HOME >> BIOLOGY >> NEWS
Key regulatory enzyme is a molecular 'octopus'

of constant stimulation," said Lefkowitz. "Years ago, we had discovered that this down-regulation occurs due to a phosphorylation of the activated receptor that triggers binding of a protein called beta arrestin. This protein stops further G protein signaling and acts as an adaptor and scaffolding that connects to other signaling molecules."

Thus, the cellular "stop signal" not only turns off the G protein, but immediately tags the receptor for recycling into the cell interior and turns on other signaling pathways, said Lefkowitz. His laboratory identified that enzyme as GRK, but a central mystery was how the family of GRK enzymes fulfills their intricate regulatory duties.

In the latest work the researchers deduced the structure of GRK2, the member of the GRK enzyme family that is active in heart muscle and many other tissues.

Critical to solving that mystery was obtaining the three-dimensional structure of GRK2 using X-ray crystallography. In this technique, pure crystals of a protein are bombarded by an intense X-ray beam, and the protein structure is deduced by analyzing the pattern of the beam's diffraction. This structural determination was done by co-author John Tesmer and his colleagues.

The resulting structure revealed the details of three regions, or domains, of the GRK2 enzyme, which had earlier been identified by biochemical studies in the Lefkowitz laboratory:

  • The central, or catalytic domain is the region that triggers the phosphorylation reaction
  • The "regulator of G protein signaling homology" (RH) domain attaches to the G protein to switch it off, and
  • The "PH" domain enables GRK2 to home in on the G protein at the cell membrane and attach to it.

To reveal how GRK2 interacts with the G protein, the researchers obtained the structure of GRK2 attached to a subunit of the G protein to which it normally binds, or complexes. Lefkowitz noted that a particularly striking achievem
'"/>

Contact: Dennis Meredith
dennis.meredith@duke.edu
919-681-8054
Duke University
19-Jun-2003


Page: 1 2 3

Related biology news :

1. Significant strides in small regulatory RNA research in plants
2. Pew report finds GM insects may offer benefits, but clear regulatory oversight is lacking
3. Researchers discover genes that control regulatory functions in malaria mosquitoes
4. Anthrax enzyme images reveal secrets of antibiotic resistance, suggest new drug design
5. First glimpse of DNA binding to viral enzyme
6. Two enzymes key to calorie-burning, Brown research shows
7. Argonne scientists determine structure of staph, anthrax enzyme
8. Brain serotonin enzyme finding might explain psychiatric disorders
9. Study finds plant enzyme function changes with location in cell
10. Basic RNA enzyme research promises single-molecule biosensors
11. Molecule that blocks key bacterial enzyme may lead to new antibiotics

Post Your Comments:
*Name:
*Comment:
*Email:


(Date:1/25/2016)... , Jan. 25, 2016  Glencoe Software, the ... pharma and publication industries, will provide the data management ... Centre (NPSC). ... Phenotypic analysis measures ... whole organisms, allowing comparisons between states such as health ...
(Date:1/20/2016)... Jan. 20, 2016 A market that just ... benefit from the explosion in genomics knowledge. Learn all ... Research. A range of dynamic trends are pushing market ... personalized medicine - pharmacogenomics - pathogen evolution - next ... markets - greater understanding of the role of genetic ...
(Date:1/15/2016)... Jan. 15, 2016 Recent publicized breaches in ... find new ways to ensure data security and user ... and Android that ties a user,s ... it into a hardware authorization token. Customer service agents ... fingerprint on their KodeKey enabled device to verify their ...
Breaking Biology News(10 mins):
(Date:2/4/2016)... , February 4, 2016 - New FDA action ... - New FDA action date of July 22, ... July 22, 2016   - ... in the past decade indicated for the treatment of signs and symptoms of ... has the potential to be the only product approved in the U.S. in ...
(Date:2/4/2016)... ... , ... Shimadzu Scientific Instruments will showcase several new products, ... sessions, and present on the analysis of mycotoxins and medical cannabis at the ... at the Georgia World Congress Center in Atlanta, Georgia. , Attendees should ...
(Date:2/4/2016)... Feb. 4, 2016 Beike Biotechnology, the ... institutions attended a ceremony in late 2015 to mark ... therapy in 2016. --> ... Platform for Personalized Cell Therapy" was hosted by the ... Center, both subsidiaries of Beike Biotechnology Co., Ltd. ...
(Date:2/4/2016)... MENLO PARK, Calif. , Feb. 4, 2016 ... the "Company"), a biopharmaceutical company focused on the development and ... present at the 18 th Annual BIO CEO ... 10:00 a.m. EST in New York, NY ... CEO, will provide an update on the ongoing clinical trial ...
Breaking Biology Technology:
Cached News: