Viruses can be elusive quarry. RNA viruses are particularly adept at defeating antiviral drugs because they are so inaccurate in making copies of themselves. With at least one error in every genome they copy, viral genomes are moving targets for antiviral drugs, creating resistant mutants as they multiply. In the best-known example of success against retroviruses, it takes multiple-drug cocktails to corner HIV and narrow its escape route.
Rather than target RNA viruses themselves, aiming at the host cells they invade could hold promise, but any such strategy would have to be harmless to the host. Now, a surprising discovery made in ribosomes may point the way to fighting fatal viral infections such as rabies.
Results were published online November 19 in Proceedings of the National Academy of Sciences.
The ribosome has traditionally been viewed as the cell's molecular machine, automatically chugging along, synthesizing proteins the cell needs to carry out the functions of life. But Amy Lee, a former graduate student in the program of virology, and Sean Whelan, HMS professor of microbiology and immunobiology, now say the ribosome appears to take a more active role, regulating the translation of specific proteins and ultimately how some viruses replicate.
The researchers were studying differences between how viruses and the host cells they infect carry out the process of translating messenger RNAs (mRNAs) into proteins. Focusing on protein components found on the surface of the ribosome, they discovered a protein that some viruses depend on to make other proteins, but that the vast majority of cellular mRNAs do not need.
Called rpL40, this ribosomal protein could represent a target for potential treatments; blocking it would disable certain viruses while leaving normal cells largely unaffected.
"Because certain viruses are very sensitive to the presence and absence of these ribosomal proteins, it might be a useful way for us to think about targeting ribosomes for therapeutic purposes from an antiviral standpoint," said Whelan. "This is a way to think about interfering with rabies virus infection. There are no therapeutics for rabies infection."
The team screened protein constituents of the ribosome to see which ones might be involved in specialized protein synthesis. Studying the vesicular stomatitis virus, a rhabdovirus in the same family as the rabies virus, they found that its mRNAs depended on rpL40 but only 7 percent of host-cellular mRNAs did. Some of the cellular mRNAs that depend upon rpL40 were stress response genes.
Experiments in yeast and human cells revealed that a class of viruses, which includes rabies and measles, depended on rpL40 for replication.
"This work reveals that the ribosome is not just an automatic molecular machine but instead also acts as a translational regulator," said first author Amy Lee, who is now a post-doctoral researcher at the University of California, Berkeley.
The concept of targeting cellular functions such as protein synthesis for antiviral therapies is being explored by a number of research groups, but there are no drugs based on this.
"We think the principle is bigger than just this single protein," Whelan said. "Viruses have an uncanny way of teaching us new biology all the time."
David Cameron | EurekAlert!
Don't Give the Slightest Chance to Toxic Elements in Medicinal Products
23.03.2018 | Physikalisch-Technische Bundesanstalt (PTB)
North and South Cooperation to Combat Tuberculosis
22.03.2018 | Universität Zürich
Satellites in near-Earth orbit are at risk due to the steady increase in space debris. But their mission in the areas of telecommunications, navigation or weather forecasts is essential for society. Fraunhofer FHR therefore develops radar-based systems which allow the detection, tracking and cataloging of even the smallest particles of debris. Satellite operators who have access to our data are in a better position to plan evasive maneuvers and prevent destructive collisions. From April, 25-29 2018, Fraunhofer FHR and its partners will exhibit the complementary radar systems TIRA and GESTRA as well as the latest radar techniques for space observation across three stands at the ILA Berlin.
The "traffic situation" in space is very tense: the Earth is currently being orbited not only by countless satellites but also by a large volume of space...
An international team of researchers has discovered a new anti-cancer protein. The protein, called LHPP, prevents the uncontrolled proliferation of cancer cells in the liver. The researchers led by Prof. Michael N. Hall from the Biozentrum, University of Basel, report in “Nature” that LHPP can also serve as a biomarker for the diagnosis and prognosis of liver cancer.
The incidence of liver cancer, also known as hepatocellular carcinoma, is steadily increasing. In the last twenty years, the number of cases has almost doubled...
In just a few weeks from now, the Chinese space station Tiangong-1 will re-enter the Earth's atmosphere where it will to a large extent burn up. It is possible that some debris will reach the Earth's surface. Tiangong-1 is orbiting the Earth uncontrolled at a speed of approx. 29,000 km/h.Currently the prognosis relating to the time of impact currently lies within a window of several days. The scientists at Fraunhofer FHR have already been monitoring Tiangong-1 for a number of weeks with their TIRA system, one of the most powerful space observation radars in the world, with a view to supporting the German Space Situational Awareness Center and the ESA with their re-entry forecasts.
Following the loss of radio contact with Tiangong-1 in 2016 and due to the low orbital height, it is now inevitable that the Chinese space station will...
Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, provider of research and development services for OLED lighting solutions, announces the founding of the “OLED Licht Forum” and presents latest OLED design and lighting solutions during light+building, from March 18th – 23rd, 2018 in Frankfurt a.M./Germany, at booth no. F91 in Hall 4.0.
They are united in their passion for OLED (organic light emitting diodes) lighting with all of its unique facets and application possibilities. Thus experts in...
A new scenario seeking to explain how Mars' putative oceans came and went over the last 4 billion years implies that the oceans formed several hundred million...
23.03.2018 | Event News
19.03.2018 | Event News
16.03.2018 | Event News
23.03.2018 | Materials Sciences
23.03.2018 | Agricultural and Forestry Science
23.03.2018 | Physics and Astronomy