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:4/11/2017)... Fla. , April 11, 2017 ... and secure authentication solutions, today announced that it ... Intelligence Advanced Research Projects Activity (IARPA) to develop ... Thor program. "Innovation has been a ... IARPA,s Thor program will allow us to innovate ...
(Date:4/11/2017)... MELBOURNE, Florida , April 11, 2017 ... "Company"), a security technology company, announces the appointment of independent ... John Bendheim to its Board of Directors, furthering the ... ... behalf of NXT-ID, we look forward to their guidance and ...
(Date:4/5/2017)... 2017 Today HYPR Corp. , leading ... component of the HYPR platform is officially FIDO® ... security architecture that empowers biometric authentication across Fortune 500 ... secured over 15 million users across the financial services ... home product suites and physical access represent a growing ...
Breaking Biology News(10 mins):
(Date:10/11/2017)... ... October 11, 2017 , ... A new study published ... frozen and fresh in vitro fertilization (IVF) transfer cycles. The multi-center ... success. , After comparing the results from the fresh and frozen transfer cohorts, ...
(Date:10/10/2017)... ... October 10, 2017 , ... Dr. Bob Harman, founder and ... San Diego Rotary Club. The event entitled “Stem Cells and Their ... 300+ attendees. Dr. Harman, DVM, MPVM was joined by two human doctors: Peter ...
(Date:10/9/2017)... SAN DIEGO , Oct. 9, 2017 /PRNewswire/ ... a biological mechanism by which its ProCell stem ... of critical limb ischemia.  The Company, demonstrated that ... the amount of limbs saved as compared to ... of the molecule HGF resulted in reduction of ...
(Date:10/7/2017)... , ... October 06, 2017 ... ... experience providing advanced instruments and applications consulting for microscopy and surface analysis, ... in application consulting, Nanoscience Analytical offers a broad range of contract analysis ...
Breaking Biology Technology:
Cached News: