Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Fluid Equilibrium in Prehistoric Organisms Sheds Light on a Turning Point in Evolution

23.09.2011
Emergence of ENaC, sodium pump coincides with first appearance of multi-celled creatures

Maintaining fluid balance in the body is essential to survival, from the tiniest protozoa to the mightiest of mammals. By researching recent genomic data, Swiss researchers have found genetic evidence that links this intricate process to a turning point in evolution.

The study was led by Bernard Rossier, Professor Emeritus, University of Lausanne, along with colleagues Romain A. Studer, Emilie Person, and Marc Robinson-Rechavi. Dr. Rossier will discuss the team’s findings at the 7th International Symposium on Aldosterone and the ENaC/Degenerin Family of Ion Channels, sponsored by the American Physiological Society. Dr. Rossier’s presentation, “Evolution of ENaC and Na-K-ATPase as Limiting Factors of Aldosterone Action,” is based in part on the team’s recent article published in the journal Physiological Genomics.

Timing Is Everything
In humans, the hormone aldosterone affects fluid balance by controlling the epithelial sodium channel (ENaC), a protein that traverses a cell’s membrane and facilitates the movement of salt into and out of the cell. By searching for genes that descended from a common ancestral DNA sequence (homologs), the researchers found that the emergence of ENaC and Na, K-ATPase (sodium pump), an enzyme that also plays a role in sodium transport, coincided with the emergence of multi-celled organisms.

Dr. Rossier and his team focused their analysis on eukaryotes—organisms whose cells contain complex structures within enclosed membranes¬—and sought to determine when and where on the eukaryotic family tree ENaC first appeared. When tracing the alpha, beta, and gamma subunits of ENaC back, the team found that the beta subunit appeared slightly before the emergence of Metazoans (multicellular animals with differentiated tissues) roughly 750 million years ago. “The alpha subunit is an old protein found everywhere, in any kind of organism, but the beta and gamma subunits appear much later in evolution,” said Dr. Rossier. “The appearance of the beta subunit is particularly significant because it is required for the function of the sodium pump. Without it, a functional sodium pump cannot be expressed at the cell surface. What is interesting is that it appeared right before the dividing point between unicellular organisms and multicellular organisms.”

The team also found homologs of ENaC in a single-celled organism, the Naegleria gruberi. Although N. gruberi is a eukaryote and shares a common ancestor with Metazoans, it is located on a different branch of the eukaryotic family tree, among the Excavates. At first glance it might make sense to assume that both Metazoans and Excavates got their ENaC from their common eukaryotic ancestor, but ENaC is absent in all other branches of the eukaryotic tree.

Dr. Rossier said that although it is possible that the genes for ENaC originated in the common ancestor of eukaryotes and were lost in all branches except the Metazoa and the Excavates, there is another possibility. There could have been a lateral transfer of genes between N. gruberi and a Metazoan ancestor, one that lived between the last common ancestor of all eukaryotes and the first Metazoans.

Whether a Metazoan transferred the genes for ENaC to N. gruberi or the other way around, Dr. Rossier is not sure. Either way, the fact that ENaC gene family appeared just before the emergence of Metazoans suggests it is somehow linked to the development of multi-celled organisms, he said.

About the Conference
The 7th International Symposium on Aldosterone and the ENaC/Degenerin Family of Ion Channels explores the relationship between fluid regulation and hypertension, the cardiovascular system and other organ systems. The American Physiological Society is sponsoring the conference which is being held September 18-22, 2011 in Pacific Grove, CA. Additional program information is online at http://www.the-aps.org/press/releases/11/24.htm

NOTE TO EDITORS: Dr. Rossier’s presentation, “Evolution of ENaC and Na-K-ATPase as Limiting Factors of Aldosterone Action,” is based in part on the team’s recent article published in the journal Physiological Genomics. To request an interview or a copy of the article, please contact Donna Krupa at 301.634.7209 or dkrupa@the-aps.org.

Physiology is the study of how molecules, cells, tissues and organs function to create health or disease. The American Physiological Society has been an integral part of the discovery process since it was established in 1887. To keep up with the science, follow @Phyziochick on Twitter.

Donna Krupa | Newswise Science News
Further information:
http://www.the-aps.org

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: In best circles: First integrated circuit from self-assembled polymer

For the first time, a team of researchers at the Max-Planck Institute (MPI) for Polymer Research in Mainz, Germany, has succeeded in making an integrated circuit (IC) from just a monolayer of a semiconducting polymer via a bottom-up, self-assembly approach.

In the self-assembly process, the semiconducting polymer arranges itself into an ordered monolayer in a transistor. The transistors are binary switches used...

Im Focus: Demonstration of a single molecule piezoelectric effect

Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale

Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...

Im Focus: Hybrid optics bring color imaging using ultrathin metalenses into focus

For photographers and scientists, lenses are lifesavers. They reflect and refract light, making possible the imaging systems that drive discovery through the microscope and preserve history through cameras.

But today's glass-based lenses are bulky and resist miniaturization. Next-generation technologies, such as ultrathin cameras or tiny microscopes, require...

Im Focus: Stem cell divisions in the adult brain seen for the first time

Scientists from the University of Zurich have succeeded for the first time in tracking individual stem cells and their neuronal progeny over months within the intact adult brain. This study sheds light on how new neurons are produced throughout life.

The generation of new nerve cells was once thought to taper off at the end of embryonic development. However, recent research has shown that the adult brain...

Im Focus: Interference as a new method for cooling quantum devices

Theoretical physicists propose to use negative interference to control heat flow in quantum devices. Study published in Physical Review Letters

Quantum computer parts are sensitive and need to be cooled to very low temperatures. Their tiny size makes them particularly susceptible to a temperature...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

2nd International Conference on High Temperature Shape Memory Alloys (HTSMAs)

15.02.2018 | Event News

Aachen DC Grid Summit 2018

13.02.2018 | Event News

How Global Climate Policy Can Learn from the Energy Transition

12.02.2018 | Event News

 
Latest News

Researchers invent tiny, light-powered wires to modulate brain's electrical signals

21.02.2018 | Life Sciences

The “Holy Grail” of peptide chemistry: Making peptide active agents available orally

21.02.2018 | Life Sciences

Atomic structure of ultrasound material not what anyone expected

21.02.2018 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>