Use of 2‐D DIGE analysis reveals altered phosphorylation in a tropomyosin mutant (Glu54Lys) linked to dilated cardiomyopathy

Abstract

Current electrophoretic methods have not been optimized to fully separate post‐translationally modified mutant forms of tropomyosin (Tm) from wild‐type cardiac samples. We describe here a method employing a modified 2‐D PAGE/2‐D DIGE protocol, to fully separate native, mutant (E54K), and phosphorylated forms of Tm. Our data demonstrate the first evidence of a significant (˜40%) decrease in Tm phosphorylation in transgenic compared to non‐transgenic mouse hearts, and indicate that altered phosphorylation may be a significant factor in the linkage of the E54K mutation to dilated cardiomyopathy.