title: Saccharomyces cerevisiae Forms D-2-Hydroxyglutarate and Couples Its Degradation to D-Lactate Formation via a Cytosolic Transhydrogenase.
abstract: The D or L form of 2-hydroxyglutarate (2HG) accumulates in certain rare neurometabolic disorders, and high D-2-hydroxyglutarate (D-2HG) levels are also found in several types of cancer. Although 2HG has been detected in Saccharomyces cerevisiae, its metabolism in yeast has remained largely unexplored. Here, we show that S. cerevisiae actively forms the D enantiomer of 2HG. Accordingly, the S. cerevisiae genome encodes two homologs of the human D-2HG dehydrogenase: Dld2, which, as its human homolog, is a mitochondrial protein, and the cytosolic protein Dld3. Intriguingly, we found that a dld3Δ knock-out strain accumulates millimolar levels of D-2HG, whereas a dld2Δ knock-out strain displayed only very moderate increases in D-2HG. Recombinant Dld2 and Dld3, both currently annotated as D-lactate dehydrogenases, efficiently oxidized D-2HG to α-ketoglutarate. Depletion of D-lactate levels in the dld3Δ, but not in the dld2Δ mutant, led to the discovery of a new type of enzymatic activity, carried by Dld3, to convert D-2HG to α-ketoglutarate, namely an FAD-dependent transhydrogenase activity using pyruvate as a hydrogen acceptor. We also provide evidence that Ser3 and Ser33, which are primarily known for oxidizing 3-phosphoglycerate in the main serine biosynthesis pathway, in addition reduce α-ketoglutarate to D-2HG using NADH and represent major intracellular sources of D-2HG in yeast. Based on our observations, we propose that D-2HG is mainly formed and degraded in the cytosol of S. cerevisiae cells in a process that couples D-2HG metabolism to the shuttling of reducing equivalents from cytosolic NADH to the mitochondrial respiratory chain via the D-lactate dehydrogenase Dld1.
authors.affiliation: From the Luxembourg Centre for Systems Biomedicine, University of Luxembourg, L-4367 Belvaux and.
authors.forename: Julia
authors.initials: J
authors.lastname: Becker-Kettern
authors.affiliation: From the Luxembourg Centre for Systems Biomedicine, University of Luxembourg, L-4367 Belvaux and.
authors.forename: Nicole
authors.initials: N
authors.lastname: Paczia
authors.affiliation: From the Luxembourg Centre for Systems Biomedicine, University of Luxembourg, L-4367 Belvaux and.
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Conrotte
authors.affiliation: From the Luxembourg Centre for Systems Biomedicine, University of Luxembourg, L-4367 Belvaux and.
authors.forename: Daniel P
authors.initials: DP
authors.lastname: Kay
authors.affiliation: the Luxembourg Institute of Science and Technology, 41 Rue du Brill, L-4422 Belvaux, Luxembourg.
authors.forename: Cédric
authors.initials: C
authors.lastname: Guignard
authors.affiliation: From the Luxembourg Centre for Systems Biomedicine, University of Luxembourg, L-4367 Belvaux and.
authors.forename: Paul P
authors.initials: PP
authors.lastname: Jung
authors.affiliation: From the Luxembourg Centre for Systems Biomedicine, University of Luxembourg, L-4367 Belvaux and carole.linster@uni.lu.
authors.forename: Carole L
authors.initials: CL
authors.lastname: Linster
mesh_terms: D000429:Alcohol Oxidoreductases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D050260:Carbohydrate Metabolism; D015870:Gene Expression; D005977:Glutarates / Q000378:metabolism*; D007655:Ketoglutarate Dehydrogenase Complex / Q000378:metabolism; D007700:Kinetics; D042844:L-Lactate Dehydrogenase (Cytochrome) / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D019344:Lactic Acid / Q000737:chemistry / Q000378:metabolism*; D062907:Oxaloacetic Acid / Q000737:chemistry; D050543:Phosphoglycerate Dehydrogenase / Q000235:genetics / Q000378:metabolism; D019289:Pyruvic Acid / Q000737:chemistry; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000254:growth & development; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D012694:Serine / Q000378:metabolism; D013379:Substrate Specificity
chemical_list: D005977:Glutarates; D029701:Saccharomyces cerevisiae Proteins; C019417:alpha-hydroxyglutarate; D062907:Oxaloacetic Acid; D019344:Lactic Acid; D012694:Serine; D019289:Pyruvic Acid; D000429:Alcohol Oxidoreductases; C000609580:Dld3 protein, S cerevisiae; D050543:Phosphoglycerate Dehydrogenase; C493278:SER3 protein, S cerevisiae; D042844:L-Lactate Dehydrogenase (Cytochrome); C487563:DLD2 protein, S cerevisiae; D007655:Ketoglutarate Dehydrogenase Complex
keywords: 2-hydroxyglutarate; dehydrogenase; enzyme kinetics; flavoprotein; inborn error of metabolism; transhydrogenase; yeast metabolism