Scientists identify new molecules important for vision and brain function
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 lightand 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 detectorsphotoreceptors 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 responsethey 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 GPCRsGPR158 and GPR179recruit 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 -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."
More information: 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.
See www.pnas.org/conte… 20/7905.long
See jcb.rupress.org/co… 711.abstract
Provided by The Scripps Research Institute
- Scientist identifies critical role for night blindness gene Aug 09, 2011 | not rated yet | 0
- Researchers Find Way to 'See' Water Molecules Hidden Inside Proteins May 21, 2010 | not rated yet | 0
- Scientists reveal first structure of a class of proteins that help guide blood cell movement Oct 07, 2010 | not rated yet | 0
- Researchers develop curious snapshot of powerful retinal pigment and its partners Feb 28, 2011 | not rated yet | 0
- Proteins that stop a major signaling pathway can also generate new proteins Apr 24, 2008 | not rated yet | 0
- Motion perception revisited: High Phi effect challenges established motion perception assumptions Apr 23, 2013 | 3 / 5 (2) | 2
- Anything you can do I can do better: Neuromolecular foundations of the superiority illusion (Update) Apr 02, 2013 | 4.5 / 5 (11) | 5
- The visual system as economist: Neural resource allocation in visual adaptation Mar 30, 2013 | 5 / 5 (2) | 9
- Separate lives: Neuronal and organismal lifespans decoupled Mar 27, 2013 | 4.9 / 5 (8) | 0
- Sizing things up: The evolutionary neurobiology of scale invariance Feb 28, 2013 | 4.8 / 5 (10) | 14
Pressure-volume curve: Elastic Recoil Pressure don't make sense
13 hours ago From pressure-volume curve of the lung and chest wall (attached photo), I don't understand why would the elastic recoil pressure of the lung is...
If you became brain-dead, would you want them to pull the plug?
May 17, 2013 I'd want the rest of me to stay alive. Sure it's a lousy way to live but it beats being all-the-way dead. Maybe if I make it 20 years they'll...
MRI bill question
May 15, 2013 Dear PFers, The hospital gave us a $12k bill for one MRI (head with contrast). The people I talked to at the hospital tell me that they do not...
Ratio of Hydrogen of Oxygen in Dessicated Animal Protein
May 13, 2013 As an experiment, for the past few months I've been consuming at least one portion of Jell-O or unflavored Knox gelatin per day. I'm 64, in very...
Alcohol and acetaminophen
May 13, 2013 Edit: sorry for the typo in the title , can't edit I looked around on google quite a bit and it's very hard to find precise information on the...
Marie Curie's leukemia
May 13, 2013 Does anyone know what might be the cause of Marie Curie's cancer
- More from Physics Forums - Medical Sciences
More news stories
In 2008 researchers from the University of Southern Denmark showed that the drug thioridazine, which has previously been used to treat schizophrenia, is also a powerful weapon against antibiotic-resistant bacteria such as ...
Medical research May 17, 2013 | 3.7 / 5 (3) | 0 |
Scientists investigating the interaction of a group of proteins in the brain responsible for protecting nerve cells from damage have identified a new target that could increase cell survival.
Medical research May 17, 2013 | 5 / 5 (1) | 0
New findings by researchers carrying out experiments at the U.S. Department of Energy Office of Science's Advanced Photon Source (APS) help explain why some drugs that interact with two kinds of human serotonin ...
Medical research May 17, 2013 | not rated yet | 0 |
Peptide molecules derived from the body's natural immune system can help boost the body's defence against life-threatening blood poisoning, joint University research has uncovered.
Medical research May 17, 2013 | 4 / 5 (1) | 0 |
A new Montréal study conducted by Dr. May Faraj, associate research professor at the Université de Montréal and invited scientist at the IRCM, along with her research team and medical collaborators, shows ...
Medical research May 17, 2013 | not rated yet | 0 |
An increasing number of U.S. children are experiencing gastrointestinal issues that require interventions to resolve, according to research presented at Digestive Disease Week (DDW).
6 hours ago | not rated yet | 0 |
Big names in medicine are set to give an upbeat assessment of the war on AIDS on Tuesday, 30 years after French researchers identified the virus that causes the disease.
14 hours ago | 5 / 5 (1) | 0
For combat veterans suffering from post-traumatic stress disorder, 'fear circuitry' in the brain never rests
Chronic trauma can inflict lasting damage to brain regions associated with fear and anxiety. Previous imaging studies of people with post-traumatic stress disorder, or PTSD, have shown that these brain regions can over-or ...
15 hours ago | 5 / 5 (1) | 0 |
The latest makeover to a massive psychiatric tome honored by some, reviled by others and even called the "Bible" of mental disorders is being released Saturday with a host of new changes.
4 hours ago | not rated yet | 0
A new case of the deadly coronavirus has been detected in Saudi Arabia where 15 people have already died after contracting it, the health ministry announced on Saturday on its Internet website.
4 hours ago | not rated yet | 0
A ground-breaking advance in colonoscopy technology signals the future of colorectal care, according to research presented today at Digestive Disease Week(DDW). Additional research focuses on optimizing the minimal withdrawal ...
6 hours ago | 5 / 5 (1) | 0