Featured Research

from universities, journals, and other organizations

Zipper action triggers bacterial invasion: Scientists discover new strategy germs use to invade cells

Date:
August 20, 2014
Source:
Albert-Ludwigs-Universität Freiburg
Summary:
The hospital germ Pseudomonas aeruginosa wraps itself into the membrane of human cells. Now researchers have identified a novel mechanism of bacterial invasion, outlining how Pseudomonas aeruginosa uses lipids in the cell membrane to make its way into host cells.

Pseudomonas aeruginosa (green) invades a synthetic vesicle (red) using the lipid zipper.
Credit: Thorsten Eierhoff

A team led by Dr. Thorsten Eierhoff and Junior Professor Dr. Winfried Römer from the Institute of Biology II, members of the Cluster of Excellence BIOSS Centre for Biological Signalling Studies of the University of Freiburg, has identified a novel mechanism of bacterial invasion: Pseudomonas aeruginosa uses lipids in the cell membrane to make its way into host cells.

Related Articles


The protein LecA on the surface of the bacteria binds to sugar on special lipid molecules, so-called Gb3 lipids, which are present in the outer membrane of human cells. When the germ docks onto a cell, the LecA molecules of the bacteria and the Gb3 lipids of the host membrane interlock -- like a zipper. In this way, the cell envelope wraps itself around the germ step by step and conveys it into the cell's interior. Römer and Eierhoff found evidence of the new mechanism in synthetic membranes as well as in cultures of human lung cells.

They published their findings in the Proceedings of the National Academy of Sciences.

Pseudomonas aeruginosa can cause serious inflammations of the skin and the lung in patients with a weakened immune system, particularly in those suffering from the genetic disorder cystic fibrosis. When the bacteria enter human cells, Gb3 lipids bind to LecA proteins and bend the membrane. This bond is enough to wrap up the bacterium, calculated Prof. Dr. Christian Fleck from Wageningen University, Netherlands. He was co-author of this study. Researchers were previously only familiar with methods of bacterial invasion involving the manipulation of signals in the host cell. These signals control actin fibers, the cell's muscles: The fibers bend the cell envelope from inside and form membrane bubbles into which the bacteria are absorbed.

In order to prove that the process runs without actin, the researchers observed the effect of Pseudomonas bacteria on synthetic membrane bubbles. The bubbles contained neither actin nor other cellular components -- only the lipid Gb3. The in vitro membrane folded in and closed in around the bacteria when they docked onto the surface. However, the wrapping process only took place when the bacteria produced the protein LecA.

"The experiment shows that Pseudomonas uses this lipid zipper to make its way into cells without manipulating actin," says Eierhoff.

The researchers demonstrated that LecA and Gb3 are also important for bacterial invasion in human lung cells: When the pair of molecules was missing, the number of germs that infiltrated the cells was reduced by up to 70 percent. These findings enabled Römer's research group to identify a potential agent against Pseudomonas aeruginosa.


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. T. Eierhoff, B. Bastian, R. Thuenauer, J. Madl, A. Audfray, S. Aigal, S. Juillot, G. E. Rydell, S. Muller, S. de Bentzmann, A. Imberty, C. Fleck, W. Romer. A lipid zipper triggers bacterial invasion. Proceedings of the National Academy of Sciences, 2014; DOI: 10.1073/pnas.1402637111

Cite This Page:

Albert-Ludwigs-Universität Freiburg. "Zipper action triggers bacterial invasion: Scientists discover new strategy germs use to invade cells." ScienceDaily. ScienceDaily, 20 August 2014. <www.sciencedaily.com/releases/2014/08/140820091259.htm>.
Albert-Ludwigs-Universität Freiburg. (2014, August 20). Zipper action triggers bacterial invasion: Scientists discover new strategy germs use to invade cells. ScienceDaily. Retrieved November 24, 2014 from www.sciencedaily.com/releases/2014/08/140820091259.htm
Albert-Ludwigs-Universität Freiburg. "Zipper action triggers bacterial invasion: Scientists discover new strategy germs use to invade cells." ScienceDaily. www.sciencedaily.com/releases/2014/08/140820091259.htm (accessed November 24, 2014).

Share This


More From ScienceDaily



More Plants & Animals News

Monday, November 24, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Ebola-Hit Sierra Leone's Late Cocoa Leaves Bitter Taste

Ebola-Hit Sierra Leone's Late Cocoa Leaves Bitter Taste

AFP (Nov. 23, 2014) — The arable district of Kenema in Sierra Leone -- at the centre of the Ebola outbreak in May -- has been under quarantine for three months as the cocoa harvest comes in. Duration: 01:32 Video provided by AFP
Powered by NewsLook.com
Anglerfish Rarely Seen In Its Habitat Will Haunt You

Anglerfish Rarely Seen In Its Habitat Will Haunt You

Newsy (Nov. 22, 2014) — For the first time Monterey Bay Aquarium recorded a video of the elusive, creepy and rarely seen anglerfish. Video provided by Newsy
Powered by NewsLook.com
Birds Around the World Take Flight

Birds Around the World Take Flight

Reuters - Light News Video Online (Nov. 22, 2014) — An imperial eagle equipped with a camera spreads its wings over London. It's just one of the many birds making headlines in this week's "animal roundup". Jillian Kitchener reports. Video provided by Reuters
Powered by NewsLook.com
Could Your Genes Be The Reason You're Single?

Could Your Genes Be The Reason You're Single?

Newsy (Nov. 21, 2014) — Researchers in Beijing discovered a gene called 5-HTA1, and carriers are reportedly 20 percent more likely to be single. 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:

Strange & Offbeat Stories

 

Plants & Animals

Earth & Climate

Fossils & Ruins

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