Featured Research

from universities, journals, and other organizations

Scientists Deconstruct Process Of Bacterial Division: Could Lead To New Antibiotics

Date:
April 22, 2008
Source:
Duke University Medical Center
Summary:
Researchers have made a major advance in understanding how bacteria divide. This could lead to new antibiotic treatments that prevent dangerous bacteria from multiplying.

Duke University researchers have made a major advance in understanding how bacteria divide. This could lead to new antibiotic treatments that prevent dangerous bacteria from multiplying.

Related Articles


Normally, bacteria divide by forming a ring that pinches the cell in two. The ring is called a "Z ring" after the protein FtsZ, which forms a ring-shaped scaffold and then squeezes it smaller. In bacteria, the Z ring also contains a dozen other proteins, all believed to be essential for division.

The Z ring normally pulls in on the cell membrane by binding to another protein, FtsA, which has one end attached to the inner cell membrane and the other end connected to FtsZ. When the Z ring constricts, it completely pulls in the membrane and nips the bacterium in two.

But cell biology research scientist Masaki Osawa, Ph.D., cut FtsA out of the system by making an FtsZ that could bind directly to the membrane, and called it "membrane targeted FtsZ" or FtsZ-mts.

First, Osawa demonstrated that the new protein, FtsZ-mts, assembled Z rings in bacteria.

Then he constructed a greatly simplified cell-division machine in microscopic oil droplets, called liposomes, that demonstrated the important role of FtsZ in the division process. He was able to assemble Z rings in this completely artificial system, the liposome, a tiny hollow sphere of fat that mimics natural cell membranes.

To do this, Osawa mixed the liposomes with FtsZ and GTP, a molecule that provides energy. On a microscope slide the liposomes fused and stretched into tubes that mimicked the shape of E. coli and other rod-shaped bacteria.

"It was a happy coincidence that the size and shape of the liposomes was similar to that of rod-shaped bacteria," says co-author Harold Erickson, professor of cell biology. "These tubular liposomes are a new micro-structure, and their formation is still a mystery."

During the experiment, fluorescently labeled FtsZ-mts was initially on the outside of the liposomes, but some of the tubular liposomes ended up with FtsZ on the inside. "We don't know how this happens, but it is a key to the discovery," Osawa said.

Inside the liposome the FtsZ formed multiple closed rings that aligned perpendicular to the length of the tube, just as Z rings form in bacteria. They also slid back and forth, and where they collided, they stayed together and formed brighter Z rings. And as the Z rings grew in brightness, they visibly pulled the wall of the liposome inward.

"The Z rings are clearly generating force and causing the constriction," Osawa said. A movie the team made shows several constrictions in the wall occurring at the sites of the bright Z rings. When the GTP in the liposome is used up, the tube eases out of its constrictions into its original shape.

"We believe our simple system may recreate the mechanism that the earliest bacteria used to divide. They probably had FtsZ alone," Erickson said. "Osawa's experiments show that FtsZ, a membrane tether, and the inside surface of a tubular membrane are all that's needed to assemble the Z ring and generate a constriction force."

The artificial Z rings were not sufficient to pinch the liposomes in half, "probably because their walls are much thicker than the membrane of a bacterium," Osawa noted. "We are now working to make thinner liposomes, so that we can achieve complete division."

Erickson said that FtsZ is the bacterial ancestor of tubulin, the protein that makes the microtubules in animal cells and is the target of a number of anti-cancer drugs like taxol. Although FtsZ is not sensitive to taxol, anything learned about the bacterial ancestor will help us understand microtubules, which help animal cells to keep their shape and control their movements, he explained.


Story Source:

The above story is based on materials provided by Duke University Medical Center. Note: Materials may be edited for content and length.


Cite This Page:

Duke University Medical Center. "Scientists Deconstruct Process Of Bacterial Division: Could Lead To New Antibiotics." ScienceDaily. ScienceDaily, 22 April 2008. <www.sciencedaily.com/releases/2008/04/080417142500.htm>.
Duke University Medical Center. (2008, April 22). Scientists Deconstruct Process Of Bacterial Division: Could Lead To New Antibiotics. ScienceDaily. Retrieved December 18, 2014 from www.sciencedaily.com/releases/2008/04/080417142500.htm
Duke University Medical Center. "Scientists Deconstruct Process Of Bacterial Division: Could Lead To New Antibiotics." ScienceDaily. www.sciencedaily.com/releases/2008/04/080417142500.htm (accessed December 18, 2014).

Share This


More From ScienceDaily



More Plants & Animals News

Thursday, December 18, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

When You Lose Weight, This Is Where The Fat Goes

When You Lose Weight, This Is Where The Fat Goes

Newsy (Dec. 17, 2014) Can fat disappear into thin air? New research finds that during weight loss, over 80 percent of a person's fat molecules escape through the lungs. Video provided by Newsy
Powered by NewsLook.com
The Hottest Food Trends for 2015

The Hottest Food Trends for 2015

Buzz60 (Dec. 17, 2014) Urbanspoon predicts whicg food trends will dominate the culinary scene in 2015. Mara Montalbano (@maramontalbano) has the story. Video provided by Buzz60
Powered by NewsLook.com
Rover Finds More Clues About Possible Life On Mars

Rover Finds More Clues About Possible Life On Mars

Newsy (Dec. 17, 2014) NASA's Curiosity rover detected methane on Mars and organic compounds on the surface, but it doesn't quite prove there was life ... yet. Video provided by Newsy
Powered by NewsLook.com
Ivory Trade Boom Swamps Law Efforts

Ivory Trade Boom Swamps Law Efforts

Reuters - Business Video Online (Dec. 17, 2014) Demand for ivory has claimed the lives of tens of thousands of African elephants and now a conservation report says the illegal trade is overwhelming efforts to enforce the law. Amy Pollock reports. Video provided by Reuters
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