Featured Research

from universities, journals, and other organizations

Toxin kills using dual mechanism

Date:
October 21, 2013
Source:
Albert-Ludwigs-Universität Freiburg
Summary:
Researchers discover a new bacterial toxin and explain its structure and mode of action.

Effect of the bacterial toxin PaTox on the larvae of the greater wax moth (Galleria mellonella) and the crystalline structure of the effective part of the toxin.
Credit: Thomas Jank - University of Freiburg

Photorhabdus bacteria live in worms that attack insects. The bacteria kill the insects, which then serve as a source of food for the worms as well as the bacteria. Studies in Australia and the USA have shown that these bacteria also cause inflammations of the skin and ulcers in humans. The substances responsible for this effect are bacterial toxins. A team of researchers led by Prof. Dr. Dr. Klaus Aktories from the Institute of Pharmacology and Toxicology of the University of Freiburg and BIOSS Centre for Biological Signalling Studies and Dr. Thomas Jank from the Institute of Pharmacology and Toxicology of the University of Freiburg has discovered the new toxin "PaTox" and elucidated its molecular mechanism. The study was published in the journal Nature Structural and Molecular Biology.

Also collaborating on the study were University of Freiburg research groups led by Prof. Dr. Carola Hunte, BIOSS Centre for Biological Signalling Studies and Institute of Biochemistry and Molecular Biology, and Prof. Dr. Bettina Warscheid, BIOSS Centre for Biological Signalling Studies and Institute of Biology II, as well as Prof. Dr. Hans Robert Kalbitzer from the Institute of Biophysics and Physical Biochemistry of the University of Regensburg. The team unraveled the structure of the toxic unit of PaTox. What is so special about the mechanism is that the toxin causes a sugar to be transferred to protein substances that serve as signaling switches in the host cell. The sugar residue attaches to the amino acid tyrosine. The scientists were able to observe this reaction for the first time ever. When the sugar attaches to the amino acid, the switch is set to "off." This obstructs processes in the cell that regulate the cytoskeleton, causing the cell and insect to die. An unexpected finding for the researchers was that the cell's signaling switch needed to be switched on for the toxin to take effect at all. Astonishingly, PaTox evidently turns on the switch itself. This requires a second mechanism of the bacterial toxin that causes the amino acid glutamine to be converted into glutamic acid, thus activating cellular signaling proteins.

The researchers have also found similar toxins in bacteria that cause diseases in fish, plants, and humans. The elucidation of the molecular mechanism of PaTox is crucial for the understanding of an entire family of toxins and lays the foundation for the development of therapeutic strategies for combating the bacteria that produce the toxin.


Story Source:

The above story is based on materials provided by Albert-Ludwigs-Universität Freiburg. Note: Materials may be edited for content and length.


Journal Reference:

  1. Thomas Jank, Xenia Bogdanović, Christophe Wirth, Erik Haaf, Michael Spoerner, Kira E Böhmer, Marcus Steinemann, Joachim H C Orth, Hans Robert Kalbitzer, Bettina Warscheid, Carola Hunte, Klaus Aktories. A bacterial toxin catalyzing tyrosine glycosylation of Rho and deamidation of Gq and Gi proteins. Nature Structural & Molecular Biology, 2013; DOI: 10.1038/nsmb.2688

Cite This Page:

Albert-Ludwigs-Universität Freiburg. "Toxin kills using dual mechanism." ScienceDaily. ScienceDaily, 21 October 2013. <www.sciencedaily.com/releases/2013/10/131021094646.htm>.
Albert-Ludwigs-Universität Freiburg. (2013, October 21). Toxin kills using dual mechanism. ScienceDaily. Retrieved July 28, 2014 from www.sciencedaily.com/releases/2013/10/131021094646.htm
Albert-Ludwigs-Universität Freiburg. "Toxin kills using dual mechanism." ScienceDaily. www.sciencedaily.com/releases/2013/10/131021094646.htm (accessed July 28, 2014).

Share This




More Plants & Animals News

Monday, July 28, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Traditional African Dishes Teach Healthy Eating

Traditional African Dishes Teach Healthy Eating

AP (July 28, 2014) — Classes are being offered nationwide to encourage African Americans to learn about cooking fresh foods based on traditional African cuisine. The program is trying to combat obesity, heart disease and other ailments often linked to diet. (July 28) Video provided by AP
Powered by NewsLook.com
Raw: Sea Turtle Hatchlings Emerge from Nest

Raw: Sea Turtle Hatchlings Emerge from Nest

AP (July 27, 2014) — A live-streaming webcam catches loggerhead sea turtle hatchlings emerging from a nest in the Florida Keys. (July 27) Video provided by AP
Powered by NewsLook.com
Russia Saves Gecko Sex Satellite, Media Has Some Fun With It

Russia Saves Gecko Sex Satellite, Media Has Some Fun With It

Newsy (July 27, 2014) — The satellite is back under ground control after a tense few days, but with a gecko sex experiment on board, the media just couldn't help themselves. Video provided by Newsy
Powered by NewsLook.com
Trees Could Save More Than 850 Lives Each Year

Trees Could Save More Than 850 Lives Each Year

Newsy (July 27, 2014) — A national study conducted by the USDA Forest Service found that trees collectively save more than 850 lives on an annual basis. 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