scholarly journals Effects of adenovirus infection on rRNA synthesis and maturation in HeLa cells.

1983 ◽  
Vol 3 (4) ◽  
pp. 662-671 ◽  
Author(s):  
C L Castiglia ◽  
S J Flint
Keyword(s):  
Hela Cells ◽  
Ribosomal Proteins ◽  
18S Rrna ◽  
Adenovirus Type ◽  
Cellular Protein ◽  
Rrna Synthesis ◽  
28S Rrna ◽  
Adenovirus Infection ◽  
Infected Cells ◽  
Infectious Cycle

The production of cytoplasmic and nucleolar rRNA species was examined in HeLa cells infected with high multiplicities of adenovirus type 5. Both 28S and 18S rRNA newly synthesized in infected cells ceased to enter the cytoplasm as reported previously (N. Ledinko, Virology 49: 79-89, 1972; H. J. Raskas, D. C. Thomas, and M. Green, Virology 40: 893-902, 1970). However, the effects on 28S cytoplasmic rRNA were observed considerably earlier in the infectious cycle than those on 18S rRNA. The inhibition of cellular protein synthesis and of the appearance in the cytoplasm of labeled cellular mRNA sequences (G. A. Beltz and S. J. Flint, J. Mol. Biol. 131: 353-373, 1979) were also monitored in infected cultures. During the later periods of an infectious cycle, from 18 h after infection, nucleolar rRNA synthesis and processing and exit of 18S rRNA from the nucleus were inhibited, probably reflecting the failure of infected cells to synthesize normal quantities of ribosomal proteins. The earliest responses of cellular RNA metabolism to adenovirus infection were, however, the rapid and apparently coordinate reductions in the levels of newly synthesized 28S rRNA and cellular mRNA sequences entering the cytoplasm.

Effects of adenovirus infection on rRNA synthesis and maturation in HeLa cells

1983 ◽  
Vol 3 (4) ◽  
pp. 662-671
Author(s):  
C L Castiglia ◽  
S J Flint
Keyword(s):  
Hela Cells ◽  
Ribosomal Proteins ◽  
18S Rrna ◽  
Adenovirus Type ◽  
Cellular Protein ◽  
Rrna Synthesis ◽  
28S Rrna ◽  
Adenovirus Infection ◽  
Infected Cells ◽  
Infectious Cycle

The production of cytoplasmic and nucleolar rRNA species was examined in HeLa cells infected with high multiplicities of adenovirus type 5. Both 28S and 18S rRNA newly synthesized in infected cells ceased to enter the cytoplasm as reported previously (N. Ledinko, Virology 49: 79-89, 1972; H. J. Raskas, D. C. Thomas, and M. Green, Virology 40: 893-902, 1970). However, the effects on 28S cytoplasmic rRNA were observed considerably earlier in the infectious cycle than those on 18S rRNA. The inhibition of cellular protein synthesis and of the appearance in the cytoplasm of labeled cellular mRNA sequences (G. A. Beltz and S. J. Flint, J. Mol. Biol. 131: 353-373, 1979) were also monitored in infected cultures. During the later periods of an infectious cycle, from 18 h after infection, nucleolar rRNA synthesis and processing and exit of 18S rRNA from the nucleus were inhibited, probably reflecting the failure of infected cells to synthesize normal quantities of ribosomal proteins. The earliest responses of cellular RNA metabolism to adenovirus infection were, however, the rapid and apparently coordinate reductions in the levels of newly synthesized 28S rRNA and cellular mRNA sequences entering the cytoplasm.

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 Association of Nonribosomal Nucleolar Proteins in Ribonucleoprotein Complexes during Interphase and Mitosis

1999 ◽  
Vol 10 (1) ◽  
pp. 77-90 ◽  
Author(s):  
Serafı́n Piñol-Roma
Keyword(s):  
Ribosomal Proteins ◽  
Rna Binding ◽  
Rrna Synthesis ◽  
28S Rrna ◽  
Ribosomal Subunits ◽  
Interphase Cell ◽  
Ribonucleoprotein Complexes ◽  
Nucleolar Proteins ◽  
M Phase ◽  
Nucleolar Rna

rRNA precursors are bound throughout their length by specific proteins, as the pre-rRNAs emerge from the transcription machinery. The association of pre-rRNA with proteins as ribonucleoprotein (RNP) complexes persists during maturation of 18S, 5.8S, and 28S rRNA, and through assembly of ribosomal subunits in the nucleolus. Preribosomal RNP complexes contain, in addition to ribosomal proteins, an unknown number of nonribosomal nucleolar proteins, as well as small nucleolar RNA-ribonucleoproteins (sno-RNPs). This report describes the use of a specific, rapid, and mild immunopurification approach to isolate and analyze human RNP complexes that contain nonribosomal nucleolar proteins, as well as ribosomal proteins and rRNA. Complexes immunopurified with antibodies to nucleolin—a major nucleolar RNA-binding protein—contain several distinct specific polypeptides that include, in addition to nucleolin, the previously identified nucleolar proteins B23 and fibrillarin, proteins with electrophoretic mobilities characteristic of ribosomal proteins including ribosomal protein S6, and a number of additional unidentified proteins. The physical association of these proteins with one another is mediated largely by RNA, in that the complexes dissociate upon digestion with RNase. Complexes isolated from M-phase cells are similar in protein composition to those isolated from interphase cell nuclear extracts. Therefore, the predominant proteins that associate with nucleolin in interphase remain in RNP complexes during mitosis, despite the cessation of rRNA synthesis and processing in M-phase. In addition, precursor rRNA, as well as processed 18S and 28S rRNA and candidate rRNA processing intermediates, is found associated with the immunopurified complexes. The characteristics of the rRNP complexes described here, therefore, indicate that they represent bona fide precursors of mature cytoplasmic ribosomal subunits.

scholarly journals Mutual Interference of Adenovirus Infection and myc Expression

2003 ◽  
Vol 77 (14) ◽  
pp. 7936-7944 ◽  
Author(s):  
Kristina Löhr ◽  
Oliver Hartmann ◽  
Helmut Schäfer ◽  
Matthias Dobbelstein
Keyword(s):  
Mrna Level ◽  
Adenovirus Type ◽  
The Other ◽  
Adenovirus Infection ◽  
Mrna Levels ◽  
Protein Levels ◽  
Other Hand ◽  
Cellular Genes ◽  
Infected Cells ◽  
Adenovirus Replication

ABSTRACT During infection with adenovirus, massive changes in the transcription of virus genes are observed, suggesting that the expression of cellular genes may also be modulated. To characterize the levels of cellular RNA species in infected cells, cDNA arrays were screened 24 h after infection of HeLa cells with wild-type adenovirus type 5, strain dl309. Despite complete transduction of the cells, fewer than 20 cellular genes (out of 4,600 analyzed and 1,200 found detectable and expressed above background) were altered more than threefold in their corresponding RNA levels compared to mock-infected cells. In particular, the expression of the myc oncogene was reduced at the mRNA level. This reduction was dependent on the replication of virus DNA and partially dependent on the presence of the adenovirus gene products E1B-55 kDa and E4orf6, but not E4orf3. On the other hand, MYC protein had an increased half-life in infected cells, resulting in roughly constant steady-state protein levels. The adenovirus E1A gene product is necessary and sufficient to stabilize MYC. Overexpressed MYC inhibited adenovirus replication and the proper formation of the virus replication centers. We conclude that adenovirus infection leads to the stabilization of MYC, perhaps as a side effect of E1A activities. On the other hand, myc mRNA levels are negatively regulated during adenovirus infection, and this may avoid the detrimental effect of excessive MYC on adenovirus replication.

scholarly journals Simultaneous detection of highly phosphorylated proteins and viral major DNA binding protein distribution in nuclei of adenovirus type 5-infected HeLa cells.

1991 ◽  
Vol 39 (5) ◽  
pp. 669-680 ◽  
Author(s):  
F Puvion-Dutilleul
Keyword(s):  
Hela Cells ◽  
Simultaneous Detection ◽  
Adenovirus Type ◽  
Protein Distribution ◽  
Viral Genomes ◽  
Phosphorylated Proteins ◽  
Infected Cells ◽  
Fibrillar Component ◽  
Adenovirus Type 5

Highly phosphorylated proteins in situ in sections of Lowicryl-embedded cells are preferentially stained by bismuth, provided that the reactivity of the amino groups is blocked by glutaraldehyde fixation. This study showed that bismuth staining can be preceded by indirect immunocytochemistry using gold particles as markers. As a result, both immunostained and bismuth-stained proteins can be detected concomitantly on the same section. This was also carried out on sections of formaldehyde-fixed cells which were immunolabeled, then post-fixed with glutaraldehyde, and finally exposed to bismuth stain. These procedures were applied to sections of adenovirus Type 5-infected HeLa cells. Bismuth ions and viral anti-72 KD antibody bound concomitantly to intranuclear virus-induced single-stranded DNA (ssDNA) accumulation sites, structures in which viral replicative activity is intermittent, and also to the fibrillogranular peripheral replicative zones which surround the ssDNA accumulation sites and in which replication of viral genomes is continuous. The delicate fibrillar network enclosed within virus-induced compact rings of unknown function is slightly bismuth stained and binds few antibodies to viral 72 KD protein. Three intranuclear structures were stained exclusively with bismuth: the fibrillar component of the nucleolus, which is involved in ribosome formation; the interchromatin granules; and the virus-induced "fibrillar spots" of unknown significance. Thus, not all highly phosphorylated proteins in adenovirus-infected cells are viral 72 KD protein. In glutaraldehyde-fixed Miller spreads of nucleic acid molecules from adenovirus-infected cells, bismuth deposits occurred over unique thick filaments, the only portion of the viral deoxyribonucleoprotein molecules shown to be associated with viral 72 KD protein. In vitro studies revealed that the latter protein, known to be multiply phosphorylated, concomitantly binds anti-72 KD antibody and bismuth ions. These data have broadened the scope of the use of bismuth staining. Taken together, they indicate that in adenovirus infection highly phosphorylated proteins accumulate over intranuclear structures related to both replication of viral genomes and alteration of ribosomal metabolism.

Distribution of viral RNA molecules during the adenovirus type 5 infectious cycle in HeLa cells

1992 ◽  
Vol 108 (3) ◽  
pp. 209-220 ◽  
Author(s):  
Francine Puvion-Dutilleul ◽  
Roussi Roussev ◽  
Edmond Puvion
Keyword(s):  
Hela Cells ◽  
Adenovirus Type ◽  
Viral Rna ◽  
Rna Molecules ◽  
Adenovirus Type 5 ◽  
Infectious Cycle

Novel intron-encoded small nucleolar RNAs with long sequence complementarities to mature rRNAs involved in ribosome biogenesis

1995 ◽  
Vol 73 (11-12) ◽  
pp. 835-843 ◽  
Author(s):  
Jean-Pierre Bachellerie ◽  
Monique Nicoloso ◽  
Liang-Hu Qu ◽  
Bernard Michot ◽  
Michèle Caizergues-Ferrer ◽  
...  
Keyword(s):  
Ribosomal Proteins ◽  
Ribosome Biogenesis ◽  
18S Rrna ◽  
Structural Basis ◽  
28S Rrna ◽  
Cis Acting ◽  
Nucleolar Proteins ◽  
Genes Encoding ◽  
Mouse Cells ◽  
Nucleolar Rnas

Recently, several new snoRNAs encoded in introns of genes coding for ribosomal, ribosome-associated, or nucleolar proteins have been discovered. We are presently studying four of these intronic snoRNAs. Three of them, U20, U21, and U24, are closely related to each other on a structural basis. They are included in genes encoding nucleolin and ribosomal proteins L5 and L7a, respectively, in warm-blooded vertebrates. These three metabolically stable snoRNAs interact with nucleolar protein fibrillarin. In addition, they display common features that make them strikingly related to snoRNA U14. U14 contains two tracts of complementarity to 18S rRNA, which are required for the production of 18S rRNA. U20 displays a 21 nucleotide (nt) long complementarity to 18S rRNA. U21 contains a 13 nt complementarity to an invariant sequence in eukaryotic 28S rRNA. U24 has two separate 12 nt long complementarities to a highly conserved tract of 28S rRNA. Phylogenetic evidences support the fundamental importance of the pairings of these three snoRNAs to pre-rRNA, which could be involved in a control of pre-rRNA folding during preribosome assembly. By transfection of mouse cells, we have also analyzed the processing of U20 and found that the -cis acting signals for its processing from intronic RNA are restricted to the mature snoRNA sequence. Finally, we have documented changes of host genes for these three intronic snoRNAs during the evolution of eukaryotes.Key words: snoRNA, pre-rRNA, folding, genes, introns.

scholarly journals Anti-Adenoviral Activity of 2-(3-Chlorotetrahydrofuran-2-yl)-4-Tosyl-5-(Perfluoropropyl)-1,2,3-Triazole

Medicina ◽  
2018 ◽  
Vol 54 (5) ◽  
pp. 81 ◽  
Author(s):  
Liubov Biliavska ◽  
Yuliia Pankivska ◽  
Olga Povnitsa ◽  
Svitlana Zagorodnya ◽  
Ganna Gudz ◽  
...  
Keyword(s):  
De Novo ◽  
Flow Cytometric Analysis ◽  
Human Adenovirus ◽  
Adenovirus Type ◽  
Moderate Activity ◽  
Adenovirus Infection ◽  
Flow Cytometric ◽  
Adults And Children ◽  
Infected Cells ◽  
Diphenyl Tetrazolium Bromide

Background and objectives: A considerable increase in the levels of adenoviral diseases among both adults and children necessitate the development of effective methods for its prevention and treatment. The synthesis of the new fluorinated 1,2,3-triazoles, and the study of the mechanisms of their action, are promising for the development of efficient antiviral drugs of our time. Materials and Methods: Antiviral activity and cell cytotoxic effect of 2-(3-chlorotetrahydrofuran-2-yl)-4-tosyl-5-(perfluoropropyl)-1,2,3-triazole (G29) were determined by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assay. The influence of the compound on the infectivity of human adenovirus type 5 (HAdV-5) was carried out via the cytomorphology method. The influence of the compound on the cell cycle under a condition of adenovirus infection was studied using flow cytometric analysis of propidium iodide-stained cells. Results: It was found that G29 suppressed HAdV-5 reproduction by 50% in concentrations of 37 μg/mL. Furthermore, the compound reduced the titer of virus obtained de novo, and inhibited HAdV-5 inclusion bodies formation by 84–90%. The use of fluorinated compounds under the conditions of adenovirus infection decreased the number of apoptotic cells by 11% and the number of cells in S phase by 21–42% compared to the profile of infected cells. Conclusions: The fluorinated compound G29 showed moderate activity against HAdV-5 based on several mechanisms. It led to the normalization of the life cycle of cells infected with adenovirus to the level of non-infected cells and caused the obstruction of HAdV-5 reproduction, inducing the formation of non-infectious virus progeny.

scholarly journals The Mre11 Cellular Protein Is Modified by Conjugation of Both SUMO-1 and SUMO-2/3 during Adenovirus Infection

