Enables DNA-binding transcription repressor activity, RNA polymerase II-specific; identical protein binding activity; and sequence-specific DNA binding activity. Involved in several processes, including circulatory system development; regulation of gene expression; and umbilical cord morphogenesis. Acts upstream of or within several processes, including cardiac muscle hypertrophy in response to stress; circulatory system development; and negative regulation of cardiac muscle cell apoptotic process. Located in cytoplasm and nucleus. Is expressed in several structures, including alimentary system; cardiovascular system; genitourinary system; nervous system; and sensory organ. Used to study aortic valve disease and tetralogy of Fallot. Orthologous to human HEY2 (hes related family bHLH transcription factor with YRPW motif 2). [provided by Alliance of Genome Resources, Apr 2022]