Navigation Links
When proteins change partners

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
Burnham Institute

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:
(Date:4/26/2016)... BANGALORE, India and LONDON ... Infosys Finacle, part of EdgeVerve Systems, a ... ), and Onegini today announced a partnership to ... banking solutions.      (Logo: ... banks to provide their customers enhanced security to ...
(Date:4/15/2016)... -- A new partnership announced today will help life ... a fraction of the time it takes today, ... insurance policies to consumers without requiring inconvenient and ... rapid testing (A1C, Cotinine and HIV) and higi,s ... pulse, BMI, and activity data) available at local ...
(Date:4/13/2016)... April 13, 2016  IMPOWER physicians supporting Medicaid patients ... a new clinical standard in telehealth thanks to a ... the higi platform, IMPOWER patients can routinely track key ... body mass index, and, when they opt in, share ... visit to a local retail location at no cost. ...
Breaking Biology News(10 mins):
(Date:6/24/2016)... , June 24, 2016  Regular discussions on a ... take place between the two entities said Poloz. ... Ottawa , he pointed to the country,s ... the federal government. ... said, "Both institutions have common economic goals, why not sit ...
(Date:6/23/2016)... ... 2016 , ... Mosio, a leader in clinical research patient ... and Retention Tips.” Partnering with experienced clinical research professionals, Mosio revisits the hurdle ... and strategies for clinical researchers. , “The landscape of how patients receive and ...
(Date:6/23/2016)... , June 23, 2016 A person commits ... the crime scene to track the criminal down. ... U.S. Food and Drug Administration (FDA) uses DNA evidence to ... Sound far-fetched? It,s not. The FDA has ... to support investigations of foodborne illnesses. Put as simply as ...
(Date:6/23/2016)... 2016  The Biodesign Challenge (BDC), a university competition ... harness living systems and biotechnology, announced its winning teams ... New York City . The ... projects at MoMA,s Celeste Bartos Theater during the daylong ... senior curator of architecture and design, and Suzanne ...
Breaking Biology Technology: