Navigation Links
Solving the puzzle of the BK ion channel
Date:6/23/2010

tage, or potential difference, across the membrane. Ligand-gated channels are triggered by the binding of a chemical messenger, such as calcium. The BK channel's gate responds to both types of stimuli.

Normally action potentials aren't strong enough to trip the BK channel's gate. But each action potential lets calcium ions into the cell. At higher calcium concentrations, the BK channel's voltage threshold is shifted to lower voltages. Now action potentials can trip the gate, opening the BK channel.

The BK channel, also called the Big K channel or MaxiK channel, lets about 200,000 potassium ions through a millisecond, roughly 20 times more than a typical potassium channel. So when the BK channels open, they quickly repolarize the membrane, lopping off the action potential.

How might a BK channel mutation lead to epilepsy? Because the mutation allows the membrane to repolarize more quickly, the nerve cell can fire at higher frequencies, an excitability that may lead to seizures.

Cui emphasizes, however, that the link between the mutation and epilepsy has not been fully worked out.

The channel's structure and mechanics

The various parts of the channel are only loosely associated, like chunks of pull-apart bread, and the voltage and calcium sensors are at some distance from the pore. So it is not at first clear how changes in the electrical field or the binding of calcium ions open the pore.

The voltage sensor includes a helix that is loaded with several copies of the positively charged amino acid arginine. The electric field across the membrane works on these positive charges, pushing the helix out of the membrane or pulling it deeper in, depending on the field's polarity.

When it is pushed up, the helix pulls on the linker chain that connects the bottom of the voltage sensor to the bottom end of a helix in the pore. So pushing the charged helix up opens the pore, and pushing it down closes th
'/>"/>

Contact: Diana Lutz
dlutz@wustl.edu
314-935-5272
Washington University in St. Louis
Source:Eurekalert  

Page: 1 2 3 4 5

Related biology news :

1. Brains problem-solving function at work when we daydream
2. Bowman Global Change says public engagement critical to solving climate crisis
3. Fossils and layers: Solving the terrane puzzle of the North American cordillera
4. Solving an avian scourge could also provide benefits to human health
5. New tool for resolving fisheries conflicts
6. Magnetic snakes control fluids, gravity-defying droplets, and solving a dragonfly mystery
7. McGill team discovers a piece of the puzzle for individualized cancer therapy via gene silencing
8. Key piece of puzzle sheds light on function of ribosomes
9. CSHL scientists harness logic of Sudoku math puzzle to vastly enhance genome-sequencing capability
10. New piece found in the puzzle of epigenetics
11. Biologists devise unifying framework to explain evolutionary puzzles
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Solving the puzzle of the BK ion channel
(Date:7/31/2014)... bigeye tuna movements in the northwestern Atlantic Ocean led ... Center at the University of Massachusetts Amherst, found among ... range with pronounced north-south movements from Georges Bank to ... off Cape Hatteras southwest of Bermuda for foraging. , ... study one of the most important commercial tuna species ...
(Date:7/31/2014)... Science Foundation (NSF), counters a widely-held scientific view ... instead that certain Arctic lakes store more greenhouse ... , The study, published this week in the ... which occur as permafrost thaws and creates surface ... what was previously frozen land into lakes. , ...
(Date:7/31/2014)... GAINESVILLE, Fla. --- By tracing nearly 3,000 genes ... moths, University of Florida scientists have created an ... to use large-scale, next-generation DNA sequencing. , ... more closely related to small moths than to ... how butterflies evolved. The study also found that ...
Breaking Biology News(10 mins):Study of bigeye tuna in Northwest Atlantic uses new tracking methods 2Study of bigeye tuna in Northwest Atlantic uses new tracking methods 3Certain Arctic lakes store more greenhouse gases than they release 2UF study advances 'DNA revolution,' tells butterflies' evolutionary history 2UF study advances 'DNA revolution,' tells butterflies' evolutionary history 3
... be complete without mosquitoes nipping at exposed skin. Or ... University team may help solve a problem that scientists ... Kun Yan Zhu, professor of entomology, and teammates ... Jianzhen Zhang, a visiting scientist from Shanxi University, China, ...
... Researchers writing in the open access journal BMC ... an adaptation in the blood of Eastern moles which ... moles, burrowing behavior. Kevin Campbell from the ... researchers to study the blood of three underground species ...
... has developed a "lab on a chip" device for ... white blood cells called T cells that are affected ... the test detects the types and levels of inflammatory ... Revzin,s team collaborated with UCLA electrical engineer Prof. Aydogan ...
Cached Biology News:K-State researchers find gene-silencing nanoparticles may put end to pesky summer pest 2Adaptation in mole blood aids tunnelling 2Novel microfluidic HIV test is quick and cheap 2
(Date:7/31/2014)... Held at the Stanford Cancer Center, the ... the disease and its treatment. Survivors will find information ... as updates on the state-of-the-art with respect to newer ... organizing this educational opportunity,” says KCA CEO Bill Bro, ... colleagues have put together a program that balances the ...
(Date:7/31/2014)... IL (PRWEB) July 31, 2014 ... of automation across the U.S., increasing unemployment, depressing ... class. It is a Catch 22—we need ... but this means fewer jobs,” says economist and ... just-released Pollina Corporate Top 10 Pro-Business States for ...
(Date:7/31/2014)... Boston, MA (PRWEB) July 31, 2014 ... ) finds itself flush with innovative adult stem cell ... patents and has three additional patent applications ... Office. , The patented inventions address two of the ... and regenerative medicine. Adult stem cells are difficult ...
(Date:7/30/2014)... July 30, 2014 W. R. ... release of the REVELERIS® Prep purification system ... preparative chromatographers, and other researchers to perform both ... single unit. , With the REVELERIS® Prep purification ... preparative chromatography modes with a simple touch of ...
Breaking Biology Technology:ITRA Global Affiliate’s Pollina Corporate Top 10 Pro-Business States Minimize the Impact of Automation on Middle Class and Unemployment 2ITRA Global Affiliate’s Pollina Corporate Top 10 Pro-Business States Minimize the Impact of Automation on Middle Class and Unemployment 3ITRA Global Affiliate’s Pollina Corporate Top 10 Pro-Business States Minimize the Impact of Automation on Middle Class and Unemployment 4The Adult Stem Cell Technology Center, LLC Launches A Marketing Campaign To License Adult Stem Cell Biotechnologies 2The Adult Stem Cell Technology Center, LLC Launches A Marketing Campaign To License Adult Stem Cell Biotechnologies 3Grace Launches New REVELERIS® Prep Purification System 2
... BHRT ) a company committed to delivering ... treat heart failure and,cardiovascular diseases, announced the adoption ... -- Shareholders approved the election of eight ... in 2009 or until their successors are,duly elected ...
... July 30 DNA Heritage has recently,overcome patent claims ... use of DNA testing and databases that allow families ... DNA. The patent covers the,use of surnames and Y-chromosomes ... (UK IPO) has now rendered a formal opinion,stating that ...
... ROCKVILLE, Md., July 30 Stem cell ... Dr. Thomas Hazel will be,rejoining the company as ... Dr. Karl Johe, Neuralstem,s Chairman and Chief Science,Officer, ... ALS,(Amytrophic Lateral Sclerosis, or Lou Gehrig,s disease), and ...
Cached Biology Technology:Bioheart, Inc. Announces Results of Annual Meeting 2Bioheart, Inc. Announces Results of Annual Meeting 3Bioheart, Inc. Announces Results of Annual Meeting 4Bioheart, Inc. Announces Results of Annual Meeting 5DNA Heritage Success in Patent Battle Helps Keep Genealogy DNA Test Prices Low 2Neuralstem Fills Key Product Development Position 2
The Cellject Elecroporator is suitable for all cell types including embryo, mammalian, plant, yeast and bacterial. Its has highly user-freindly programing and can be used remotely, for example in a l...
Request Info...
... Virus Reverse Transcriptase (AMV RT) catalyzes the ... or RNA:DNA hybrids (1). It requires a ... RNA primers) as well as Mg2+ or ... H activity. Both nonionic detergents and sulfhydryl ...
Request Info...
Biology Products: