Featured Research

from universities, journals, and other organizations

Virus Mimics Human Protein To Hijack Cell Division Machinery

Date:
May 10, 2008
Source:
University of Wisconsin-Madison
Summary:
Viruses are masters of deception, duping their host's cells into helping them grow and spread. A new study has found that human cytomegalovirus can mimic a common regulatory protein to hijack normal cell growth machinery, disrupting a cell's primary anti-cancer mechanism.

Viruses are masters of deception, duping their host's cells into helping them grow and spread. A new study has found that human cytomegalovirus (HCMV) can mimic a common regulatory protein to hijack normal cell growth machinery, disrupting a cell's primary anti-cancer mechanism.

Related Articles


Writing in the May 9 issue of Science, researchers from the University of Wisconsin-Madison and Harvard Medical School report that a viral protein, called UL97, masquerades as a normal regulatory enzyme to modify a tumor-suppressing protein in human cells. Unlike the normal enzyme, which can be switched on and off by the cell as needed, the viral stand-in lacks an off switch and evades cellular control. The findings represent a previously unknown way that viruses can cause uncontrolled cell growth and division.

Cells normally have tight regulatory mechanisms in place to limit multiplication to appropriate situations, such as replacing worn-out cells or repairing damage. Uncontrolled cell proliferation can lead to cancer and other disorders.

One of the most important cellular control mechanisms works through a protein called the retinoblastoma tumor suppressor protein, which slows cell growth.

"The retinoblastoma pathway is like the brakes on a car. It prevents tumor cells from growing out of control," says Robert Kalejta, an assistant professor in the UW-Madison Institute for Molecular Virology and McArdle Laboratory for Cancer Research, who led the new study. "This pathway is mutated in essentially all human cancers."

Disrupting this pathway is also advantageous for viruses. Unable to reproduce on their own, viruses rely on co-opting their host's cellular machinery, like an occupying army taking over a local factory. They are especially good at overriding or bypassing built-in control mechanisms, Kalejta says.

"Viruses are well known to encode proteins that have similar activities to cellular proteins, but they're just different enough that they're beneficial to the virus," he says. "[UL97] shares the same activities as the cellular protein, but it lacks all of the control mechanisms."

In essence, UL97 disables the brakes and hits the gas. Once a host cell is primed toward growth, HCMV takes over and steals the cell's machinery to reproduce itself.

The virus's bloodhound-like ability to seek out and target the most essential pieces of a cell's machinery makes it a valuable research tool, Kalejta says.

"Viruses are smarter than we are. They know a lot more about cells than we do, because their life depends on it - they're obligate intracellular parasites," he says. "If they attack a part of the cell - a process or a protein - you know it's important for the cell. If the virus pays attention to it, you should too."

Kalejta next hopes to use UL97 to find other proteins that may be important for cell growth. He also sees potential clinical applications down the road. HCMV infection is very common and, though it remains asymptomatic in most people, it has been implicated in some cancers and can cause trouble in people with compromised or suppressed immune systems, such as AIDS patients and transplant recipients. In addition, UL97-like proteins are also found in the other seven human herpes viruses, some of which are directly linked to cancers.

The advantages of the research are two-fold, Kalejta says. "We're studying a virus that causes human disease and might eventually find a way to treat that infection and help patients. At the same time, we're learning about how the cell works, which has implications for patients that don't have infections," he says. "You get two for the price of one."

Other authors on the paper include Adam Hume, Jonathan Finkel, and Michael Culbertson from UW-Madison and Jeremy Kamil and Donald Coen from Harvard Medical School. The work was funded by grants from the National Institutes of Health, the Wisconsin Partnership for a Healthy Future, the Burroughs Wellcome Fund, and the American Heart Association.


Story Source:

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


Cite This Page:

University of Wisconsin-Madison. "Virus Mimics Human Protein To Hijack Cell Division Machinery." ScienceDaily. ScienceDaily, 10 May 2008. <www.sciencedaily.com/releases/2008/05/080508143310.htm>.
University of Wisconsin-Madison. (2008, May 10). Virus Mimics Human Protein To Hijack Cell Division Machinery. ScienceDaily. Retrieved March 27, 2015 from www.sciencedaily.com/releases/2008/05/080508143310.htm
University of Wisconsin-Madison. "Virus Mimics Human Protein To Hijack Cell Division Machinery." ScienceDaily. www.sciencedaily.com/releases/2008/05/080508143310.htm (accessed March 27, 2015).

Share This


More From ScienceDaily



More Plants & Animals News

Friday, March 27, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Jockey Motion Tracking Reveals Racing Prowess

Jockey Motion Tracking Reveals Racing Prowess

Reuters - Innovations Video Online (Mar. 26, 2015) — Using motion tracking technology, researchers from the Royal Veterinary College (RVC) are trying to establish an optimum horse riding style to train junior jockeys, as well as enhance safety, health and well-being of both racehorses and jockeys. Matthew Stock reports. Video provided by Reuters
Powered by NewsLook.com
Bear Cubs Tumble for the Media

Bear Cubs Tumble for the Media

Reuters - Light News Video Online (Mar. 26, 2015) — Two Andean bear cubs are unveiled at the U.S. National Zoo in Washington, D.C. Alicia Powell reports. Video provided by Reuters
Powered by NewsLook.com
Botswana Talks to End Illegal Wildlife Trade

Botswana Talks to End Illegal Wildlife Trade

AFP (Mar. 25, 2015) — Experts are gathering in Botswana to try to end the illegal wildlife trade that is decimating populations of elephants, rhinos and other threatened species. Duration: 01:05 Video provided by AFP
Powered by NewsLook.com
Elephants Help Keep 18-Wheeler From Toppling Over

Elephants Help Keep 18-Wheeler From Toppling Over

Newsy (Mar. 25, 2015) — The Natchitoches Parish Sheriff&apos;s Office discovered two elephants keeping a tractor-trailer that had gotten stuck in some mud upright on a highway. 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