Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

UCSD Researchers Determine Mechanism For Degradation of G Proteins

23.07.2003


Researchers at the University of California, San Diego (UCSD) School of Medicine have identified a previously unknown component of the body’s cellular garbage disposal called the ubiquitin system, which is responsible for regulation of cell function by removal of abnormal and unneeded proteins.

Published in the July 8, 2003 issue of Proceedings of the National Academy of Sciences, the study provides the first description of a molecule called GAIP interacting protein N terminus (GIPN) that plays a key role in the degradation of G proteins, which are switches that turn activities on or off in the cell.

Senior author Marilyn Farquhar, Ph.D., a UCSD professor and chair of the Department of Cellular and Molecular Medicine, noted the findings should be of interest to the pharmaceutical industry since G proteins regulate everything from hormone secretion to the beating of the heart.



The researchers found that GIPN appears to specifically target G proteins for degradation and thereby regulates G protein signaling by controlling the amount of G protein expressed in the cell. This occurs via GIPN binding to the N terminus of G alpha interacting proteins (GAIP), which is the mechanism that sets the ubiquitin system in motion.

The ubiquitin system is used extensively by the cell for the turnover and degradation of proteins in both the cytoplasm, the material surrounding the nucleus, and in cell membranes. Ubiquitin, itself, is a small peptide tag that marks a protein for destruction. The interaction of GIPN and GAIP, which was also discovered by the UCSD team, is part of the machinery that places the little ubiquitin tag on a protein.

A source of study by numerous research labs, the ubiquitin system is crucial for nearly every significant activity in the cell. Although this system of protein turnover was first identified in the 1930s, the molecular mechanisms responsible for the process have remained largely unknown.

Ubiquitin-mediated degradation of proteins plays an important role in the control of numerous processes, such as the way in which extracellular materials are incorporated into a cell, the movement of biochemical signals from the cell membrane, and the regulation of cellular functions such as transcriptional on-off switches. The ubiquitin system has been implicated in the immune response and development. Abnormalities in the system are known to cause pathological conditions, including malignant transformation.

"As usual with scientific projects like this one, you have to go much more into the details of the mechanism," Farquhar said. "We have a number of experiments now underway to firm up the precise mechanism."

"Discovery is finding something new—in this case, a new protein; then, it takes a long time to work out the biology," she added.

The co-first authors of the PNAS paper are Thierry Fischer, Ph.D., an assistant project scientist in Farquhar’s laboratory, and Luc De Vries, Ph.D., a former UCSD post-doctoral student who currently works at the Institut de Recherche Pierre Fabre CRPF, Castres Cedex, France. An additional contributor to the study is Timo Meerloo, B.S., a UCSD research specialist.

The study was funded by the National Institutes of Health.

Sue Pondrom | UCSD
Further information:
http://health.ucsd.edu/news/

More articles from Life Sciences:

nachricht Shedding light on the brown color of algae
14.07.2020 | Johannes Gutenberg-Universität Mainz

nachricht New substance library to accelerate the search for active compounds
14.07.2020 | Helmholtz-Zentrum Berlin für Materialien und Energie

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Electron cryo-microscopy: Using inexpensive technology to produce high-resolution images

Biochemists at Martin Luther University Halle-Wittenberg (MLU) have used a standard electron cryo-microscope to achieve surprisingly good images that are on par with those taken by far more sophisticated equipment. They have succeeded in determining the structure of ferritin almost at the atomic level. Their results were published in the journal "PLOS ONE".

Electron cryo-microscopy has become increasingly important in recent years, especially in shedding light on protein structures. The developers of the new...

Im Focus: The spin state story: Observation of the quantum spin liquid state in novel material

New insight into the spin behavior in an exotic state of matter puts us closer to next-generation spintronic devices

Aside from the deep understanding of the natural world that quantum physics theory offers, scientists worldwide are working tirelessly to bring forth a...

Im Focus: Excitation of robust materials

Kiel physics team observed extremely fast electronic changes in real time in a special material class

In physics, they are currently the subject of intensive research; in electronics, they could enable completely new functions. So-called topological materials...

Im Focus: Electrons in the fast lane

Solar cells based on perovskite compounds could soon make electricity generation from sunlight even more efficient and cheaper. The laboratory efficiency of these perovskite solar cells already exceeds that of the well-known silicon solar cells. An international team led by Stefan Weber from the Max Planck Institute for Polymer Research (MPI-P) in Mainz has found microscopic structures in perovskite crystals that can guide the charge transport in the solar cell. Clever alignment of these "electron highways" could make perovskite solar cells even more powerful.

Solar cells convert sunlight into electricity. During this process, the electrons of the material inside the cell absorb the energy of the light....

Im Focus: The lightest electromagnetic shielding material in the world

Empa researchers have succeeded in applying aerogels to microelectronics: Aerogels based on cellulose nanofibers can effectively shield electromagnetic radiation over a wide frequency range – and they are unrivalled in terms of weight.

Electric motors and electronic devices generate electromagnetic fields that sometimes have to be shielded in order not to affect neighboring electronic...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Contact Tracing Apps against COVID-19: German National Academy Leopoldina hosts international virtual panel discussion

07.07.2020 | Event News

International conference QuApps shows status quo of quantum technology

02.07.2020 | Event News

Dresden Nexus Conference 2020: Same Time, Virtual Format, Registration Opened

19.05.2020 | Event News

 
Latest News

Shedding light on the brown color of algae

14.07.2020 | Life Sciences

Color barcode becomes ISO standard

14.07.2020 | Information Technology

New substance library to accelerate the search for active compounds

14.07.2020 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>