FIG. 2.

The CnAβ promoter is induced by agonist stimulation. (A) Transient transfection assays of neonatal cardiomyocyte cultures with the indicated CnAβ promoter-luciferase fusion construct, the control construct pGL3-basic (promoterless), or pGL3-control (SV40 promoter). Twenty-four hours after transfection, myocytes were stimulated in serum-free medium and with 100 μM PE or 100 nM Endo-1 for an additional 24 h (*, P < 0.05 versus unstimulated). (B and C) Transient transfection assays in cultured neonatal cardiac myocytes with the pGL3-CnAβ2322 or pGL3-CnAβ819 promoter-luciferase fusion constructs. Cells were stimulated with 100 μM PE in the presence of the indicated adenovirus (which was infected 24 h previously). Cells were harvested 24 h later, and luciferase activities were measured as relative light units per microgram of protein (*, P < 0.05 versus Adβgal PE stimulated). DN, dominant negative. (D) Transient transfection assays in cultured neonatal cardiac myocytes with the pGL3-CnAβ2322 or pGL3-CnAβ819 promoter-luciferase fusion constructs in the absence or presence of PE and the indicated concentration of BAPTA-AM (*, P < 0.05 versus PE stimulated without BAPTA-AM). All data are represented as mean values obtained from a representative experiment performed in triplicate, although similar results were obtained in two additional independent experiments.