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POPSThe Promise and Power of RNA RNA interference, or RNAi, discovered only about 10 years ago, is attracting huge interest for its seeming ability to knock out disease-causing genes. There are already at least six RNAi drugs being tested in people, for illnesses including cancer and an eye disease. And while there are still huge challenges to surmount, that number could easily double in the coming year. “I’ve never found a gene that couldn’t be down-regulated by RNAi,” said Tod Woolf, president of RXi Pharmaceuticals, one of the many companies that have sprung up in the last few years to pursue RNA-based medicines. The two scientists credited with discovering the basic mechanism of RNA interference won the Nobel Prize in Physiology or Medicine in 2006, only eight years after publishing their seminal paper. And three scientists credited with discovering the closely related micro-RNA in the 1990s won Lasker Awards for medical research this year.
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POPSDon't Stress! Bacterial Cell's 'Crisis Command Center' Revealed If a bacteria cell finds itself in a dangerous situation - for example, if the temperature or saltiness of the bacteria's environment reach dangerous levels which threaten the survival of the bacteria -a warning signal from the cell's surface is transmitted into the cell. Using cutting edge electron microscopy imaging techniques the authors of the new research observed that the stressosomes receive this warning signal, and in response several proteins called RSBT break away from the large stressosome. This breakaway triggers a cascade of signals within the cell which results in over 150 proteins being produced - proteins which enable the cell to adapt, react and survive in its new environment.
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POPS68 Molecules that hold the key to all Cellular Life Currently, the vast majority of medical research looks to the human genome and proteome for answers, but those answers remain elusive, and perhaps for good reason. “We have now found instances where the pathogenesis of widespread and chronic diseases can be attributed to a change in the glycome, for example, in the absence of definable changes in the genome or proteome,” Marth said, adding that, as biomedical researchers, “we need to begin to cultivate the integration of disciplines in a holistic and rigorous way in order to perceive and most effectively manipulate the biological mechanisms of health and disease.” Marth believes that biology should become more integrative both in academic and research settings. “I’m one who believes that we don’t need to sacrifice breadth of knowledge in order to acquire depth of understanding.”
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POPSResearchers turn one form of adult mouse cell directly into another Joan Brugge, Chair of the Department of Cell Biology at Harvard Medical School, said the new study "provides exciting new insights into yet another aspect of cell plasticity that was not appreciated previously and that offers great potential therapeutically. Direct reprogramming represents a more straight-forward strategy to treat diseases involving loss of function of specific cell populations than approaches requiring an intermediate embryonic stem cell," she said.
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POPSFuture for clean energy lies in 'big bang' of evolution For humans now there is the tantalising possibility of tweaking the photosynthetic reactions of cyanobacteria to produce fuels we want such as hydrogen, alcohols or even hydrocarbons, rather than carbohydrates. Progress at the research level has been rapid, boosting prospects of harnessing photosynthesis not just for energy but also for manufacturing valuable compounds for the chemical and biotechnology industries. Such research is running on two tracks, one aimed at genetically engineering real plants and cyanobacteria to yield the products we want, and the other to mimic their processes in artificial photosynthetic systems built with human-made components. Both approaches hold great promise and will be pursued in parallel, as was discussed at a recent workshop focusing on the photosynthetic reaction centres of cyanobacteria, organised by the European Science Foundation (ESF).
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POPSThe Secret Of Fast Complex Brain Restructuring Up to now, it had been assumed that nerve cells can only exchange information via the synapses which are special contact points. However, synapses require up to two days to become fully functional - a waste of time and energy if the contact is to be broken down again. The brain could take almost 1000 years to develop if a synapse had to mature at each cell contact. It appears that nerve cells can also obtain information about their neighbours even without a synapse. Neurobiologists Christian Lohmann and Tobias Bonhoeffer from the Max Planck Institute for Neurobiology have now explained how they do that. The secret to how the information is exchanged: local calcium signals very quickly transmit all the necessary information to the cell. A synapse only actually develops when the cell and the contact point prove to be suitable candidates for long-term contact.
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POPSTHE ORIGIN OF BIOLOGICAL INFORMATION Yet Muller and Newman insist that population genetics, and thus evolutionary biology, has not identified a specifically causal explanation for the origin of true morphological novelty during the history of life. Central to their concern is what they see as the inadequacy of the variation of genetic traits as a source of new form and structure. They note, following Darwin himself, that the sources of new form and structure must precede the action of natural selection (2003:3)–that selection must act on what already exists. Yet, in their view, the “genocentricity” and “incrementalism” of the neo-Darwinian mechanism has meant that an adequate source of new form and structure has yet to be identified by theoretical biologists. Instead, Muller and Newman see the need to identify epigenetic sources of morphological innovation during the evolution of life. In the meantime, however, they insist neo-Darwinism lacks any “theory of the generative”
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POPSViruses can catch colds, says study that redefines life itself Prof La Scola and his colleagues were surprised to spot a smaller type of virus attached to the virus-making factory inside infected cells. The new virus - Sputnik - was unable to infect cells by itself but seemed to hijack the larger to achieve its infectious aims. By regulating the growth and death of plankton, giant viruses - and satellite viruses such as Sputnik - could be a major influence on ocean nutrient cycles and climate. "These viruses could be major players in global systems," Nature is told by Prof Curtis Suttle, an expert in marine viruses at the University of British Columbia in Vancouver.
