Navigation Links
When proteins change partners
Date:9/11/2009

LA JOLLA, Calif., September 11, 2009 Dieter Wolf, M.D., and colleagues at Burnham Institute for Medical Research (Burnham) have illuminated how competition between proteins enhances combinatorial diversity during ubiquitination (the process that marks proteins for destruction). Using S. pombe fission yeast as a model, the Wolf laboratory uncovered an intricate relationship, in which an array of Fbox proteins alternately attach to and are kicked off of a cullin-RING ubiquitin ligase (CRL1) containing CUL1 and Skp1. Without the Fbox, CRL1 cannot attach to the protein substrate or recruit ubiquitin, potentially preserving aberrant proteins. The research was published in the journal Molecular Cell on September 11.

S. pombe expresses 16 different Fbox proteins, some of which are regulated by the COP9 signalosome (CSN). The study shows that these proteins attach to CRL1 but are kicked off by the competing protein CAND1. Fbox proteins and CAND1 continue to trade places until they come in contact with the appropriate substrate of the protein being degraded. This phosphorylated substrate recruits the protein N8, which attaches to the complex and stabilizes the Fbox protein. Then the complex can attach to the substrate and recruit ubiquitin. Once this process is completed, N8 is removed, Fbox is destabilized and the process begins again.

"The tension between CAND1 and Fbox gives more Fbox proteins the opportunity to attach to CRL1," says Dr. Wolf. "Without CAND1, more prevalent Fbox proteins would dominate the process. We also found that, to bind to CRL1, the Fbox proteins must contain a specific proline residue. Only when the substrate is present can the Fbox protein be stabilized in the complex."

The laboratory tested eight of the 16 Fbox proteins. They found that five of the eight were regulated by the CSN and that CSN-insensitive proteins were missing a proline residue. They also found that the proline residue was required for CRL1 complex formation. The laboratory also determined that CAND1 deficiency and CSN deficiency produced different phenotypes, outlining the different roles they play in stabilizing CRL1.


'/>"/>

Contact: Josh Baxt
jbaxt@burnham.org
858-795-5236
Burnham Institute
Source:Eurekalert

Related biology news :

1. Researchers identify proteins involved in new neurodegenerative syndrome
2. NIH awards researcher $1.5 million new innovator grant for fruit-fly studies of prion proteins
3. Depression, aging, and proteins made by a virus may all play role in heart disease
4. New approach builds better proteins inside a computer
5. Legionnaires bacterial proteins work together to survive
6. Proteins pack tighter in crowded native state
7. MIT IDs proteins key to brain function
8. Cystic fibrosis proteins photographed interacting
9. Using carbon nanotubes to seek and destroy anthrax toxin and other harmful proteins
10. The precise role of seminal proteins in sustaining post-mating responses in fruit flies
11. Carnegie Mellon scientists develop fluorescent proteins for live cell imaging, biosensor design
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:4/28/2016)... First quarter 2016:   , Revenues amounted ... quarter of 2015 The gross margin was 49% (27) ... the operating margin was 40% (-13) Earnings per share ... operations was SEK 249.9 M (21.2) , Outlook   ... M. The operating margin for 2016 is estimated to ...
(Date:4/15/2016)... -- Research and Markets has announced the ...  report to their offering.  ,      ... gait biometrics market is expected to grow at ... Gait analysis generates multiple variables such ... compute factors that are not or cannot be ...
(Date:3/29/2016)... RATON, Florida , March 29, 2016 ... or the "Company") LegacyXChange "LEGX" and SelectaDNA/CSI Protect are ... DNA in ink used in a variety of writing ... theft. Buyers of originally created collectibles from athletes on ... through forensic analysis of the DNA. ...
Breaking Biology News(10 mins):
(Date:6/23/2016)... , June 23, 2016   Boston Biomedical ... novel compounds designed to target cancer stemness pathways, ... been granted Orphan Drug Designation from the U.S. ... of gastric cancer, including gastroesophageal junction (GEJ) cancer. ... designed to inhibit cancer stemness pathways by targeting ...
(Date:6/23/2016)... , June 23, 2016  The Prostate Cancer Foundation (PCF) is ... treatments and faster cures for prostate cancer. Members of the Class of 2016 ... countries. Read More About the Class of 2016 PCF ... ... ...
(Date:6/23/2016)... ... 2016 , ... In a new case report published today in STEM CELLS ... developed lymphedema after being treated for breast cancer benefitted from an injection of stem ... with this debilitating, frequent side effect of cancer treatment. , Lymphedema refers ...
(Date:6/23/2016)... ... June 23, 2016 , ... ... at the Pennsylvania Convention Center and will showcase its product’s latest features from ... also be presenting a scientific poster on Disrupting Clinical Trials in The Cloud ...
Breaking Biology Technology: