scholarly journals Small Cajal Body–specific RNAs of Drosophila Function in the Absence of Cajal Bodies

2009 ◽  
Vol 20 (24) ◽  
pp. 5250-5259 ◽  
Author(s):  
Svetlana Deryusheva ◽  
Joseph G. Gall
Keyword(s):  
Fluorescent In Situ Hybridization ◽  
Xenopus Oocyte ◽  
Cajal Body ◽  
Cajal Bodies ◽  
Marker Protein ◽  
Wild Type ◽  
Guide Rnas ◽  
Small Nuclear Rnas ◽  
Covalent Modifications

During their biogenesis small nuclear RNAs (snRNAs) undergo multiple covalent modifications that require guide RNAs to direct methylase and pseudouridylase enzymes to the appropriate nucleotides. Because of their localization in the nuclear Cajal body (CB), these guide RNAs are known as small CB-specific RNAs (scaRNAs). Using a fluorescent primer extension technique, we mapped the modified nucleotides in Drosophila U1, U2, U4, and U5 snRNAs. By fluorescent in situ hybridization (FISH) we showed that seven Drosophila scaRNAs are concentrated in easily detectable CBs. We used two assays based on Xenopus oocyte nuclei to demonstrate that three of these Drosophila scaRNAs do, in fact, function as guide RNAs. In flies null for the CB marker protein coilin, CBs are absent and there are no localized FISH signals for the scaRNAs. Nevertheless, biochemical experiments show that scaRNAs are present at normal levels and snRNAs are properly modified. Our experiments demonstrate that several scaRNAs are concentrated as expected in the CBs of wild-type Drosophila, but they function equally well in the nucleoplasm of mutant flies that lack CBs. We propose that the snRNA modification machinery is not limited to CBs, but is dispersed throughout the nucleoplasm of cells in general.

scholarly journals Nopp140-chaperoned 2’-O-methylation of small nuclear RNAs in Cajal bodies ensures splicing fidelity

2021 ◽  
Author(s):  
Jonathan Bizarro ◽  
Svetlana Deryusheva ◽  
Ludivine Wacheul ◽  
Varun Gupta ◽  
Felix G.M. Ernst ◽  
...  
Keyword(s):  
Alternative Splicing ◽  
Small Molecule ◽  
Mode Of Action ◽  
Hematological Malignancies ◽  
Mrna Splicing ◽  
Cajal Body ◽  
Cajal Bodies ◽  
Small Nuclear Rnas ◽  
Splicing Patterns ◽  
Ck2 Inhibitors

ABSTRACTSpliceosomal small nuclear RNAs (snRNAs) are modified by small Cajal body (CB) specific ribonucleoproteins (scaRNPs) to ensure snRNP biogenesis and pre-mRNA splicing. However, the function and subcellular site of snRNA modification are largely unknown. We show that CB localization of the protein Nopp140 is essential for concentration of scaRNPs in that nuclear condensate; and that phosphorylation by casein kinase 2 (CK2) at some 80 serines targets Nopp140 to CBs. Transiting through CBs, snRNAs are apparently modified by scaRNPs. Indeed, Nopp140 knockdown-mediated release of scaRNPs from CBs severely compromises 2’-O-methylation of spliceosomal snRNAs, identifying CBs as the site of scaRNP catalysis. Additionally, alternative splicing patterns change indicating that these modifications in U1, U2, U5, and U12 snRNAs safeguard splicing fidelity. Given the importance of CK2 in this pathway, compromised splicing could underlie the mode of action of small molecule CK2 inhibitors currently considered for therapy in cholangiocarcinoma, hematological malignancies, and COVID-19.

scholarly journals Minimized human telomerase maintains telomeres and resolves endogenous roles of H/ACA proteins, TCAB1, and Cajal bodies

eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
Jacob M Vogan ◽  
Xiaozhu Zhang ◽  
Daniel T Youmans ◽  
Samuel G Regalado ◽  
Joshua Z Johnson ◽  
...  
Keyword(s):  
Binding Sites ◽  
Telomere Maintenance ◽  
Biologically Active ◽  
Cajal Body ◽  
Cajal Bodies ◽  
Cellular Interaction ◽  
Wild Type ◽  
Human Telomerase ◽  
And Function ◽  
Assembly Pathways

We dissected the importance of human telomerase biogenesis and trafficking pathways for telomere maintenance. Biological stability of human telomerase RNA (hTR) relies on H/ACA proteins, but other eukaryotes use other RNP assembly pathways. To investigate additional rationale for human telomerase assembly as H/ACA RNP, we developed a minimized cellular hTR. Remarkably, with only binding sites for telomerase reverse transcriptase (TERT), minimized hTR assembled biologically active enzyme. TERT overexpression was required for cellular interaction with minimized hTR, indicating that H/ACA RNP assembly enhances endogenous hTR-TERT interaction. Telomere maintenance by minimized telomerase was unaffected by the elimination of the telomerase holoenzyme Cajal body chaperone TCAB1 or the Cajal body scaffold protein Coilin. Surprisingly, wild-type hTR also maintained and elongated telomeres in TCAB1 or Coilin knockout cells, with distinct changes in telomerase action. Overall, we elucidate trafficking requirements for telomerase biogenesis and function and expand mechanisms by which altered telomere maintenance engenders human disease.

