Transcription factor that regulates metabolic homeostasis in response to oxidative stress. Binds to the consensus sequence 5'-TT[G/A]TTTTG-3' and the related Daf-16 family binding element (DBE) with consensus sequence 5'-TT[G/A]TTTAC-3'. Main regulator of redox balance and osteoblast numbers and controls bone mass. Orchestrates the endocrine function of the skeleton in regulating glucose metabolism. Also acts as a key regulator of chondrogenic commitment of skeletal progenitor cells in response to lipid availability: when lipids levels are low, translocates to the nucleus and promotes expression of sox9, which induces chondrogenic commitment and suppresses fatty acid oxidation. Acts synergistically with atf4 to suppress osteocalcin/bglap activity, increasing glucose levels and triggering glucose intolerance and insulin insensitivity. Also suppresses the transcriptional activity of runx2, an upstream activator of osteocalcin/bglap. Shuttles between the cytoplasm and nucleus. Phosphorylated by AKT1; insulin-induced. IGF1 rapidly induces phosphorylation of Thr-28, Ser-240 and Ser-303. Phosphorylation of Ser-240 decreases DNA-binding activity and promotes the phosphorylation of Thr-28, and Ser-303, which leads to nuclear exclusion and loss of function. Phosphorylation of Ser-313 is independent of IGF1 and leads to reduced function (By similarity).