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:8/21/2014)... skin fungus linked to dandruff, eczema and other itchy, ... even further global reachesincluding Hawaiian coral reefs and the ... , A review in the scientific journal PLOS ... the fungi of the genus Malassezia in ... datasets from around the world. , University of Hawai,i ...
(Date:8/21/2014)... AWI geologist Juliane Mller the Fram Strait is a key ... of this passage between Greenland and Svalbard warm Atlantic water ... the west side cold Arctic water masses and sea ice ... Atlantic. A considerable portion of the Atlantic water cools here ... layers. The circulation of the water caused in this manner ...
(Date:8/21/2014)... A team of researchers at Louisiana Tech ... using affordable, consumer-grade 3D printers and materials ... contain antibacterial and chemotherapeutic compounds for targeted ... doctoral students and research faculty from Louisiana ... collaborated to create filament extruders that can ...
Breaking Biology News(10 mins):From dandruff to deep sea vents, an ecologically hyper-diverse fungus 2Arctic sea ice influenced force of the Gulf Stream 2Arctic sea ice influenced force of the Gulf Stream 3Louisiana Tech University researchers use 3D printers to create custom medical implants 2Louisiana Tech University researchers use 3D printers to create custom medical implants 3
(Date:8/22/2014)... (PRWEB) August 22, 2014 “Our ... acknowledgement is a national disgrace. Furthermore, every governmental ... establishing the current, deplorable state of unorganized dysfunction ... great mistakes," to merely serve as a device ... extent of colossal failure(s) that have accumulated through ...
(Date:8/21/2014)... N.Y. , Aug. 21, 2014  BioSpecifics ... biopharmaceutical company developing first in class collagenase-based products ... or CCH) in the U.S. and XIAPEX ® ... significant results from a randomized, double-blind Phase 2a ... cellulite, or edematous fibrosclerotic panniculopathy. The results showed ...
(Date:8/21/2014)... PA & Rockville, MD (PRWEB) August 21, 2014 ... (ITI) is making progress in its development of ... to Japanese red cedar pollen. Phase IC studies began ... a real solution to hay fever. , The Japanese ... over 35 million people in Japan. Mountain Cedar pollen ...
(Date:8/21/2014)... for Molecular Medicine Finland (FIMM), University of Helsinki, ... "man and machine" decision support system for diagnosing ... in PLOS One scientific journal today, ... vision algorithms similar to those used in facial ... diagnostically most relevant areas. Tablet computers can be ...
Breaking Biology Technology:5 Great Mistakes in Healthcare and How to Fix Them by Dr. Ira Williams 2BioSpecifics Technologies Corp. Announces Positive Data from Phase 2a Study of CCH for Treatment of Cellulite 2BioSpecifics Technologies Corp. Announces Positive Data from Phase 2a Study of CCH for Treatment of Cellulite 3BioSpecifics Technologies Corp. Announces Positive Data from Phase 2a Study of CCH for Treatment of Cellulite 4BioSpecifics Technologies Corp. Announces Positive Data from Phase 2a Study of CCH for Treatment of Cellulite 5Relief for Allergy Sufferers Finally in Sight: Immunomic Therapeutics Closes in on Treatment for Hay Fever in Japan, U.S. 2Relief for Allergy Sufferers Finally in Sight: Immunomic Therapeutics Closes in on Treatment for Hay Fever in Japan, U.S. 3Relief for Allergy Sufferers Finally in Sight: Immunomic Therapeutics Closes in on Treatment for Hay Fever in Japan, U.S. 4A novel 'man and machine' decision support system makes malaria diagnostics more effective 2
Cached News: