Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

A wolf in sheep’s clothing: plague bacteria reveal one of their virulence tricks

21.09.2006
The bacterium that causes the plague belongs to a virulent family of bacteria called Yersinia, a group that also includes a pathogen responsible for food poisoning.

These bacteria insert into their host cells proteins and other virulence factors, which kill by — among other things — disrupting the cells' normal structure. One of these proteins, called YpkA, attacks a cell’s internal skeleton. Now, a study published by Rockefeller University researchers in the most recent issue of Cell shows exactly how YpkA does this, proving the protein’s mechanism from the atomic to the organismal level and providing a potential target for new antibiotic drugs.

C. Erec Stebbins, associate professor and head of the Laboratory of Structural Microbiology, and graduate student Gerd Prehna solved the structure for one region of the YpkA protein, a “binding domain” where it interlocks with another protein on the host cell’s membrane. By looking at the crystal structure of this protein-protein complex, Prehna discovered that the configuration looked just like one formed by some of the host’s own signaling proteins. And it’s this mimicry, he found, that leads to a signaling shutdown and deregulation of the cell’s normal structure.

After establishing this effect, Prehna set about disrupting it by mutation. Using the structure to guide him, he changed three amino acids of YpkA that contacted host proteins, and then looked at how the mutated bacteria affected human cells compared to the original wild-type Yersinia. His results confirmed the hypothesis from the structural study: While the wild-type YpkA wreaked havoc on their host cells’ cytoskeletons, the mutant left the actin-based skeleton intact.

... more about:
»Prehna »Yersinia »YpkA »virulence »wild-type

Then, the researchers took it one step further. Stebbins and Prehna worked with collaborators at Stony Brook University, who created Yersinia bacteria with Prehna’s mutations. The Stony Brook researchers then injected mice with the wild-type and mutant strains of Yersinia. All the mice infected with the wild-type bacteria died within nine days of exposure. But the group that received the YpkA mutant had an 80 percent survival rate, showing that Prehna’s mutation drastically lowered Yersinia’s harmful effects. “Altering this binding site not only impairs the bacteria’s ability to disrupt the host cytoskeleton,” Stebbins says, “but it decreases its virulence significantly.”

“It’s rare to find something that has such a strong effect that you can hit one protein so specifically, knock out essentially half its activity, and have such a dramatic result,” he says. “Not only did we have a mechanistic explanation, but we could connect what we were seeing in animal studies all the way down to what was happening at the atomic level.”

Kristine Kelly | EurekAlert!
Further information:
http://www.rockefeller.edu

Further reports about: Prehna Yersinia YpkA virulence wild-type

More articles from Life Sciences:

nachricht What happens in the cell nucleus after fertilization
06.12.2016 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt

nachricht Researchers uncover protein-based “cancer signature”
05.12.2016 | Universität Basel

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

Simple processing technique could cut cost of organic PV and wearable electronics

06.12.2016 | Materials Sciences

3-D printed kidney phantoms aid nuclear medicine dosing calibration

06.12.2016 | Medical Engineering

Robot on demand: Mobile machining of aircraft components with high precision

06.12.2016 | Power and Electrical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>