Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Virus mimics human protein to hijack cell division machinery

09.05.2008
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.

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."

Robert Kalejta | EurekAlert!
Further information:
http://www.wisc.edu

More articles from Studies and Analyses:

nachricht Win-win strategies for climate and food security
02.10.2017 | International Institute for Applied Systems Analysis (IIASA)

nachricht The personality factor: How to foster the sharing of research data
06.09.2017 | ZBW – Leibniz-Informationszentrum Wirtschaft

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

Osaka university researchers make the slipperiest surfaces adhesive

18.10.2017 | Materials Sciences

Space radiation won't stop NASA's human exploration

18.10.2017 | Physics and Astronomy

Los Alamos researchers and supercomputers help interpret the latest LIGO findings

18.10.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>