Figure 1.

Western blotting. Homogenates from human cardiac atria were subjected to gel electrophoresis and Western blotting as described in the Methods section. (a) Detection of whole lanes is given for one exemplary patient to demonstrate quality of antibodies used in this study. A typical marker lane (Mr) is shown on the left side. P and M are the pentameric and monomeric mobility forms of phospholamban. (b) Representative Western blots of plakophilin, plakoglobin and Cypher/ZASP. Calsequestrin (CSQ) was studied as cardiomyocyte-specific loading control. (c) Representative Western blots of three SR proteins (CSQ as cardiomyocyte-specific loading control; sarcoplasmic reticulum Ca²⁺ ATPase, SERCA; phospholamban, PLB). Apparent molecular weights are added in kDa (kilo Dalton). (b,c) Left hand lanes (I, III) are from a younger patient, right hand lanes (II, IV) are from an older patient.