Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New binding target for oncogenic viral protein

28.02.2005


The DNA tumor virus simian virus 40 produces the Large T antigen which inactivates two of the cell’s most important cancer-preventing proteins, p53 and pRb. In a study published in the Journal of Biological Chemistry, researchers at the Fred Hutchinson Cancer Research Center report the discovery of an additional target for T antigen--a protein called Fbw7.



The Fbw7 gene is located in a chromosomal region that is deleted in up to 30% of human tumors. "Fbw7 is itself an important tumor suppressor which makes it an attractive choice for inactivation by Large T," explained Dr. Markus Welcker, the study’s first author.

The research appears as the "Paper of the Week" in the March 4 issue of the Journal of Biological Chemistry, an American Society for Biochemistry and Molecular Biology journal.


DNA tumor viruses proliferate by hijacking their host cell’s DNA replication machinery. In order to do this, they have evolved mechanisms to override normal cellular replication controls. Simian virus 40 (SV40) accomplishes this task by producing the highly oncogenic large T antigen. This protein corrupts the cellular checkpoint mechanisms that guard cell division and the transcription, replication and repair of DNA. T antigen also inactivates some of the most important proteins that protect cells against malignant transformation, including tumor suppressor proteins p53 and pRb.

In the Journal of Biological Chemistry paper, Dr. Welcker and Dr. Bruce Clurman report that T antigen also binds to another tumor suppressor, Fbw7. This protein is part of a ubiquitin ligase complex that adds ubiquitin to proteins to mark them for destruction by the cell. Fbw7 recognizes a destruction signal on certain proteins that need to be degraded and brings them in close proximity to the enzymes that attach ubiquitin. The proteins recognized by Fbw7 play key roles in cell division, cell growth, differentiation, and cell death. "These proteins are also some of the most broadly acting cellular oncogenes, and include cyclin E, c-Myc, Notch, and c-Jun," noted Dr. Clurman. "When Fbw7 is mutated in cancers, deregulation of these oncogenic Fbw7 targets is thought to contribute to cancer. SV40 T antigen contains a motif that mimics the destruction signal found in these proteins." However, unlike the other substrates recognized by Fbw7, T antigen is not destroyed by the cell.

Drs. Clurman and Welcker suspect that by acting as a decoy and binding to Fbw7, T antigen protects cellular Fbw7 targets that facilitate viral replication and tumorigenesis. "I think this work underlines the importance of Fbw7 as an emerging tumor suppressor and the consequences of its loss in tumors," Dr. Welcker emphasized.

"The study of DNA tumors viruses has been an extremely important tool in understanding the cellular pathways that regulate cell division and are disrupted in cancer. Understanding the mechanisms through which these viruses interact with the cellular machinery that regulates cell division may lead to new insights into the pathways that cause cancer. This is an important step to designing new cancer treatment strategies that target these pathways," concluded Dr. Clurman.

Nicole Kresge | EurekAlert!
Further information:
http://www.asbmb.org
http://www.jbc.org

More articles from Life Sciences:

nachricht Designer cells: artificial enzyme can activate a gene switch
22.05.2018 | Universität Basel

nachricht Flow of cerebrospinal fluid regulates neural stem cell division
22.05.2018 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: LZH showcases laser material processing of tomorrow at the LASYS 2018

At the LASYS 2018, from June 5th to 7th, the Laser Zentrum Hannover e.V. (LZH) will be showcasing processes for the laser material processing of tomorrow in hall 4 at stand 4E75. With blown bomb shells the LZH will present first results of a research project on civil security.

At this year's LASYS, the LZH will exhibit light-based processes such as cutting, welding, ablation and structuring as well as additive manufacturing for...

Im Focus: Self-illuminating pixels for a new display generation

There are videos on the internet that can make one marvel at technology. For example, a smartphone is casually bent around the arm or a thin-film display is rolled in all directions and with almost every diameter. From the user's point of view, this looks fantastic. From a professional point of view, however, the question arises: Is that already possible?

At Display Week 2018, scientists from the Fraunhofer Institute for Applied Polymer Research IAP will be demonstrating today’s technological possibilities and...

Im Focus: Explanation for puzzling quantum oscillations has been found

So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics

Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...

Im Focus: Dozens of binaries from Milky Way's globular clusters could be detectable by LISA

Next-generation gravitational wave detector in space will complement LIGO on Earth

The historic first detection of gravitational waves from colliding black holes far outside our galaxy opened a new window to understanding the universe. A...

Im Focus: Entangled atoms shine in unison

A team led by Austrian experimental physicist Rainer Blatt has succeeded in characterizing the quantum entanglement of two spatially separated atoms by observing their light emission. This fundamental demonstration could lead to the development of highly sensitive optical gradiometers for the precise measurement of the gravitational field or the earth's magnetic field.

The age of quantum technology has long been heralded. Decades of research into the quantum world have led to the development of methods that make it possible...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Save the date: Forum European Neuroscience – 07-11 July 2018 in Berlin, Germany

02.05.2018 | Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

 
Latest News

Designer cells: artificial enzyme can activate a gene switch

22.05.2018 | Life Sciences

PR of MCC: Carbon removal from atmosphere unavoidable for 1.5 degree target

22.05.2018 | Earth Sciences

Achema 2018: New camera system monitors distillation and helps save energy

22.05.2018 | Trade Fair News

VideoLinks
Science & Research
Overview of more VideoLinks >>>