| First Author | Liu S | Year | 2011 |
| Journal | Biochem Biophys Res Commun | Volume | 404 |
| Issue | 2 | Pages | 581-6 |
| PubMed ID | 21130738 | Mgi Jnum | J:168703 |
| Mgi Id | MGI:4936783 | Doi | 10.1016/j.bbrc.2010.11.116 |
| Citation | Liu S, et al. (2011) FRET-based direct detection of dynamic protein kinase A activity on the sarcoplasmic reticulum in cardiomyocytes. Biochem Biophys Res Commun 404(2):581-6 |
| abstractText | The second messenger cAMP-dependent protein kinase A (PKA) plays an important role in the various cellular and physiological responses. On the sarcoplasmic reticulum (SR) in cardiomyocytes, PKA regulates the calcium cycling for exciting-contraction coupling, which is often dysfunctional in a variety of heart diseases including heart failure. Here, we have developed a novel FRET-based A-kinase activity biosensor (AKAR), termed SR-AKAR3, to visualize the PKA dynamics on the SR. Activation of adrenergic receptor induces a rapid and significant increase in SR-AKAR3 FRET ratio, which is dependent on agonist occupation of the receptor and inhibited by H-89, a PKA inhibitor. Interestingly, direct activation of adenylyl cyclases or application of a cAMP analog 8-Br-cAMP induced much slower and smaller increases in SR-AKAR3 FRET ratio. These data indicate that the signaling induced by adrenergic stimulation displays a preferential access to the SR in comparison to those by direct activation of adenylyl cyclases. More, SR-AKAR3 mimics endogenous protein phospholamban on the SR for PKA-mediated phosphorylation and myocyte contraction response under adrenergic stimulation. Together, this new PKA activity biosensor provides a useful tool to directly visualize the dynamic regulation of PKA activity on the SR in cardiomyocytes under various physiological and clinical conditions. |
