(Press-News.org) Controlling nerve cells with the aid of light: this is made possible by optogenetics. It enables, for example, the investigation of neurobiological processes with unprecedented spatial and temporal precision. The key tool of optogenetics is the light-activated protein channelrhodopsin. Biophysicists from Bochum and Berlin have now succeeded in explaining the switching mechanism through an interdisciplinary approach. The researchers report on their findings in the Journal of Biological Chemistry.
Redistribution of water molecules
Until now, little has been known about the mechanism of the protein - especially about how the channel opens. However, deeper understanding is a prerequisite in order to be able to use the light-controlled protein specifically for neurobiological applications. In a new, multi-disciplinary approach, the Bochum scientists led by Prof. Dr. Klaus Gerwert (Department of Biophysics at the RUB) and their cooperation partners in Berlin have been able to shed light on the switching mechanism. The result: the light-induced change in the charge state of amino acid glutamate 90 (E90) triggers an increased penetration of water molecules, so that the protein can now purposefully conduct ions through the cell membrane.
Three methods combined
Using time-resolved infrared spectroscopy, the RUB biophysicists Jens Kuhne and Dr. Erik Freier have been able to show for the first time that the channel is opened through the deprotonation of the amino acid glutamate 90 (E90). In addition, the electrophysiological experiments of the researchers in Berlin confirm that a mutation of the amino acid leads to a change in the ion permeability of the protein. Instead of using safety goggles and lab coats, the two biophysicists Kirstin Eisenhauer and Dr. Steffen Wolf at the Department of Biophysics used supercomputers to simulate how the protonation change of the glutamate opens the channel and allows water molecules to penetrate.
Internationally preeminent
The work has attained particular distinction right now, because shortly after the Bochum pre-publication on the Internet, Japanese researchers published the three-dimensional structure of a channelrhodopsin online in "Nature". "The structure work impressively confirms our biomolecular simulations and the key role played by the amino acid E90 in the switching of the channel", says Prof. Klaus Gerwert. "We are therefore particularly proud to have been preeminent in this internationally competitive field." In 2010, optogenetics was distinguished by "Nature Methods" as the "Method of the Year". Using this method, researchers have succeeded, for example, in restoring the eyesight of blind mice.
INFORMATION:
Bibliographic record
K. Eisenhauer, J. Kuhne, E. Ritter, A. Berndt, S. Wolf, E. Freier, F. Bartl, P. Hegemann, K. Gerwert,: In channelrhodopsin-2 E90 is crucial for ion selectivity and is deprotonated during the photocycle, Journal of Biological Chemistry, Vol. 287, Issue 9, 6904-6911, 2012, DOI: 10.1074/jbc.M111.327700
Further information
Prof. Dr. Klaus Gerwert, Department of Biophysics, Faculty of Biology and Biotechnology at the Ruhr-Universität Bochum, Tel. +49 234 32 24461, gerwert@bph.rub.de
Editor: Jens Wylkop
END
During depression, the brain becomes less plastic and adaptable, and thus less able to perform certain tasks, like storing memories. Researchers at the Swedish medical university Karolinska Institutet have now traced the brain's lower plasticity to reduced functionality in its support cells, and believe that learning more about these cells can pave the way for radical new therapies for depression.
"We were able to cure memory dysfunction in 'depressed' rats by giving them doses of D-serine," says Mia Lindskog, biologist and Assistant Professor at Karolinska Institutet's ...
Providing clean delivery kits and improving birthing practices could halve the number of neonatal deaths following home births in South Asia, according to research funded by the Wellcome Trust.
Around half a million babies die in the first month of life from sepsis and around a third of these infections are transmitted at the time of birth. In South Asia, more than half of deliveries occur at home, most without skilled birth attendance. Maintaining clean delivery practices at home can be challenging for mothers and their birthing companions.
One way to potentially ...
Amsterdam, February 28, 2012 - Elsevier, a world-leading provider of scientific, technical and medical information products and services, announced today the publication of an important clinical guide from the European Menopause and Andropause Society (EMAS) in the February issue of Maturitas. This clinical guide details the role of selective estrogen receptor modulators (SERMs) against postmenopausal osteoporosis as the European Medicines Agency (EMA) has approved the use of bazedoxifene and lasofoxifene.
Postmenopausal osteoporosis and resulting fractures have a major ...
They achieved this by utilising the phenomena of objects moving slower and shortening in length from Einstein's theory of relativity, along with two pieces of gold foil and a micrometre screw.
In Niels Bohr's model of the atom, electrons orbit the nucleus in 'shells' – the so-called stationary states. Light is emitted by a quantum leap between a high-lying shell and one nearer the nucleus. However, it is impossible to find the electron between the two shells, so it could be thought that the light emission process itself was instantaneous: the electron is in the outer shell ...
When the Icelandic banking system was privatised in 2003, it inaugurated a period of furious expansion of both loans and risky investments. The bubble burst in 2008. At that time, the nominal assets of the three largest banks was 14 times bigger than Iceland's entire GDP.
The crash shook Icelandic society to its foundations with mass bankruptcy, drastic increases in unemployment, loss of savings, increased indebtedness and raised taxes. Deteriorating health care and emigration of highly educated people are other consequences that will affect Iceland for a long time to ...
Blue Tax Inc. announced that they have reached an agreement with Professional Bull Rider Ryan Dirteater to be his Official Helmet Sponsor.
Blue Tax Inc. will activate the partnership through a camera-visible rider's helmet during the PBR's Built Ford Tough Series events in Glendale, Ariz.; Indianapolis; Uncasville, Conn.; Boise, Idaho; and Pueblo, Colo.
Blue Tax will provide three custom-painted helmets for Dirteater to wear during his quest to win the PBR World Championship.
"Blue Tax Inc. approached me and said that I was a rider that they wanted to put ...
Several specific regions of our brains are activated in a two-part process when we are exposed to deceptive advertising, according to new research conducted by a North Carolina State University professor. The work opens the door to further research that could help us understand how brain injury and aging may affect our susceptibility to fraud or misleading marketing.
The study utilized functional magnetic resonance imaging (fMRI) to capture images of the brain while study participants were shown a series of print advertisements. The fMRI images allowed researchers to ...
We make our eye movements earlier or later in order to coordinate with movements of our arms, New York University neuroscientists have found. Their study, which appears in the journal Neuron, points to a mechanism in the brain that allows for this coordination and may have implications for rehabilitation and prosthetics.
Researchers have sought to understand the neurological processes behind eye and arm movements. For example, when you reach for an object, what goes on in our brains so that our eyes and arms are in sync? Such coordination is central to the way different ...
ANN ARBOR, Mich. — Nearly one in three women who have breast cancer surgery will need to return to the operating room for additional surgery after the tumor is evaluated by a pathologist.
A new service at the University of Michigan Comprehensive Cancer Center cuts that number drastically by having pathologists on-site in the operating suite to assess tumors and lymph nodes immediately after they are removed. Meanwhile, the surgeon and patient remain in the operating room until the results are back, and any additional operating can be done immediately.
This cut the number ...
According to a 2003 study by German and American scientists, a component of the Lily of the Valley scent known as Bourgeonal alters the calcium balance of human sperm and attracts the sperm. The "Lily of the Valley phenomenon" – also the title of a book about smelling – was born as a result of this discovery that sperm act as swimming olfactory cells which follow a "scent trail" laid by the egg. However, a detailed explanation for the Lily of the Valley phenomenon remained illusive as neither Bourgeonal nor other scents could be identified in the female sex organ. Scientists ...
