Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

A drug-sensitive 'traffic cop' tells potassium channels to get lost

04.09.2007
Our brains are buzzing with electrical activity created by sodium and potassium ions moving in and out of neurons through specialized pores. To prevent the constant chatter from descending into chaos the activity of these ion channels has to be tightly regulated.

One possibility is to issue the channels a ticket straight to the cellular dumpster, discovered researchers at the Salk Institute for Biological Studies. A novel intracellular traffic coordinator pulls potassium channels from their job and whisks them to the recycling plant when not needed to put a damper on brain cells’ excitability, they report in the September issue of Nature Neuroscience.

“Neurons have the task of integrating many incoming signals from other neurons and must strictly regulate their intrinsic membrane excitability,” says Paul A. Slesinger, Ph.D., an associate professor in the Peptide Biology Laboratory at the Salk Institute who led the study. “Controlling the surface expression of ion channels with the help of trafficking molecules is a very efficient way to do it,” he adds.

Brain cells signal by sending electrical impulses along their axons, long, hair-like extensions that reach out to neighboring nerve cells. They make contact via specialized structures called synapses, from the Greek word meaning “to clasp together.” When an electrical signal reaches the end of an axon, the voltage change triggers the release of neurotransmitters, the brain’s chemical messengers.

... more about:
»GIRK »Membrane »SNX27 »Slesinger »neurons »potassium »trafficking

These neurotransmitter molecules then travel across the space between neurons and set off an electrical signal in the adjacent cell — unless the receiving end is decorated with so called GIRK channels, that is. In response to incoming signals, these channels open up, creating many little “potassium leaks” and as a result the signal fizzles.

GIRK channels (short for G-protein-coupled inwardly rectifying potassium channels) – a subtype of the many different potassium channels in the brain – are widely distributed in the brain and regulate neuron-to-neuron communication. Research from the Slesinger lab discovered previously a role for GIRK channels in regulating the response to illicit drugs and alcohol.

Now, using a proteomics approach, Slesinger and his team searched for proteins that might regulate the activity of GIRK3 channels and found SNX27. “We knew that the GIRK3 subtype has a unique code on its tail, like a signpost, that might interact with other proteins” says Slesinger.

SNX27 is a member of the sorting nexin-family, a diverse group of proteins that can bind cellular membranes and make contact with other proteins, which testifies to their role as facilitators for membrane trafficking and protein sorting. Indeed, increasing SNX27 protein in cells led to reduced GIRK activity. A closer look revealed that SNX27 colocalizes with GIRK channels in the hippocampus, a structure that plays an important role in learning and memory.

“The expression of different types of GIRK channel subunits in neurons along with varying levels of specific trafficking proteins, such as SNX27, could dictate the ultimate expression levels on the surface of the plasma membrane, and therefore the strength of inhibitory signaling in the brain,” says Slesinger.

Interestingly, independent researchers found previously that abused drugs such as cocaine and methamphetamine increase the activity of the SNX27 gene in rats. “Changes in the expression of SNX27 may establish an important link between trafficking of GIRK channels and the action of drugs in the brain, possibly opening up new avenues for the treatment of drug addictions,” says Slesinger.

Gina Kirchweger | EurekAlert!
Further information:
http://www.salk.edu

Further reports about: GIRK Membrane SNX27 Slesinger neurons potassium trafficking

More articles from Life Sciences:

nachricht Could this protein protect people against coronary artery disease?
17.11.2017 | University of North Carolina Health Care

nachricht Microbial resident enables beetles to feed on a leafy diet
17.11.2017 | Max-Planck-Institut für chemische Ökologie

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

Im Focus: Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs

Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.

During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....

Im Focus: Researchers Develop Data Bus for Quantum Computer

The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.

Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...

Im Focus: Wrinkles give heat a jolt in pillared graphene

Rice University researchers test 3-D carbon nanostructures' thermal transport abilities

Pillared graphene would transfer heat better if the theoretical material had a few asymmetric junctions that caused wrinkles, according to Rice University...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

NASA detects solar flare pulses at Sun and Earth

17.11.2017 | Physics and Astronomy

NIST scientists discover how to switch liver cancer cell growth from 2-D to 3-D structures

17.11.2017 | Health and Medicine

The importance of biodiversity in forests could increase due to climate change

17.11.2017 | Studies and Analyses

VideoLinks
B2B-VideoLinks
More VideoLinks >>>