Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Scientists Identify New Molecules Important for Vision and Brain Function

12.06.2012
In a pair of related studies, scientists from the Florida campus of The Scripps Research Institute have identified several proteins that help regulate cells’ response to light—and the development of night blindness, a rare disease that abolishes the ability to see in dim light.

In the new studies, published recently in the journals Proceedings of the National Academy of Sciences (PNAS) and The Journal of Cell Biology, Scripps Florida scientists were able to show that a family of proteins known as Regulator of G protein Signaling (RGS) proteins plays an essential role in vision in a dim-light environment.

“We were looking at the fundamental mechanisms that shape our light sensation,” said Kirill Martemyanov, a Scripps Research associate professor who led the studies. “In the process, we discovered a pair of molecules that are indispensible for our vision and possibly play critical roles in the brain.”

In the PNAS study, Martemyanov and his colleagues identified a pair of regulator proteins known as RGS7 and RGS11 that are present specifically in the main relay neurons of the retina called the ON-bipolar cells. “The ON-bipolar cells provide an essential link between the retinal light detectors—photoreceptors and the neurons that send visual information to the brain,” explained Martemyanov. “Stimulation with light excites these neurons by opening the channel that is normally kept shut by the G proteins in the dark. RGS7 and RGS11 facilitate the G protein inactivation, thus promoting the opening of the channel and allowing the ON-bipolar cells to transmit the light signal. It really takes a combined effort of two RGS proteins to help the light overcome the barrier for propagating the excitation that makes our dim vision possible.”

In the Journal of Cell Biology study, Martemyanov and his colleagues unraveled another key aspect of the RGS7/RGS11 regulatory response—they identified a previously unknown pair of orphan G protein-coupled receptors (GPCRs) that interact with these RGS proteins and dictate their biological function.

GPCRs are a large family of more than 700 proteins, which sit in the cell membrane and sense various molecules outside the cell, including odors, hormones, neurotransmitters, and light. After binding these molecules, GPCRs trigger the appropriate response inside the cell. However, for many GPCRs the activating molecules have not yet been identified and these are called “orphan” receptors.

The Martemyanov group has found that two orphan GPCRs—GPR158 and GPR179—recruit RGS proteins and thus help serve as brakes for the conventional GPCR signaling rather than play an active signaling role.

In the case of retinal ON-bipolar cells, GPR179 is required for the correct localization of RGS7 and RGS11. Their mistargeting in animal models lacking GPR179 or human patients with mutations in the GPR179 gene may account for their night blindness, according to the new study. Intriguingly, in the brain GPR158 appears to play a similar role in localizing RGS proteins, but instead of contributing to vision, it helps RGS proteins regulate the m-opioid receptor, a GPCRs that mediates pleasurable and pain-killing effects of opioids.

“We are really in the very beginning of unraveling this new biology and understanding the role of discovered orphan GPR158/179 in regulation of neurotransmitter signaling in the brain and retina,” Martemyanov said. “The hope is that better understanding of these new molecules will lead to the design of better treatments for addictive disorders, pain, and blindness.”

The first author of the PNAS study, “Regulators of G Protein Signaling RGS7 and RGS11 Determine the Onset of the Light Response in ON Bipolar Neurons” is Yan Cao of The Scripps Research Institute. Other authors include Johan Pahlberg and Alapakkam P. Sampath of the University of Southern California; Ignacio Sarria of The Scripps Research Institute; and Naomi Kamasawa of the Max Planck Florida Institute. See http://www.pnas.org/content/109/20/7905.long

The first author of the Journal of Cell Biology study, “GPR158/179 Regulate G Protein Signaling by Controlling Localization and Activity of the RGS7 Complexes” is Cesare Orlandi of The Scripps Research Institute. Other authors include Ekaterina Posokhova and Ikuo Masuho of The Scripps Research Institute and Thomas A. Ray, Nazarul Hasan, and Ronald G. Gregg of the University of Louisville, Kentucky. See http://jcb.rupress.org/content/197/6/711.abstract

Both studies were supported by the National Institutes of Health. The PNAS study was also supported by the McKnight Endowment Fund for Neurosciences

The first study was published in the May 15, 2012 issue of the journal Proceedings of the National Academy of Sciences. The second study was published June 11, 2012 by The Journal of Cell Biology.

About The Scripps Research Institute

The Scripps Research Institute is one of the world's largest independent, not-for-profit organizations focusing on research in the biomedical sciences. Over the past decades, Scripps Research has developed a lengthy track record of major contributions to science and health, including laying the foundation for new treatments for cancer, rheumatoid arthritis, hemophilia, and other diseases. The institute employs about 3,000 people on its campuses in La Jolla, CA, and Jupiter, FL, where its renowned scientists—including three Nobel laureates—work toward their next discoveries. The institute's graduate program, which awards Ph.D. degrees in biology and chemistry, ranks among the top ten of its kind in the nation. For more information, see www.scripps.edu.
For information:
Office of Communications
Tel: 858-784-8134
Fax: 858-784-8136
press@scripps.edu

Mika Ono | EurekAlert!
Further information:
http://www.scripps.edu

More articles from Life Sciences:

nachricht Researchers identify potentially druggable mutant p53 proteins that promote cancer growth
09.12.2016 | Cold Spring Harbor Laboratory

nachricht Plant-based substance boosts eyelash growth
09.12.2016 | Fraunhofer-Institut für Angewandte Polymerforschung IAP

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Electron highway inside crystal

Physicists of the University of Würzburg have made an astonishing discovery in a specific type of topological insulators. The effect is due to the structure of the materials used. The researchers have now published their work in the journal Science.

Topological insulators are currently the hot topic in physics according to the newspaper Neue Zürcher Zeitung. Only a few weeks ago, their importance was...

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

Researchers identify potentially druggable mutant p53 proteins that promote cancer growth

09.12.2016 | Life Sciences

Scientists produce a new roadmap for guiding development & conservation in the Amazon

09.12.2016 | Ecology, The Environment and Conservation

Satellites, airport visibility readings shed light on troops' exposure to air pollution

09.12.2016 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>