Succinate Dehydrogenase Complex Assembly Factor 3 (SDHAF3)

ACN9 encodes a protein of the mitochondrial intermembrane space that is required for growth on acetate and other nonfermentable carbon sources. Mutations in ACN9 lead to elevated levels of enzymes of the glyoxylate cycle, gluconeogenesis, and acetyl-CoA metabolism. Although the exact function of Acn9p is unknown, the protein is thought to be involved in gluconeogenesis as acn9 mutants share several phenotypes observed in mutants defective for gluconeogenic enzymes.

ACN9 is expressed approximately 100-fold less than tricarboxylic acid and glyoxylate cycle genes and expression is only slightly repressed in the presence of glucose. Acn9p homologs have been identified in humans, nematodes, and mice.