Navigation Links
Bacteria gauge cold with molecular measuring stick
Date:10/19/2010

HOUSTON -- (Oct. 19, 2010) -- Some bacteria react to the cold by subtly changing the chemistry of their outer wall so that it remains pliable as temperatures drop. Scientists identified a key protein in this response mechanism a few years ago, but the question of how bacteria sense cold in the first place remained a mystery. Based on a study by scientists at Rice University and Argentina's National University of Rosario, the answer is: They use a measuring stick.

The study, published in the September issue of Current Biology, involved a series of intricate experiments on the bacteria Bacillus subtilis. The researchers found a specialized protein that protrudes through the bacteria's outer cell wall acts as a measuring stick that's tuned to give a signal when temperatures outside the cell drop.

Scientists have long known that cells use specialized proteins called "transmembrane" proteins to sense and react to the outside world. Transmembrane proteins protrude through the cell's outer wall, or membrane.

"All living cells have the ability to respond to external stimuli, but in most cases that we are aware of, signal recognition -- the event that triggers the response -- occurs when a transmembrane protein binds physically to another chemical outside the cell," said study co-author Ariel Fernandez, research professor at Rice.

Fernandez said the Bacillus subtilis study is one of the first to determine how a transmembrane protein can respond indirectly to a physical stimulus outside the cell. The research was highlighted in review articles in both Current Biology and Nature Reviews Microbiology.

He and colleagues examined a transmembrane protein called DesK (pronounced des-KAY). In previous studies, scientists had found that DesK responded to cold temperatures by causing the cell to make a special compound that keeps the membrane pliable. Without the compound, the fatty acids inside the cell wall become more rigid as temperatures fall.

Fernandez and colleagues found that the part of the DesK protein that protrudes outside the cell contains a sensitized tip. As long as the tip remains in contact with water molecules outside the cell, DesK remains switched off. As temperatures fall and the cell membrane becomes more rigid, the membrane also becomes thicker. As it thickens, it engulfs the sensitized end of the temperature probe, cutting off contact with water molecules outside the cell. This, in turn, activates DesK and sends the signal to release the cold-protecting chemicals. This mechanism, which Fernandez named the buried buoy trigger, was proposed by Fernandez and probed experimentally by the Argentinean team.

The molecular biology and experimental probes were conducted in the laboratory of Diego de Mendoza at the National University of Rosario in Rosario, Argentina. To confirm the findings, the group constructed versions of DesK proteins of varying lengths. Using these as longer or shorter measuring sticks, the researchers confirmed that the signaling mechanism was triggered based upon whether the tip of the transmembrane sensor remained in contact with water molecules outside the membrane.


'/>"/>

Contact: Jade Boyd
jadeboyd@rice.edu
713-348-6778
Rice University
Source:Eurekalert

Related biology news :

1. TYRX AIGISRx antibacterial envelope shows low infection rate, high CIED procedure success
2. NIH-funded scientists sequence genomes of lyme disease bacteria
3. Key difference in how TB bacteria degrade doomed proteins
4. Gambling on bacteria
5. UCLA-led research team finds that bacteria can stand up and walk
6. Scientists trick bacteria with small molecules
7. Notre Dame researcher helps discover walking properties of bacteria
8. Life-saving in the bacterial world: How Campylobacter rely on Pseudomonas to infect humans
9. Bacteria keep tabs on state of oil field
10. FSU researchers examine how bacteria become resistant to antibiotics
11. Scientists reveal important clues to how bacteria and viruses are identified as enemies
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:5/6/2017)... , May 5, 2017 ... just announced a new breakthrough in biometric authentication ... exploits quantum mechanical properties to perform biometric authentication. These ... smart semiconductor material created by Ram Group and ... finance, entertainment, transportation, supply chains and security. Ram ...
(Date:4/17/2017)... 2017 NXT-ID, Inc. (NASDAQ: NXTD ) ... of its 2016 Annual Report on Form 10-K on Thursday April ... ... in the Investor Relations section of the Company,s website at ... at http://www.sec.gov . 2016 Year Highlights: ...
(Date:4/11/2017)... , Apr. 11, 2017 Research and ... Market 2017-2021" report to their offering. ... The global eye tracking market to grow at a ... report, Global Eye Tracking Market 2017-2021, has been prepared based on ... covers the market landscape and its growth prospects over the coming ...
Breaking Biology News(10 mins):
(Date:6/22/2017)... Linda, Ca (PRWEB) , ... June 22, 2017 , ... ... worldwide. It took 20 years until the first data on cross-contamination of human cell ... lines has been an increasing issue in cell culture labs and is associated with ...
(Date:6/20/2017)... ... June 20, 2017 , ... Biologist Dawn Maslar MS has ... her latest book, Men Chase, Women Choose: The Neuroscience of Meeting, Dating, Losing Your ... physiological effect on men. ”The logical next step, in my estimation, was to scientifically ...
(Date:6/20/2017)... ... ... Do More with OHAUS , With the launch of the new laboratory equipment ... to extending its expertise across the entire laboratory to a range of life science ... for its customers to 'Do More' in the lab. , Efficiency and Safety ...
(Date:6/19/2017)... PA (PRWEB) , ... June 19, 2017 , ... ... companies for over 50 years. One of the biggest challenges faced by life sciences, ... firm’s regulatory affairs services team is Kati Abraham , who is well known ...
Breaking Biology Technology: