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Reddy PG, Bhuyan DK, Bhuyan KC. Lens-specific regulation of the thioredoxin-1 gene, but not thioredoxin-2, upon in vivo photochemical oxidative stress in the Emory mouse. Biochem Biophys Res Commun 1999; 265:345-9. [PMID: 10558869 DOI: 10.1006/bbrc.1999.1691] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Thioredoxin (TRX)-1 and TRX-2 redox-regulatory genes were analyzed in the lens and some other tissues of the Emory mouse, a model for age-related human cataract. The cDNA transcripts of mRNAs encoding TRX-1 and TRX-2 genes were isolated and cloned by RT-PCR from the lens, liver, kidney, and tail, and the cDNA sequences were similar to the reported sequences of murine TRX-1 and TRX-2 genes. In vivo photochemical oxidative stress to the Emory mice resulted in fivefold upregulation of the lens TRX-1 gene at 3 weeks and declined thereafter. Western blot analysis revealed a fourfold increase of TRX-1 protein in the lens at 3 weeks after oxidative stress. The TRX-2 gene in the lens was not changed up to 5 weeks and decreased by 50% thereafter. However, the expressions of these genes in the liver, kidney, and tail were not changed. Fluorescent light or riboflavin alone did not affect the expressions of TRX-1 and TRX-2 genes in the lens. Thus, we show the expressions of TRX-1 and TRX-2 genes in the lens, liver, kidney, and tail and lens-specific upregulation of the TRX-1 gene and protein expressions, possibly as a protective response to the altered redox state of the lens after in vivo oxidative stress to the Emory mouse.
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Affiliation(s)
- P G Reddy
- Membrane Biochemistry Laboratory, Department of Ophthalmology, College of Physicians and Surgeons, Columbia University, 630 West 168th Street, New York, New York, 10032, USA
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52
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Motchoulski A, Liscum E. Arabidopsis NPH3: A NPH1 photoreceptor-interacting protein essential for phototropism. Science 1999; 286:961-4. [PMID: 10542152 DOI: 10.1126/science.286.5441.961] [Citation(s) in RCA: 197] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Phototropism of Arabidopsis thaliana seedlings in response to a blue light source is initiated by nonphototropic hypocotyl 1 (NPH1), a light-activated serine-threonine protein kinase. Mutations in three loci [NPH2, root phototropism 2 (RPT2), and NPH3] disrupt early signaling occurring downstream of the NPH1 photoreceptor. The NPH3 gene, now cloned, encodes a NPH1-interacting protein. NPH3 is a member of a large protein family, apparently specific to higher plants, and may function as an adapter or scaffold protein to bring together the enzymatic components of a NPH1-activated phosphorelay.
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Affiliation(s)
- A Motchoulski
- Division of Biological Sciences, University of Missouri, Columbia, MO 65211, USA
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53
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Bode K, Hooks MA, Couee I. Identification, separation, and characterization of acyl-coenzyme A dehydrogenases involved in mitochondrial beta-oxidation in higher plants. PLANT PHYSIOLOGY 1999; 119:1305-1314. [PMID: 10198089 PMCID: PMC32015 DOI: 10.1104/pp.119.4.1305] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/1998] [Accepted: 12/18/1998] [Indexed: 05/23/2023]
Abstract
The existence in higher plants of an additional beta-oxidation system in mitochondria, besides the well-characterized peroxisomal system, is often considered controversial. Unequivocal demonstration of beta-oxidation activity in mitochondria should rely on identification of the enzymes specific to mitochondrial beta-oxidation. Acyl-coenzyme A dehydrogenase (ACAD) (EC 1.3.99.2,3) activity was detected in purified mitochondria from maize (Zea mays L.) root tips and from embryonic axes of early-germinating sunflower (Helianthus annuus L.) seeds, using as the enzyme assay the reduction of 2,6-dichlorophenolindophenol, with phenazine methosulfate as the intermediate electron carrier. Subcellular fractionation showed that this ACAD activity was associated with mitochondrial fractions. Comparison of ACAD activity in mitochondria and acyl-coenzyme A oxidase activity in peroxisomes showed differences of substrate specificities. Embryonic axes of sunflower seeds were used as starting material for the purification of ACADs. Two distinct ACADs, with medium-chain and long-chain substrate specificities, respectively, were separated by their chromatographic behavior, which was similar to that of mammalian ACADs. The characterization of these ACADs is discussed in relation to the identification of expressed sequenced tags corresponding to ACADs in cDNA sequence analysis projects and with the potential roles of mitochondrial beta-oxidation in higher plants.
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Affiliation(s)
- K Bode
- Station de Physiologie Vegetale, Institut National de la Recherche Agronomique, Centre de Recherches de Bordeaux, Boite Postale 81, 33883 Villenave d'Ornon cedex, France
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54
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Abstract
BACKGROUND Valproic acid (2-propyl-N-pentanoic acid, VPA) causes severe hepatic dysfunction, similar to Reye's syndrome, in a small number of patients. An enhanced excretion of dicarboxylic acids by patients indicates an interference with mitochondrial beta-oxidation. We investigated the expression of various acyl-coenzyme A (acyl-CoA) dehydrogenases (ACD), which catalyze the first step of beta-oxidation in VPA-treated rats. METHODS The control group received normal saline and the experimental group received VPA (500 mg/kg per day) by intraperitoneal injections for 7 days. Various clinical chemistry parameters in rat blood and free and total carnitine levels in plasma and tissue were determined. Mitochondria were isolated from rat liver and heart and the relative amount of each ACD protein was determined by immunoblot analysis. Total RNA was prepared from various tissues and the mRNA levels for various ACD were measured by slot-blot hybridization analysis using respective cDNA probes. RESULTS Administration of VPA to rats caused various metabolic effects including hypoglycemia, hyperammonemia and decreased beta-hydroxybutyrate concentration. Free carnitine levels in plasma and heart were also decreased. Enzyme activities of various acyl-CoA dehydrogenases, which are involved in fatty acid oxidation, decreased moderately in heart (57-79%), and slightly in liver (78-95%). The most prominent effects were observed in mRNA levels involved in fatty acid oxidation (short-, medium- and long-chain acyl-CoA dehydrogenase). Each mRNA increased in the liver, kidney, skeletal muscle and heart to varying degrees when rats were fed ad libitum. The increase of short- and medium- chain acyl-CoA dehydrogenase mRNA in the heart were particularly large. However, 3 day starvation strongly inhibited expression of ACD in VPA-treated rats. There was an apparent decrease in the amount of ACD mRNA and proteins in VPA-treated liver. CONCLUSIONS Valproic acid causes enhanced expression of fatty ACD mRNA, especially in the heart, by a feedback mechanism related to inhibition of beta-oxidation in rats fed ad libitum. However, it impairs the expression of ACD in the liver when there is a drastic change in nutritional state.
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Affiliation(s)
- M Kibayashi
- Department of Pediatrics, National Otaru Hospital, Japan
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55
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Kurtz DM, Tolwani RJ, Wood PA. Structural characterization of the mouse long-chain acyl-CoA dehydrogenase gene and 5' regulatory region. Mamm Genome 1998; 9:361-5. [PMID: 9545492 DOI: 10.1007/s003359900770] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Long-chain acyl-CoA dehydrogenase (LCAD) is one of four enzymes involved in the initial step of mitochondrial beta-oxidation of straight-chain fatty acids. It is a member of the acyl-CoA dehydrogenase (Acad or ACAD) gene family of enzymes, which also includes very-long-chain (VLCAD), medium-chain (MCAD), and short-chain (SCAD) acyl-CoA dehydrogenases. These enzymes all have similar activity but differ only in the chain length specificity for their substrate. Mitochondrial beta-oxidation provides an important source of energy especially during times of fasting. In order to understand the role of LCAD in this pathway, we have cloned and characterized the entire mouse (Mus musculus) gene encoding LCAD (Acadl). Acadl is a single-copy, nuclear encoded gene approximately 35 kb in size. We have sequenced the entire coding region, all intron/exon boundaries, 1.7 kb of its 5' regulatory region, and mapped the transcription start site. The gene contains 11 coding exons ranging in size from 67 bp to 275 bp, interrupted by 10 introns ranging in size from 1.0 kb to 6.6 kb in size. The Acadl 5' regulatory region, like other members of the Acad family, lacks a TATA or CAAT box and is GC rich. This region does contain multiple, putative cis-acting DNA elements recognized by either SP1 or members of the steroid-thyroid family of nuclear receptors, which has been shown with other members of the ACAD gene family to be important in regulated expression. The characterization of the mouse Acadl gene will allow further study of LCAD in an in vivo model, and how its expression may be coordinated with other members of the Acad gene family.
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Affiliation(s)
- D M Kurtz
- Department of Comparative Medicine, Volker Hall, Room 401, Schools of Medicine and Dentistry, The University of Alabama at Birmingham, Birmingham, Alabama 35294-0019, USA
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56
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Barile M, Brizio C, De Virgilio C, Delfine S, Quagliariello E, Passarella S. Flavin adenine dinucleotide and flavin mononucleotide metabolism in rat liver--the occurrence of FAD pyrophosphatase and FMN phosphohydrolase in isolated mitochondria. EUROPEAN JOURNAL OF BIOCHEMISTRY 1997; 249:777-85. [PMID: 9395326 DOI: 10.1111/j.1432-1033.1997.00777.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
In order to gain some insight into mitochondrial flavin biochemistry, rat liver mitochondria essentially free of lysosomal and microsomal contamination were prepared and their capability to metabolise externally added and endogenous FAD and FMN tested both spectroscopically and via HPLC. The existence of two novel mitochondrial enzymes, namely FAD pyrophosphatase (EC 3.6.1.18) and FMN phosphohydrolase (EC 3.1.3.2), which catalyse FAD-->FMN and FMN-->riboflavin conversion, respectively, is shown. They differ from each other and from extramitochondrial enzymes, as judged by their pH profile and inhibitor sensitivity, and can be separated in a partial FAD pyrophosphatase purification. Digitonin titration and subfractionation experiments show that FAD pyrophosphatase is located in the outer mitochondrial membrane and FMN phosphohydrolase in the intermembrane space. Since these enzymes can metabolise endogenous FAD and FMN, which are made available by using both Triton X-100 and the effector oxaloacetate, a proposal is made that FAD pyrophosphatase and FMN phosphohydrolase play a major role in mitochondrial flavoprotein turnover.
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Affiliation(s)
- M Barile
- Dipartimento di Biochimica e Biologia Molecolare, Università di Bari, and Centro di Studio sui Mitocondri e Metabolismo Energetico, C.N.R., Italy.
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57
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Bross P, Andresen BS, Gregersen N. Impaired folding and subunit assembly as disease mechanism: the example of medium-chain acyl-CoA dehydrogenase deficiency. PROGRESS IN NUCLEIC ACID RESEARCH AND MOLECULAR BIOLOGY 1997; 58:301-37. [PMID: 9308370 DOI: 10.1016/s0079-6603(08)60040-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Rapid progress in DNA technology has entailed the possibility of readily detecting mutations in disease genes. In contrast to this, techniques to characterize the effects of mutations are still very time consuming. It has turned out that many of the mutations detected in disease genes are missense mutations. Characterization of the effect of these mutations is particularly important in order to establish that they are disease causing and to estimate their severity. We use the experiences with investigation of medium-chain acyl-CoA dehydrogenase deficiency as an example to illustrate that (i) impaired folding is a common effect of missense mutations occurring in genetic diseases, (ii) increasing the level of available chaperones may augment the level of functional mutant protein in vivo, and (iii) one mutation may have multiple effects. The interplay between the chaperones assisting folding and proteases that attack folding intermediates is decisive for how large a proportion of a mutant polypeptide impaired in folding acquires the functional structure. This constitutes a protein quality control system, and the handling of a given mutant protein by this system may vary due to environmental conditions or genetic variability in its components. The possibility that intraindividual differences in the handling of mutant proteins may be a mechanism accounting for phenotypic variability is discussed.
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Affiliation(s)
- P Bross
- Center for Medical Molecular Biology, Aarhus University Hospital, Denmark
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58
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Otto A, Stoltz M, Sailer HP, Brandsch R. Biogenesis of the covalently flavinylated mitochondrial enzyme dimethylglycine dehydrogenase. J Biol Chem 1996; 271:9823-9. [PMID: 8621665 DOI: 10.1074/jbc.271.16.9823] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Rat dimethylglycine dehydrogenase (Me2GlyDH) was used as model protein to study the biogenesis of a covalently flavinylated mitochondrial enzyme. Here we show that: 1) enzymatically active holoenzyme correlated with trypsin resistance of the protein; 2) folding of the reticulocyte lysate-translated protein into the trypsin-resistant, holoenzyme form was a slow process that was stimulated by the presence of the flavin cofactor and was more efficient at 15 degrees C than at 30 degrees C; 3) the mitochondrial presequence reduced the extent but did not prevent holoenzyme formation; 4) covalent attachment of FAD to the Me2GlyDH apoenzyme proceeded spontaneously and did not require a mitochondrial protein factor; 5) in vitro only the precursor, but not the mature form, of the protein was imported into isolated rat liver mitochondria; in vivo, in stably transfected HepG2 cells, both the precursor and the mature form were imported into the organelle; 6) holoenzyme formation in the cytoplasm did not prevent the translocation of the proteins into the mitochondria in vivo; and 7) lack of vitamin B2 in the tissue culture medium resulted in a reduced recovery of the precursor and the mature form of Me2GlyDH from cell mitochondria, suggesting a decreased efficiency of mitochondrial protein import.
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Affiliation(s)
- A Otto
- Biochemisches Institut, Universitat Freiburg, Germany
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59
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Serra EC, Krapp AR, Ottado J, Feldman MF, Ceccarelli EA, Carrillo N. The precursor of pea ferredoxin-NADP+ reductase synthesized in Escherichia coli contains bound FAD and is transported into chloroplasts. J Biol Chem 1995; 270:19930-5. [PMID: 7650008 DOI: 10.1074/jbc.270.34.19930] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The precursor of the chloroplast flavoprotein ferredoxin-NADP+ reductase from pea was expressed in Escherichia coli as a carboxyl-terminal fusion to glutathione S-transferase. The fused protein was soluble, and the precursor could be purified in a few steps involving affinity chromatography on glutathione-agarose, cleavage of the transferase portion by protease Xa, and ion exchange chromatography on DEAE-cellulose. The purified prereductase contained bound FAD but displayed marginally low levels of activity. Removal of the transit peptide by limited proteolysis rendered a functional protease-resistant core exhibiting enzymatic activity. The FAD-containing precursor expressed in E. coli was readily transported into isolated pea chloroplasts and was processed to the mature size, both inside the plastid and by incubation with stromal extracts in a plastid-free reaction. Import was dependent on the presence of ATP and was stimulated severalfold by the addition of plant leaf extracts.
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Affiliation(s)
- E C Serra
- Departamento de Ciencias Biológicas, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Argentina
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60
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Abrams VA, Han CC, White HB. Riboflavin-deficient chicken embryos: hypoglycemia without dicarboxylic aciduria. Comp Biochem Physiol B Biochem Mol Biol 1995; 111:233-41. [PMID: 7599988 DOI: 10.1016/0305-0491(94)00247-r] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Chicken embryos in eggs laid by hens that are genetically unable to deposit riboflavin into their eggs die on or about the 13th day of incubation. We show that these riboflavin-deficient embryos grow normally until the day of death and that their heart rate is normal to within an hour of death. The embryos have symptoms of impaired fatty acid oxidation, including decreased activity of FAD-dependent medium-chain acyl CoA dehydrogenase in liver and heart along with a significant accumulation of intermediates of fatty acid oxidation (C10, C12, and C14 acids). Unlike riboflavin-deficient mammals, the embryos do not accumulate dicarboxylic acids derived from omega-oxidation of fatty acids. Blood glucose is near normal on day 10 but declines to undetectable levels by the time of death. Allantoic fluid from the riboflavin-deficient embryos of 11 days or older contains more lactate than 3-hydroxybutyrate, while in normal embryos the reverse is true. No appreciable amounts of glycine-conjugated acids were found. We conclude that the major and perhaps primary pathological effect of riboflavin deficiency in chicken embryos is the impairment of fatty acid beta-oxidation, and that the subsequent depletion of limited carbohydrate reserves leads to sudden death.
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Affiliation(s)
- V A Abrams
- Department of Chemistry and Biochemistry, University of Delaware, Newark 19716, USA
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61
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Stoltz M, Rysavy P, Kalousek F, Brandsch R. Folding, flavinylation, and mitochondrial import of 6-hydroxy-D-nicotine oxidase fused to the presequence of rat dimethylglycine dehydrogenase. J Biol Chem 1995; 270:8016-22. [PMID: 7713902 DOI: 10.1074/jbc.270.14.8016] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
We analyzed the folding, covalent flavinylation, and mitochondrial import of the rabbit reticulocyte lysate-translated bacterial 6-hydroxy-D-nicotine oxidase (6-HDNO) fused to the mitochondrial targeting sequence of rat liver dimethylglycine dehydrogenase. Translation of 6-HDNO in FAD-supplemented reticulocyte lysate resulted in a protein that contained covalently incorporated FAD, exhibited enzyme activity, and was trypsin-resistant, a characteristic of the tight conformation of the holoenzyme. The attached mitochondrial presequence did not prevent folding, binding of FAD, or enzyme activity of the 6-HDNO moiety of the fusion protein (pre-6-HDNO). Pre-6-HDNO was imported into rat liver mitochondria and processed by the mitochondrial processing peptidase. Incubation of the trypsin-resistant pre-holo-6-HDNO protein with deenergized rat liver mitochondria demonstrated that upon contact with mitochondria, the protein was unfolded and became trypsin sensitive. Mitochondrial import assays showed that the unfolded pre-holo-6-HDNO with covalently attached FAD was imported into rat liver mitochondria. Inside the mitochondrion the holo-6-HDNO was refolded into the trypsin-resistant conformation. However, when pre-apo-6-HDNO was imported only part of the protein became trypsin resistant (approximately 20%). Addition of FAD and the allosteric effector glycerol 3-phosphate to apo-6-HDNO containing mitochondrial matrix was required to transform the protein into the trypsin-resistant conformation characteristic of holo-6-HDNO.
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Affiliation(s)
- M Stoltz
- Biochemisches Institut, Universität Freiburg, Federal Republic of Germany
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62
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Saijo T, Tanaka K. Isoalloxazine ring of FAD is required for the formation of the core in the Hsp60-assisted folding of medium chain acyl-CoA dehydrogenase subunit into the assembly competent conformation in mitochondria. J Biol Chem 1995; 270:1899-907. [PMID: 7829528 DOI: 10.1074/jbc.270.4.1899] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
We studied the role of FAD in the intramitochondrial folding and assembly of medium-chain acyl-CoA dehydrogenase (MCAD), a homotetrameric mitochondrial enzyme containing a molecule of non-covalently bound FAD/monomer. In the MCAD molecule, FAD is buried in a crevice containing the active center. We have previously shown that upon import into mitochondria, newly processed MCAD is first incorporated into a high molecular weight (hMr) complex and that the hMr complex mainly consisted of MCAD-heat-shock protein 60 (hsp60) complex (Saijo, T., Welch, W.J., and Tanaka, K (1994) J. Biol. Chem. 269, 4401-4408). In the present study, we incubated in vitro synthesized precursor MCAD with mitochondria isolated from normal and riboflavin-deficient rat liver for 10-60 min and fractionated the solubilized mitochondria using gel filtration. The amount of MCAD in the hMr complex was larger and that of tetramer was smaller in riboflavin-deficient mitochondria than in control at any time point. In addition, riboflavin-deficient mitochondria were solubilized after 10-min import in a buffer containing ATP and were chased in the presence of FAD, FMN, or NAD+ or without any addition. The mitochondrial proteins were analyzed using gel filtration or immunoprecipitated with anti-hsp60 antibody. After 60-min chase in the presence of FAD, the majority of MCAD in the complex with hsp60 was transferred to tetramer, whereas no such transfer occurred after the chase in the absence of FAD. When chase was done in the presence of FMN, a significant amount of MCAD was transferred from the complex with hsp60 to tetramer, but the transfer was not as efficient as in the presence of FAD. The chase in the presence of NAD+ resulted in no transfer. These data suggest that isoalloxazine ring of FAD plays a critical role, exerting nucleating effect, in the hsp60-assisted folding of MCAD subunit into an assembly competent conformation, probably assisting the formation of the core.
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Affiliation(s)
- T Saijo
- Department of Genetics, Yale University School of Medicine, New Haven, Connecticut 06510
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63
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New Aspects in Mitochondrial Transport and Metabolism of Metabolites and Vitamin Derivatives. ACTA ACUST UNITED AC 1995. [DOI: 10.1016/b978-0-444-82235-2.50019-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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64
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Araki E, Kobayashi T, Kohtake N, Goto I, Hashimoto T. A riboflavin-responsive lipid storage myopathy due to multiple acyl-CoA dehydrogenase deficiency: an adult case. J Neurol Sci 1994; 126:202-5. [PMID: 7853027 DOI: 10.1016/0022-510x(94)90274-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
A 62-year-old man was admitted to our hospital because of easy fatigability of the lower limbs during walking. The biopsied muscle specimen showed excessive lipid accumulation. The carnitine concentration in the muscle was at the lower level of the normal range. Organic acid urinalysis was consistent with the diagnosis of multiple acyl-CoA dehydrogenase deficiency or glutaric acidemia type II. In cultured lymphoblastoid cells from this patient there was impaired beta-oxidation, but the activities of acyl-CoA dehydrogenases were normal. Riboflavin therapy resulted in a dramatic improvement in both clinical and biochemical aspects. In this patient, the defect in coenzyme binding to electron transfer flavoprotein (ETF) or ETF-dehydrogenase was suspected. In the adult case of lipid storage myopathy, multiple acyl-CoA dehydrogenase deficiency should be suspected as one of its pathogenesis and riboflavin therapy should be considered.
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Affiliation(s)
- E Araki
- Department of Neurology, Faculty of Medicine, Kyushu University, Fukuoka, Japan
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65
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Intramitochondrial folding and assembly of medium-chain acyl-CoA dehydrogenase (MCAD). Demonstration of impaired transfer of K304E-variant MCAD from its complex with hsp60 to the native tetramer. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(17)41794-7] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
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66
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Nagao M, Parimoo B, Tanaka K. Developmental, nutritional, and hormonal regulation of tissue-specific expression of the genes encoding various acyl-CoA dehydrogenases and alpha-subunit of electron transfer flavoprotein in rat. J Biol Chem 1993. [DOI: 10.1016/s0021-9258(20)80500-6] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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67
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Krähenbühl S. Alterations in mitochondrial function and morphology in chronic liver disease: pathogenesis and potential for therapeutic intervention. Pharmacol Ther 1993; 60:1-38. [PMID: 8127921 DOI: 10.1016/0163-7258(93)90020-e] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Studies assessing mitochondrial function and structure in livers from humans or experimental animals with chronic liver disease, including liver cirrhosis, revealed a variety of alterations in comparison with normal subjects or control animals. Depending on the etiology of chronic liver disease, the function of the electron transport chain and/or ATP synthesis was found to be impaired, leading to decreased oxidative metabolism of various substrates and to impaired recovery of the hepatic energy state after a metabolic insult. Changes in mitochondrial structure include megamitochondria with reduced cristae, dilatation of mitochondrial cristae and crystalloid inclusions in the mitochondrial matrix. The most important strategies to maintain an adequate mitochondrial function per liver are mitochondrial proliferation and increases in the activity of critical enzymes or in the content of cofactors per mitochondrion. Possibilities to assess hepatic mitochondrial function and to treat mitochondrial dysfunction in patients with chronic liver disease are discussed.
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Affiliation(s)
- S Krähenbühl
- Department of Internal Medicine, University of Berne, Switzerland
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68
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Tanaka K, Yokota I, Coates PM, Strauss AW, Kelly DP, Zhang Z, Gregersen N, Andresen BS, Matsubara Y, Curtis D. Mutations in the medium chain acyl-CoA dehydrogenase (MCAD) gene. Hum Mutat 1992; 1:271-9. [PMID: 1363805 DOI: 10.1002/humu.1380010402] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Medium chain acyl-CoA dehydrogenase (MCAD) catalyzes the first reaction of the beta-oxidation cycle for 4-10-carbon fatty acids. MCAD deficiency is one of the most frequent inborn metabolic disorders in populations of northwestern European origin. In the compilation of data from a worldwide study of 172 unrelated patients each representing an independent pedigree, a total of 8 different mutations have been identified. Among them, a single prevalent mutation, 985A-->G, was found in 90% of 344 variant alleles. 985A-->G causes glutamate substitution for lysine-304 in the mature MCAD subunit, which causes impairment of tetramer assembly and instability of the protein. Three of 7 rarer mutations have been identified in a few unrelated patients, while the remaining 4 have each been found in only a single pedigree. In addition to tabulating the mutations, the acyl-CoA dehydrogenase gene family, the structure of the MCAD gene and the evolution of 985A-->G mutation are briefly discussed.
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Affiliation(s)
- K Tanaka
- Department of Genetics, Yale University School of Medicine, New Haven, Connecticut 06510
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