A&B, JP-2 shRNA (64 hrs) knocked down the protein expression level of JP-2 by 49% (n=4, 4 for both control and JP-2 shRNA groups, p<0.01). C&D, JP-2 shRNA transfected myocytes had worse t-tubule organization and a significant reduction in t-tubule integrity than control (p<0.01). E&F, JP-2 shRNA knockdown shifted the TTpower histogram leftward, in comparison with that of scrambled control shRNA infected myocytes (n=57 and 43 cells, respectively).