Navigation Links
Researchers discover how bacteria sense their environments

When humans taste or smell, receptors unique to each nerve cell detect the chemical and send signals to the brain, where many cells process the message to understand what we are smelling or tasting. But a bacterium is just a single cell, and it must use many different receptors to sense and interpret everything around it.

Bacteria can sense in their environments changes in molecular concentrations as small as 0.1 percent, the equivalent of one drop diluted in a pool of a 1,000 drops. How do they do it?

New Cornell research, highlighted on the cover of the May issue of Nature Structural and Molecular Biology, reveals that receptors assemble into a kind of cooperative lattice on a bacterium's surface to amplify infinitesimal changes in the environment and kick off processes that lead to specific responses within the cell.

"Bacteria sense a lot of different things. But assume it's a sugar molecule that a bacterium needs as a nutrient -- even a 0.1 percent change in concentration can be detected, and this sensitivity is maintained over five orders of magnitude in nutrient concentration," said Brian Crane, assistant professor of chemistry and chemical biology and corresponding author of the paper. "Biologically, I know of no other system that is so sensitive over such a large range."

Crane believes the kind of cooperative lattice found in bacterial receptors may in fact point to a general mechanism for cellular signaling and serve as inspiration for developing molecular devices. Such devices could be used to sense a wide range of chemicals, light, ionic strength (salt), pH and heavy metals with great sensitivity, gain and dynamic range. Scientists are interested in developing synthetic systems with such sensing properties as well as engineering bacteria that respond to stimuli such as pollutants or explosives.

Using a combination of X-ray crystallography to determine the structure of receptors and enzymes and a novel spectroscopi c technique for measuring interactions between them, Crane's group was able to develop a model for how the complex of receptors is organized. Jack Freed, Cornell professor of chemistry and chemical biology and director of the National Biomedical Center for Advanced ESR Studies at Cornell, developed the spectroscopic technique, called pulsed electron spin resonance dipolar spectroscopy.

The researchers suggest that when one receptor detects, for example, a sugar in its environment, communication of some sort triggers an array of linked receptors to rearrange itself, much like when water freezes, all the water molecules assort themselves into a new structure. Through this reorganization, the bacterium's receptor array amplifies the signal that a specific molecule has been sensed outside the cell. This structural shift then activates kinases, or enzymes, within the cell, starting a chain reaction that leads to a response, such as changing how the flagella (or tails) spin. This allows the bacterium to move toward or away from what it has sensed.

Such a mechanism of amplification allows signals from the receptors to travel hundreds of angstroms, a distance used in atomic physics that is a virtual marathon in the world of intracellular communication. Ten angstroms equal a nanometer, which is one-billionth of a meter.

Sang-Youn Park, a former graduate student in Cornell's Department of Chemistry and Chemical Biology, and senior research associates Peter Borbat and Alexandrine Bilwes were the study's lead authors. The research was funded by the National Institutes of Health.


'"/>

Source:Cornell University News Service


Related biology news :

1. Researchers discover way to make cells in the eye sensitive to light
2. Researchers find how protein allows insects to detect and respond to pheromones
3. Researchers Uncover Key Step In Manufacture of Memory Protein
4. Researchers reveal the infectious impact of salmon farms on wild salmon
5. Researchers identify target for cancer drugs
6. Researchers discover molecule that causes secondary stroke
7. Researchers find missing genes of ancient organism
8. Researchers trace evolution to relatively simple genetic changes
9. Researchers add new tool to tumor-treatment arsenal
10. UF Researchers Map Bacterial Proteins That Cause Tooth Loss
11. VCU Researchers Identify Networks Of Genes Responding To Alcohol In The Brain
Post Your Comments:
*Name:
*Comment:
*Email:


(Date:3/29/2017)... the health IT company that operates the largest health ... today announced a Series B investment from BlueCross BlueShield ... investment and acquisition accelerates higi,s strategy to create the ... activities through the collection and workflow integration of ambient ... secures data today on behalf of over 36 million ...
(Date:3/27/2017)... ROCKVILLE CENTRE, N.Y. , March 27, 2017 ... by Healthcare Information and Management Systems Society (HIMSS) ... Analytics Outpatient EMR Adoption Model sm . In ... top 12% of U.S. hospitals using an electronic ... recognized CHS for its high level of EMR ...
(Date:3/24/2017)... , Mar 24, 2017 Research and Markets ... System Market Analysis & Trends - Industry Forecast to 2025" ... ... grow at a CAGR of around 15.1% over the next decade ... industry report analyzes the market estimates and forecasts for all the ...
Breaking Biology News(10 mins):
(Date:10/10/2017)... firm Parks Associates announced today that Tom Kerber , ... Meeting , October 11 in Scottsdale, Arizona . Kerber ... smart safety and security products impact the competitive landscape. ... Parks Associates: Smart Home Devices: Main Purchase Driver ... "The residential security market has experienced continued growth, and the introduction ...
(Date:10/9/2017)...  BioTech Holdings announced today identification and patenting ... stem cell therapy prevents limb loss in animal ... that treatment with ProCell resulted in more than ... to standard bone marrow stem cell administration.  Interestingly, ... of therapeutic effect.  ...
(Date:10/9/2017)... Antonio, Texas (PRWEB) , ... ... ... new study published on October 5, 2017, in the medical journal, Epilepsia, ... equivalence with the gold standard, video EEG, in detecting generalized tonic-clonic seizures ...
(Date:10/6/2017)... ... 2017 , ... The HealthTech Venture Network (HTVN) is proud ... annual Conference where founders, investors, innovative practitioners and collaborators are invited to a ... early stage digital health and med tech companies. , This day-long event will ...
Breaking Biology Technology: