| First Author | Stelzer JE | Year | 2006 |
| Journal | Circ Res | Volume | 99 |
| Issue | 8 | Pages | 884-90 |
| PubMed ID | 16973906 | Mgi Jnum | J:126504 |
| Mgi Id | MGI:3761439 | Doi | 10.1161/01.RES.0000245191.34690.66 |
| Citation | Stelzer JE, et al. (2006) Protein kinase A-mediated acceleration of the stretch activation response in murine skinned myocardium is eliminated by ablation of cMyBP-C. Circ Res 99(8):884-90 |
| abstractText | Beta-adrenergic agonists induce protein kinase A (PKA) phosphorylation of the cardiac myofilament proteins myosin binding protein C (cMyBP-C) and troponin I (cTnI), resulting in enhanced systolic function, but the relative contributions of cMyBP-C and cTnI to augmented contractility are not known. To investigate possible roles of cMyBP-C in this response, we examined the effects of PKA treatment on the rate of force redevelopment and the stretch activation response in skinned ventricular myocardium from both wild-type (WT) and cMyBP-C null (cMyBP-C(-/-)) myocardium. In WT myocardium, PKA treatment accelerated the rate of force redevelopment and the stretch activation response, resulting in a shorter time to the peak of delayed force development when the muscle was stretched to a new isometric length. Ablation of cMyBP-C accelerated the rate of force redevelopment and stretch activation response to a degree similar to that observed in PKA treatment of WT myocardium; however, PKA treatment had no effect on the rate of force development and the stretch activation response in null myocardium. These results indicate that ablation of cMyBP-C and PKA treatment of WT myocardium have similar effects on cross-bridge cycling kinetics and suggest that PKA phosphorylation of cMyBP-C accelerates the rate of force generation and thereby contributes to the accelerated twitch kinetics observed in living myocardium during beta-adrenergic stimulation. |
