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:12/22/2016)... -- As part of its longstanding mission to improve genetic literacy ... released its latest children,s book, titled The One ... topics of inheritance and variation of traits that are part ... school classrooms in the US. The book ... Killoran , whose previous book with 23andMe, You ...
(Date:12/19/2016)... , 19 de diciembre de 2016  Mosaic Biomedicals SL ... desarrollo acelerado de MSC-1, un anticuerpo humanizado que se espera comenzar ... 2017, con múltiples sitios previstos a lo largo de Europa y ... MSC-1 es ... inhibidor de leucemia (LIF), una citoquina pleiotrópica que se sobreexpresa en ...
(Date:12/15/2016)... VANCOUVER, Canada and BADEN-BADEN, Germany ... Solutions, a leading global financial services provider, today announced an ... in passive behavioural biometrics, to join forces. The partnership will ... fraud mitigation strategies in compliance with local data protection regulation. ... In ...
Breaking Biology News(10 mins):
(Date:1/11/2017)... , ... January 11, 2017 , ... ... Clinical Cancer Research show early promise of the investigational anti-cancer agent tucatinib (formerly ... median 5 previous treatment regimens. Twenty-seven percent of these heavily pretreated patients saw ...
(Date:1/11/2017)... ... January 11, 2017 , ... As ... in Peru studying the pathogens that cause malaria and tuberculosis. Seeing firsthand the ... of discovery. , Now, as an assistant professor of biology and biotechnology at ...
(Date:1/11/2017)... 2017  Brian Mehling, M.D., world-renowned stem cell researcher, ... International (BHI), will be attending the 47th Annual World ... from January 17-20, 2017. This will be Dr. Mehling,s ... theme of this year,s forum is Responsive and Responsible ... address strategies for fostering greater social inclusion and human ...
(Date:1/11/2017)... ... January 11, 2017 , ... While the most ... it is becoming increasingly clear that the evolution and transmission dynamics of resistance ... in the study of clinical resistance, has vastly underestimated these reservoirs of resistance ...
Breaking Biology Technology: