Interaction of glutaric aciduria type 1-related glutaryl-CoA dehydrogenase with mitochondrial matrix proteins.
Glutaric aciduria type 1 (GA1) is an inherited neurometabolic disorder caused by mutations in the GCDH gene encoding glutaryl-CoA dehydrogenase (GCDH), which forms homo- and heteromeric complexes in the mitochondrial matrix. GA1 patients are prone to the development of encephalopathic crises which lead to an irreversible disabling dystonic movement disorder. The clinical and biochemical manifestations of GA1 vary considerably and lack correlations to the genotype. Using an affinity chromatography approach we report here for the first time on the identification of mitochondrial proteins interacting directly with GCDH. Among others, dihydrolipoamide S-succinyltransferase (DLST) involved in the formation of glutaryl-CoA, and the β-subunit of the electron transfer flavoprotein (ETFB) serving as electron acceptor, were identified as GCDH binding partners. We have adapted the yellow fluorescent protein-based fragment complementation assay and visualized the oligomerization of GCDH as well as its direct interaction with DLST and ETFB in mitochondria of living cells. These data suggest that GCDH is a constituent of multimeric mitochondrial dehydrogenase complexes, and the characterization of their interrelated functions may provide new insights into the regulation of lysine oxidation and the pathophysiology of GA1.
Department of Biochemistry, Children's Hospital, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
Jessica
J
Schmiesing
Department of Clinical Chemistry, Laboratory for Mass Spectrometric Proteomics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
Hartmut
H
Schlüter
Department of Biochemistry, Children's Hospital, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
Kurt
K
Ullrich
Department of Biochemistry, Children's Hospital, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
Thomas
T
Braulke
Department of Biochemistry, Children's Hospital, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
Chris
C
Mühlhausen
D000217:Acyltransferases / Q000378:metabolism*; D000592:Amino Acid Metabolism, Inborn Errors / Q000201:enzymology*; D015153:Blotting, Western; D001928:Brain Diseases, Metabolic / Q000201:enzymology*; D002846:Chromatography, Affinity; D044927:Electron-Transferring Flavoproteins / Q000378:metabolism*; D005977:Glutarates / Q000378:metabolism*; D050770:Glutaryl-CoA Dehydrogenase / Q000172:deficiency* / Q000378:metabolism*; D006801:Humans; D047468:Immunoprecipitation; D024101:Mitochondrial Proteins / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism
D044927:Electron-Transferring Flavoproteins; D005977:Glutarates; D024101:Mitochondrial Proteins; D011993:Recombinant Fusion Proteins; D050770:Glutaryl-CoA Dehydrogenase; D000217:Acyltransferases; C021515:dihydrolipoamide succinyltransferase