Gates open on understanding potassium channel controls

Jun 03, 2010
Dr. Jacqui Gulbis and Mr. Oliver Clarke from the Walter and Eliza Hall Institute in Melbourne, Australia, have made a significant advance in understanding how potassium channels, which permit the flow of electric currents central to many of the body's biological processes, control the flow of these currents. Credit: Czesia Markiewicz, Walter and Eliza Hall Institute

Walter and Eliza Hall Institute scientists have made a significant advance in understanding how potassium channels, which permit the flow of electric currents central to many of the body's biological processes, control the flow of these currents.

Dr Jacqui Gulbis from the institute's Structural Biology division, who led the research, said previous studies that had identified what potassium channels look like had provided valuable insights into how they work. However, the way the channels open and close in response to regulatory signals has not been well understood.

"Potassium currents are central to many cellular processes, and particularly communication between cells," Dr Gulbis said.

"In the central nervous system, for example, electrical signaling underlies perception and movement; whilst in the heart, cardiac contraction relies upon the rhythmic ebb-and-flow of potassium. The electricity comes from the tiny charge associated with each .

"Just as one would use a light switch to turn electrical current on and off, potassium channels use molecular gates to switch conduction on and off in response to physiological signals," Dr Gulbis said. "However, the nature of the gates and the gating process has remained unclear."

This video is not supported by your browser at this time.
Dr. Jacqui Gulbis and Mr. Oliver Clarke from the Walter and Eliza Hall Institute in Melbourne, Australia, explain how potassium channels, which permit the flow of electric currents central to many of the body’s biological processes, control the flow of these currents. Their findings are published online this week in Cell. Credit: Cameron Wells, Walter and Eliza Hall Institute

are specialised pores in cell membranes. They have a signature region termed the ion selectivity filter, which is responsible for ensuring that only potassium, and not sodium, permeates the membrane.

Dr Gulbis, with Mr Oliver Clarke, Dr Brian Smith and Mr Alex Caputo from the institute's Structural Biology division, in collaboration with Dr Jamie Vandenberg and Dr Adam Hill from the Victor Chang Cardiac Research Institute, has illuminated key aspects of the gating process.

Although previous studies have implicated a constriction in the ion conduction pathway in gating, this study describes a gate that is located in the ion selectivity filter.

Using the Australian Synchrotron, Dr Gulbis's team determined that once the conformation of a regulatory domain - which is the part of the channel that sits inside the cell - changes, it allows the selectivity filter to act as an on/off switch.

The findings have been published today in the journal Cell.

Explore further: Genomes of malaria-carrying mosquitoes sequenced

Provided by Walter and Eliza Hall Institute

5 /5 (2 votes)
add to favorites email to friend print save as pdf

Related Stories

Unraveling the mysteries of poison

Apr 13, 2006

Researchers from the Max Planck Institite for Biophysical Chemistry and other German and French colleagues have combined magnetic resonance spectroscopy (solid-state NMR) with special protein synthesis procedures to uncover ...

Recommended for you

Genomes of malaria-carrying mosquitoes sequenced

2 hours ago

Nora Besansky, O'Hara Professor of Biological Sciences at the University of Notre Dame and a member of the University's Eck Institute for Global Health, has led an international team of scientists in sequencing ...

How calcium regulates mitochondrial carrier proteins

Nov 26, 2014

Mitochondrial carriers are a family of proteins that play the key role of transporting a chemically diverse range of molecules across the inner mitochondrial membrane. Mitochondrial aspartate/glutamate carriers are part of ...

Team conducts unprecedented analysis of microbial ecosystem

Nov 26, 2014

An international team of scientists from the Translational Genomics Research Institute (TGen) and The Luxembourg Centre for Systems Biomedicine (LCSB) have completed a first-of-its-kind microbial analysis of a biological ...

Students create microbe to weaken superbug

Nov 25, 2014

A team of undergraduate students from the University of Waterloo have designed a synthetic organism that may one day help doctors treat MRSA, an antibiotic-resistant superbug.

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.