Figure 4.

Comparison of the activities of CaN and CaMKII in hearts of transgenic mice that were fed regular chow and chow containing carvedilol. (A) Relative luc levels from cardiac protein extracts from 4-month-old mice containing NFAT-luc, in a WT AKAP5 (AKAP5^+/+) background or in a homozygous AKAP5 (AKAP5^−/−) background. All data were shown relative to background (no luc transgene), which were set a value of 1. (B) Comparison of the activity of CaN in cardiac extracts from control or AKAP5^−/− mice. (C) CaMKII activity assayed in heart homogenate of 4-month-old (AKAP5^+/+) or AKAP5^−/− mice in the absence of CaM/Ca²⁺ (open rectangle) or the presence of CaM/Ca²⁺ (closed rectangle). (D) Ratios of phospho-CaMKII (Thr²⁸⁶)/total δ-CaMKII in cardiac extracts prepared from WT or KO mice. (E) Four-month-old mice containing NFAT-luc, in a WT AKAP5 (AKAP5^+/+) background or in a homozygous AKAP5 (AKAP5^−/−) background, were fed regular diet or diet containing carvedilol for 10 days. Cardiac extracts were prepared and assayed for the activity of luciferase. (F) CaMKII activity was assayed in the presence of CaM/Ca²⁺ in heart homogenates prepared from 4-month-old WT or KO mice that were fed regular chow (open square) or chow containing carvedilol (closed square). In (A–E), the P-value represents WT vs. KO. In (E), the P-value represents treatment with carvedilol vs. without carvedilol for each group.