Navigation Links
Site used by sodium to control sensitivity of certain potassium ion channels
Date:9/18/2008

RICHMOND, Va. (Sept. 18, 2008) Virginia Commonwealth University School of Medicine researchers have uncovered how sodium is able to control specific potassium ion channels in cells, according to new study findings published online this week in Nature Chemical Biology.

These findings, published Sept. 14, may help researchers gain a greater understanding of the mechanisms involved in ion channel gating and may one day set the stage for new approaches in drug design.

Intracellular-sodium is known to control the opening and closing of certain potassium channels. Using a computational-experimental approach, researchers examined the interaction between sodium and a group of potassium channels known as Kir channel proteins. The team had previously shown that Kir3 channels are sensitive to sodium, but had not shown how sodium is coordinated by specific amino acids found in several Kir channel proteins.

"We have a fairly good molecular understanding of how the sodium ions are coordinated and we have a compelling hypothesis of how the coordination of sodium may be affecting this particular type of potassium ion channel to open it," said Diomedes Logothetis, Ph.D., an internationally recognized leader in the study of ion channels and chair of the VCU School of Medicine's Department of Physiology and Biophysics.

According to Logothetis, ion channel proteins are found in the plasma membrane of cells and provide a path for hydrated cations such as calcium, potassium or sodium to pass through the membrane and travel in and out of the cell. Generally, hydrated ions do not travel through the lypophillic, or fat-based, plasma membrane because they are surrounded with water and require a pathway to travel from one side of the membrane to the other.

"By applying the knowledge of the sodium coordination site, we identified the Kir5.1 channel that was not previously suspected to be sodium-sensitive. By examining in which cells these sodium-sensitive channels are expressed and how sodium may be critical for the function of these cells, we hope to uncover the physiological importance of sodium-mediated activation of potassium channels," Logothetis said. Cells in the kidney and specific areas in the brain express the Kir5.1 channel, he added. In kidney cells, the Kir channel is expressed in cells that are responsible for reabsorbing sodium, a process relevant in hypertension as sodium and water are retained in blood vessels.

One critical characteristic of the sodium-reabsorbing kidney cells is that they maintain a negative-membrane potential, meaning the inside is more negative than the outside, which creates a driving force for sodium entry into the cells. This negative membrane potential is accomplished by potassium flowing out of the cell through potassium channels.

If Kir5.1 is linked to sodium reabsorption, then malfunctions of this channel could interfere with the sodium uptake mechanisms from blood vessels through the kidney cells and lead to hypertension. Logothetis and his collaborators in New York and Oxford, England, are in the process of testing this hypothesis.

"Once we understand the importance of sodium regulation of ion channels, then we can start thinking about how we design drugs that may mimic the net effect of sodium regulation of channel activity and ultimately help any pathophysiology dependent on these processes," he said.


'/>"/>

Contact: Sathy Achia Abraham
sbachia@vcu.edu
804-827-0890
Virginia Commonwealth University
Source:Eurekalert

Related biology news :

1. Biologists identify genes controlling rhythmic plant growth
2. Biological clock genes control plant growth
3. JDRF-funded clinical trial demonstrates continuous glucose monitoring improves blood sugar control
4. Biocontrol insect exacerbates invasive weed
5. Study shows more genes are controlled by biological clocks
6. Iowa State University researcher shows proteins have controlled motions
7. Scientists to assess Beijing Olympics air pollution control efforts
8. Scripps scientists will assess Beijing Olympics air pollution control efforts
9. People with heart disease still have trouble controlling blood lipid levels
10. Caltech researchers find dual-use sexual attraction and population-control chemicals in nematodes
11. Researchers discover cells quality control mechanism
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:4/5/2017)... Allen Institute for Cell Science today announces the launch ... dynamic digital window into the human cell. The website ... deep learning to create predictive models of cell organization, ... suite of powerful tools. The Allen Cell Explorer will ... resources created and shared by the Allen Institute for ...
(Date:4/4/2017)...   EyeLock LLC , a leader of iris-based ... Patent and Trademark Office (USPTO) has issued U.S. Patent ... an iris image with a face image acquired in ... 45 th issued patent. "The ... the multi-modal biometric capabilities that have recently come to ...
(Date:3/30/2017)... HONG KONG , March 30, 2017 ... developed a system for three-dimensional (3D) fingerprint identification by adopting ground ... technology into a new realm of speed and accuracy for use ... applications at an affordable cost. ... ...
Breaking Biology News(10 mins):
(Date:10/12/2017)... ... October 12, 2017 , ... ... of a complex biological network, a depiction of a system of linkages and ... Dmitry Korkin, PhD, associate professor of computer science at Worcester Polytechnic Institute (WPI) ...
(Date:10/12/2017)... , ... October 12, 2017 , ... ... Vilnius, Lithuania, announced today that they have entered into a multiyear collaboration to ... provide CRISPR researchers with additional tools for gene editing across all applications. , ...
(Date:10/12/2017)... ... October 12, 2017 , ... ... with the addition of its newest module, US Hemostats & Sealants. , SmartTRAK’s ... hemostats, absorbable hemostats, fibrin sealants, synthetic sealants and biologic sealants used in surgical ...
(Date:10/12/2017)... ... October 12, 2017 , ... ... analysis platform specifically designed for life science researchers to analyze and interpret ... Rosalind Franklin, who made a major contribution to the discovery of the ...
Breaking Biology Technology: