Featured Research

from universities, journals, and other organizations

New Rendering Of Ion Channel Suggests How Neurons Fire

Date:
January 30, 2008
Source:
Rockefeller University
Summary:
Four years ago the first ever structure of a voltage-dependent potassium ion channel -- a protein that controls the flow of potassium ions across nerve cell membranes and opens and closes in response to changes in cell membrane voltage was published. Now the same scientist has released new renderings of these channels that describe a possible mechanism for how the paddle carries its charged cargo through the channel as well as how the charged paddles are stabilized within the cell's membrane.

Changed channel. Lipid molecules (yellow and red) are an integral part of the voltage-dependent ion channel and confer stability to it. MacKinnon's structural renderings show that lipid molecules are most dense in the concave semicircles between the voltage sensors.
Credit: Image courtesy of Rockefeller University

Four years ago, Roderick MacKinnon, head of the Laboratory of Molecular Neurobiology and Biophysics at Rockefeller University, together with several members of his lab, published the first ever structure of a voltage-dependent potassium ion channel — a protein that controls the flow of potassium ions across nerve cell membranes and opens and closes in response to changes in cell membrane voltage. At that time, MacKinnon and his colleagues proposed that a structure called the paddle senses the membrane voltage, enabling the channels to open and close. In the journal Nature he and lab members Steve Long, Xiao Tao and Ernest Campbell released new renderings of these channels that describe a possible mechanism for how the paddle carries its charged cargo through the channel as well as how the charged paddles are stabilized within the cell’s membrane.

Along with his colleagues, MacKinnon, a Nobel laureate and an investigator at the Howard Hughes Medical Institute as well as the university’s John D. Rockefeller Jr. Professor, took advantage of the paddle’s unique transplantability to create a hybrid ion channel — one of only a handful of eukaryotic membrane proteins whose structures have been determined through recombinant expression.

In the presence of lipid molecules, the hybrid ion channel formed a crystalline lattice that enabled MacKinnon and his team to describe the structure with unprecedented atomic detail. Within the crystals, the lipid molecules organized themselves around the several ion channel proteins, forming a lipid bilayer that mimicked the channel’s natural environment. Knowing how the lipids organized themselves around the ion channel, the researchers were then able to demonstrate how positively charged amino acids within the voltage sensor’s paddle remained stable despite the potentially destabilizing forces surrounding them. The structure also shows how movement of the gating charge across the membrane directly influences the opening and closing of the pore’s gate.

Voltage-dependent ion channels are important therapeutic targets for future treatment of pathological conditions such as epilepsy and cardiac arrhythmia. The new methods being developed for eukaryotic membrane protein structure determination, particularly in a native membrane environment, promise to advance our understanding of these therapeutic targets.

Journal reference: Nature 450(7168): 376–382 (November 15, 2007)


Story Source:

The above story is based on materials provided by Rockefeller University. Note: Materials may be edited for content and length.


Cite This Page:

Rockefeller University. "New Rendering Of Ion Channel Suggests How Neurons Fire." ScienceDaily. ScienceDaily, 30 January 2008. <www.sciencedaily.com/releases/2008/01/080124140526.htm>.
Rockefeller University. (2008, January 30). New Rendering Of Ion Channel Suggests How Neurons Fire. ScienceDaily. Retrieved August 21, 2014 from www.sciencedaily.com/releases/2008/01/080124140526.htm
Rockefeller University. "New Rendering Of Ion Channel Suggests How Neurons Fire." ScienceDaily. www.sciencedaily.com/releases/2008/01/080124140526.htm (accessed August 21, 2014).

Share This




More Plants & Animals News

Thursday, August 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Drug Used To Treat 'Ebola's Cousin' Shows Promise

Drug Used To Treat 'Ebola's Cousin' Shows Promise

Newsy (Aug. 21, 2014) — An experimental drug used to treat Marburg virus in rhesus monkeys could give new insight into a similar treatment for Ebola. Video provided by Newsy
Powered by NewsLook.com
Terrifying City-Dwelling Spiders Are Bigger And More Fertile

Terrifying City-Dwelling Spiders Are Bigger And More Fertile

Newsy (Aug. 21, 2014) — According to a new study, spiders that live in cities are bigger, fatter and multiply faster. Video provided by Newsy
Powered by NewsLook.com
Lost Brain Cells To Blame For Sleep Problems Among Seniors

Lost Brain Cells To Blame For Sleep Problems Among Seniors

Newsy (Aug. 21, 2014) — According to a new study, elderly people might have trouble sleeping because of the loss of a certain group of neurons in the brain. Video provided by Newsy
Powered by NewsLook.com
Ramen Health Risks: The Dark Side of the Noodle

Ramen Health Risks: The Dark Side of the Noodle

AP (Aug. 21, 2014) — South Koreans eat more instant ramen noodles per capita than anywhere else in the world. But American researchers say eating too much may increase the risk of diabetes, heart disease and stroke. (Aug. 21) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins