvement of CBs in modification or transport of preU2 RNA.

scholarly journals snRNP: Rich Nuclear Bodies inHyacinthus orientalisL. Microspores and Developing Pollen Cells

2009 ◽  
Vol 2009 ◽  
pp. 1-12 ◽  
Author(s):  
K. Zienkiewicz ◽  
E. Bednarska
Keyword(s):  
Pollen Development ◽  
Rna Synthesis ◽  
Generative Cell ◽  
Pollen Grains ◽  
Strong Relationship ◽  
Nuclear Bodies ◽  
Cajal Body ◽  
Sm Proteins ◽  
Hyacinthus Orientalis

The aim of the present work was the characterization of nuclear bodies in the microspore and developing pollen cells ofHyacinthus orientalisL.. The combination of Ag-NOR, immunofluorescence and immunogold techniques was used in this study. The obtained results showed the presence of highly agyrophylic extranucleolar bodies in microspore and developing pollen cells, which were finally identified as Cajal bodies. In all cases, a strong accumulation of snRNP-indicating molecules including TMG cap, Sm proteins and U2 snRNA, was observed in the examined nuclear bodies. In contrast to their number the size of the identified structures did not change significantly during pollen development. In the microspore and the vegetative cell of pollen grains CBs were more numerous than in the generative cell. At later stages of pollen development, a drastic decrease in CB number was observed and, just before anthesis, a complete lack of these structures was indicated in both pollen nuclei. On the basis of these results, as well as our previous studies, we postulate a strong relationship between Cajal body numbers and the levels of RNA synthesis and splicing machinery elements in microspore and developing pollen cells.

scholarly journals The dynamics of coiled bodies in the nucleus of adenovirus-infected cells.

1996 ◽  
Vol 7 (7) ◽  
pp. 1137-1151 ◽  
Author(s):  
L Rebelo ◽  
F Almeida ◽  
C Ramos ◽  
K Bohmann ◽  
A I Lamond ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Hela Cells ◽  
Host Protein ◽  
Coiled Body ◽  
Adenovirus Infection ◽  
Protein Synthesis Inhibitors ◽  
Coiled Bodies ◽  
Infected Cells ◽  
Host Protein Synthesis ◽  
Small Nuclear Ribonucleoproteins

The coiled body is a specific intranuclear structure of unknown function that is enriched in splicing small nuclear ribonucleoproteins (snRNPs). Because adenoviruses make use of the host cell-splicing machinery and subvert the normal subnuclear organization, we initially decided to investigate the effect of adenovirus infection on the coiled body. The results indicate that adenovirus infection induces the disassembly of coiled bodies and that this effect is probably secondary to the block of host protein synthesis induced by the virus. Furthermore, coiled bodies are shown to be very labile structures, with a half-life of approximately 2 h after treatment of HeLa cells with protein synthesis inhibitors. After blocking of protein synthesis, p80 coilin was detected in numerous microfoci that do not concentrate snRNP. These structures may represent precursor forms of the coiled body, which goes through a rapid cycle of assembly/disassembly in the nucleus and requires ongoing protein synthesis to reassemble.

scholarly journals Promyelocytic leukemia nuclear bodies behave as DNA damage sensors whose response to DNA double-strand breaks is regulated by NBS1 and the kinases ATM, Chk2, and ATR

2006 ◽  
Vol 175 (1) ◽  
pp. 55-66 ◽  
Author(s):  
Graham Dellaire ◽  
Reagan W. Ching ◽  
Kashif Ahmed ◽  
Farid Jalali ◽  
Kenneth C.K. Tse ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Dna Damage ◽  
Cellular Response ◽  
Cell Cycle Progression ◽  
Nuclear Body ◽  
Promyelocytic Leukemia ◽  
S Phase ◽  
Nuclear Bodies ◽  
Structural Basis ◽  
Loss Of Function

The promyelocytic leukemia (PML) nuclear body (NB) is a dynamic subnuclear compartment that is implicated in tumor suppression, as well as in the transcription, replication, and repair of DNA. PML NB number can change during the cell cycle, increasing in S phase and in response to cellular stress, including DNA damage. Although topological changes in chromatin after DNA damage may affect the integrity of PML NBs, the molecular or structural basis for an increase in PML NB number has not been elucidated. We demonstrate that after DNA double-strand break induction, the increase in PML NB number is based on a biophysical process, as well as ongoing cell cycle progression and DNA repair. PML NBs increase in number by a supramolecular fission mechanism similar to that observed in S-phase cells, and which is delayed or inhibited by the loss of function of NBS1, ATM, Chk2, and ATR kinase. Therefore, an increase in PML NB number is an intrinsic element of the cellular response to DNA damage.

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