Functional effects of a tropomyosin mutation linked to FHC contribute to maladaptation during acidosis

► Contractility is less depressed by acidosis in cells and papillary muscles expressing the FHC-linked Tm-E180G mutation. ► Myofilament Ca2+ sensitivity is increased in skinned fibers from mice expressing mutated Tm both at normal and acidic pH. ► The smaller depression in contractility is not due to altered Tm phosphorylation or differences in intracellular pH.