Enables DNA binding activity. Predicted to be involved in several processes, including cellular response to glucose starvation; endoplasmic reticulum unfolded protein response; and negative regulation of myotube differentiation. Predicted to act upstream of or within several processes, including glucose homeostasis; intracellular distribution of mitochondria; and mitochondrial calcium ion transmembrane transport. Located in nucleus. Orthologous to human BHLHA15 (basic helix-loop-helix family member a15). [provided by Alliance of Genome Resources, Apr 2022]