DHTKD1 and OGDH display in vivo substrate overlap and form a hybrid ketoacid dehydrogenase complex

Leandro, João; Dodatko, Tetyana; Aten, Jan; Hendrickson, Ronald C.; Sánchez, Roberto; Yu, Chunli; DeVita, Robert J.

doi:10.1101/645689

Cited by 6 publications

(7 citation statements)

References 38 publications

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“…Remarkably, hyperlysinemia and α-aminoadipic and α-ketoadipic aciduria (Dancis et al, 1983;Houten et al, 2013;Stiles et al, 2016), two other defects in lysine metabolism, are considered biochemical phenotypes of questionable clinical significance (Goodman and Duran, 2014).…”

Section: Introductionmentioning

confidence: 99%

DHTKD1 and OGDH display substrate overlap in cultured cells and form a hybrid 2-oxo acid dehydrogenase complex in vivo

Leandro

Dodatko

Aten

et al. 2020

Human Molecular Genetics

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Glutaric aciduria type 1 (GA1) is an inborn error of lysine degradation characterized by a specific encephalopathy that is caused by toxic accumulation of lysine degradation intermediates. Substrate reduction through inhibition of DHTKD1, an enzyme upstream of the defective glutaryl-CoA dehydrogenase, has been investigated as a potential therapy, but revealed the existence of an alternative enzymatic source of glutaryl-CoA. Here, we show that loss of DHTKD1 in glutaryl-CoA dehydrogenase-deficient HEK-293 cells leads to a 2-fold decrease in the established GA1 clinical biomarker glutarylcarnitine and demonstrate that oxoglutarate dehydrogenase (OGDH) is responsible for this remaining glutarylcarnitine production. We furthermore show that DHTKD1 interacts with OGDH, dihydrolipoyl succinyltransferase and dihydrolipoamide dehydrogenase to form a hybrid 2-oxoglutaric and 2-oxoadipic acid dehydrogenase complex. In summary, 2-oxoadipic acid is a substrate for DHTKD1, but also for OGDH in a cell model system. The classical 2-oxoglutaric dehydrogenase complex can exist as a previously undiscovered hybrid containing DHTKD1 displaying improved kinetics towards 2-oxoadipic acid.

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Section: Introductionmentioning

confidence: 99%

DHTKD1 and OGDH display substrate overlap in cultured cells and form a hybrid 2-oxo acid dehydrogenase complex in vivo

Leandro

Dodatko

Aten

et al. 2020

Human Molecular Genetics

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“…In general, 2-oxo acid dehydrogenase complexes have unique E1 and E2 components, but share the same E3 component. DHTKD1 and OGDH are an exception, because they share both the E2 (DLST) and E3 (DLD) components (4, 8), which allows for functional and regulatory cross-talk between the citric acid cycle and L-lysine degradation (5,8).…”

Section: Introductionmentioning

confidence: 99%

Inhibition and Crystal Structure of the Human DHTKD1-Thiamin Diphosphate Complex

et al. 2020

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DHTKD1 is the E1 component of the 2-oxoadipic acid dehydrogenase complex (OADHc), which functions in the L-lysine degradation pathway. Mutations in DHTKD1 have been associated with 2-aminoadipic and 2-oxoadipic aciduria, Charcot-Marie-Tooth disease type 2Q (CMT2Q) and eosinophilic esophagitis (EoE). A crystal structure and inhibitors of DHTKD1 could improve the understanding of these clinically distinct disorders, but are currently not available. Here we report the identification of adipoylphosphonic acid and tenatoprazole as DHTKD1 inhibitors using targeted and high throughput screening, respectively. We furthermore elucidate the DHTKD1 crystal structure with thiamin diphosphate bound at 2.1 Å. The protein assembles as a dimer with residues from both monomers contributing to cofactor binding. We also report the impact of ten DHTKD1 missense mutations on the encoded proteins by enzyme kinetics, thermal stability and structural modeling. Some DHTKD1 variants displayed impaired folding (S777P and S862I), whereas other substitutions rendered the enzyme inactive (L234G, R715C and R455Q) or affected the thermal stability and catalytic efficiency (V360A and P773L). Three variants (R163Q, Q305H and G729R) surprisingly showed wild type like properties. Our work provides a structural basis for further understanding of the function of DHTKD1 and a starting point for selective small molecule inhibitors of the enzyme, which could help tease apart the role of this enzyme in several human pathologies.

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“…The transcriptomic data are extracted from OGDH, despite a rather high level of the OGDH activity in reaction with 2-oxoadipate in vitro. Delineation of the physiological role(s) of the DHTKD1-encoded protein in in vivo studies is complicated by tissue specificity of the DHTKD1-dependent changes 24 , significant variation in the DHTKD1 expression in a population 27,35 and specific environmental conditions when the effects of the DHTKD1 expression acquire significance 24,27 . For instance, in liver, the DHTKD1-encoded protein is shown to be a primary regulator of 2-aminoadipate 27 , but this may be different in other tissues.…”

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Synthetic analogues of 2-oxo acids discriminate metabolic contribution of the 2-oxoglutarate and 2-oxoadipate dehydrogenases in mammalian cells and tissues

Artiukhov

Grabarska

Gumbarewicz

et al. 2020

Sci Rep

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The biological significance of the DHTKD1-encoded 2-oxoadipate dehydrogenase (OADH) remains obscure due to its catalytic redundancy with the ubiquitous OGDH-encoded 2-oxoglutarate dehydrogenase (OGDH). In this work, metabolic contributions of OADH and OGDH are discriminated by exposure of cells/tissues with different DHTKD1 expression to the synthesized phosphonate analogues of homologous 2-oxodicarboxylates. The saccharopine pathway intermediates and phosphorylated sugars are abundant when cellular expressions of DHTKD1 and OGDH are comparable, while nicotinate and non-phosphorylated sugars are when DHTKD1 expression is order(s) of magnitude lower than that of OGDH. Using succinyl, glutaryl and adipoyl phosphonates on the enzyme preparations from tissues with varied DHTKD1 expression reveals the contributions of OADH and OGDH to oxidation of 2-oxoadipate and 2-oxoglutarate in vitro. In the phosphonates-treated cells with the high and low DHTKD1 expression, adipate or glutarate, correspondingly, are the most affected metabolites. the marker of fatty acid β-oxidation, adipate, is mostly decreased by the shorter, OGDH-preferring, phosphonate, in agreement with the known OGDH dependence of β-oxidation. The longest, OADHpreferring, phosphonate mostly affects the glutarate level. Coupled decreases in sugars and nicotinate upon the OADH inhibition link the perturbation in glucose homeostasis, known in OADH mutants, to the nicotinate-dependent NAD metabolism. 2-Oxo acid dehydrogenase complexes comprise a family of multimeric enzymes functioning at the intersections of metabolic pathways involving carbohydrates, lipids and amino acids 1. The family includes the well-characterized 2-oxoglutarate dehydrogenase complex (OGDHC), which couples the tricarboxylic acid (TCA) cycle with degradation of amino acids of the 2-oxoglutarate group, namely, glutamate, glutamine, arginine, histidine, and proline. The substrate-specific 2-oxoglutarate dehydrogenase (OGDH, EC 1.2.4.1, encoded by the OGDH gene, also known as E1o component of the complex), is a well-known and rate-limiting component of OGDHC. The complex also comprises two other types of enzymes: E2o (EC 2.3.1.61) and E3 (EC 1.8.1.4), encoded by the dihydrolipoamide succinyltransferase (DLST) and dihydrolipoamide dehydrogenase (DLD) genes, respectively. Multiple copies of the E1, E2 and E3 component enzymes form multienzyme complexes schematically exemplified in Fig. 1A. The multimeric structure allows effective coupling of the 2-oxoglutarate oxidative decarboxylation

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DHTKD1 and OGDH display in vivo substrate overlap and form a hybrid ketoacid dehydrogenase complex

Cited by 6 publications

References 38 publications

DHTKD1 and OGDH display substrate overlap in cultured cells and form a hybrid 2-oxo acid dehydrogenase complex in vivo

DHTKD1 and OGDH display substrate overlap in cultured cells and form a hybrid 2-oxo acid dehydrogenase complex in vivo

Inhibition and Crystal Structure of the Human DHTKD1-Thiamin Diphosphate Complex

Synthetic analogues of 2-oxo acids discriminate metabolic contribution of the 2-oxoglutarate and 2-oxoadipate dehydrogenases in mammalian cells and tissues

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