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:
TAG: Key regulatory enzyme molecular octopus

(Date:10/16/2014)... tract infections and worldwide claims the lives of ... Ghent University have succeeded in developing a promising ... , Xavier Saelens (VIB/UGent): "We discovered a ... the development of a novel approach to vaccination ... numerous small children and elderly people." , ...
(Date:10/15/2014)... ,Models of Life, is a non-traditional biophysics textbook and ... book is a journey of discovery into biological systems ... and biological regulation. It is about how our genes ... between the billions of cells in an organism. It ... between principles, which can be found on both large ...
(Date:10/15/2014)... will be awarded the 44th Rosenstiel Award for Distinguished ... pioneering research exploring the mechanisms of genomic instability and ... Alt is the second alumnus to win the Rosenstiel ... in 2003. , Alt is the Charles A. Janeway ... Medical School and an investigator at the Howard Hughes ...
Breaking Biology News(10 mins):New perspectives for development of an RSV vaccine 2New book about life as seen from physics 2Brandeis awards 44th Rosenstiel Award to pioneering geneticist Fred Alt 2
(Date:10/22/2014)... (PRWEB) October 22, 2014 Grace Century, ... and healthcare projects, announces the addition of Dr. ... to its advisory team. Dr. Siddiqui will provide further ... , A graduate of University College Medical School ... degreed in medicine in 2001. With further certification as ...
(Date:10/22/2014)... 22, 2014 Nuvilex, Inc. (OTCQB: NVLX) – ... people worldwide are living with diabetes, with  that number ... The global market for diabetes treatments is approximately $500 ... worldwide died from pancreatic cancer.  Pancreatic cancer is the ... in the United States , and ...
(Date:10/20/2014)... 2014 Convey Computer , the ... from Iowa State University won first place in the ... Convey HC-2ex, the team’s solution achieved the highest overall ... the second place finisher. , Experts from all segments ... month long challenge, using a variety of design tools, ...
(Date:10/20/2014)... -- PureTech , a science and technology ... announced today the closing of a $55 million ... Perpetual, a $120 Billion group of funds. The ... pipeline forward and to advance new healthcare related ... to really go for the big ideas that ...
Breaking Biology Technology:Dr. Yousef Siddiqui joins the Grace Century Advisory Team 2Nuvilex Brief Analyst Report: Thinking Outside the Box by BrokerBank Securities, Inc. 2Team from Iowa State Wins 2014 MemoCODE Design Contest Using Convey HC-2ex 2Team from Iowa State Wins 2014 MemoCODE Design Contest Using Convey HC-2ex 3PureTech Announces Expansion with Oversubscribed $55M Funding Round 2PureTech Announces Expansion with Oversubscribed $55M Funding Round 3PureTech Announces Expansion with Oversubscribed $55M Funding Round 4PureTech Announces Expansion with Oversubscribed $55M Funding Round 5PureTech Announces Expansion with Oversubscribed $55M Funding Round 6
Cached News: