Scientists have examined a protein that will find application in optogenetics and could be used to control muscle and neuronal cells. The paper on the light-sensitive NsXeR protein of the xenorhodopsin class was published in Science Advances by the international team of researchers from MIPT, Forschungszentrum Jülich, and Institut de Biologie Structurale.
Why it matters
Researchers described a new optogenetic tool -- a protein called NsXeR, which belongs to the class of xenorhodopsins. When exposed to light, it can activate individual neurons, making them send set signals to the nervous system. Apart from applications in nervous system research, xenorhodopsins may also take over muscle cell control.
Credit: MIPT Press Office
Optogenetics is a new technique that uses light to control neurons or muscle cells in living tissue. It has found wide application in nervous system studies. Optogenetic manipulations are so precise that they make it possible to control individual neurons by switching certain information transfer pathways on or off. Similar methods are also used to partially reverse eyesight or hearing loss as well as to control muscle contractions.
The main tools of optogenetics are light-sensitive proteins that are intentionally inserted into particular cells. After the insertion, the protein becomes attached to the cell surface and moves ions across the membrane upon exposure to light.
Thus, in a modified neuron cell, a correctly chosen light impulse may activate a neural signal or, on the contrary, suppress all the signals, depending on which protein is used. By activating signals from individual neurons, it is possible to imitate the functioning of certain brain regions -- a technique that modulates the behavior of the organism under study. If such proteins are inserted in muscle cells, an external signal can tense or relax them.
The authors of the paper, which was published in Science Advances, described a new optogenetic tool -- a protein called NsXeR, which belongs to the class of xenorhodopsins. When exposed to light, it can activate individual neurons, making them send set signals to the nervous system.
Apart from applications in nervous system research, xenorhodopsins may also take over muscle cell control. To activate these cells, it is preferable that calcium ion transport be blocked, because alterations in the ion concentration can affect them. When using proteins that transport various positive ions (such as calcium) nonselectively, undesirable side effects are likely to appear.
The discovered protein helps to bypass uncontrolled calcium translocation: It is selective and pumps nothing but the protons into the cell. Because of this selectivity, it has a considerable advantage over its chief rival channelrhodopsin, which is being extensively used in research but does not discriminate between positively charged ions.
What is more, xenorhodopsin acts as a reliable pump, transporting protons both into and out of the cell regardless of their concentration, whereas channelrhodopsin only allows ions to move from an area of higher concentration to an area of lower concentration.
In both cases a positive charge inflow into an excitable cell reduces the tension between its inner and outer membrane surfaces. Such membrane depolarization generates a nerve or muscle impulse. The ability to induce such an impulse by pumping nothing but protons will reduce possible side effects during research.
"So far we have all the necessary data on how the protein functions. This will become the basis of our further research aimed at optimizing and adjusting the protein parameters to the needs of optogenetics," says Vitaly Shevchenko, the lead author of the paper and a staff member at the MIPT Laboratory for Advanced Studies of Membrane Proteins.
This research was supported ERA.Net RUS PLUS and the Ministry of Education and Science of the Russian Federation (project ID 323, RFMEFI58715X0011).
Asya Shepunova | EurekAlert!
Gut microbiome regulates the intestinal immune system, researchers find
19.12.2018 | Brown University
Greener days ahead for carbon fuels
19.12.2018 | DOE/Lawrence Berkeley National Laboratory
Different eras of civilization are defined by the discovery of new materials, as new materials drive new capabilities. And yet, identifying the best material...
Researchers from the University of Basel have reported a new method that allows the physical state of just a few atoms or molecules within a network to be controlled. It is based on the spontaneous self-organization of molecules into extensive networks with pores about one nanometer in size. In the journal ‘small’, the physicists reported on their investigations, which could be of particular importance for the development of new storage devices.
Around the world, researchers are attempting to shrink data storage devices to achieve as large a storage capacity in as small a space as possible. In almost...
The more objects we make "smart," from watches to entire buildings, the greater the need for these devices to store and retrieve massive amounts of data quickly without consuming too much power.
Millions of new memory cells could be part of a computer chip and provide that speed and energy savings, thanks to the discovery of a previously unobserved...
What if, instead of turning up the thermostat, you could warm up with high-tech, flexible patches sewn into your clothes - while significantly reducing your...
A widely used diabetes medication combined with an antihypertensive drug specifically inhibits tumor growth – this was discovered by researchers from the University of Basel’s Biozentrum two years ago. In a follow-up study, recently published in “Cell Reports”, the scientists report that this drug cocktail induces cancer cell death by switching off their energy supply.
The widely used anti-diabetes drug metformin not only reduces blood sugar but also has an anti-cancer effect. However, the metformin dose commonly used in the...
12.12.2018 | Event News
10.12.2018 | Event News
06.12.2018 | Event News
19.12.2018 | Materials Sciences
19.12.2018 | Materials Sciences
19.12.2018 | Life Sciences