From the combination of knowledge and actions, someone can improve their skill and ability. It will lead them to live and work much better. This is why, the students, workers, or even employers should have reading habit for books. Any book will give certain knowledge to take all benefits. This is what this the interferon system tells you. It will add more knowledge of you to life and work better. Try it and prove it.

The Interferon System

On the varied biologic effects of interferon

It is well established that insulin and serum stimulate gene expression at the level of mRNA translation in animal cells, and previous studies have mainly focused on the initiation process. Here we show that, in Chinese hamster ovary cells expressing the human insulin receptor, insulin causes decreased phosphorylation of elongation factor eEF-2 and that this is associated with stimulation of the rate of peptide-chain elongation. eEF-2 is phosphorylated by a very specific Ca 2+/calmodulin-dependent protein kinase (eEF-2 kinase) causing its complete inactivation. The decrease in eEF-2 phosphorylation induced by insulin reflects a fall in eEF-2 kinase activity. Rapamycin, a macrolide immunosuppressant which blocks the signalling pathway leading to the stimulation of the 70/85 kDa ribosomal protein S6 kinases, substantially blocks the activation of elongation, the fall in eEF-2 phosphorylation and the decrease in eEF-2 kinase activity, suggesting that p7O S6 kinase (p70s6k) and eEF-2 kinase may tie on a common signalling pathway. Wortmannin, an inhibitor of phosphatidylinositide-3-OH kinase, had similar effects. eEF-2 kinase was phosphorylated in vitro by purified p70s6k but this had no significant effect on the in vitro activity of eEF-2 kinase.

https://www.embopress.org/doi/pdf/10.1002/j.1460-2075.1996.tb00582.x

Regulation of translation elongation factor‐2 by insulin via a rapamycin‐sensitive signalling pathway.

The rhabdoviruses are ubiquitous, highly infectious agents of animal and plant disease and are generally transmitted by arthropods. Assignment of viruses to the taxon rhabdoviruses (rod-shaped viruses) was originally based entirely on morphology. This classification has turned out to be fortuitously fortunate because later biochemical studies have revealed remarkable uniformity among these structurally similar viruses isolated from extremely diverse hosts. It is perhaps not farfetched to postulate a common ancestor for all the rhabdoviruses of plants, arthropods, and vertebrates. Classification of a virus as a rhabdovirus should be based on the following most important characteristics: 

1.

Rhabdoviruses are rod-shaped particles, varying considerably in length (60–400 nm) but of a reasonably consistent width (60–85 nm).




2.

Animal rhabdoviruses tend to be bullet-shaped in appearance, flat at one end and a tapered sphere at the other. Plant rhabdoviruses are usually bacilliform in shape, quite elongated and with two round ends.




3.

All rhabdoviruses appear to be surrounded by a membranous envelope with protruding spikes. All these viruses probably contain lipids and are, therefore, susceptible to disruption by ether and detergents.

Reproduction of Rhabdoviruses

Interferon (IFN) is an important immune system molecule capable of inducing an antiviral state within cells. Herpes simplex virus type 1 (HSV-1) replication is somewhat reduced in tissue culture in the presence of IFN, presumably due to decreased viral transcription. Here, we show mutations that inactivate immediate-early (IE) gene product ICP0 render HSV-1 exquisitely sensitive to IFN inhibition, resulting in greatly decreased levels of viral mRNA transcripts and the resulting polypeptides and a severe reduction in plaque formation ability. Mutations in other HSV-1 genes, including the genes coding for virion transactivator VP16 and the virion host shutoff protein vhs, IE gene ICP22, and the protein kinase UL13 gene, do not increase the IFN sensitivity of HSV-1. Interestingly, ICP0 mutants demonstrate the same level of sensitivity to IFN as wild-type virus on U2OS cells, an osteosarcoma cell line that is known to complement mutations in ICP0 and VP16. Thus, in some cell types, functional ICP0 is required for HSV-1 to efficiently bypass the inhibitory effects of IFN in order to ensure its replication. The significance of this link between ICP0 and IFN resistance is discussed.

