Featured Research

from universities, journals, and other organizations

Malaria-resistant Mosquitoes Battle Disease With 'Molecular Warhead'

Date:
July 9, 2007
Source:
UT Southwestern Medical Center
Summary:
Researchers have discovered why some mosquitoes are resistant to malaria, a finding that may one day help fight a disease that afflicts and kills millions of people.

A team led by UT Southwestern Medical Center researchers has discovered why some mosquitoes are resistant to malaria, a finding that may one day help fight a disease that afflicts and kills millions of people.

A team led by UT Southwestern Medical Center researchers has discovered why some mosquitoes are resistant to malaria, a finding that may one day help fight a disease that afflicts and kills millions of people.

The researchers focused on TEP1, a protein in the mosquito's immune system. When a mosquito is infected with a parasite that causes malaria, a biochemical reaction is triggered that physically transforms TEP1 into an active state capable of grabbing on to the parasite's surface and targeting it for termination.

In a study appearing online this week in the Proceedings of the National Academy of Sciences, the UT Southwestern group used a method called X-ray crystallography to uncover TEP1's three-dimensional structure. They found that the genetic differences between mosquitoes that are resistant and those that are susceptible to the parasite mostly manifest in a region of the TEP1 protein dubbed "the warhead," the portion that grabs the malarial parasite.

"TEP1 is a scout that finds the enemy, in this case malarial parasites, then plants a homing signal on the enemy and calls in the air strike," said Dr. Richard Baxter, a postdoctoral researcher in biochemistry at UT Southwestern and lead author of the study.

Understanding how some mosquitoes can fend off malaria might someday lead to reducing or even eliminating the mosquito's capacity to transmit the devastating disease, Dr. Baxter said.

"We have been trying to cure people of malaria for over a century," said Dr. Baxter, who also is a research associate with the Howard Hughes Medical Institute at UT Southwestern. "Only recently have people started to think about curing mosquitoes of malaria."

Nobel laureate Dr. Johann Deisenhofer, who is senior author of the study, said, "This finding opened my eyes to the fact that mosquitoes are almost as unhappy about malaria as we are. "They try to get rid of it." Dr. Johann Deisenhofer is a professor of biochemistry, an HHMI investigator and holder of the Virginia and Edward Linthicum Distinguished Chair in Biomolecular Science. He was awarded the 1988 Nobel Prize in chemistry for using X-ray crystallography to describe the structure of a protein involved in photosynthesis.

Malaria is one of the leading causes of disease and death in the world. About 350 million to 500 million worldwide are infected with malaria, according to the Bill and Melinda Gates Foundation. Each year more than one million die, primarily children in Africa.

About 40 percent of the world's population lives in areas with mosquitoes that carry malaria. Prevention and treatment have been hampered by cost, the rise of drug-resistant malarial parasites, and the lack of a vaccine.

Malaria is caused by parasites of the genus Plasmodium, which are spread to humans through mosquito bites. A mosquito picks up the parasite via infected human blood. The parasite then embeds itself in the mosquito's gut wall and reproduces, eventually passing to the salivary glands. The mosquito then infects new people during subsequent bites.

The research group's French collaborators, using a Plasmodium species that infects rodents, previously determined that the gene for TEP1 occurs in two forms, or alleles. One, called TEP1r, occurs in mosquitoes that are resistant to malarial infection. Another, TEP1s, is found in mosquitoes that are vulnerable to infection.

The TEP1r and TEP1s proteins are 93 percent genetically identical, and the new study, in which TEP1r was structurally analyzed, shows that the differences cluster around the warhead area, Dr. Baxter said. This finding reinforces the theory that the warhead is a key element of the overall immune response to malaria in mosquitoes.

In future studies, the researchers will genetically manipulate the warhead to study its binding properties, Dr. Baxter said. In addition, further research is needed to determine what other elements of the mosquito's immune system are activated once TEP1 binds to an invader.

Other UT Southwestern researchers involved in the study were Dr. Chung-I Chang, a former postdoctoral researcher, and Yogarany Chelliah, an HHMI research specialist. Researchers from the Institut de Biologie Molιculaire et Cellulaire in Strasbourg, France, also participated.

The work was supported by The Welch Foundation.


Story Source:

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


Cite This Page:

UT Southwestern Medical Center. "Malaria-resistant Mosquitoes Battle Disease With 'Molecular Warhead'." ScienceDaily. ScienceDaily, 9 July 2007. <www.sciencedaily.com/releases/2007/07/070706090033.htm>.
UT Southwestern Medical Center. (2007, July 9). Malaria-resistant Mosquitoes Battle Disease With 'Molecular Warhead'. ScienceDaily. Retrieved September 2, 2014 from www.sciencedaily.com/releases/2007/07/070706090033.htm
UT Southwestern Medical Center. "Malaria-resistant Mosquitoes Battle Disease With 'Molecular Warhead'." ScienceDaily. www.sciencedaily.com/releases/2007/07/070706090033.htm (accessed September 2, 2014).

Share This




More Health & Medicine News

Tuesday, September 2, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Get on Your Bike! London Cycling Popularity Soars Despite Danger

Get on Your Bike! London Cycling Popularity Soars Despite Danger

AFP (Sep. 1, 2014) — Wedged between buses, lorries and cars, cycling in London isn't for the faint hearted. Nevertheless the number of people choosing to bike in the British capital has doubled over the past 15 years. Duration: 02:27 Video provided by AFP
Powered by NewsLook.com
Can You Train Your Brain To Eat Healthy?

Can You Train Your Brain To Eat Healthy?

Newsy (Sep. 1, 2014) — New research says if you condition yourself to eat healthy foods, eventually you'll crave them instead of junk food. Video provided by Newsy
Powered by NewsLook.com
We've Got Mites Living In Our Faces And So Do You

We've Got Mites Living In Our Faces And So Do You

Newsy (Aug. 30, 2014) — A new study suggests 100 percent of adult humans (those over 18 years of age) have Demodex mites living in their faces. Video provided by Newsy
Powered by NewsLook.com
Liberia Continues Fight Against Ebola

Liberia Continues Fight Against Ebola

AFP (Aug. 30, 2014) — Authorities in Liberia try to stem the spread of the Ebola epidemic by raising awareness and setting up sanitation units for people to wash their hands. Duration: 00:41 Video provided by AFP
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