scholarly journals A Distant Coilin Homologue Is Required for the Formation of Cajal Bodies in Arabidopsis

2006 ◽  
Vol 17 (7) ◽  
pp. 2942-2951 ◽  
Author(s):  
Sarah Collier ◽  
Alison Pendle ◽  
Kurt Boudonck ◽  
Tjeerd van Rij ◽  
Liam Dolan ◽  
...  
Keyword(s):  
Body Size ◽  
Plant Species ◽  
Cajal Body ◽  
Cajal Bodies ◽  
Wild Type ◽  
Arabidopsis Mutants ◽  
Body Formation ◽  
Insertional Mutant ◽  
In The Wild ◽  
Distant Homolog

Cajal bodies (CBs) are subnuclear bodies that are widespread in eukaryotes, being found in mammals, many other vertebrates and in all plant species so far examined. They are mobile structures, moving, fusing, and budding within the nucleus. Here we describe a screen for Arabidopsis mutants with altered CBs and describe mutants that have smaller Cajal bodies (ncb-2, ncb-3), lack them altogether (ncb-1), have increased numbers of CBs (pcb) or have flattened CBs (ccb). We have identified the gene affected in the ncb mutants as a distant homolog of the vertebrate gene that encodes coilin (At1g13030) and have termed the resulting protein Atcoilin. A T-DNA insertional mutant in this gene (ncb-4) also lacks Cajal bodies. Overexpression of Atcoilin cDNA in ncb-1 restores Cajal bodies, which recruit U2B″ as in the wild type, but which are, however, much larger than in the wild type. Thus we have shown that At1g13030 is required for Cajal body formation in Arabidopsis, and we hypothesize that the level of its expression is correlated with Cajal body size. The Atcoilin gene is unaffected in pcb and ccb, suggesting that other genes can also affect CBs.

1796: Analysis of Chromosomal Aneuploidy in Patients with Oligoasthenoteratozoospermia(OAT) Using Fluorescent in-situ Hybridization

2007 ◽  
Vol 177 (4S) ◽  
pp. 596-597
Author(s):  
Joseph P. Alukal ◽  
Bobby B. Najari ◽  
Wilson Chuang ◽  
Lata Murthy ◽  
Monica Lopez-Perdomo ◽  
...  
Keyword(s):  
In Situ Hybridization ◽  
Fluorescent In Situ Hybridization ◽  
Chromosomal Aneuploidy

The URNA Genes of Herpesvirus Saimiri (Strain C488) Are Dispensable for Transformation of Human T Cells In Vitro

1999 ◽  
Vol 73 (12) ◽  
pp. 10551-10555 ◽  
Author(s):  
Armin Ensser ◽  
André Pfinder ◽  
Ingrid Müller-Fleckenstein ◽  
Bernhard Fleckenstein
Keyword(s):  
Cell Culture ◽  
Herpesvirus Saimiri ◽  
Wild Type Virus ◽  
Type Virus ◽  
Wild Type ◽  
Human T Cell ◽  
Human T Cells ◽  
Small Nuclear Rnas ◽  
T Cell Lines

ABSTRACT The herpesvirus saimiri strain C488 genome contains five genes for small nuclear RNAs, termed herpesvirus saimiri URNAs (or HSURs). Using a cosmid-based approach, all HSURs were precisely deleted from the genome. The mutant virus replicated at levels that were similar to those of wild-type viruses in OMK cells. Although the HSURs are expressed in wild-type virus-transformed human T-cell lines, the deletion does not affect viral transformation in cell culture.

scholarly journals Simultaneous genotypic and immunophenotypic analysis of interphase cells using dual-color fluorescence: a demonstration of lineage involvement in polycythemia vera

Blood ◽  
1992 ◽  
Vol 80 (4) ◽  
pp. 1033-1038 ◽  
Author(s):  
CM Price ◽  
EJ Kanfer ◽  
SM Colman ◽  
N Westwood ◽  
AJ Barrett ◽  
...  
Keyword(s):  
Polycythemia Vera ◽  
Fluorescent In Situ Hybridization ◽  
Chromosomal Abnormalities ◽  
Myeloproliferative Disorders ◽  
Chromosome 8 ◽  
Dual Fluorescence ◽  
Interphase Cell ◽  
Molecular Alterations ◽  
Interphase Cells

Abstract Fluorescent in situ hybridization has become a useful technique by which chromosomal abnormalities may be shown in interphase cells. We present a dual-fluorescence method whereby a chromosomal and immunophenotypic marker can be visualized simultaneously in the same interphase cell. Two patients with the myeloproliferative disorder polycythemia vera and trisomy for chromosome 8 have been studied using this technique and selective involvement of the myeloid and erythrocyte lineages has been shown by the detection of the trisomy in immunophenotyped cells. Simultaneous analysis of genotype and immunophenotype in individual cells from patients with myeloproliferative disorders or leukemia may help identify the developmental and lineage status of cells in which molecular alterations have resulted in clonal advantage.

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