Herpes Simplex Virus ICP0 Mutants Are Hypersensitive to Interferon

The particle-bound RNA polymerase activity of vesicular stomatitis virus (VSV) can be demonstrated in vivo. Linear synthesis of viral RNA persists for 5 to 6 hours at 34°C in infected monolayers of chick embryo cells treated with cycloheximide and actinomycin D to block synthesis of protein and cell-specific RNA. At least 55 percent of the RNA made under these conditions is complementary to virion RNA. RNA synthesis mediated by VSV polymerase activity is inhibited in cells first treated with chick-derived interferon or polyriboinosinate• polyribocytidylate, but not by mouse interferon. The RNA product of VSV polymerase activity is present throughout the cytoplasm, and its synthesis is inhibited by the interferon system, as judged by autoradiographs that show the physical distribution, in cells, of RNA produced by virion polymerase in the absence of translation—a demonstration of the transcription product of the viral genome.

http://science.sciencemag.org/content/sci/174/4009/593.full.pdf

Interferon action: inhibition of vesicular stomatitis virus RNA synthesis induced by virion-bound polymerase.

We have investigated the regulation of protein synthesis in animal cells by serum factors. Withdrawal of serum from the medium of actively dividing Vero cells resulted in an immediate decline in the rate of peptide chain elongation (Hassell and Engelhardt, 1973). Assay of elongation factor I (EFI) activity in the post-ribosomal supernatant as well as that associated with the ribosomes revealed that serum deprivation resulted also in reduction in the activity of this factor. The decline in the activity of EFI after serum deprivation occurred to the same extent and at the same time as the decline in the in vivo rate of protein synthesis and the in vitro peptide synthetic capacity of cell-free extracts. A temporal correlation therefore exists among the in vivo rate of protein synthesis, the peptide synthetic activity of cell-free extracts, and the activity of EFI. The activity of peptidyl transferase was not altered by serum deprivation. The loss of extract peptide synthetic activity resulting from serum deprivation was reversible since serum addition to previously serum-starved cultures resulted in full restoration of activity for polyphenylalanine (polyPhe) synthesis within 3 h. Moreover, RNA synthesis was not required for this turn-on of polyPhe synthesis. Vased on these data we conclude that a translational control mechanism is operative in Vero cells deprived of serum.

The regulation of protein synthesis in animal cells by serum factors

Cytoplasmic extracts of green monkey kidney-Vero M3 cells that have been grown to high cell density and have entered the stationary phase of growth lose the capacity to synthesize proteins after they have been frozen and thawed. The same loss of protein synthetic capacity is not observed when cytoplasmic extracts of low cell density Vero M3 or HeLa S-3 cells are frozen and thawed before assay, nor when high cell density Vero M3 cell extract is assayed without having been frozen. The loss of the protein synthesis capacity of the frozen and thawed extracts of stationary phase Vero M3 cells is accounted for by the appearance of an inhibitor. The inhibitor is precipitated in the 30 to 70% ammonium sulfate fraction of the 100,000 g supernatant. It is inactivated by heat and is non-dialyzable. It blocks the transfer of amino acids from tRNA to growing peptide chains.



The amount of this inhibitor in the extract (measured by relative inhibition of in vitro protein synthesis) increases as a function of the density of the cells from which the extract was made, and the increase can be correlated with the progressive turnoff of protein synthesis in whole cells.

An inhibitor of protein synthesis in cytoplasmic extracts of density inhibited cells

A chromatographic procedure is described which can discriminate among single-stranded ribonucleic acid (RNA) molecules in solution on the basis of the extent of their secondary structure. The assay is effected through chromatography at different temperatures with columns of cellulose CF-11. When Sindbis virus RNA is chromatographed in this system, the ratio of the amounts of RNA eluting in the single-stranded peak to those eluting in the double-stranded peak increases at higher temperatures, presumably a measure of the relative amounts of Sindbis virus RNA secondary structure at different temperatures. With this assay, Sindbis virus RNA, phage f2 RNA, and polyuridylate have been found to have different amounts of secondary structure.

Dean L. Engelhardt

Papers

Interferon action: inhibition of vesicular stomatitis virus RNA synthesis induced by virion-bound polymerase.

The regulation of protein synthesis in animal cells by serum factors

An inhibitor of protein synthesis in cytoplasmic extracts of density inhibited cells

Assay for Secondary Structure in Ribonucleic Acid

Translational inhibition in extracts from serum-deprived animal cells