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POPSPrevailing theory of aging challenged in Stanford worm study To see whether these signal molecules were part of a wear-and-tear aging mechanism, the researchers exposed worms to stresses thought to cause aging, such as heat (a known stressor for nematode worms), free-radical oxidation, radiation and disease. But none of the stressors affected the genes that make the worms get old. So it looked as though worm aging wasn’t a storm of chemical damage. Instead, Kim said, key regulatory pathways optimized for youth have drifted off track in older animals. Natural selection can’t fix problems that arise late in the animals’ life spans, so the genetic pathways for aging become entrenched by mistake. Kim’s team refers to this slide as “developmental drift.”
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POPSResearchers Discover Remnant of an Ancient 'RNA World'
Breaker's lab solved a decades-old mystery by describing how tiny circular RNA molecules called cyclic di-GMP are able to turn genes on and off. This process determines whether the bacterium swims or stays stationary, and whether it remains solitary or joins with other bacteria to form organic masses called biofilms. Bacterial use of RNA to trigger major changes without the involvement of proteins resolves one of the questions about the origin of life: If proteins are needed to carry out life's functions and DNA is needed to make proteins, how did DNA arise? The answer is what Breaker and other researchers call the RNA World. They believe that billions of years ago, single strands of nucleotides that comprise RNA were the first forms of life and carried out some of the complicated cellular functions now done by proteins. The riboswitches are highly conserved in bacteria, illustrating their importance and ancient ancestry, Breaker said.
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POPSNewly described 'dragon' protein could be key to bird flu cure This unexpected relationship between the two subunits could inspire a number of different therapies or vaccines for H5N1 that rely on muzzling the "dragon's" jaws with another molecule or chemical compound that would block the PB1 subunit's access to the PA site, according to Joachimiak. "If we can put a bit in the dragon's mouth, we can slow or even potentially someday stop the spread of avian flu," he said. "Since we are talking about a relatively small protein surface area, finding a way to inhibit RNA replication in H5N1 seems very feasible."
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POPSNew Mode Of Gene Regulation Discovered In Mammals As research advances, the more it becomes clear, that gene regulation networks are actually complex computing machines. DNA is not a mere repository of information. What's more, the newly discovered mechanism is self referential, which adds another later of complexity to gene regulation processes.
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POPSGene silencer and quantum dots reduce protein production to a whisper Each quantum dot was surrounded by a proton sponge that carried a positive charge. Without any quantum dots attached, the siRNA's negative charge would prevent it from penetrating a cell's wall. With the quantum-dot chaperone, the more weakly charged siRNA complex crosses the cellular wall, escapes from the endosome (a fatty bubble that surrounds incoming material) and accumulates in the cellular fluid, where it can do its work disrupting protein manufacture. Key to the newly published approach is that researchers can adjust the chemical makeup of the quantum dot's proton-sponge coating, allowing the scientists to precisely control how tightly the dots attach to the siRNA. Quantum dots were dramatically better than existing techniques at stopping gene activity. In experiments, a cell's production of a test protein dropped to 2 percent when siRNA was delivered with quantum dots. By contrast, the test protein was produced at 13 percent to 51 percent of normal levels when the siRNA
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POPSGenetically engineered cells make their own nanomagnets, providing clear MRI images. If genetically engineering cells to produce their own magnetic nanoparticles proves successful, this provides a new window through which to view many biological processes as they unfold, from the formation of tumors to the migration of stem cells injected to treat disease. "It's just amazing that they can get a mammalian cell to actually make the material," says Lee Josephson, an associate professor at the Harvard Medical School's Center for Molecular Imaging Research. "I think it's a really meaningful piece of work."
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POPSThe More We Know About Genes, the Less We Understand About 95 percent of the rewired bacteria did just fine with their new networks. They went on with their lives, feeding, growing and dividing. Some even performed better than microbes with the original wiring, under some conditions. The tolerance these bacteria showed reveals something important about how evolution works. Humans can randomly rewire cells, and so can mutations. There's something about gene networks that allow them to thrive despite these mutations, and, in some cases, to even gain an edge in the evolutionary race.
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POPSThe 100$ Genome Five years away, thats impressive. It means individualy tailored medicine within 10-15 years.
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