title: Retinal oxidation activity and biological role of human cytosolic aldehyde dehydrogenase.
abstract: The major cytosolic aldehyde dehydrogenase isozyme (ALDH1) exhibits strong activity for oxidation of retinal to retinoic acid, while the major mitochondrial ALDH2 and the stomach cytosolic ALDH3 have no such activity. The Km of ALDH1 for retinal is about 0.06 mumol/l at pH 7.5, and the catalytic efficiency (Vmax/Km) for retinal is about 600 times higher than that for acetaldehyde. Thus, ALDH1 can efficiently produce retinoic acid from retinal in tissues with low retinal concentrations (< 0.01 mumol/l). The gene for ALDH1 has hormone response elements. These findings suggest that the major physiological substrate of human ALDH1 is retinal, and that its primary biological role is generation of retinoic acid resulting in modulation of cell differentiation including hormone-mediated development.
authors.affiliation: Department of Biochemical Genetics, Beckman Research Institute of the City of Hope, Duarte, Calif.
authors.forename: A
authors.initials: A
authors.lastname: Yoshida
authors.forename: L C
authors.initials: LC
authors.lastname: Hsu
authors.forename: V
authors.initials: V
authors.lastname: Davé
mesh_terms: D000444:Aldehyde Dehydrogenase / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D003600:Cytosol / Q000201:enzymology; D013196:Dihydrotestosterone / Q000494:pharmacology; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism*; D007700:Kinetics; D008099:Liver / Q000201:enzymology*; D008930:Mitochondria, Liver / Q000201:enzymology*; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction; D011994:Recombinant Proteins / Q000378:metabolism; D012172:Retinaldehyde / Q000378:metabolism*; D013270:Stomach / Q000201:enzymology*; D014212:Tretinoin / Q000378:metabolism
chemical_list: D007527:Isoenzymes; D011994:Recombinant Proteins; D013196:Dihydrotestosterone; D014212:Tretinoin; D000444:Aldehyde Dehydrogenase; D012172:Retinaldehyde