Navigation Links
UCSD study reveals the regulatory mechanism of key enzyme

Research conducted at the University of California, San Diego (UCSD) School of Medicine has shed new light on the structure and function of one of the key proteins in all mammalian cells, protein kinase A (PKA), an enzyme which plays an essential role in memory formation, communication between nerve cells, and cardiac function.

Utilizing a process called x-ray crystallography, the scientists solved the structure of the large PKA complex, revealing a totally new structure that shows PKAs amazing ability to function as a scaffold, that supports and controls the release of chemicals involved in transmitting signals. The structure is shown in the September 21 issue of the journal Cell, featuring the study that describes the dynamic regulatory subunit of PKA.

PKA belongs to a large superfamily of proteins whose activity is regulated by an important small molecule, cyclic AMP (cAMP), in the cell. Protein kinases transmit chemical signals within the cell to regulate a host of functions, such as cell growth or metabolism. Certain protein kinases have been implicated in the uncontrolled growth of cells; for example, when PKA somehow stays on, its prolonged activation can lead to cardiac disease and breast cancer.

By revealing its highly accurate three-dimensional structure, the UCSD scientists have shown how PKA is inhibited and activated by cAMP. PKA contains two components, the regulatory and catalytic subunits. When the subunits are together in the absence of cAMP, the signaling is turned off; when the two parts break apart after being activated by cAMP, PKA is turned on.

We knew how the two subunits, the catalytic and regulatory subunits, looked as separate entities. But we didnt understand how they actually fit together and are activated by cAMP until we saw this structure, said Susan Taylor, Ph.D., Howard Hughes Medical Institute Investor and professor of pharmacology at UCSD School of Medicine, who headed the study.

Discovery of this enzymes molecular structure may help researchers to design drugs that specifically block the protein kinase activity involved in cancer or cardiac disease.

Scientists didnt really understand how the structure unfolded before now, said Taylor, adding that preventing the subunits from coming apart may be an effective way to inhibit diseases caused when PKA is activated and cant turn itself off. Taylor said the researchers were surprised at how much the structure changed when PKA is turned off. The regulatory subunit opens up and literally wraps itself around the catalytic subunit, thus completely turning the signal off, she said.

Taylor is one of the worlds leading experts on the cAMP-dependent protein kinase, an enzyme that serves as a prototype for the entire protein kinase family. This family of enzymes has more than 500 members that are critical for regulation in all multi-cellular organisms, such as humans.

Taylors work in 1991 (reported in the July 26, 1991 issue of the journal Science) revealed the first-ever molecular structure of the catalytic subunit of a protein kinase, one involved in the action of adrenalin within cells. Understanding its structure was a sort of Rosetta stone for learning the structure of all protein kinases, because they all share certain fundamental characteristics.


Contact: Debra Kain
University of California - San Diego

Related medicine news :

1. Rural Canadians travel far for specialists: study
2. A new study surpasses Gene Therapy Hurdle
3. Tomato Sauce reduces Cancer Risk- Study
4. A question on study of Adult Stem Cell
5. Study on obesity and heart failure
6. National Lung Study in the process
7. Marijuana gateway theory strengthened by study of twins
8. Old theory of adaptation confirmed by new study
9. Study casts doubt on keyboard ills
10. Gene study links endometriosis, infertility
11. Study reveals how stress can make you sick
Post Your Comments:
(Date:11/27/2015)... ... November 27, 2015 , ... CBD College is proud ... Education Programs (CAAHEP) awarded accreditation to its Diagnostic Medical Sonography program. CBD College is ... only one of twelve colleges and universities in the state of California make the ...
(Date:11/27/2015)... (PRWEB) , ... November 27, 2015 , ... Dr. ... Medical Associates, Inc. and Dr. Tucker Bierbaum with Emergency Medicine at St., ... observed that both STEMI and Sepsis conditions present in similar ways and require time-critical ...
(Date:11/27/2015)... ... November 27, 2015 , ... Indosoft Inc., ... the incorporation of Asterisk 11 LTS (Long Term Support) into its Q-Suite 5.10 ... brings Q-Suite 5.10 up-to-date with a version of Asterisk that will receive not ...
(Date:11/26/2015)... ... 2015 , ... Inevitably when people think Thanksgiving, they also think Holiday sales ... Black Friday and Cyber Monday massage chair sales to receive the best ... low to find the best massage chair deals, they can see all of the ...
(Date:11/26/2015)... ... November 26, 2015 , ... Somu Sivaramakrishnan announced today that ... Somu now offers travelers, value and care based Travel Services, including exclusive pricing ... well as, cabin upgrades and special amenities such as, shore excursions, discounted fares, ...
Breaking Medicine News(10 mins):
(Date:11/26/2015)... 26, 2015 ... of the  "2016 Future Horizons and ... Surface Marker Testing Market: Supplier Shares, ... their offering.  --> ... the  "2016 Future Horizons and Growth ...
(Date:11/25/2015)... WASHINGTON , Nov. 25, 2015  The ... Obstetricians and Gynecologists (ACOG), and the March of ... bipartisan Protecting Our Infants Act of 2015 ... the number of newborns born exposed to drugs, ... Since the bill,s introduction, all three organizations have ...
(Date:11/25/2015)... 25, 2015  ARKRAY USA , ... provide evidence demonstrating the accuracy of its blood glucose ... Insulin Resistance, Diabetes and Cardiovascular Disease in ... Company,s GLUCOCARD ® 01 meter and the Assure ... The ability to accurately measure glucose levels in blood ...
Breaking Medicine Technology: