The ALAS1 gene is transcribed to yield mRNA and the mRNA is translated in the cytosol to yield precursor protein. The ALAS1 precursor is imported into the mitochodrial matrix where it catalyzes the synthesis of 5-aminolevulinate from glycine and succinyl-CoA as part of heme biosynthesis.
ERR1 (ERRalpha) probably interacts with coactivator PG-1beta to activate ALAS1 (Shao et al. Shao et al. 2010).