Alpha-aminoadipic semialdehyde dehydrogenase (ALDH7A1) is a multifunctional enzyme present in mitochondria, nucleus and the cytosol and plays an important role in protecting against hyperosmotic stress and metabolising toxic aldehydes. It is able to oxidise the osmolyte precursor betaine aldehyde (BETALD) to betaine (BET) (as well as the intermediate lysine degradation product, alpha-aminoadipic semialdehyde, not shown here) (Brocker et al. 2010). The mitochondrial isoform of ALDH7A1 is shown here.
Alpha-aminoadipic semialdehyde dehydrogenase (ALDH7A1) catalyzes the reaction of alpha-aminoadipic semialdehyde and NAD+ to form alpha-aminoadipate and NADH + H+ (Mills et al. 2006). Unpublished crystallographic data (PDB 2J6L) indicate that the enzyme is a homodimer. Recent immunofluorescence studies of both endogenous and GFP-tagged ALDH7A1 proteins in cultured human embryonic kidney cells indicate that the protein is present in both mitochondria and the cytosol (Wong et al. 2010).