Plays a role of stimulator of transcription factors and nuclear receptors activities. Activates transcriptional activity of estrogen receptor alpha, nuclear respiratory factor 1 (NRF1) and glucocorticoid receptor in the presence of glucocorticoids. May play a role in constitutive non-adrenergic-mediated mitochondrial biogenesis as suggested by increased basal oxygen consumption and mitochondrial number when overexpressed. May be part of the pathways regulating the elevation of gluconeogenesis, beta-oxidation of fatty acids and ketogenesis during fasting. Stimulates SREBP-mediated lipogenic gene expression in the liver. Induces energy expenditure and antagonizes obesity when overexpressed. Induces also the expression of mitochondrial genes involved in oxidative metabolism. Induces the expression of PERM1 in the skeletal muscle in an ESRRA-dependent manner. Interacts with estrogen receptor alpha/ESR1. Interacts with Sterol regulatory binding transcription factor 1/SREBF1, PPAR-alpha/PPARA, thyroid hormone receptor beta/THRB and host cell factor/HCFC1. Interacts with Estrogen-related receptor gamma/ESRRG and alpha/ESRRA. Interacts with PRDM16 (By similarity). Ubiquitous with higher expression in heart, brown adipose tissue. Induced by combination of forskolin and dexamethasone in primary hepatocytes. Contains 3 Leu-Xaa-Xaa-Leu-Leu (LXXLL) motif, which are usually required for the association with nuclear receptors.