Featured Research

from universities, journals, and other organizations

How bacteria sense salt stress

Date:
July 6, 2012
Source:
National University of Singapore
Summary:
Scientists' finding is a major breakthrough in understanding a decades-old problem of how bacteria detect environmental changes.

Spring action of salt-sensor proteins (Photo credit: NUS): Salt-sensor proteins in bacteria operate like molecular springs. Under low salt conditions in the environment, the proteins oscillate between ‘stretched’ and ‘compressed’ forms. The 3-Dimensional structure of the proteins are shown as blue-white and green ribbons where ‘N’ denotes the front end (N-terminus) of the protein while ‘C’ denotes the back end of the protein (C-terminus). Salts in the environment dampen these spring-like movements and favour the ‘compressed’ form. This change in springiness is used by the bacteria to detect salts in their environments.
Credit: Image courtesy of National University of Singapore

Scientists' finding is a major breakthrough in understanding a decades-old problem of how bacteria detect environmental changes.

A team of scientists led by Assistant Professor Ganesh S Anand and Professor Linda J. Kenney from the National University of Singapore (NUS) Department of Biological Sciences (DBS) and the Mechanobiology Institute (MBI) has discovered how bacteria respond to salts in their environment and the ways in which salts can alter the behaviour of specialised salt sensor bacterial proteins.

This novel finding sheds light on how microbes detect levels of salts or sugars in their watery environments -- a problem in biology that has been studied for more than 30 years.

The NUS scientists found that microbes do this by specialised molecules or proteins on the bacterial surface that change shape in response to changes in salt concentration. This is relevant not only to bacteria, but also cells from all organisms which detect and respond to changes in environmental salts and sugars.

The scientists from NUS and the University of Illinois-Chicago (UIC) first published their findings in the EMBO Journal on 30 May 2012.

Salt detecting proteins are like springs

Bacteria have elaborate mechanisms for sensing and responding to changes in the environment. One of the important environmental stresses for bacteria is the changing concentration of salts. For instance, some can live in fresh water (a low salt environment) or in the guts of humans (high salt environment).

Using a powerful combination of a tool called amide hydrogen/deuterium exchange mass spectrometry (HDXMS), accompanied by molecular biology and biochemistry, the scientists from NUS probed how changes in salt concentrations are sensed by a receptor protein.

They found that salt detecting proteins are like molecular springs, or "slinky toys." The proteins are constantly shifting from a condensed spring form to an extended form. Increasing the salt concentration dampens this spring-like movement, which activates the protein. In other words, the less spring-like the protein, the higher is its activity. This protein movement may provide a unified model of how bacteria sense their environment.

Application of the phenomenon

This study is an example of basic science with immediate applications. Recognising that diverse proteins operate as molecular springs whose spring-like movement can be dampened is fundamental to understanding how these proteins work. This study also underscores the role of water in biology. It demonstrates how salts and sugars can alter biological properties of proteins through the effects on water and is relevant for understanding life processes across species from bacteria to humans.

The NUS research team is now working on studying the protein in its native membrane by embedding the bacterial sensor protein in an artificial membrane. They hope to understand how the membrane contributes to overall protein activity, structure, stability and responses to salts.


Story Source:

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


Journal Reference:

  1. Loo Chien Wang, Leslie K Morgan, Pahan Godakumbura, Linda J Kenney, Ganesh S Anand. The inner membrane histidine kinase EnvZ senses osmolality via helix-coil transitions in the cytoplasm. The EMBO Journal, 2012; 31 (11): 2648 DOI: 10.1038/emboj.2012.99

Cite This Page:

National University of Singapore. "How bacteria sense salt stress." ScienceDaily. ScienceDaily, 6 July 2012. <www.sciencedaily.com/releases/2012/07/120706105424.htm>.
National University of Singapore. (2012, July 6). How bacteria sense salt stress. ScienceDaily. Retrieved September 2, 2014 from www.sciencedaily.com/releases/2012/07/120706105424.htm
National University of Singapore. "How bacteria sense salt stress." ScienceDaily. www.sciencedaily.com/releases/2012/07/120706105424.htm (accessed September 2, 2014).

Share This




More Plants & Animals News

Tuesday, September 2, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

U.N. Says Ebola Travel Restrictions Will Cause Food Shortage

U.N. Says Ebola Travel Restrictions Will Cause Food Shortage

Newsy (Sep. 2, 2014) — The U.N. says the problem is two-fold — quarantine zones and travel restrictions are limiting the movement of both people and food. Video provided by Newsy
Powered by NewsLook.com
Sharks Off the Menu and on the Tourist Trail in Palau

Sharks Off the Menu and on the Tourist Trail in Palau

AFP (Sep. 2, 2014) — Tourists in Palau clamour to dive with sharks thanks to a pioneering conservation initiative -- as the island nation plans to completely ban commercial fishing in its vast ocean territory. 01:15 Video provided by AFP
Powered by NewsLook.com
We've Got Mites Living In Our Faces And So Do You

We've Got Mites Living In Our Faces And So Do You

Newsy (Aug. 30, 2014) — A new study suggests 100 percent of adult humans (those over 18 years of age) have Demodex mites living in their faces. Video provided by Newsy
Powered by NewsLook.com
Coffee Then Napping: The (New) Key To Alertness

Coffee Then Napping: The (New) Key To Alertness

Newsy (Aug. 30, 2014) — Researchers say having a cup of coffee then taking a nap is more effective than a nap or coffee alone. Video provided by Newsy
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