Featured Research

from universities, journals, and other organizations

UCSD Researchers Determine Mechanism For Degradation Of G Proteins

Date:
July 31, 2003
Source:
University Of California - San Diego
Summary:
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.

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.


Story Source:

The above story is based on materials provided by University Of California - San Diego. Note: Materials may be edited for content and length.


Cite This Page:

University Of California - San Diego. "UCSD Researchers Determine Mechanism For Degradation Of G Proteins." ScienceDaily. ScienceDaily, 31 July 2003. <www.sciencedaily.com/releases/2003/07/030725075520.htm>.
University Of California - San Diego. (2003, July 31). UCSD Researchers Determine Mechanism For Degradation Of G Proteins. ScienceDaily. Retrieved April 17, 2014 from www.sciencedaily.com/releases/2003/07/030725075520.htm
University Of California - San Diego. "UCSD Researchers Determine Mechanism For Degradation Of G Proteins." ScienceDaily. www.sciencedaily.com/releases/2003/07/030725075520.htm (accessed April 17, 2014).

Share This



More Health & Medicine News

Thursday, April 17, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Obama: 8 Million Healthcare Signups

Obama: 8 Million Healthcare Signups

AP (Apr. 17, 2014) President Barack Obama gave a briefing Thursday announcing 8 million people have signed up under the Affordable Care Act. He blasted continued Republican efforts to repeal the law. (April 17) Video provided by AP
Powered by NewsLook.com
Is Apathy A Sign Of A Shrinking Brain?

Is Apathy A Sign Of A Shrinking Brain?

Newsy (Apr. 17, 2014) A recent study links apathetic feelings to a smaller brain. Researchers say the results indicate a need for apathy screening for at-risk seniors. Video provided by Newsy
Powered by NewsLook.com
Could Even Casual Marijuana Use Alter Your Brain?

Could Even Casual Marijuana Use Alter Your Brain?

Newsy (Apr. 16, 2014) A new study conducted by researchers at Northwestern and Harvard suggests even casual marijuana use can alter your brain. Video provided by Newsy
Powered by NewsLook.com
Thousands Of Vials Of SARS Virus Go Missing

Thousands Of Vials Of SARS Virus Go Missing

Newsy (Apr. 16, 2014) A research institute in Paris somehow misplaced more than 2,000 vials of the deadly SARS virus. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins