Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Newly discovered protein suggests novel tumorigenic pathway

22.10.2004


Scientists in Tokyo have discovered a new protein, named PICT-1, that is involved in regulating PTEN, the second most commonly mutated tumor suppressor in human tumors. This discovery suggests the possibility of a new tumorigenic pathway that is due to defects in a protein involved in stabilizing PTEN rather than defects in PTEN itself.


The research appears as the "Paper of the Week" in the October 29 issue of the Journal of Biological Chemistry, an American Society for Biochemistry and Molecular Biology journal.


Mutations in the PTEN tumor suppressor are found in a variety of human cancers including breast and prostate cancers. Approximately 20 percent of the mutations are located in a segment of 70 amino acids at the C-terminus of PTEN. These mutations lead to the rapid degradation of PTEN in cells, indicating that this region is critical for ensuring PTEN stability.

Studies have shown that cells add phosphate molecules to specific serine and threonine residues within the C-terminal segment to stabilize PTEN. Curious about the proteins involved in this stabilization, Dr. Tomohiko Maehama and his colleagues at the Tokyo Metropolitan Institute of Medical Science and the Tokyo Metropolitan University screened a library of human brain cDNA to find proteins that interact with PTEN. They identified a new protein that binds to the C-terminus of PTEN and named it PICT-1 (protein interacting with the carboxyl terminus 1).



Maehama and his colleagues discovered that PTEN molecules with mutations in their C-terminus are unable to bind to PICT-1, and that PICT-1 stabilizes PTEN by regulating the phosphorylation of a serine in the C-terminal segment. "From scientific point of view, it should be noted that PICT-1 is the first protein that interacts with the PTEN protein and regulates its phosphorylation," said Maehama.

The researchers hypothesize that PICT-1 may affect phosphorylation by activating a kinase or inhibiting a phosphatase. The identification of PTEN regulators has been a tremendously difficult problem and this research represents a huge breakthrough.

Maehama explained that this discovery indicates that cells with impaired PICT-1 function may become cancerous because of the resulting instability in PTEN. This would represent a new tumorigenic pathway that is not due to a defective PTEN gene but rather a loss of PTEN function caused by PICT-1. If this is the case, then this new type of tumor may be treated with rapamycin or related drugs that are often used in cancers resulting from PTEN loss of function.

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

More articles from Life Sciences:

nachricht Cryo-electron microscopy achieves unprecedented resolution using new computational methods
24.03.2017 | DOE/Lawrence Berkeley National Laboratory

nachricht How cheetahs stay fit and healthy
24.03.2017 | Forschungsverbund Berlin e.V.

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

Im Focus: Researchers Imitate Molecular Crowding in Cells

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Argon is not the 'dope' for metallic hydrogen

24.03.2017 | Materials Sciences

Astronomers find unexpected, dust-obscured star formation in distant galaxy

24.03.2017 | Physics and Astronomy

Gravitational wave kicks monster black hole out of galactic core

24.03.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>