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Rose J, Brian C, Pappa A, Panayiotidis MI, Franco R. Mitochondrial Metabolism in Astrocytes Regulates Brain Bioenergetics, Neurotransmission and Redox Balance. Front Neurosci 2020; 14:536682. [PMID: 33224019 PMCID: PMC7674659 DOI: 10.3389/fnins.2020.536682] [Citation(s) in RCA: 66] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Accepted: 10/14/2020] [Indexed: 01/17/2023] Open
Abstract
In the brain, mitochondrial metabolism has been largely associated with energy production, and its dysfunction is linked to neuronal cell loss. However, the functional role of mitochondria in glial cells has been poorly studied. Recent reports have demonstrated unequivocally that astrocytes do not require mitochondria to meet their bioenergetics demands. Then, the question remaining is, what is the functional role of mitochondria in astrocytes? In this work, we review current evidence demonstrating that mitochondrial central carbon metabolism in astrocytes regulates overall brain bioenergetics, neurotransmitter homeostasis and redox balance. Emphasis is placed in detailing carbon source utilization (glucose and fatty acids), anaplerotic inputs and cataplerotic outputs, as well as carbon shuttles to neurons, which highlight the metabolic specialization of astrocytic mitochondria and its relevance to brain function.
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Affiliation(s)
- Jordan Rose
- Redox Biology Center, University of Nebraska-Lincoln, Lincoln, NE, United States.,School of Veterinary Medicine and Biomedical Sciences, University of Nebraska-Lincoln, Lincoln, NE, United States
| | - Christian Brian
- Redox Biology Center, University of Nebraska-Lincoln, Lincoln, NE, United States.,School of Veterinary Medicine and Biomedical Sciences, University of Nebraska-Lincoln, Lincoln, NE, United States
| | - Aglaia Pappa
- Department of Molecular Biology and Genetics, Democritus University of Thrace, Alexandroupolis, Greece
| | - Mihalis I Panayiotidis
- Department of Electron Microscopy & Molecular Pathology, Cyprus Institute of Neurology & Genetics, Nicosia, Cyprus
| | - Rodrigo Franco
- Redox Biology Center, University of Nebraska-Lincoln, Lincoln, NE, United States.,School of Veterinary Medicine and Biomedical Sciences, University of Nebraska-Lincoln, Lincoln, NE, United States
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Vamecq J, Papegay B, Nuyens V, Boogaerts J, Leo O, Kruys V. Mitochondrial dysfunction, AMPK activation and peroxisomal metabolism: A coherent scenario for non-canonical 3-methylglutaconic acidurias. Biochimie 2019; 168:53-82. [PMID: 31626852 DOI: 10.1016/j.biochi.2019.10.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Accepted: 10/10/2019] [Indexed: 12/13/2022]
Abstract
The occurrence of 3-methylglutaconic aciduria (3-MGA) is a well understood phenomenon in leucine oxidation and ketogenesis disorders (primary 3-MGAs). In contrast, its genesis in non-canonical (secondary) 3-MGAs, a growing-up group of disorders encompassing more than a dozen of inherited metabolic diseases, is a mystery still remaining unresolved for three decades. To puzzle out this anthologic problem of metabolism, three clues were considered: (i) the variety of disorders suggests a common cellular target at the cross-road of metabolic and signaling pathways, (ii) the response to leucine loading test only discriminative for primary but not secondary 3-MGAs suggests these latter are disorders of extramitochondrial HMG-CoA metabolism as also attested by their failure to increase 3-hydroxyisovalerate, a mitochondrial metabolite accumulating only in primary 3-MGAs, (iii) the peroxisome is an extramitochondrial site possessing its own pool and displaying metabolism of HMG-CoA, suggesting its possible involvement in producing extramitochondrial 3-methylglutaconate (3-MG). Following these clues provides a unifying common basis to non-canonical 3-MGAs: constitutive mitochondrial dysfunction induces AMPK activation which, by inhibiting early steps in cholesterol and fatty acid syntheses, pipelines cytoplasmic acetyl-CoA to peroxisomes where a rise in HMG-CoA followed by local dehydration and hydrolysis may lead to 3-MGA yield. Additional contributors are considered, notably for 3-MGAs associated with hyperammonemia, and to a lesser extent in CLPB deficiency. Metabolic and signaling itineraries followed by the proposed scenario are essentially sketched, being provided with compelling evidence from the literature coming in their support.
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Affiliation(s)
- Joseph Vamecq
- Inserm, CHU Lille, Univ Lille, Department of Biochemistry and Molecular Biology, Laboratory of Hormonology, Metabolism-Nutrition & Oncology (HMNO), Center of Biology and Pathology (CBP) Pierre-Marie Degand, CHRU Lille, EA 7364 RADEME, University of North France, Lille, France.
