Analyse des Vermehrungsmechanismus des Newcastle disease Virus (NDV) mit Hilfe verschiedener Inhibitoren

1967 ◽  
Vol 22 (12) ◽  
pp. 1319-1330 ◽  
Author(s):  
Werner Schäfer ◽  
Liselotte Pister ◽  
Rita Schneider
Keyword(s):  
Chick Embryo ◽  
Viral Antigen ◽  
Rna Synthesis ◽  
Protein S ◽  
Viral Rna ◽  
Chick Embryo Fibroblast ◽  
Sensitive Material ◽  
Sensitive Phase ◽  
Antigenic Material ◽  
Structural Antigen

The reproduction of NDV in chick-embryo-fibroblast cultures was studied with 6-Azauridine, 8-Azaguanine, Parafluorophenylalanine (FPA) and Puromycine as inhibitors. The results suggest that no virus initiated FPA-sensitive material is needed for the uncoating of the infecting particles, and that viral parental RNA is able to induce the formation of protein (s) needed for viral RNA-synthesis (“RNA-protein“) as well as the production of viral structural antigen (s). Further antigenic material appears after the beginning of new viral RNA-synthesis. The “RNA-protein (s)“become (s) detectable between 2 and 3 hours after infection and is (are) stable in its function over several hours. According to the formation of viral antigenic material parental viral RNA can act as a messenger longer than 9 hours. The capacity for the production of hemagglutinating units appears after the viral antigen producing capacity, when viral RNA can already be synthesized. This capacity is separated from that to produce plaque forming particles by a FPA-sensitive phase. The character of the corresponding FPA-sensititve material is unknown.

Interferon Action:Effect on the Formation of Poxvirus Specific Polysomes and Viral RNA

1970 ◽  
Vol 25 (10) ◽  
pp. 1164-1170 ◽  
Author(s):  
I. Horak ◽  
J. Hilfenhaus ◽  
W. Siegert ◽  
C. Jungwirth ◽  
G. Bodo ◽  
...  
Keyword(s):  
Chick Embryo ◽  
Viral Rna ◽  
Fibroblast Cells ◽  
Cowpox Virus ◽  
Chick Embryo Fibroblast ◽  
L Cells ◽  
Chicken Fibroblast

Treatment of chick embryo fibroblast cells or mouse L-cells with homologous interferon resulted in a reduced formation of poxvirus specific polysomes and of viral RNA. In chick cells infected with cowpox virus the reduced formation of viral polysomes and virus-specific RNA after pretreatment of cells with interferon was observed at all timepoints studied (1 - 6 hours p. i.). Exposure of cells to poly I: poly C caused a similar effect. In mouse L-cells infected with vaccinia WR virus pretreatment with interferon did not result in a reduced formation of viral polysomes or virus-specific RNA up to 1 hour p. i. At about 45 min even a slight increase of the formation of viral polysomes and RNA was observed. At later stages of infection (2 -4 hours p. i.) a reduced synthesis of viral polysomes and RNA was seen, similar to that found in the chicken fibroblast system.

scholarly journals Nucleolar necklaces in chick embryo fibroblast cells. II. Microscope observations of the effect of adenosine analogues on nucleolar necklace formation.

1975 ◽  
Vol 65 (2) ◽  
pp. 418-427 ◽  
Author(s):  
D Granick
Keyword(s):  
Chick Embryo ◽  
Ribosomal Rna ◽  
Messenger Rna ◽  
Rna Synthesis ◽  
Rrna Synthesis ◽  
Fibroblast Cells ◽  
Chick Embryo Fibroblast ◽  
Adenosine Analogues ◽  
Nucleolar Apparatus ◽  
Extensive Degradation

The round nucleoli of chick embryo fibroblast cells, when exposed to adenosine (2 mM)or to a number of adenosine analogues, lose material and unravel over a period of several hours to become beaded strands, 20 mu M in length, termed nucleolar necklaces (NN). Light microscope observations on this process are described. Biochemical experiments have revealed that most of these analogues interfere with both messenger RNA synthesis and ribosome synthesis, causing extensive degradation of the preribosome species containing 32S RNA although most of the preribosomes containing 18S RNA survive. We suggest that it is the depletion from the nucleolus of the adhesive 32S and 28S RNA preribosomes which allows the remaining nucleolar apparatus to spread apart into the NN configuration. Also required for the maintenance of the NN structure is the synthesis of some ribosomal RNA (rRNA) possibly present as rRNA "feathers" on the DNA. The addition of inhibitors of rRNA synthesis such as actinomycin D to the NN-containing cells causes loss of rRNA. Then a contraction and collapse of the NN structure into small dense spheres is observed.

scholarly journals Nucleolar necklaces in chick embryo fibroblast cells. I. Formation of necklaces by dichlororibobenzimidazole and other adenosine analogues that decrease RNA synthesis and degrade preribosomes.

