Featured Research

from universities, journals, and other organizations

Bacterium uses natural 'thermometer' to trigger diarrheal disease, scientists find

Date:
May 21, 2013
Source:
Ohio University
Summary:
How does the bacterium Shigella -- the cause of a deadly diarrheal disease -- detect that it's in a human host? Scientists have found that a biological "RNA thermometer" monitors whether the environment is right for the bacterium to produce the factors it needs to survive within the body, according to a new study.

How does the bacterium Shigella -- the cause of a deadly diarrheal disease -- detect that it's in a human host? Ohio University scientists have found that a biological "RNA thermometer" monitors whether the environment is right for the bacterium to produce the factors it needs to survive within the body, according to a study published May 21 in the journal PLOS ONE.

The scientists have been seeking more information about the genetic pathways of Shigella in the hope of finding new treatment options for the disease it causes. Shigellosis kills more than a million people worldwide each year and is becoming more resistant to antibiotics, said Erin Murphy, an assistant professor in Ohio University's Heritage College of Osteopathic Medicine.

The recent study led by Murphy and Andrew Kouse, a doctoral student in molecular and cellular biology, found that when Shigella was in a 37 degree Celsius environment (or at "body temperature"), it efficiently produced the ShuA protein from the corresponding messenger RNA molecule. The bacterium needs the ShuA protein to obtain iron from heme, the most abundant source of this essential nutrient within the human body. Without iron, the invading Shigella would not survive, Murphy explained.

At room temperature, 25 degrees Celsius, production of the ShuA protein from the corresponding messenger RNA was inhibited. The scientists suggest that the structure of the RNA thermometer was blocking genetic expression by preventing protein synthesis.

"This may be an evolutionary adaptation, as it would be wasteful for the bacterium to make this protein before it was in the host," Murphy said.

But once at body temperature, part of the structure of the thermometer "melts away," she said, triggering the bacterium to synthesize the ShuA protein.

The new study marks the first time that researchers have observed a "RNA thermometer" in the Shigella bacterium.

This particular thermometer belongs to a subclass called "FourU RNA thermometers" that was first characterized by study co-author Franz Narberhaus of the Ruhr University Bochum, Germany. These thermometers have been identified in only two other bacteria, Salmonella and Yersinia, both of which can cause serious human illnesses.

"I find it fascinating that an entirely new class of genes has been found to be controlled by an RNA thermometer," Narberhaus said.

Now that the scientists have identified the RNA thermometer in the ShuA gene, they'll look for this structure in the other genes that regulate Shigella's ability to survive in the human host and cause disease.

"The findings could have practical implications for drug design," Murphy said.


Story Source:

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


Journal Reference:

  1. Andrew B. Kouse, Francesco Righetti, Jens Kortmann, Franz Narberhaus, Erin R. Murphy. RNA-Mediated Thermoregulation of Iron-Acquisition Genes in Shigella dysenteriae and Pathogenic Escherichia coli. PLoS ONE, 2013; 8 (5): e63781 DOI: 10.1371/journal.pone.0063781

Cite This Page:

Ohio University. "Bacterium uses natural 'thermometer' to trigger diarrheal disease, scientists find." ScienceDaily. ScienceDaily, 21 May 2013. <www.sciencedaily.com/releases/2013/05/130521194003.htm>.
Ohio University. (2013, May 21). Bacterium uses natural 'thermometer' to trigger diarrheal disease, scientists find. ScienceDaily. Retrieved April 16, 2014 from www.sciencedaily.com/releases/2013/05/130521194003.htm
Ohio University. "Bacterium uses natural 'thermometer' to trigger diarrheal disease, scientists find." ScienceDaily. www.sciencedaily.com/releases/2013/05/130521194003.htm (accessed April 16, 2014).

Share This



More Health & Medicine News

Wednesday, April 16, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Ebola Outbreak Now Linked To 121 Deaths

Ebola Outbreak Now Linked To 121 Deaths

Newsy (Apr. 15, 2014) The ebola virus outbreak in West Africa is now linked to 121 deaths. Health officials fear the virus will continue to spread in urban areas. Video provided by Newsy
Powered by NewsLook.com
Cognitive Function: Is It All Downhill From Age 24?

Cognitive Function: Is It All Downhill From Age 24?

Newsy (Apr. 15, 2014) A new study out of Canada says cognitive motor performance begins deteriorating around age 24. Video provided by Newsy
Powered by NewsLook.com
How Mt. Everest Helped Scientists Research Diabetes

How Mt. Everest Helped Scientists Research Diabetes

Newsy (Apr. 15, 2014) British researchers were able to use Mount Everest's low altitudes to study insulin resistance. They hope to find ways to treat diabetes. Video provided by Newsy
Powered by NewsLook.com
Carpenter's Injury Leads To Hundreds Of 3-D-Printed Hands

Carpenter's Injury Leads To Hundreds Of 3-D-Printed Hands

Newsy (Apr. 14, 2014) Richard van As lost all fingers on his right hand in a woodworking accident. Now, he's used the incident to create a prosthetic to help hundreds. 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