NRF1 (also known as nuclear respiratory factor 1, alpha palindromic binding protein and alpha-pal) is the mammalian homolog to the erect wing (ewg) Drosophila protein that is required for proper development of the central nervous system and indirect flight muscles. In mammals NRF1 functions as a transcription factor that activates the expression of the EIF2S1 (EIF2-alpha) gene. This protein links the transcriptional modulation of key metabolic genes to cellular growth and development and has been implicated in the control of nuclear genes required for respiration, heme biosynthesis, and mitochondrial DNA transcription and replication. NRF1 forms a homodimer and binds DNA as a dimer. NRF1 shows a nuclear localization and is widely expressed in embryonic, fetal, and adult tissues. Phosphorylation of NRF1 enhances DNA binding. Multiple splice variants have been identified for this protein.