| | - Bérengère Papegay
- Laboratory of Experimental Medicine (ULB unit 222), University Hospital Center, Charleroi, (CHU Charleroi), Belgium
| | - Vincent Nuyens
- Laboratory of Experimental Medicine (ULB unit 222), University Hospital Center, Charleroi, (CHU Charleroi), Belgium
| | - Jean Boogaerts
- Laboratory of Experimental Medicine (ULB unit 222), University Hospital Center, Charleroi, (CHU Charleroi), Belgium
| | - Oberdan Leo
- Laboratory of Immunobiology, Department of Molecular Biology, ULB Immunology Research Center (UIRC), Free University of Brussels (ULB), Gosselies, Belgium
| | - Véronique Kruys
- Laboratory of Molecular Biology of the Gene, Department of Molecular Biology, ULB Immunology Research Center (UIRC), Free University of Brussels (ULB), Gosselies, Belgium
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Goudarzi A. The recent insights into the function of ACAT1: A possible anti-cancer therapeutic target. Life Sci 2019; 232:116592. [PMID: 31228515 DOI: 10.1016/j.lfs.2019.116592] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2019] [Revised: 06/18/2019] [Accepted: 06/18/2019] [Indexed: 12/22/2022]
Abstract
Acetoacetyl-CoA thiolase also known as acetyl-CoA acetyltransferase (ACAT) corresponds to two enzymes, one cytosolic (ACAT2) and one mitochondrial (ACAT1), which is thought to catalyse reversible formation of acetoacetyl-CoA from two molecules of acetyl-CoA during ketogenesis and ketolysis respectively. In addition to this activity, ACAT1 is also involved in isoleucine degradation pathway. Deficiency of ACAT1 is an inherited metabolic disorder, which results from a defect in mitochondrial acetoacetyl-CoA thiolase activity and is clinically characterized with patients presenting ketoacidosis. In this review I discuss the recent findings, which unexpectedly expand the known functions of ACAT1, indicating a role for ACAT1 well beyond its classical activity. Indeed ACAT1 has recently been shown to possess an acetyltransferase activity capable of specifically acetylating Pyruvate DeHydrogenase (PDH), an enzyme involved in producing acetyl-CoA. ACAT1-dependent acetylation of PDH was shown to negatively regulate this enzyme with a consequence in Warburg effect and tumor growth. Finally, the elevated ACAT1 enzyme activity in diverse human cancer cell lines was recently reported. These important novel findings on ACAT1's function and expression in cancer cell proliferation point to ACAT1 as a potential new anti-cancer target.
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Affiliation(s)
- Afsaneh Goudarzi
- Department of Clinical Biochemistry, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
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Nakao N, Kaneda H, Tsushima N, Tanaka M. Characterization of primary structure and post-hatching increase in chicken cytosolic acetoacetyl-coA thiolase in the liver. Poult Sci 2016; 95:1406-10. [PMID: 26944984 DOI: 10.3382/ps/pew045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2015] [Accepted: 12/03/2015] [Indexed: 11/20/2022] Open
Abstract
Acetoacetyl-CoA thiolase (EC 2.3.1.9) catalyzes the cleavage of acetoacetyl-CoA into acetyl-CoA and its reverse reaction, the synthesis of acetoacetyl-CoA. Cytosolic acetoacetyl-CoA thiolase ( CT: ) is a key enzyme in the initial step of the cholesterol synthesis pathway. In the present study, we characterized the amino acid sequence of chicken CT and the tissue distribution of its mRNA and protein, together with their developmental changes in the liver. The amino acid sequence encoded by the nucleotide sequence of chicken CT cDNA showed a higher overall identity with those of human (74.3%) and rat (74.6%) CTs. Amino acid residues known to participate in enzymatic activity in human CT are conserved in chicken CT. Real-time PCR analysis revealed the expression of CT mRNA in the liver, kidney, adrenal gland, jejunum and ovary of adult hens, with higher levels in the liver, kidney, adrenal gland and ovary. Western blot analysis detected an immunoreactive protein of 41 kDa from cytoplasmic fraction but not particulate fractions of adult chicken liver. The immunoreactive protein was detected in all the tissues. The mRNA levels in the liver rapidly increased after hatching, with a maximum on d 5 post-hatching, after which they gradually decreased to adult levels. A similar change was observed in the protein levels. The increase in transcription and protein synthesis of CT suggests that the synthetic pathway of cholesterol from acetyl-CoA produced by CT replaces the hydrolysis of accumulated cholesteryl ester in the liver, in response to a change in the nutrient source from the lipid-rich yolk to a lower-lipid diet during the early post-hatching period.
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Affiliation(s)
- N Nakao
- Laboratory of Animal Physiology, Department of Animal Science, Faculty of Applied Life Science, Nippon Veterinary and Life Science University, 1-7-1 Kyonancho, Musashino, Tokyo, 180-8602, Japan
| | - H Kaneda
- Laboratory of Animal Physiology, Department of Animal Science, Faculty of Applied Life Science, Nippon Veterinary and Life Science University, 1-7-1 Kyonancho, Musashino, Tokyo, 180-8602, Japan
| | - N Tsushima
- Laboratory of Animal Physiology, Department of Animal Science, Faculty of Applied Life Science, Nippon Veterinary and Life Science University, 1-7-1 Kyonancho, Musashino, Tokyo, 180-8602, Japan
| | - M Tanaka
- Laboratory of Animal Physiology, Department of Animal Science, Faculty of Applied Life Science, Nippon Veterinary and Life Science University, 1-7-1 Kyonancho, Musashino, Tokyo, 180-8602, Japan
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5
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Impact of high-fat diet on the proteome of mouse liver. J Nutr Biochem 2016; 31:10-9. [DOI: 10.1016/j.jnutbio.2015.12.012] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Revised: 10/06/2015] [Accepted: 12/22/2015] [Indexed: 11/22/2022]
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Isezaki N, Sekiba A, Itagaki S, Nagayama K, Ochiai H, Ohmachi T. Dictyostelium acetoacetyl-CoA thiolase is a dual-localizing enzyme that localizes to peroxisomes, mitochondria and the cytosol. MICROBIOLOGY-SGM 2015; 161:1471-84. [PMID: 25911059 DOI: 10.1099/mic.0.000102] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Acetoacetyl-CoA thiolase is an enzyme that catalyses both the CoA-dependent thiolytic cleavage of acetoacetyl-CoA and the reverse condensation reaction. In Dictyostelium discoideum, acetoacetyl-CoA thiolase (DdAcat) is encoded by a single acat gene. The aim of this study was to assess the localization of DdAcat and to determine the mechanism of its cellular localization. Subcellular localization of DdAcat was investigated using a fusion protein with GFP, and it was found to be localized to peroxisomes. The findings showed that the targeting signal of DdAcat to peroxisomes is a unique nonapeptide sequence (15RMYTTAKNL23) similar to the conserved peroxisomal targeting signal-2 (PTS-2). Cell fractionation experiments revealed that DdAcat also exists in the cytosol. Distribution to the cytosol was caused by translational initiation from the second Met codon at position 16. The first 18 N-terminal residues also exhibited function as a mitochondrial targeting signal (MTS). These results indicate that DdAcat is a dual-localizing enzyme that localizes to peroxisomes, mitochondria and the cytosol using both PTS-2 and MTS signals, which overlap each other near the N-terminus, and the alternative utilization of start codons.
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Affiliation(s)
- Nana Isezaki
- 1 Department of Biochemistry and Molecular Biology, Faculty of Agriculture and Life Science, Hirosaki University, Hirosaki, Japan
| | - Atsushi Sekiba
- 1 Department of Biochemistry and Molecular Biology, Faculty of Agriculture and Life Science, Hirosaki University, Hirosaki, Japan
| | - Shoko Itagaki
- 1 Department of Biochemistry and Molecular Biology, Faculty of Agriculture and Life Science, Hirosaki University, Hirosaki, Japan
| | - Koki Nagayama
- 1 Department of Biochemistry and Molecular Biology, Faculty of Agriculture and Life Science, Hirosaki University, Hirosaki, Japan
| | - Hiroshi Ochiai
- 1 Department of Biochemistry and Molecular Biology, Faculty of Agriculture and Life Science, Hirosaki University, Hirosaki, Japan 2 Division of Biological Sciences, Graduate School of Science, Hokkaido University, Sapporo, Japan
| | - Tetsuo Ohmachi
- 1 Department of Biochemistry and Molecular Biology, Faculty of Agriculture and Life Science, Hirosaki University, Hirosaki, Japan
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Kim SJ, Hong M, Song KD, Lee HK, Ryoo S, Heo TH. Normalization of the levels of inflammatory molecules in Mycobacterium smegmatis-infected U937 cells by fibrate pretreatment. Biol Res 2014; 47:42. [PMID: 25299393 PMCID: PMC4177238 DOI: 10.1186/0717-6287-47-42] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2014] [Accepted: 09/05/2014] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Tuberculosis (TB) is a respiratory tract disease caused by Mycobacterium tuberculosis infection. M. tuberculosis exploits immune privilege to grow and divide in pleural macrophages. Fibrates are associated with the immune response and control lipid metabolism through glycolysis with β-oxidation of fatty acids. RESULTS In this study, we investigated the effect of fibrate pretreatment on the immune response during M. smegmatis infection in U937 cells, a human leukemic monocyte lymphoma cell line. The protein expression of tumor necrosis factor α (TNF-α), an inflammatory marker, and myeloid differentiation primary response gene 88 (MyD88), a toll like receptor adaptor molecule, in the infected group increased at 1 and 6 h after M. smegmatis infection of U937 cells. Acetyl coenzyme A acetyl transferase-1 (ACAT-1), peroxisome proliferator-activated receptor-α (PPAR-α), TNF-α, and MyD88 decreased in U937 cells treated with fibrates at 12 and 24 h after treatment. More than a 24 h pretreatment with fibrate resulted in similar expression levels of ACAT-1 and PPAR-α between infected vehicle control and infected groups which were pretreated with fibrate for 24 h. However, upon exposure to M. smegmatis, the cellular expression of the TNF-α and MyD88 in the infected groups pretreated with fibrate for 24 h decreased significantly compared to that in the infected vehicle group. CONCLUSION These results suggest that fibrate pretreatment normalized the levels of inflammatory molecules in Mycobacterium smegmatis-infected U937 cells. Further studies are needed to confirm the findings on pathophysiology and immune defense mechanism of U937 by fibrates during M. tuberculosis infection.
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Affiliation(s)
- Sung-Jo Kim
- Department of Biotechnology, Hoseo University, 165, Baebang, Asan, Chungnam, 336-795, Republic of Korea.
| | - Minho Hong
- Department of Biotechnology, Hoseo University, 165, Baebang, Asan, Chungnam, 336-795, Republic of Korea.
| | - Ki Duk Song
- The Animal Genomics and Breeding Center, Han-Kyong National University, Anseong, 336-795, Republic of Korea.
| | - Hak-Kyo Lee
- The Animal Genomics and Breeding Center, Han-Kyong National University, Anseong, 336-795, Republic of Korea.
| | - Sungweon Ryoo
- Korean Institute of Tuberculosis, Mansu-ri 482, Gangoe-myeon, Chungcheongbuk-do, 363-954, Cheongwon-gun,Republic of Korea.
| | - Tae-Hwe Heo
- Laboratory of Immunology, Integrated Research Institute of Pharmaceutical Sciences, College of Pharmacy, The Catholic University of Korea, Bucheon, 420-743, Republic of Korea. .,NP512, Hall of Cardinal Jin-Suk Cheong, The Catholic University of Korea, 43 Jibong-ro, Wonmi-gu, Bucheon-si, Gyeonggi-do, 420-743, Republic of Korea.
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8
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Conversion of 4-hydroxybutyrate to acetyl coenzyme A and its anapleurosis in the Metallosphaera sedula 3-hydroxypropionate/4-hydroxybutyrate carbon fixation pathway. Appl Environ Microbiol 2014; 80:2536-45. [PMID: 24532060 DOI: 10.1128/aem.04146-13] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The extremely thermoacidophilic archaeon Metallosphaera sedula (optimum growth temperature, 73°C, pH 2.0) grows chemolithoautotrophically on metal sulfides or molecular hydrogen by employing the 3-hydroxypropionate/4-hydroxybutyrate (3HP/4HB) carbon fixation cycle. This cycle adds two CO2 molecules to acetyl coenzyme A (acetyl-CoA) to generate 4HB, which is then rearranged and cleaved to form two acetyl-CoA molecules. Previous metabolic flux analysis showed that two-thirds of central carbon precursor molecules are derived from succinyl-CoA, which is oxidized to malate and oxaloacetate. The remaining one-third is apparently derived from acetyl-CoA. As such, the steps beyond succinyl-CoA are essential for completing the carbon fixation cycle and for anapleurosis of acetyl-CoA. Here, the final four enzymes of the 3HP/4HB cycle, 4-hydroxybutyrate-CoA ligase (AMP forming) (Msed_0406), 4-hydroxybutyryl-CoA dehydratase (Msed_1321), crotonyl-CoA hydratase/(S)-3-hydroxybutyryl-CoA dehydrogenase (Msed_0399), and acetoacetyl-CoA β-ketothiolase (Msed_0656), were produced recombinantly in Escherichia coli, combined in vitro, and shown to convert 4HB to acetyl-CoA. Metabolic pathways connecting CO2 fixation and central metabolism were examined using a gas-intensive bioreactor system in which M. sedula was grown under autotrophic (CO2-limited) and heterotrophic conditions. Transcriptomic analysis revealed the importance of the 3HP/4HB pathway in supplying acetyl-CoA to anabolic pathways generating intermediates in M. sedula metabolism. The results indicated that flux between the succinate and acetyl-CoA branches in the 3HP/4HB pathway is governed by 4-hydroxybutyrate-CoA ligase, possibly regulated posttranslationally by the protein acetyltransferase (Pat)/Sir2-dependent system. Taken together, this work confirms the final four steps of the 3HP/4HB pathway, thereby providing the framework for examining connections between CO2 fixation and central metabolism in M. sedula.
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Antonenkov VD, Hiltunen JK. Transfer of metabolites across the peroxisomal membrane. Biochim Biophys Acta Mol Basis Dis 2011; 1822:1374-86. [PMID: 22206997 DOI: 10.1016/j.bbadis.2011.12.011] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2011] [Revised: 12/08/2011] [Accepted: 12/15/2011] [Indexed: 02/08/2023]
Abstract
Peroxisomes perform a large variety of metabolic functions that require a constant flow of metabolites across the membranes of these organelles. Over the last few years it has become clear that the transport machinery of the peroxisomal membrane is a unique biological entity since it includes nonselective channels conducting small solutes side by side with transporters for 'bulky' solutes such as ATP. Electrophysiological experiments revealed several channel-forming activities in preparations of plant, mammalian, and yeast peroxisomes and in glycosomes of Trypanosoma brucei. The properties of the first discovered peroxisomal membrane channel - mammalian Pxmp2 protein - have also been characterized. The channels are apparently involved in the formation of peroxisomal shuttle systems and in the transmembrane transfer of various water-soluble metabolites including products of peroxisomal β-oxidation. These products are processed by a large set of peroxisomal enzymes including carnitine acyltransferases, enzymes involved in the synthesis of ketone bodies, thioesterases, and others. This review discusses recent data pertaining to solute permeability and metabolite transport systems in peroxisomal membranes and also addresses mechanisms responsible for the transfer of ATP and cofactors such as an ATP transporter and nudix hydrolases.
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Affiliation(s)
- Vasily D Antonenkov
- Department of Biochemistry and Biocenter, University of Oulu, Oulu, Finland.
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Tanaka T, Shima Y, Ogawa N, Nagayama K, Yoshida T, Ohmachi T. Expression, identification and purification of Dictyostelium acetoacetyl-coa thiolase expressed in Escherichia coli. Int J Biol Sci 2010; 7:9-17. [PMID: 21209787 PMCID: PMC3014551 DOI: 10.7150/ijbs.7.9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2010] [Accepted: 12/22/2010] [Indexed: 11/05/2022] Open
Abstract
Acetoacetyl-CoA thiolase (AT) is an enzyme that catalyses the CoA-dependent thiolytic cleavage of acetoacetyl-CoA to yield 2 molecules of acetyl-CoA, or the reverse condensation reaction. A full-length cDNA clone pBSGT-3, which has homology to known thiolases, was isolated from Dictyostelium cDNA library. Expression of the protein encoded in pBSGT-3 in Escherichia coli, its thiolase enzyme activity, and the amino acid sequence homology search revealed that pBSGT-3 encodes an AT. The recombinant AT (r-thiolase) was expressed in an active form in an E. coli expression system, and purified to homogeneity by selective ammonium sulfate fractionation and two steps of column chromatography. The purified enzyme exhibited a specific activity of 4.70 mU/mg protein. Its N-terminal sequence was (NH₂)-Arg-Met-Tyr-Thr-Thr-Ala-Lys-Asn-Leu-Glu-, which corresponds to the sequence from positions 15 to 24 of the amino acid sequence deduced from pBSGT-3 clone. The r-thiolase in the inclusion body expressed highly in E. coli was the precursor form, which is slightly larger than the purified r-thiolase. When incubated with the cell-free extract of Dictyostelium cells, the precursor was converted to the same size to the purified r-thiolase, suggesting that the presequence at the N-terminus is removed by a Dictyostelium processing peptidase.
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Affiliation(s)
- Takeshi Tanaka
- Department of Biochemistry and Molecular Biology, Faculty of Agriculture and Life Science, Hirosaki University, 3 Bunkyo-cho, Hirosaki 036-8561, Japan
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Kim EJ, Kim E, Kwon EY, Jang HS, Hur CG, Choi MS. Network analysis of hepatic genes responded to high-fat diet in C57BL/6J mice: nutrigenomics data mining from recent research findings. J Med Food 2010; 13:743-56. [PMID: 20553184 DOI: 10.1089/jmf.2009.1350] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Obesity and its associated complications, including diabetes, dyslipidemia, atherosclerosis, and some cancers, have been a global health problem with a rapid increase of the obese population. In this study, we selected 31 obesity candidate genes in the liver of high-fat-induced obese C57BL/6J mice through investigation of literature search and analyzed functional protein-protein interaction of the genes using the STRING database. Most of the obesity candidate genes were closely connected through lipid metabolism, and in particular acyl-coenzyme A oxidase 1 appeared to be a core obesity gene. Overall, genes involved in fatty acid beta-oxidation, fatty acid synthesis, and gluconeogenesis were up-regulated, and genes involved in sterol biosynthesis, insulin signaling, and oxidative stress defense system were down-regulated with a high-fat diet. Future identification of core obesity genes and their functional targets is expected to provide a new way to prevent obesity by phytochemicals or functional foods on the basis of food and nutritional genomics.
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Affiliation(s)
- Eun Jung Kim
- Department of Food Science and Nutrition, Food and Nutritional Genomics Research Center, Kyungpook National University, Daegu, Republic of Korea
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12
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Anthonio EA, Brees C, Baumgart-Vogt E, Hongu T, Huybrechts SJ, Van Dijck P, Mannaerts GP, Kanaho Y, Van Veldhoven PP, Fransen M. Small G proteins in peroxisome biogenesis: the potential involvement of ADP-ribosylation factor 6. BMC Cell Biol 2009; 10:58. [PMID: 19686593 PMCID: PMC3224584 DOI: 10.1186/1471-2121-10-58] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2009] [Accepted: 08/17/2009] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Peroxisomes execute diverse and vital functions in virtually every eukaryote. New peroxisomes form by budding from pre-existing organelles or de novo by vesiculation of the ER. It has been suggested that ADP-ribosylation factors and COPI coatomer complexes are involved in these processes. RESULTS Here we show that all viable Saccharomyces cerevisiae strains deficient in one of the small GTPases which have an important role in the regulation of vesicular transport contain functional peroxisomes, and that the number of these organelles in oleate-grown cells is significantly upregulated in the arf1 and arf3 null strains compared to the wild-type strain. In addition, we provide evidence that a portion of endogenous Arf6, the mammalian orthologue of yeast Arf3, is associated with the cytoplasmic face of rat liver peroxisomes. Despite this, ablation of Arf6 did neither influence the regulation of peroxisome abundance nor affect the localization of peroxisomal proteins in cultured fetal hepatocytes. However, co-overexpression of wild-type, GTP hydrolysis-defective or (dominant-negative) GTP binding-defective forms of Arf1 and Arf6 caused mislocalization of newly-synthesized peroxisomal proteins and resulted in an alteration of peroxisome morphology. CONCLUSION These observations suggest that Arf6 is a key player in mammalian peroxisome biogenesis. In addition, they also lend strong support to and extend the concept that specific Arf isoform pairs may act in tandem to regulate exclusive trafficking pathways.
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Affiliation(s)
- Erin A Anthonio
- Department of Molecular Cell Biology, Catholic University of Leuven, Leuven, Belgium.
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Bilbao E, Cajaraville MP, Cancio I. Cloning and expression pattern of peroxisomal β-oxidation genes palmitoyl-CoA oxidase, multifunctional protein and 3-ketoacyl-CoA thiolase in mussel Mytilus galloprovincialis and thicklip grey mullet Chelon labrosus. Gene 2009; 443:132-42. [DOI: 10.1016/j.gene.2009.05.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2009] [Revised: 04/24/2009] [Accepted: 05/13/2009] [Indexed: 11/17/2022]
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Huybrechts SJ, Van Veldhoven PP, Hoffman I, Zeevaert R, de Vos R, Demaerel P, Brams M, Jaeken J, Fransen M, Cassiman D. Identification of a novel PEX14 mutation in Zellweger syndrome. BMJ Case Rep 2009; 2009:bcr07.2008.0503. [PMID: 21686775 DOI: 10.1136/bcr.07.2008.0503] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Here we report a patient with Zellweger syndrome, who presented at the age of 3 months with icterus, dystrophy, axial hypotonia, and hepatomegaly. Abnormal findings of metabolic screening tests included hyperbilirubinaemia, hypoketotic dicarboxylic aciduria, increased C(26:0) and decreased C(22:0) plasma levels, and strongly reduced plasmalogen concentrations. In fibroblasts, both peroxisomal α- and β-oxidation were impaired. Liver histology revealed bile duct paucity, cholestasis, arterial hyperplasia, very small branches of the vena portae, and parenchymatic destruction. Immunocytochemical analysis of cultured fibroblasts demonstrated that the cells contain peroxisomal remnants lacking apparent matrix protein content and PEX14, a central membrane component of the peroxisomal matrix protein import machinery. Transfection of fibroblasts with a plasmid coding for wild-type PEX14 restored peroxisomal matrix protein import. Mutational analysis of this gene revealed a genomic deletion leading to the deletion of exon 3 from the coding DNA (c.85-?_170+?del) and a concomitant change of the reading frame (p.[Ile29_Lys56del;Gly57GlyfsX2]).
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Affiliation(s)
- Sofie J Huybrechts
- K.U.Leuven, Moleculaire Celbiologie, Campust Gasthuisberg ON1, Herestraat 49 box 601, Leuven, 3000, Belgium
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Ahumada I, Cairó A, Hemmerlin A, González V, Pateraki I, Bach TJ, Rodríguez-Concepción M, Campos N, Boronat A. Characterisation of the gene family encoding acetoacetyl-CoA thiolase in Arabidopsis. FUNCTIONAL PLANT BIOLOGY : FPB 2008; 35:1100-1111. [PMID: 32688858 DOI: 10.1071/fp08012] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2008] [Accepted: 07/30/2008] [Indexed: 05/26/2023]
Abstract
Thiolases are ubiquitous enzymes involved in many essential biochemical processes. Biosynthetic thiolases, also known as acetoacetyl-CoA thiolases (AACT), catalyse a reversible Claisen-type condensation of two acetyl-CoA molecules to form acetoacetyl-CoA. Here, we report the characterisation of two genes from Arabidopsis thaliana L., ACT1 and ACT2, which encode two closely related AACT isoforms (AACT1 and AACT2, respectively). Transient expression of constructs encoding AACT1 and AACT2 fused to GFP revealed that the two proteins show a different subcellular localisation. While AACT1 is found in peroxisomes, AACT2 localises in the cytosol and the nucleus. The peroxisomal localisation of AACT1 depends on the presence of a C-terminal peroxisomal targeting sequence (PTS1) motif (Ser-Ala-Leu) not previously found in other organisms. ACT1 and ACT2 genes are also differentially expressed. Whereas ACT2 is expressed at relatively high level in all plant tissues, the expression of ACT1 is restricted to roots and inflorescences and its transcript is present at very low levels. The obtained results are in agreement with the involvement of AACT2 in catalysing the first step of the mevalonate pathway. The metabolic function of AACT1 is not clear at present, although its particular peroxisomal localisation might exclude a role in isoprenoid biosynthesis.
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Affiliation(s)
- Iván Ahumada
- Departament de Bioquímica i Biologia Molecular, Facultat de Biologia, Universitat de Barcelona, Avda. Diagonal 645, 08028 Barcelona, Spain
| | - Albert Cairó
- Departament de Bioquímica i Biologia Molecular, Facultat de Biologia, Universitat de Barcelona, Avda. Diagonal 645, 08028 Barcelona, Spain
| | - Andréa Hemmerlin
- Centre National de la Recherche Scientifique, UPR 2357, Institut de Biologie Moléculaire des Plantes, 28 rue Goethe, 67083 Strasbourg Cedex, France
| | - Víctor González
- Departament de Bioquímica i Biologia Molecular, Facultat de Biologia, Universitat de Barcelona, Avda. Diagonal 645, 08028 Barcelona, Spain
| | - Irene Pateraki
- Departament de Bioquímica i Biologia Molecular, Facultat de Biologia, Universitat de Barcelona, Avda. Diagonal 645, 08028 Barcelona, Spain
| | - Thomas J Bach
- Centre National de la Recherche Scientifique, UPR 2357, Institut de Biologie Moléculaire des Plantes, 28 rue Goethe, 67083 Strasbourg Cedex, France
| | - Manuel Rodríguez-Concepción
- Departament de Bioquímica i Biologia Molecular, Facultat de Biologia, Universitat de Barcelona, Avda. Diagonal 645, 08028 Barcelona, Spain
| | - Narciso Campos
- Departament de Bioquímica i Biologia Molecular, Facultat de Biologia, Universitat de Barcelona, Avda. Diagonal 645, 08028 Barcelona, Spain
| | - Albert Boronat
- Departament de Bioquímica i Biologia Molecular, Facultat de Biologia, Universitat de Barcelona, Avda. Diagonal 645, 08028 Barcelona, Spain
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16
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Zhou Y, Zhang X, Chen L, Wu J, Dang H, Wei M, Fan Y, Zhang Y, Zhu Y, Wang N, Breyer MD, Guan Y. Expression profiling of hepatic genes associated with lipid metabolism in nephrotic rats. Am J Physiol Renal Physiol 2008; 295:F662-71. [PMID: 18614621 DOI: 10.1152/ajprenal.00046.2008] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Hyperlipidemia is one of the major features of nephrotic syndrome (NS). Although many factors have been implicated in the pathogenesis of NS-related dyslipidemia, the underlying mechanisms remain largely uncharacterized. The present study was designed to examine the gene profile associated with lipid metabolism in the livers of nephrotic rats. NS was created in male Sprague-Dawley rats (n = 6) receiving sequential intraperitoneal injections of puromycin aminonucleoside. Analysis by Affymetrix assay, quantitative RT-PCR, and Northern and Western blotting revealed 21 genes associated with cholesterol and fatty acid metabolism. Eight genes involved in cholesterol metabolism, Apo A-I, Acly, Acat, Mpd, Fdps, Ss, Lss, and Nsdhl, were significantly upregulated under NS. Four genes involved in fatty acid biosynthesis, Acc, FAS, ELOVL 2, and ELOVL6, and three critical for triglyceride biosynthesis, Gpam, Agpat 3, and Dgat 1, were significantly upregulated, whereas two genes involved in fatty acid oxidation, Dci and MCAD, were downregulated. Expression of several genes in sterol-regulatory element-binding protein (SREBP)-1 activation was also aberrantly altered in nephrotic livers. The expression and transcriptional activity of SREBP-1 but not SREBP-2 were increased in nephrotic rats as assessed by real-time PCR, immunoblotting, and gel shift assays. The upregulation of hepatic genes involved in cholesterol biosynthesis may play an important role in the pathogenesis of hypercholesterolemia, whereas upregulation of genes participating in hepatic fatty acid and triglyceride biosynthesis and downregulation of genes involved in hepatic fatty acid oxidation may contribute to hypertriglyceridemia in nephrotic rats. Activation of SREBP-1 transcription factor may represent an underlying molecular mechanism of hyperlipidemia in NS.
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Affiliation(s)
- Yunfeng Zhou
- Department of Physiology and Pathophysiology, Peking University Health Science Center, 38 Xueyuan Rd., Beijing, China
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Dolt KS, Karar J, Mishra MK, Salim J, Kumar R, Grover SK, Qadar Pasha MA. Transcriptional downregulation of sterol metabolism genes in murine liver exposed to acute hypobaric hypoxia. Biochem Biophys Res Commun 2007; 354:148-53. [PMID: 17207770 DOI: 10.1016/j.bbrc.2006.12.159] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2006] [Accepted: 12/21/2006] [Indexed: 09/30/2022]
Abstract
Ascent to high-altitude results in decreased inspired partial pressure of oxygen because of a decrease in barometric pressure. Altitude acclimatization requires physiological and metabolic changes to improve tolerance to altitude hypoxia. Cellular response to hypoxia results into changes in the profile of gene expression and the present study explored the same in murine model. Liver being the largest metabolic organ, the molecular details of acute hypobaric hypoxia (AHH) induced transcriptional changes in the tissue were investigated. Swiss albino mice were exposed to hypobaric hypoxia ( approximately 426mmHg) in a decompression chamber and cDNA microarray was used to study the transcriptional profile in liver. Notably, by the tenth hour several of the genes involved in sterol metabolism such as SREBF1, INSIG1, HMGCS1, FDFT1, SQLE, and HSD3B4 were downregulated more than 2-fold suggesting that AHH suppresses sterol biosynthesis in the liver. Real-time PCR helped validate the downregulation of SREBF1, HMGCS1, FDFT1, and HSD3B4 genes. However, no significant change was observed in the serum cholesterol levels throughout the AHH exposure. The findings are indicative of transcriptional downregulation of SREBP target genes as a part of acclimatization response to hypoxia. The study highlights the significance of SREBP in the regulation of sterol metabolism under the acute hypoxic response.
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Affiliation(s)
- Karamjit S Dolt
- Institute of Genomics and Integrative Biology, Delhi, India; Department of Biochemistry, Jamia Hamdard, New Delhi, India
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18
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Kovacs WJ, Tape KN, Shackelford JE, Duan X, Kasumov T, Kelleher JK, Brunengraber H, Krisans SK. Localization of the pre-squalene segment of the isoprenoid biosynthetic pathway in mammalian peroxisomes. Histochem Cell Biol 2006; 127:273-90. [PMID: 17180682 DOI: 10.1007/s00418-006-0254-6] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/31/2006] [Indexed: 10/23/2022]
Abstract
Previous studies have indicated that the early steps in the isoprenoid/cholesterol biosynthetic pathway occur in peroxisomes. However, the role of peroxisomes in cholesterol biosynthesis has recently been questioned in several reports concluding that three of the peroxisomal cholesterol biosynthetic enzymes, namely mevalonate kinase, phosphomevalonate kinase, and mevalonate diphosphate decarboxylase, do not localize to peroxisomes in human cells even though they contain consensus peroxisomal targeting signals. We re-investigated the subcellular localization of the cholesterol biosynthetic enzymes of the pre-squalene segment in human cells by using new stable isotopic techniques and data computations with isotopomer spectral analysis, in combination with immunofluorescence and cell permeabilization techniques. Our present findings clearly show and confirm previous studies that the pre-squalene segment of the cholesterol biosynthetic pathway is localized to peroxisomes. In addition, our data are consistent with the hypothesis that acetyl-CoA derived from peroxisomal beta-oxidation of very long-chain fatty acids and medium-chain dicarboxylic acids is preferentially channeled to cholesterol synthesis inside the peroxisomes without mixing with the cytosolic acetyl-CoA pool.
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Affiliation(s)
- Werner J Kovacs
- Department of Biology, San Diego State University, San Diego, CA, USA.
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Kursula P, Sikkilä H, Fukao T, Kondo N, Wierenga RK. High resolution crystal structures of human cytosolic thiolase (CT): a comparison of the active sites of human CT, bacterial thiolase, and bacterial KAS I. J Mol Biol 2005; 347:189-201. [PMID: 15733928 DOI: 10.1016/j.jmb.2005.01.018] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2004] [Revised: 01/05/2005] [Accepted: 01/06/2005] [Indexed: 10/25/2022]
Abstract
Thiolases belong to a superfamily of condensing enzymes that includes also beta-ketoacyl acyl carrier protein synthases (KAS enzymes), involved in fatty acid synthesis. Here, we describe the high resolution structure of human cytosolic acetoacetyl-CoA thiolase (CT), both unliganded (at 2.3 angstroms resolution) and in complex with CoA (at 1.6 angstroms resolution). CT catalyses the condensation of two molecules of acetyl-CoA to acetoacetyl-CoA, which is the first reaction of the metabolic pathway leading to the synthesis of cholesterol. CT is a homotetramer of exact 222 symmetry. There is an excess of positively charged residues at the interdimer surface leading towards the CoA-binding pocket, possibly important for the efficient capture of substrates. The geometry of the catalytic site, including the three catalytic residues Cys92, His 353, Cys383, and the two oxyanion holes, is highly conserved between the human and bacterial Zoogloea ramigera thiolase. In human CT, the first oxyanion hole is formed by Wat38 (stabilised by Asn321) and NE2(His353), and the second by N(Cys92) and N(Gly385). The active site of this superfamily is constructed on top of four active site loops, near Cys92, Asn321, His353, and Cys383, respectively. These loops were used for the superpositioning of CT on the bacterial thiolase and on the Escherichia coli KAS I. This comparison indicates that the two thiolase oxyanion holes also exist in KAS I at topologically equivalent positions. Interestingly, the hydrogen bonding interactions at the first oxyanion hole are different in thiolase and KAS I. In KAS I, the hydrogen bonding partners are two histidine NE2 atoms, instead of a water and a NE2 side-chain atom in thiolase. The second oxyanion hole is in both structures shaped by corresponding main chain peptide NH-groups. The possible importance of bound water molecules at the catalytic site of thiolase for the reaction mechanism is discussed.
