In the November 15 issue of Nature, one group of researchers shows that a part of ion channels called the paddle is uniquely transplantable between different channels. Writing in the same issue, another group exploited this property to probe the three-dimensional structure of ion channels on an atomic scale.
"The effects of many toxins and therapeutic drugs, as well as some diseases, can be wholly explained by changes in ion channel function," says Story Landis, Ph.D., director of the National Institute of Neurological Disorders and Stroke (NINDS), part of the NIH. "We also know that ion channels are at least a contributing player in epilepsy, chronic pain, Parkinson's disease and other disorders. As we learn more about how channels work, we're able to pursue more approaches to treatment."
Ion channels are proteins that control the flow of electrically charged salt particles (ions) across the nerve cell membrane. It's the opening and closing of these channels that enables nerve cells to fire off bursts of electrical activity. A built-in voltmeter, called a voltage sensor, pops the channel open when the nerve cell is ready to fire. The papers in Nature hone in on a part of the voltage sensor called the paddle, named for its shape.
In the first study, a team led by NINDS senior investigator Kenton Swartz, Ph.D., shows that the paddle works as a modular unit. Using recombinant DNA technology, they swapped the paddle from an ion channel found in an ancient, volcano-dwelling bacterium to a channel found in rat brain. As long as the paddle was intact, the hybrid channel still worked. This portability could one day be exploited to test potential drugs. For example, researchers who want to target a paddle from a poorly characterized ion channel could stick it into a well-studied channel where the effects of drugs are easier to measure.
Other results in the paper suggest that the paddle itself will be a useful target for new therapeutic drugs. Dr. Swartz's group found that the paddle is the docking site for certain toxins in tarantula venom, which are known to interfere with ion channel opening. There are hints that scorpions, sea anemones and cone snails make similar toxins, Dr. Swartz said. If nature has found ways to manipulate ion channel function, medicinal chemists might be able to do the same, he said.
In the second study, supported by the National Institute of General Medical Sciences (NIGMS), researchers took advantage of the paddle's unique transplantability to create a hybrid ion channel ideal for structural studies. Led by Roderick MacKinnon, M.D. – a Nobel Laureate, an investigator of the Howard Hughes Medical Institute and a biophysicist at Rockefeller University in New York – the team produced data that explain how the voltage sensor is positioned within the membrane and how it triggers channel opening.
"The determination of the three-dimensional structures of ion channels has yielded a framework to understand their fascinating functional properties," says NIGMS director Jeremy M. Berg, Ph.D. "These new results show how clever experimental designs can focus on key questions and steer the direction of additional studies."
Bergamotene - alluring and lethal for Manduca sexta
21.04.2017 | Max-Planck-Institut für chemische Ökologie
How to color a lizard: From biology to mathematics
13.04.2017 | Université de Genève
More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.
Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...
Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.
"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...
The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.
Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...
The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...
Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.
Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...
20.04.2017 | Event News
18.04.2017 | Event News
03.04.2017 | Event News
27.04.2017 | Life Sciences
27.04.2017 | Physics and Astronomy
27.04.2017 | Earth Sciences