Ras key editor virus

Jingwei Bian wrote the manuscript. Rongsheng Zhao and Suodi Zhai discussed the content of manuscript and provided some advice. Zijian Li designed this manuscript, reviewed and edited it before submission.

National Center for Biotechnology Information , U. Acta Pharm Sin B. Published online Apr Author information Article notes Copyright and License information Disclaimer. Zijian Li: nc. Production and hosting by Elsevier B. This article has been cited by other articles in PMC.

Acknowledgments The authors acknowledge funding support from the National Natural Science Foundation of China , , , and and Beijing Municipal Natural Science Foundation , China. Author contributions All authors researched data for the article and discussed its content.

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You could just join the ski patrol They purchased RAS at the beginning of the year for their system. RAS will completely circumvent even a properly programmed two way radio, unless you have the correct and matching RAS key and a valid ID. Really, you should just become an authorized user. It would be interesting to hear why a ski area would need to encrypt their communications. I've lived next to a big one for 25 years and have monitored their radio system for all of that. I haven't heard anything that would need to remain confidential.

Because its free. And because it keeps people from listening and protects their business operations. Oh, and because they can. Every radio system I install, I encrypt if it has the capability. Last edited: Nov 30, Forts Mentor Database Admin. Dmrdecode still works fine on systems using RAS as far as I know As well as DSD. It just keeps out the interlopers with real radios.

TampaTyron Member. It is very effective at keeping interlopers from TXing or RXing anything on the system. TT Forts said:. Joined Dec 25, Messages 3. Notwithstanding this PI3K activation, phosphorylation of the major PI3K downstream molecule Akt at this early stage was not significant, and became prominent only at post-entry stages Figure 5B.

These kinetics of Akt phosphorylation are consistent with a previous report, where transient Akt phosphorylation is detected with lesser amplitude than that observed at a late stage, in a manner specific on cell contexts and viral strain [13].

These observations regarding the small amplitude of Akt phosphorylation may be accounted for by the restricted activation of PI3K in early endosomes, as we presented here, and the proportion of Akt activated by Ras-PI3K to total Akt can determine the extent of phosphorylated Akt detected by immunoblotting.

Alternatively, given that the expression of wild-type or dominant-negative forms of Akt does not significantly alter virus entry [13] , [14] , PI3K in the endosomes may utilize PIP 3 binding factors other than Akt to regulate virus entry.

On the other hand, our findings do not rule out the implication of PI3K-Akt signaling in late events of infection such as replication. In fact, prominent Akt phosphorylation was observed at 6 h.

The PI3K—Akt pathway is also reported to participate in events associated with late steps, including the regulation of interferon production through interferon regulatory factor IRF -3 phosphorylation in response to double-stranded RNA [13] , [31] , [32]. How influenza viruses upregulate Ras—PI3K signaling at an early stage for their efficient entry remains obscure. The first step of influenza virus infection is adsorption to sialylated proteins on the cell surface.

Thus, the type of sialylation of cell surface proteins is of great importance to determine virus host specificity; however, none of the sialylated proteins has been identified as a single specific receptor for this virus to date.

On the other hand, it has recently been reported that the mannose 6-phosphate receptor is a sialic acid-independent receptor for influenza viruses in macrophages [33]. Given that the PR8 strain, used in this study and capable to activate Ras, cannot bind to the macrophage cell surface molecules, including this receptor, after sialidase treatment [33] , signal transducers from influenza virus to Ras should be sialylated proteins.

In this regard, it is noteworthy that the receptor tyrosine kinase fibroblast growth factor receptor is in a list of host factors implicated in influenza virus infection in several genome-wide studies [3] , [4] , [5] , [6]. However, other acceptor mechanism s are likely to be dominant; our preliminary experiments show that the receptor inhibitor produced marginal effects on the infection and the level of phosphorylated tyrosine in the total cell lysate was not strikingly altered by the infection data not shown.