1975 ◽  
Vol 65 (2) ◽  
pp. 398-417 ◽  
Author(s):  
D Granick
Keyword(s):  
Chick Embryo ◽  
Messenger Rna ◽  
Rna Synthesis ◽  
28S Rrna ◽  
Chick Embryo Fibroblast ◽  
Adenosine Analogues ◽  
Biochemical Alterations ◽  
High Concentrations ◽  
Precursor Rna ◽  
Extensive Degradation

A number of chemicals, mostly adenosine analogues, cause the nucleolus of the chick embryo fibroblast to lose material and unravel over a period of several hours into beaded strands termed nucleolar necklaces (NN). The results of analyses of the fibroblasts, treated with the NN-forming chemical dichlororibobenzimidazole (DRB), suggests that the following biochemical alterations occur: DRB almost completely prevents the increase in both messenger RNA (mRNA) and heterogeneous nuclear RNA. It interferes with ribosome synthesis by decreasing the rate of 45S ribosomal RNA (rRNA) accumulation by 50%, slowing the rate of 18S rRNA appearance by 50%, and causing an extensive degradation (80%) of the 32S and 28S rRNA-containing preribisomes. Most of this preribosome degration probably occurs at or before the 32S rRNA preribosome stage. The degradation of these preribosomes appears to be due to the formation of defective 45S rRNA preribosomes rather than to a direct DRB interference with preribosome processing enzyme action. DRB inhibits total cellular RNA synthesis in less than 15 min, suggesting a direct interference with RNA synthesis. DRB also inhibits the uptake of nucleosides into the cell. DRB in the concentrations used does not appear to directly interfere with the translation of mRNA (i.e., protein synthesis). Other NN-forming adenoside analogues and high concentrations of adenosine (2 mM) cause biochemical alterations similar to those produced by DRB. To explain the preribosome degradation, we propose the hypothesis that DRB inhibits the synthesis of mRNA; as a consequence, some of the preribosomal proteins that normally coat the 32S rRNA portion of the 45S precursor RNA become limiting, and this defective portion is then subject to degradation by nucleases.

scholarly journals Ebola Virus VP35 Interaction with Dynein LC8 Regulates Viral RNA Synthesis

2015 ◽  
Vol 89 (9) ◽  
pp. 5148-5153 ◽  
Author(s):  
Priya Luthra ◽  
David S. Jordan ◽  
Daisy W. Leung ◽  
Gaya K. Amarasinghe ◽  
Christopher F. Basler
Keyword(s):  
Rna Synthesis ◽  
Ebola Virus ◽  
Mutational Analysis ◽  
Cytoplasmic Dynein ◽  
Viral Rna ◽  
Interferon Production ◽  
Dynein Light Chain ◽  
High Affinity ◽  
Functional Consequences ◽  
Oligomerization Domain

Ebola virus VP35 inhibits alpha/beta interferon production and functions as a viral polymerase cofactor. Previously, the 8-kDa cytoplasmic dynein light chain (LC8) was demonstrated to interact with VP35, but the functional consequences were unclear. Here we demonstrate that the interaction is direct and of high affinity and that binding stabilizes the VP35 N-terminal oligomerization domain and enhances viral RNA synthesis. Mutational analysis demonstrates that VP35 interaction is required for the functional effects of LC8.

Plant Viral RNA Synthesis in Cell-Free Systems

1994 ◽  
Vol 32 (1) ◽  
pp. 311-335 ◽  
Author(s):  
M de Graaff ◽  
E M J Jaspars
Keyword(s):  
Rna Synthesis ◽  
Viral Rna

Studies of two temperature-sensitive mutants of Mengo virus

1979 ◽  
Vol 57 (6) ◽  
pp. 902-913 ◽  
Author(s):  
Patrick W. K. Lee ◽  
John S. Colter
Keyword(s):  
Rna Synthesis ◽  
Viral Rna ◽  
Temperature Sensitive ◽  
Supporting Evidence ◽  
Structural Polypeptide ◽  
Infected Cells ◽  
Mengo Virus ◽  
In Vitro Stability

Studies of the synthesis of viral ribonucleates and polypeptides in cells infected with two RNA−ts mutants of Mengo virus (ts 135 and ts 520) have shown that when ts 135 infected cells are shifted from the permissive (33 °C) to the nonpermissive (39 °C) temperature: (i) the synthesis of all three species of viral RNA (single stranded, replicative form, and replicative intermediate) is inhibited to about the same extent, and (ii) the posttranslational cleavage of structural polypeptide precursors A and B is partially blocked. Investigations of the in vivo and in vitro stability of the viral RNA replicase suggest that the RNA− phentotype reflects a temperature-sensitive defect in the enzyme. The second defect does not appear to result from the inhibition of viral RNA synthesis at 39 °C, since normal cleavage of polypeptides A and B occurs in wt Mengo-infected cells in which viral RNA synthesis is blocked by cordycepin, and at the nonpermissive temperature in ts 520 infected cells. Considered in toto, the evidence suggests that ts 135 is a double mutant.Subviral (53 S) particles have been shown to accumulate in ts 520 (but not ts 135) infected cells when cultures are shifted from 33 to 39 °C. This observation provides supporting evidence for the proposal that this recently discovered particle is an intermediate in the assembly pathway of Mengo virions.

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