Coiled Bodies

2016 ◽  
pp. 1117-1117
Keyword(s):  
Author(s):  
Robert L. Ochs

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.


Author(s):  
K. Brasch ◽  
J. Williams ◽  
D. Gallo ◽  
T. Lee ◽  
R. L. Ochs

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.


2015 ◽  
Vol 9 (1) ◽  
pp. 2-8 ◽  
Author(s):  
Roberta Diehl Rodriguez ◽  
Lea Tenenholz Grinberg

Argyrophilic grain disease (AGD) is an under-recognized, distinct, highly frequent sporadic tauopathy, with a prevalence reaching 31.3% in centenarians. The most common AGD manifestation is slowly progressive amnestic mild cognitive impairment, accompanied by a high prevalence of neuropsychiatric symptoms. AGD diagnosis can only be achieved postmortem based on the finding of its three main pathologic features: argyrophilic grains, oligodendrocytic coiled bodies and neuronal pretangles. AGD is frequently seen together with Alzheimer's disease-type pathology or in association with other neurodegenerative diseases. Recent studies suggest that AGD may be a defense mechanism against the spread of other neuropathological entities, particularly Alzheimer's disease. This review aims to provide an in-depth overview of the current understanding on AGD.


2000 ◽  
Vol 11 (9) ◽  
pp. 2987-2998 ◽  
Author(s):  
Kelly P. Smith ◽  
Jeanne Bentley Lawrence

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.


1996 ◽  
Vol 7 (7) ◽  
pp. 1137-1151 ◽  
Author(s):  
L Rebelo ◽  
F Almeida ◽  
C Ramos ◽  
K Bohmann ◽  
A I Lamond ◽  
...  

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.


1997 ◽  
Vol 230 (1) ◽  
pp. 84-93 ◽  
Author(s):  
Carol E. Lyon ◽  
Kerstin Bohmann ◽  
Judith Sleeman ◽  
Angus I. Lamond

2006 ◽  
Vol 98 (5) ◽  
pp. 1320-1333 ◽  
Author(s):  
Lucile Espert ◽  
Patrick Eldin ◽  
Céline Gongora ◽  
Bernard Bayard ◽  
Francis Harper ◽  
...  
Keyword(s):  

1999 ◽  
Vol 10 (10) ◽  
pp. 3425-3434 ◽  
Author(s):  
Michel Bellini ◽  
Joseph G. Gall

Coiled bodies are discrete nuclear organelles often identified by the marker protein p80-coilin. Because coilin is not detected in the cytoplasm by immunofluorescence and Western blotting, it has been considered an exclusively nuclear protein. In theXenopus germinal vesicle (GV), most coilin actually resides in the nucleoplasm, although it is highly concentrated in 50–100 coiled bodies. When affinity-purified anti-coilin antibodies were injected into the cytoplasm of oocytes, they could be detected in coiled bodies within 2–3 h. Coiled bodies were intensely labeled after 18 h, whereas other nuclear organelles remained negative. Because the nuclear envelope does not allow passive diffusion of immunoglobulins, this observation suggests that anti-coilin antibodies are imported into the nucleus as an antigen–antibody complex with coilin. Newly synthesized coilin is not required, because cycloheximide had no effect on nuclear import and subsequent targeting of the antibodies. Additional experiments with myc-tagged coilin and myc-tagged pyruvate kinase confirmed that coilin is a shuttling protein. The shuttling of Nopp140, NO38/B23, and nucleolin was easily demonstrated by the targeting of their respective antibodies to the nucleoli, whereas anti-SC35 did not enter the germinal vesicle. We suggest that coilin, perhaps in association with Nopp140, may function as part of a transport system between the cytoplasm and the coiled bodies.


1999 ◽  
Vol 73 (5) ◽  
pp. 4208-4219 ◽  
Author(s):  
Juinn-Lin Liu ◽  
Ying Ye ◽  
Zheng Qian ◽  
Yongyi Qian ◽  
Dennis J. Templeton ◽  
...  

ABSTRACT Marek’s disease virus, an avian alphaherpesvirus, has been used as an excellent model to study herpesvirus oncogenesis. One of its potential oncogenes, MEQ, has been demonstrated to transform a rodent fibroblast cell line, Rat-2, in vitro by inducing morphological transformation and anchorage- and serum-independent growth and by protecting cells from apoptosis induced by tumor necrosis factor alpha, C2-ceramide, UV irradiation, or serum deprivation. In this report, we show that there is a cell cycle-dependent colocalization of MEQ protein and cyclin-dependent kinase 2 (CDK2) in coiled bodies and the nucleolar periphery during the G1/S boundary and early S phase. To our knowledge, this is the first demonstration that CDK2 is found to localize to coiled bodies. Such an in vivo association and possibly subsequent phosphorylation may result in the cytoplasmic translocation of MEQ protein. Indeed, MEQ is expressed in both the nucleus and the cytoplasm during the G1/S boundary and early S phase. In addition, we were able to show in vitro phosphorylation of MEQ by CDKs. We have mapped the CDK phosphorylation site of MEQ to be serine 42, a residue in the proximity of the bZIP domain. An indirect-immunofluorescence study of the MEQ S42D mutant, in which the CDK phosphorylation site was mutated to a charged residue, reveals more prominent cytoplasmic localization. This lends further support to the notion that the translocation of MEQ is regulated by phosphorylation. Furthermore, phosphorylation of MEQ by CDKs drastically reduces the DNA binding activity of MEQ, which may in part account for the lack of retention of MEQ oncoprotein in the nucleus. Interestingly, the localization of CDK2 in coiled bodies and the nucleolar periphery is observed only in MEQ-transformed Rat-2 cells, implicating MEQ in modifying the subcellular localization of CDK2. Taken together, our data suggest that there is a novel reciprocal modulation between the herpesvirus oncoprotein MEQ and CDK2.


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