Figure 5.

Abnormalities in ER refill and leak rate are caused by ER mislocalization of R321X mutant. (A) Representative traces of the speed of calcium re‐uptake into depleted ER as measured in real time with D1ER in HEK293 cells expressing either mCh‐Lamin A (black trace) or mCh‐R321X (grey trace). Statistical analysis of the refill rate based on the initial slope of the ratio increase after 2 mM Ca²⁺ readdition. Data are expressed as mean ± S.E.. Statistical analysis was performed on three independent experiments and significance calculated by Student's t‐test for unpaired samples. **P < 0.01 versus mCh‐Lamin A. (B) Representative traces of the speed of calcium leak from the ER after blockade of the SERCA pump as measured in real time with D1ER in HEK293 cells expressing either mCh‐Lamin A (black trace) or mCh‐R321X (grey trace). Statistical analysis of the leak rate based on the initial slope of the ratio decrease after 20 μM CPA addition. Data are expressed as mean ± S.E.. Statistical analysis was performed on three independent experiments and significance calculated by Student's t‐test for unpaired samples. ***P < 0.001 versus Lamin A.