Transcriptional regulator (PubMed:33078707). Component of a feedback loop involving atfs-1, atgl-1 and hlh-11 (PubMed:33078707). Binds to the promoter of the atgl-1 lipase to negatively regulate the expression of atgl-1, and thereby promoting fat oxidation in response to mitochondrial stress and mitochondrial respiration in the intestine (PubMed:33078707). In addition, functions with atfs-1 to maintain lifespan (PubMed:33078707). May have a role in fertility and in positively regulating body size (PubMed:19855932). Expressed in the pharynx, nerve cords, the H-shaped excretory cell, vulva muscles, and the anal depressor (at protein level) (PubMed:19855932). Expressed in the intestine (at protein level) (PubMed:19855932, PubMed:33078707). In males, it is also expressed in the spicules and hyp7 cells of the hypodermis (at protein level) (PubMed:19855932).