title: Protein kinase C-epsilon regulates local calcium signaling in airway smooth muscle cells.
abstract: Protein kinase C (PKC) is known to regulate ryanodine receptor (RyR)-mediated local Ca(2+) signaling (Ca(2+) spark) in airway and vascular smooth muscle cells (SMCs), but its specific molecular mechanisms and functions still remain elusive. In this study, we reveal that, in airway SMCs, specific PKCepsilon peptide inhibitor and gene deletion significantly increased the frequency of Ca(2+) sparks, and decreased the amplitude of Ca(2+) sparks in the presence of xestospogin-C to eliminate functional inositol 1,4,5-triphosphate receptors. PKCepsilon activation with phorbol-12-myristate-13-acetate significantly decreased Ca(2+) spark frequency and increased Ca(2+) spark amplitude. The effect of PKCepsilon inhibition or activation on Ca(2+) sparks was completely lost in PKCepsilon(-/-) cells. PKCepsilon inhibition or PKCepsilon activation was unable to affect Ca(2+) sparks in RyR1(-/-) and RyR1(+/-) cells. Modification of RyR2 activity by FK506-binding protein 12.6 homozygous or RyR2 heterozygous gene deletion did not prevent the effect of PKCepsilon inhibition or activation. RyR3 homogenous gene deletion did not block the effect of PKCepsilon inhibition and activation, either. PKCepsilon inhibition promotes agonist-induced airway muscle contraction, whereas PKCepsilon activation produces an opposite effect. Taken together, these results indicate that PKCepsilon regulates Ca(2+) sparks by specifically interacting with RyR1, which plays an important role in the control of contractile responses in airway SMCs.
authors.affiliation: Center for Cardiovascular Sciences, Albany Medical College, Albany, New York 12208, USA.
authors.forename: Qing-Hua
authors.initials: QH
authors.lastname: Liu
authors.forename: Yun-Min
authors.initials: YM
authors.lastname: Zheng
authors.forename: Amit S
authors.initials: AS
authors.lastname: Korde
authors.forename: Xiao-Qiang
authors.initials: XQ
authors.lastname: Li
authors.forename: Jianjie
authors.initials: J
authors.lastname: Ma
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Takeshima
authors.forename: Yong-Xiao
authors.initials: YX
authors.lastname: Wang
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism; D020013:Calcium Signaling; D017353:Gene Deletion; D006720:Homozygote; D008297:Male; D051379:Mice; D008856:Microscopy, Fluorescence; D008954:Models, Biological; D032342:Muscle Cells / Q000378:metabolism; D009119:Muscle Contraction; D032389:Myocytes, Smooth Muscle / Q000378:metabolism*; D051744:Protein Kinase C-epsilon / Q000378:metabolism*; D019837:Ryanodine Receptor Calcium Release Channel / Q000378:metabolism; D015398:Signal Transduction
chemical_list: D019837:Ryanodine Receptor Calcium Release Channel; D051744:Protein Kinase C-epsilon; D002118:Calcium