Enables ankyrin binding activity. Involved in regulation of relaxation of cardiac muscle. Acts upstream of or within several processes, including chordate embryonic development; forward locomotion; and heart development. Located in M band and Z disc. Is expressed in several structures, including diaphragm; embryo mesenchyme; heart; musculature; and tarsus. Used to study autosomal recessive limb-girdle muscular dystrophy type 2J; dilated cardiomyopathy 1G; and tibial muscular dystrophy. Human ortholog(s) of this gene implicated in intrinsic cardiomyopathy (multiple) and myopathy (multiple). Orthologous to human TTN (titin). [provided by Alliance of Genome Resources, Apr 2022]