ISRN Virology ◽  
2014 ◽  
Vol 2014 ◽  
pp. 1-14 ◽  
Author(s):  
Elizabeth Castillo-Villanueva ◽  
Grisel Ballesteros ◽  
Melanie Schmid ◽  
Paloma Hidalgo ◽  
Sabrina Schreiner ◽  
...  
Keyword(s):  
Adenovirus Type ◽  
Cellular Protein ◽  
Cellular Proteins ◽  
Cellular Targets ◽  
Orf3 Protein ◽  
Mrn Complex ◽  
Early Proteins ◽  
Sumo Ligase ◽  
Cullin 5 ◽  
Infected Cells

The adenovirus type 5 (Ad5) E1B 55 kDa and E4 Orf6 proteins assemble a Cullin 5-E3 ubiquitin (Ub) ligase that targets, among other cellular proteins, p53 and the Mre11-Rad50-Nbs1 (MRN) complex for degradation. The latter is also inhibited by the E4 Orf3 protein, which promotes the recruitment of Mre11 into specific nuclear sites to promote viral DNA replication. The activities associated with the E1B 55 kDa and E4 Orf6 viral proteins depend mostly on the assembly of this E3-Ub ligase. However, E1B 55 kDa can also function as an E3-SUMO ligase, suggesting not only that regulation of cellular proteins by these viral early proteins may depend on polyubiquitination and proteasomal degradation but also that SUMOylation of target proteins may play a key role in their activities. Since Mre11 is a target of both the E1B/E4 Orf6 complex and E4 Orf3, we decided to determine whether Mre11 displayed similar properties to those of other cellular targets, in Ad5-infected cells. We have found that during Ad5-infection, Mre11 is modified by SUMO-1 and SUMO-2/3 conjugation. Unexpectedly, SUMOylation of Mre11 is not exclusively dependent on E1B 55 kDa, E4 Orf6, or E4 Orf3, rather it seems to be influenced by a molecular interplay that involves each of these viral early proteins.

scholarly journals E1B 55-Kilodalton-Associated Protein: a Cellular Protein with RNA-Binding Activity Implicated in Nucleocytoplasmic Transport of Adenovirus and Cellular mRNAs

1998 ◽  
Vol 72 (10) ◽  
pp. 7960-7971 ◽  
Author(s):  
Stefan Gabler ◽  
Holger Schütt ◽  
Peter Groitl ◽  
Hans Wolf ◽  
Thomas Shenk ◽  
...  
Keyword(s):  
Rna Binding ◽  
Protein A ◽  
Adenovirus Type ◽  
Nucleocytoplasmic Transport ◽  
Cellular Protein ◽  
Binding Activity ◽  
Rna Transport ◽  
Mrna Accumulation ◽  
Genes Encoding ◽  
Infected Cells

ABSTRACT The adenovirus type 5 (Ad5) early 1B 55-kDa protein (E1B-55kDa) is a multifunctional phosphoprotein that regulates viral DNA replication and nucleocytoplasmic RNA transport in lytically infected cells. In addition, E1B-55kDa provides functions required for complete oncogenic transformation of rodent cells in cooperation with the E1A proteins. Using the far-Western technique, we have isolated human genes encoding E1B-55kDa-associated proteins (E1B-APs). The E1B-AP5 gene encodes a novel nuclear RNA-binding protein of the heterogeneous nuclear ribonucleoprotein (hnRNP) family that is highly related to hnRNP-U/SAF-A. Immunoprecipitation experiments indicate that two distinct segments in the 55-kDa polypeptide which partly overlap regions responsible for p53 binding are required for complex formation with E1B-AP5 in Ad-infected cells and that this protein interaction is modulated by the adenovirus E4orf6 protein. Expression of E1B-AP5 efficiently interferes with Ad5 E1A/E1B-mediated transformation of primary rat cells. Furthermore, stable expression of E1B-AP5 in Ad-infected cells overcomes the E1B-dependent inhibition of cytoplasmic host mRNA accumulation. These data suggest that E1B-AP5 might play a role in RNA transport and that this function is modulated by E1B-55kDa in Ad-infected cells.

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