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Affiliation(s)
- Petri Kursula
- Department of Biochemistry and Biocenter Oulu, P.O. Box 3000, FIN-90014 University of Oulu, Oulu, Finland
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Pantazaki AA, Ioannou AK, Kyriakidis DA. A thermostable #x003B2;-ketothiolase of polyhydroxyalkanoates (PHAs) in Thermus thermophilus: Purification and biochemical properties. Mol Cell Biochem 2005; 269:27-36. [PMID: 15786714 DOI: 10.1007/s11010-005-2992-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Polyhydroxyalkanoates (PHAs) are polyesters of hydroxyalkanoates (HAs) synthesised by numerous bacteria as intracellular carbon and energy storage compounds which accumulate as granules in the cytoplasm of the cells. The biosynthesis of PHAs, in the thermophilic bacterium T. thermophilus grown in a mineral medium supplemented with sodium gluconate as sole carbon source has been recently reported. Here, we report the purification at apparent homogeneity of a beta-ketoacyl-CoA thiolase from T. thermophilus, the first enzyme of the most common biosynthetic pathway for PHAs. B-Ketoacyl-CoA thiolase appeared as a single band of 45.5-kDa molecular mass on SDS/PAGE. The enzyme was purified 390-fold with 7% recovery. The native enzyme is a multimeric protein of a molecular mass of approximately of 182 kDa consisting of four identical subunits of 45.5 kDa, as identified by an in situ renaturation experiment on SDS-PAGE. The enzyme exhibited an optimal pH of approximately 8.0 and highest activity at 65 degrees C for both direction of the reaction. The thiolysis reaction showed a substrate inhibition at high concentrations; when one of the substrates (acetoacetyl CoA or CoA) is varied, while the concentrations of the second substrates (CoA or acetoacetyl CoA respectively) remain constant. The initial velocity kinetics showed a pattern of a family of parallel lines, which is in accordance with a ping-pong mechanism. beta-Ketothiolase had a relative low Km of 0.25 mM for acetyl-CoA and 11 microM and 25 microM for CoA and acetoacetyl-CoA, respectively. The enzyme was inhibited by treatment with 1 mM N-ethylmaleimide either in the presence or in the absence of 0.5 mM of acetyl-CoA suggesting that possibly a cysteine is located at/or near the active site of beta-ketothiolase.
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Affiliation(s)
- Anastasia A Pantazaki
- Laboratory of Biochemistry, Department of Chemistry, Aristotle University of Thessaloniki, Thessaloniki, Greece
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21
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Antonenkov VD, Sormunen RT, Hiltunen JK. The behavior of peroxisomes in vitro: mammalian peroxisomes are osmotically sensitive particles. Am J Physiol Cell Physiol 2004; 287:C1623-35. [PMID: 15306541 DOI: 10.1152/ajpcell.00142.2004] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
It has been known for a long time that mammalian peroxisomes are extremely fragile in vitro. Changes in the morphological appearance and leakage of proteins from purified particles demonstrate that peroxisomes are damaged during isolation. However, some properties of purified peroxisomes, e.g., the latency of catalase, imply that their membranes are not disrupted. In the current study, we tried to ascertain the mechanism of this unusual behavior of peroxisomes in vitro. Biochemical and morphological examination of isolated peroxisomes subjected to sonication or to freezing and thawing showed that the membrane of the particles seals after disruption, restoring permeability properties. Transient damage of the membrane leads to the formation of peroxisomal "ghosts" containing nucleoid but nearly devoid of matrix proteins. The rate of leakage of matrix proteins from broken particles depended inversely on their molecular size. The effect of polyethylene glycols on peroxisomal integrity indicated that these particles are osmotically sensitive. Peroxisomes suffered an osmotic lysis during isolation that was resistant to commonly used low-molecular-mass osmoprotectors, e.g., sucrose. Damage to peroxisomes was partially prevented by applying more "bulky" osmoprotectors, e.g., polyethylene glycol 1500. A method was developed for the isolation of highly purified and nearly intact peroxisomes from rat liver by using polyethylene glycol 1500 as an osmoprotector.
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Affiliation(s)
- Vasily D Antonenkov
- Department of Biochemistry and Biocenter Oulu, University of Oulu, PO Box 3000, FIN-90014 Oulu, Finland.
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22
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Bremer J. The biochemistry of hypo- and hyperlipidemic fatty acid derivatives: metabolism and metabolic effects. Prog Lipid Res 2001; 40:231-68. [PMID: 11412891 DOI: 10.1016/s0163-7827(01)00004-2] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
A selection of amphipatic hyper- and hypolipidemic fatty acid derivatives (fibrates, thia- and branched chain fatty acids) are reviewed. They are probably all ligands for the peroxisome proliferation activation receptor (PPARalpha) which has a low selectivity for its ligands. These compounds give hyper- or hypolipidemic responses depending on their ability to inhibit or stimulate mitochondrial fatty acid oxidation in the liver. The hypolipidemic response is explained by the following metabolic effects: Lipoprotein lipase is induced in liver where it is normally not expressed. Apolipoprotein CIII is downregulated. These two effects in liver lead to a facilitated (re)uptake of chylomicrons and VLDL, thus creating a direct transport of fatty acids from the gut to the liver. Fatty acid metabolizing enzymes in the liver (CPT-I and II, peroxisomal and mitochondrial beta-oxidation enzymes, enzymes of ketogenesis, and omega-oxidation enzymes) are induced and create an increased capacity for fatty acid oxidation. The increased oxidation of fatty acids "drains" fatty acids from the body, reduces VLDL formation, and ultimately explains the antiadiposity and improved insulin sensitivity observed after administration of peroxisome proliferators.
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Affiliation(s)
- J Bremer
- Institute of Medical Biochemistry, University of Oslo, Pb 1112 Blindern, 0317, Oslo, Norway
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