Featured Research

from universities, journals, and other organizations

Aimless proteins may be crucial to disease

Date:
March 31, 2011
Source:
University of Pittsburgh
Summary:
A supposedly inactive protein actually plays a crucial role in the ability of one the world's most prolific pathogens to cause disease and could also be important to other such pathogen-based diseases as malaria.

Researchers from the University of Pittsburgh and Stanford University discovered that a supposedly inactive protein actually plays a crucial role in the ability of one the world's most prolific pathogens to cause disease, findings that suggest the possible role of similarly errant proteins in other diseases.

The team reports in the Proceedings of the National Academy of Sciences (PNAS) that Toxoplasma gondii -- the parasitic protozoa behind toxoplasmosis -- attacks healthy cells by first injecting them with pseudokinases, which are enzymes that have abandoned their original function of transferring phosphates. When the researchers engineered strains of T. gondii without a particular pseudokinase gene cluster called ROP5, the pathogen was subsequently unable to cause disease in mice -- a notable loss of potency in an organism that can infect nearly any warm-blooded animal.

These results are among the first to implicate pseudokinases as indispensible actors in pathogen-based disease, said senior author Jon Boyle, a professor in the Department of Biological Sciences in Pitt's School of Arts and Sciences. Boyle coauthored the paper with John Boothroyd, a professor of microbiology and immunology in the Stanford School of Medicine. Boyle and Boothroyd worked with Michael Reese, a postdoctoral researcher in Boothroyd's lab, as well as Gusti Zeiner and Jeroen Saeij, former postdoctoral researchers under Boothroyd.

The Pitt-Stanford project suggests that the significance of these aimless enzymes to T. gondii could apply to pseudokinases in other pathogens, Boyle said, including the parasite's close relative Plasmodium, which causes malaria.

"Our work shows that just because these proteins have lost their original function does not mean they don't do anything," Boyle said. "T. gondii cannot cause disease without them, and if one is trying to understand how pathogens work, the role of these proteins should obviously be considered."

The ROP5, or rhoptry protein 5, gene cluster -- so named for the specialized organelle rhoptry, which secretes them -- belongs to a larger family of approximately 40 pseudokinases present in T. gondii. Once T. gondii injects ROP5 into the host cell, the parasite enters the cell and forms a protective membrane pocket, or vacuole, around itself to which ROP5 and other proteins attach. While the other secreted kinases are known to help disable or disrupt activity in the host cell, the ROP5 cluster, a kind of infectious ringleader, appeared to have a more dominant role in causing severe disease in mice than other virulence factors, Boyle said.

The team plans to further investigate the significance of ROP5 to T. gondii's survival within the host, Boyle said. In the PNAS paper, the researchers suggest that ROP5 has undergone multiple rounds of gene duplication followed by mutation of the individual copies. Thus, the authors propose, the ROP5 cluster may act like a genetic Swiss Army Knife, a multipurpose tool that allows T. gondii to adapt to and infect its famously wide variety of hosts.


Story Source:

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


Journal Reference:

  1. M. L. Reese, G. M. Zeiner, J. P. J. Saeij, J. C. Boothroyd, J. P. Boyle. Polymorphic family of injected pseudokinases is paramount in Toxoplasma virulence. Proceedings of the National Academy of Sciences, 2011; DOI: 10.1073/pnas.1015980108

Cite This Page:

University of Pittsburgh. "Aimless proteins may be crucial to disease." ScienceDaily. ScienceDaily, 31 March 2011. <www.sciencedaily.com/releases/2011/03/110331151345.htm>.
University of Pittsburgh. (2011, March 31). Aimless proteins may be crucial to disease. ScienceDaily. Retrieved September 3, 2014 from www.sciencedaily.com/releases/2011/03/110331151345.htm
University of Pittsburgh. "Aimless proteins may be crucial to disease." ScienceDaily. www.sciencedaily.com/releases/2011/03/110331151345.htm (accessed September 3, 2014).

Share This



More Health & Medicine News

Wednesday, September 3, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Snack Attack: Study Says Action Movies Make You Snack More

Snack Attack: Study Says Action Movies Make You Snack More

Newsy (Sep. 2, 2014) You're more likely to gain weight while watching action flicks than you are watching other types of programming, says a new study published in JAMA. Video provided by Newsy
Powered by NewsLook.com
U.N. Says Ebola Travel Restrictions Will Cause Food Shortage

U.N. Says Ebola Travel Restrictions Will Cause Food Shortage

Newsy (Sep. 2, 2014) The U.N. says the problem is two-fold — quarantine zones and travel restrictions are limiting the movement of both people and food. Video provided by Newsy
Powered by NewsLook.com
Doctors Fear They're Losing Battle Against Ebola

Doctors Fear They're Losing Battle Against Ebola

AP (Sep. 2, 2014) As a third American missionary is confirmed to have contracted Ebola in Liberia, doctors on the ground in West Africa fear they're losing the battle against the outbreak. (Sept. 2) Video provided by AP
Powered by NewsLook.com
Tech Giants Bet on 3D Headsets for Gaming, Healthcare

Tech Giants Bet on 3D Headsets for Gaming, Healthcare

AFP (Sep. 2, 2014) When Facebook acquired the virtual reality hardware developer Oculus VR in March for $2 billion, CEO Mark Zuckerberg hailed the firm's technology as "a new communication platform." Duration: 02:24 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