One may raise a concern about the use of fibroblasts as a model because the expression pattern of this molecule has been thought to be restricted within leukocytes. In the present study, the genetic ablation in fibroblasts indeed resulted in a decreased endocytic ability and influenza infectivity Figures 1 — 3. Among the stages of the influenza life cycle, viral entry is one of the remaining sanctuaries to be targeted for prevention and therapy.

In addition, virus internalization after adsorption is a relatively non-specific process and is conserved over a range of viral subtypes and species. It therefore presents a promising target for achieving potent therapeutics with a broad spectrum of efficacy and a lower rate of resistance. However, expression of a dominant-negative form of Eps15 and knockdown of epsin 1, both of which are involved in clathrin-mediated endocytosis, do not hamper influenza virus infection [41] , [43].

In contrast, ablation of the Ras—PI3K interaction restrained influenza virus internalization via inhibiting clathrin-independent endocytosis Figures 1 and 3 , underscoring Ras—PI3K-mediated, clathrin-independent endocytosis as one of the key pathways of influenza virus entry, whereas clathrin-dependent endocytosis is a supportive one. Our finding may also be applied to other viruses, apart from influenza viruses, namely the severe acute respiratory syndrome SARS coronavirus or dengue virus, both of which are known to infect via clathrin-independent endocytosis [44] , [45].

In summary, the Ras—PI3K interaction, identified here as a host-oriented mechanism for influenza internalization, is implicated in very specific cellular phenomena, including clathrin-independent endocytosis and endosomal maturation, and is separate from clathrin-dependent endocytosis, which is necessary for a number of important biological events, such as receptor downregulation and low-density lipoprotein incorporation.

In fact, adult mice deficient in Ras binding to PI3Ks are healthy [23]. Inhibiting this signaling pathway could lead to the development of a useful, well-tolerated prevention strategy against a variety of viral infections, which would aid in the development of effective countermeasures against viral pandemics.

Stephen the Babraham Institute, UK. Matsuda Kyoto University, Kyoto, Japan [48]. Starting at 2 days, the cells were cultured in DMEM containing 0. Expression of each protein was confirmed by immunoblotting see Figure S1C. Stably transfected cells were maintained in DMEM supplemented with 0.

For transfection, expression plasmids were introduced with FuGene HD Roche, Basel, Switzerland according to the manufacturer's recommendations. The anti-NP antibody was a kind gift from A. Takada Hokkaido University, Sapporo, Japan. The inoculum was aspirated, and the cells were incubated with DMEM for 2 days.

The amount of infectious virus in the cell supernatants was determined using common plaque assays as described previously [49] , [50]. Briefly, confluent monolayers of MDCK cells in well plates were inoculated with the supernatants. To assess endocytosis, cells plated on a collagen-coated 35 mm diameter glass base dish Asahi Techno Glass Co. For the analysis of endosome maturation, cells were simultaneously labeled with AlexaFluordextran and nM LysoTracker Red for 10 minutes.

After washing with PBS, the cells were further incubated with LysoTracker Red, followed by quantification as described above. Hattori Kitasato University, Tokyo, Japan. Detection of GTP-bound Ras was performed essentially as described previously [26] with slight modifications [47].

GTP-bound Ras was detected by immunoblotting. All data, unless otherwise specified, are expressed as box and whisker plots, where the highest and lowest boundaries of the box represent the 25th and 75th percentiles, respectively, and whiskers above and below the box designate the 5th and 95th percentiles, respectively; the line within the box indicates the median value.

Data were subjected to one-way analysis of variance, followed by comparison using a Student's t -test to evaluate the differences. P values obtained from the test are found in the figure legends. Establishment of cell lines stably expressing wild-type or mutant PI3K that lack the ability to bind Ras. The cells were then observed by confocal microscopy. The right panels show whole-cell images to indicate where the left panels are from A. Note that overlapping peaks indicate colocalization B.

The data shown are representative of three independent experiments. Cells processed as in Figure 1C were observed using a confocal microscope. Delayed virus trafficking in the absence of the Ras—PI3K interaction.

A Total virus particles visualized by an anti-NP antibody were plotted. Note that the total number of virus particles, including adsorbed viruses and incorporated viruses, is comparable throughout the experimental conditions. B Representative images are shown.