Enables actin filament binding activity. Involved in cardiac muscle contraction; positive regulation of heart rate by epinephrine; and ventricular cardiac muscle tissue morphogenesis. Acts upstream of or within in utero embryonic development. Located in myofibril. Is expressed in several structures, including central nervous system; gut; heart; limb segment; and musculature. Used to study dilated cardiomyopathy 1Y and hypertrophic cardiomyopathy 3. Human ortholog(s) of this gene implicated in dilated cardiomyopathy 1Y; familial hypertrophic cardiomyopathy; and hypertrophic cardiomyopathy 3. Orthologous to human TPM1 (tropomyosin 1). [provided by Alliance of Genome Resources, Apr 2022]