| First Author | Ji Y | Year | 2003 |
| Journal | J Biol Chem | Volume | 278 |
| Issue | 27 | Pages | 25063-71 |
| PubMed ID | 12692124 | Mgi Jnum | J:84333 |
| Mgi Id | MGI:2667420 | Doi | 10.1074/jbc.M302193200 |
| Citation | Ji Y, et al. (2003) Targeted inhibition of Ca2+/calmodulin-dependent protein kinase II in cardiac longitudinal sarcoplasmic reticulum results in decreased phospholamban phosphorylation at threonine 17. J Biol Chem 278(27):25063-71 |
| abstractText | To investigate the role of Ca2+/calmodulin-dependent kinase II in cardiac sarcoplasmic reticulum function, transgenic mice were designed and generated to target the expression of a Ca2+/calmodulin-dependent kinase II inhibitory peptide in cardiac longitudinal sarcoplasmic reticulum using a truncated phospholamban transmembrane domain. The expressed inhibitory peptide was highly concentrated in cardiac sarcoplasmic reticulum. This resulted in a 59.7 and 73.6% decrease in phospholamban phosphorylation at threonine 17 under basal and beta-adrenergic stimulated conditions without changing phospholamban phosphorylation at serine 16. Sarcoplasmic reticulum Ca2+ uptake assays showed that the Vmax was decreased by approximately 30% although the apparent affinity for Ca2+ was unchanged in heterozygous hearts. The in vivo measurement of cardiac function showed no significant reductions in positive and negative dP/dt, but a moderate 18% decrease in dP/dt40, indicative of isovolumic contractility, and a 26.1% increase in the time constant of relaxation (tau) under basal conditions. The changes in these parameters indicate a moderate cardiac dysfunction in transgenic mice. Although the 3 and 4-month-old transgenic mice displayed no overt signs of cardiac disease, when stressed by gestation and parturition, the 7-month-old female mice develop dilated heart failure, suggesting the important role of Ca2+/calmodulin-dependent kinase II pathway in the development of cardiac disease. |
