Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Johns Hopkins researchers detect sweet cacophony while listening to cellular cross-talk

22.10.2008
Johns Hopkins scientists were dubious in the early 1980s when they stumbled on small sugar molecules lurking in the centers of cells; not only were they not supposed to be there, but they certainly weren't supposed to be repeatedly attaching to and detaching from proteins, effectively switching them on and off.

The conventional wisdom was that the job of turning proteins on and off -- and thus determining their actions -- fell to phosphates, in a common and easy-to-detect chemical step in which phosphates fasten to and unfasten from proteins; a process called phosphorylation.

Now, after decades of investigating the "new" sugar-based protein modification they discovered, the Johns Hopkins team admits that they themselves were surprised by their latest results. Published recently in the Proceedings of the National Academy of Sciences, their findings show that the surreptitious sugar switch is likely as influential and ubiquitous as its phosphate counterpart and, indeed, even plays a role in regulating phosphorylation itself.

More to the point, the work has implications for finding new treatments for a number of diseases such as diabetes, neurodegeneration and cancer, because the new switches form yet another potential target for manipulation by drugs.

"Like dark matter in the cosmos, it's hard to find even though it's very abundant," says Gerald Hart, Ph.D., the DeLamar Professor and director of biological chemistry at the Johns Hopkins School of Medicine, referring to the sugar (O-GlcNAc, pronounced oh-GLICK-nac) that carries out GlcNAcylation.

For years, Hart's team thought of GlcNAcylation as phosphorylation's foil; a simple, classic case of either-or. New technologies involving molecular sleuthing with a mass spectrometer allowed them to measure the extent to which the addition of sugar to proteins affects phosphorylation.

Of 428 sites on which phosphate was being added to and taken off of proteins, all responded in some way to increased O-GlcNAc: 280 decreased phosphorylation and 148 increased phosphorylation.

"The influence of sugar is striking," Hart says. "The presence of O-GlcNAc causes the enzymes that add the phosphate to do something different, and this cross-talk itself can modify proteins."

Because both sugar and phosphate modifications are linked to how cells work, they are fundamental to understanding and eventual control of the molecular processes that underlie many diseases.

"With regard to cancer, diabetes and Alzheimer's," says Hart, "most people in the world today have been studying the yang (phosphorylation) but not the yin (GlcNAcylation). There's another whole side that people were unaware of where diabetes diagnostics and cancer therapies could be targeted."

The research was funded by the National Institutes of Health.

Authors on the paper are Zihao Wang, Marjan Gucek and Gerald W. Hart, all of Johns Hopkins.

Maryalice Yakutchik | EurekAlert!
Further information:
http://www.jhmi.edu
http://www.pnas.org/
http://biolchem.bs.jhmi.edu/members/facultydetail.asp?PersonID=679

More articles from Life Sciences:

nachricht Fingerprint' technique spots frog populations at risk from pollution
27.03.2017 | Lancaster University

nachricht Parallel computation provides deeper insight into brain function
27.03.2017 | Okinawa Institute of Science and Technology (OIST) Graduate University

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

Northern oceans pumped CO2 into the atmosphere

27.03.2017 | Earth Sciences

Fingerprint' technique spots frog populations at risk from pollution

27.03.2017 | Life Sciences

Big data approach to predict protein structure

27.03.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>