Navigation Links
A drug-sensitive 'traffic cop' tells potassium channels to get lost
Date:9/2/2007

La Jolla, CA 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 brains chemical messengers.

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.


'/>"/>
Contact: Gina Kirchweger
Kirchweger@salk.edu
858-453-4100 x1340
Salk Institute
Source:Eurekalert

Related medicine news :

1. Traffic Violations Result in Safer Drivers
2. Drug trafficking via Internet a growing threat
3. Traffic pollution linked to severe asthma attacks
4. Traffic Smoke May Damage DNA
5. HIV Infection Higher In Drug Trafficking Countries
6. Alcohol And Drug Abuse (Cannabis) Leading Causes For Road Traffic Accidents
7. Trafficking of Women from Asia and East Europe For Flesh Trade
8. Travel And Tourism Industry Calls For Global Efforts To Limit Sexual Trafficking Of Children
9. Asthma Risk Pronounced In Children Living Close to Traffic Ridden Roads
10. Striking Doctors Form Human Chain, Block Traffic
11. Road Traffic Accidents Kill 4,000 people in Delhi
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:5/23/2017)... , ... May 23, 2017 , ... Patients in need ... Dr. Angela Cotey’s practice to schedule an appointment, with or without a referral. Dr. ... offers pulpotomy treatments to pediatric patients as a healthy alternative to a tooth extraction. ...
(Date:5/22/2017)... Washington, MO (PRWEB) , ... May 22, 2017 , ... ... clinic in Washington, MO with a public ribbon cutting ceremony. Since opening ... by offering an alternative to the emergency room. The new Our Urgent Care ...
(Date:5/22/2017)... ... May 22, 2017 , ... Faithfully following pop culture, people ... stretched, jumped, toned and shaped through fitness programs. It carries on to skin nourished, ... off with an irresistible, radiant smile. CDA has found that just like ...
(Date:5/21/2017)... ... May 19, 2017 , ... ... the appointment of James (Jim) Vertino as Chief Information Officer (CIO). He will ... leader who drives innovation and business performance. He defines strategic roadmaps by reimagining ...
(Date:5/21/2017)... Amarillo, Texas (PRWEB) , ... May 21, 2017 ... ... Feminism International Conference has brought together a cross-disciplinary group of scholars, policymakers, and ... Breastfeeding, Social Justice, and Equity is the third book from a ...
Breaking Medicine News(10 mins):
(Date:5/8/2017)... , May 8, 2017 MACRA ... transition from fee for service reimbursement. Black Book Research ... 1.       The Market for MIPS Compliance ... 77% of physician practices with 3 or more clinicians ... Solutions by Q4. "Given the magnitude of the changes, ...
(Date:5/6/2017)... , May 5, 2017   Provista , a proven ... than 200,000 customers, today announced Jim Cunniff as ... of executive and business experience to Provista, including most recently ... in California . He assumed his new ... is a great fit for Provista," says Jody Hatcher ...
(Date:5/6/2017)... FALLS, N.Y. , May 5, 2017  Hill-Rom ... that will add approximately 100,000 square feet to its ... in September 2016 its commitment to bring more than ... , where Welch Allyn has maintained a significant ... will help accommodate these new positions, a large portion ...
Breaking Medicine Technology: