| First Author | Wellman GC | Year | 2001 |
| Journal | Am J Physiol Cell Physiol | Volume | 281 |
| Issue | 3 | Pages | C1029-37 |
| PubMed ID | 11502581 | Mgi Jnum | J:105179 |
| Mgi Id | MGI:3614292 | Doi | 10.1152/ajpcell.2001.281.3.C1029 |
| Citation | Wellman GC, et al. (2001) Role of phospholamban in the modulation of arterial Ca(2+) sparks and Ca(2+)-activated K(+) channels by cAMP. Am J Physiol Cell Physiol 281(3):C1029-37 |
| abstractText | Phospholamban (PLB) inhibits the sarcoplasmic reticulum (SR) Ca(2+)-ATPase, and this inhibition is relieved by cAMP-dependent protein kinase (PKA)-mediated phosphorylation. The role of PLB in regulating Ca(2+) release through ryanodine-sensitive Ca(2+) release channels, measured as Ca(2+) sparks, was examined using smooth muscle cells of cerebral arteries from PLB-deficient ('knockout') mice (PLB-KO). Ca(2+) sparks were monitored optically using the fluorescent Ca(2+) indicator fluo 3 or electrically by measuring transient large-conductance Ca(2+)-activated K(+) (BK) channel currents activated by Ca(2+) sparks. Basal Ca(2+) spark and transient BK current frequency were elevated in cerebral artery myocytes of PLB-KO mice. Forskolin, an activator of adenylyl cyclase, increased the frequency of Ca(2+) sparks and transient BK currents in cerebral arteries from control mice. However, forskolin had little effect on the frequency of Ca(2+) sparks and transient BK currents from PLB-KO cerebral arteries. Forskolin or PLB-KO increased SR Ca(2+) load, as measured by caffeine-induced Ca(2+) transients. This study provides the first evidence that PLB is critical for frequency modulation of Ca(2+) sparks and associated BK currents by PKA in smooth muscle. |
