A new concept in the field of voltage-gated ion channels

Aug 21, 2012 By Sathya Achia Abraham

(Phys.org) -- Virginia Commonwealth University School of Medicine researchers have uncovered a novel way by which the activity of voltage-gated potassium channels are regulated, according to a study published online last week in the Early Edition of the Proceedings of the National Academy of Sciences.

The findings may allow researchers to better understand and control how external signals – for example, hormones and neurotransmitters – can modulate excitability of cells. This understanding provides critical information on how to adjust cellular excitability when it needs to be stimulated.

By conducting basic science research, the team, led by Diomedes Logothetis, Ph.D., an internationally recognized leader in the study of and chair of the VCU School of ’s Department of Physiology and Biophysics, is hoping to understand the fundamental mechanisms by which membrane lipid-protein interactions regulate the of proteins, such as potassium (Kv) channels.

In this new study, Logothetis and his team have clarified the role of phospholipid phosphatidylinositol-bisphosphate, PIP2, a minor component of the inner leaflet of the plasma membrane that controls the activity of most ion channels and transporters.

They found PIP2 to be responsible for controlling the activation mechanism of Kv channels that reside in cells that generate electrical impulses to control heart rate and brain signaling.

Since the 1980s, investigators have known that the part of voltage-gated channels that senses membrane voltage changes is coupled to the pore via a linker called the S4-S5 linker. But it was not known until now that PIP2 regulates the activity of Kv channels by interacting with this helical linker.

“Our study showed that this helical structure interacts with PIP2 in the membrane to regulate how much the voltage sensor can pull on the pore to open it,” said Logothetis.

Explore further: New method to analyse how cancer cells die

More information: www.pnas.org/content/early/2012/08/10/1207901109.long

add to favorites email to friend print save as pdf

Related Stories

Simple, model-free analysis of voltage-gated channels

Dec 12, 2011

A new study in the Journal of General Physiology provides fresh insight into voltage-gated channels—transmembrane ion channels that play a critical role in the function of neuronal and muscle tissue.

Recommended for you

New method to analyse how cancer cells die

4 hours ago

(Phys.org) —A team from The University of Manchester – part of the Manchester Cancer Research Centre - have found a new method to more efficiently manufacture a chemical used to monitor cancer cells.

The anti-inflammatory factory

Apr 22, 2014

Russian scientists, in collaboration with their colleagues from Pittsburgh University, have discovered how lipid mediators are produced. The relevant paper was published in Nature Chemistry. Lipid mediators are molecules that p ...

User comments : 2

Adjust slider to filter visible comments by rank

Display comments: newest first

1 / 5 (2) Aug 21, 2012
The cytoplasm is a gel, and gels possess an innate ability to produce ionic gradients without the need for pumps and channels. According to Gerald Pollack, treating the cytoplasm as an aqueous fluid confined by the cell membrane ignores the observational fact that many cells of the human body are observed to continue to operate even when their cell membranes have been compromised. Pollack demonstrates quite clearly in his book, Cells, Gels and the Engines of Life, that not only was the concept of magnetic resonance imaging initially based upon the structured water - cytoplasm-as-gel hypothesis, but a pathway for the origin of life also becomes apparent once a person understands that polymers also look like they have pumps and channels. The pump-and-channel inference is something that the students of biology should take a far closer look at, and people should be permitted to hold their own opinions on this, as it is a debate which has raged for more than half a century.
not rated yet Sep 08, 2012
The favored weapon in the microbial world is a protein complex that punches a hole in the membrane of a cell. Holes mean death. http://en.wikiped..._complex
Hannes is spouting pure gobbledygook.

More news stories

New method to analyse how cancer cells die

(Phys.org) —A team from The University of Manchester – part of the Manchester Cancer Research Centre - have found a new method to more efficiently manufacture a chemical used to monitor cancer cells.

Mantis shrimp stronger than airplanes

(Phys.org) —Inspired by the fist-like club of a mantis shrimp, a team of researchers led by University of California, Riverside, in collaboration with University of Southern California and Purdue University, ...

New breast cancer imaging method promising

The new PAMmography method for imaging breast cancer developed by the University of Twente's MIRA research institute and the Medisch Spectrum Twente hospital appears to be a promising new method that could ...

Research proves nanobubbles are superstable

The intense research interest in surface nanobubbles arises from their potential applications in microfluidics and the scientific challenge for controlling their fundamental physical properties. One of the ...

Using antineutrinos to monitor nuclear reactors

When monitoring nuclear reactors, the International Atomic Energy Agency has to rely on input given by the operators. In the future, antineutrino detectors may provide an additional option for monitoring. ...