Predicted to enable RNA polymerase II cis-regulatory region sequence-specific DNA binding activity and nuclear receptor activity. Acts upstream of or within heart development and positive regulation of sarcomere organization. Predicted to be part of RNA polymerase II transcription regulator complex. Predicted to be active in nucleus. Is expressed in several structures, including blastodisc; cardiovascular system; mandibular arch skeleton; nervous system; and pleuroperitoneal region. Human ortholog(s) of this gene implicated in congenital nongoitrous hypothyroidism 6 and renal cell carcinoma. Orthologous to human THRA (thyroid hormone receptor alpha).