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:7/28/2014)... About 100 drugs already approved by the U.S. Food ... prevent the growth of certain bacterial pathogens inside human ... Mediterranean spotted fever. The findings, published in mBio ... for Microbiology, demonstrate a new way of identifying non-antibiotic ... , A handful of drugs on the list ...
(Date:7/28/2014)... discovery of two additional coral communities showing signs of damage ... of the 2010 spill in the Gulf of Mexico. The ... professor of biology at Penn State University. A paper describing ... in the Gulf of Mexico will be published during the ... of the journal Proceedings of the National Academy of ...
(Date:7/28/2014)... Norwegian explorer Roald Amundsen reached the South Pole in ... arrived long before any human. , Using data from ... the Antarctic continent, including the South Pole, a group ... (DRI) in Reno, Nevada, created the most accurate and ... southernmost continent. The new record, described in an article ...
Breaking Biology News(10 mins):New route to identify drugs that can fight bacterial infections 2Impact of Deepwater Horizon oil spill on coral is deeper and broader than predicted 2Lead pollution beat explorers to South Pole, persists today 2Lead pollution beat explorers to South Pole, persists today 3
(Date:7/25/2014)...  Galmed Pharmaceuticals Ltd. (Nasdaq: GLMD ) ... and commercialization of a once-daily, oral therapy for the ... financial results for the period ended June 30, 2014. ... Reported cash and cash equivalents totaling $37.4 million on ... 2013.  , Reported a net loss of $3.9 ...
(Date:7/25/2014)... July 25, 2014 At the request ... granted a 60-day extension for the public comment period ... Rule for Model Aircraft established by Congress as part ... The 60-day extension establishes the new deadline for comments ... Department of Transportation/FAA notice published in the Federal Register ...
(Date:7/24/2014)... - July 24, 2014 -- Keryx Biopharmaceuticals, Inc. (Nasdaq:KERX) ... long-term, randomized, active control Phase 3 study of Zerenex ... binder, for the treatment of hyperphosphatemia in patients with ... (PhosphatE binding and iRon delivery with FErric CiTrate in ... of the American Society of Nephrology ( JASN ...
(Date:7/24/2014)... CA (PRWEB) July 24, 2014 ... the Global Supply Chain of the biotech industry. ... SCM Innovation Awards, brought to you by the ... global organization of supply chain management professionals for ... given to stakeholders of the Biotech industry – ...
Breaking Biology Technology:Galmed Pharmaceuticals Reports First Half 2014 Financial Results 2Galmed Pharmaceuticals Reports First Half 2014 Financial Results 3Galmed Pharmaceuticals Reports First Half 2014 Financial Results 4Galmed Pharmaceuticals Reports First Half 2014 Financial Results 5Galmed Pharmaceuticals Reports First Half 2014 Financial Results 6FAA Grants Comment Extension at the Request of AMA 2Zerenex (ferric citrate) long-term Phase 3 study results published in JASN 2Zerenex (ferric citrate) long-term Phase 3 study results published in JASN 3Zerenex (ferric citrate) long-term Phase 3 study results published in JASN 4Call for Submission: BSMA’s Supply Chain Management Innovation Awards 2Call for Submission: BSMA’s Supply Chain Management Innovation Awards 3
Cached News: