Fig. 1.

Effects of human histidine-rich calcium binding protein wild type (HRC^WT) and HRC^S96A overexpression on intracellular Ca²⁺ transients. A: quantitative immunoblotting showed total HRC protein was increased by ∼50% in both the human Ad.HRC^WT- and Ad.HRC^S96A-infected cells, compared with Ad.GFP. There were no alternations in the expression levels of sarco(endo)plasmic reticulum Ca²⁺-ATPase 2a (SERCA2a), calsequestrin (CSQ), phospholamban (PLN), ryanodine receptor (RyR), and junctin between these groups. B: triadin protein level was increased in HRC^WT and HRC^S96A, compared with GFP. C: confocal line-scan images of Ca²⁺ transients under 0.5-Hz field stimulations. D: corresponding time courses of Ca²⁺ transients. E and F: statistical results of Ca²⁺ transient amplitude and decay time (T50, time from peak amplitude to 50% decrease of Ca²⁺ transients). n = 30 to 36 cells from 6–7 hearts for each group. *P < 0.05, compared with GFP. ^#P < 0.05, compared with HRC^WT.