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Tonazzi A, Giangregorio N, Console L, Palmieri F, Indiveri C. The Mitochondrial Carnitine Acyl-carnitine Carrier (SLC25A20): Molecular Mechanisms of Transport, Role in Redox Sensing and Interaction with Drugs. Biomolecules 2021; 11:biom11040521. [PMID: 33807231 PMCID: PMC8066319 DOI: 10.3390/biom11040521] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 03/23/2021] [Accepted: 03/26/2021] [Indexed: 12/22/2022] Open
Abstract
The SLC25A20 transporter, also known as carnitine acyl-carnitine carrier (CAC), catalyzes the transport of short, medium and long carbon chain acyl-carnitines across the mitochondrial inner membrane in exchange for carnitine. The 30-year story of the protein responsible for this function started with its purification from rat liver mitochondria. Even though its 3D structure is not yet available, CAC is one of the most deeply characterized transport proteins of the inner mitochondrial membrane. Other than functional, kinetic and mechanistic data, post-translational modifications regulating the transport activity of CAC have been revealed. CAC interactions with drugs or xenobiotics relevant to human health and toxicology and the response of the carrier function to dietary compounds have been discovered. Exploiting combined approaches of site-directed mutagenesis with chemical targeting and bioinformatics, a large set of data on structure/function relationships have been obtained, giving novel information on the molecular mechanism of the transport catalyzed by this protein.
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Affiliation(s)
- Annamaria Tonazzi
- Institute of Biomembranes, Bioenergetics and Molecular Biotechnologies (IBIOM), National Research Council, Via Orabona 4, 70126 Bari, Italy; (A.T.); (N.G.)
| | - Nicola Giangregorio
- Institute of Biomembranes, Bioenergetics and Molecular Biotechnologies (IBIOM), National Research Council, Via Orabona 4, 70126 Bari, Italy; (A.T.); (N.G.)
| | - Lara Console
- Unit of Biochemistry and Molecular Biotechnology, Department DiBEST (Biologia, Ecologia, Scienze della Terra), University of Calabria, Via P. Bucci 4C, 87036 Arcavacata di Rende, Italy;
| | - Ferdinando Palmieri
- Institute of Biomembranes, Bioenergetics and Molecular Biotechnologies (IBIOM), National Research Council, Via Orabona 4, 70126 Bari, Italy; (A.T.); (N.G.)
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, 70125 Bari, Italy
- Correspondence: (F.P.); (C.I.); Tel.: +39-080-544-3323 (F.P.); Tel.: +39-0984-492939 (C.I.)
| | - Cesare Indiveri
- Institute of Biomembranes, Bioenergetics and Molecular Biotechnologies (IBIOM), National Research Council, Via Orabona 4, 70126 Bari, Italy; (A.T.); (N.G.)
- Unit of Biochemistry and Molecular Biotechnology, Department DiBEST (Biologia, Ecologia, Scienze della Terra), University of Calabria, Via P. Bucci 4C, 87036 Arcavacata di Rende, Italy;
- Correspondence: (F.P.); (C.I.); Tel.: +39-080-544-3323 (F.P.); Tel.: +39-0984-492939 (C.I.)
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Comparative transcriptome analysis between an evolved abscisic acid-overproducing mutant Botrytis cinerea TBC-A and its ancestral strain Botrytis cinerea TBC-6. Sci Rep 2016; 6:37487. [PMID: 27892476 PMCID: PMC5124961 DOI: 10.1038/srep37487] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Accepted: 10/31/2016] [Indexed: 12/21/2022] Open
Abstract
Abscisic acid (ABA) is a classical phytohormone which plays an important role in plant stress resistance. Moreover, ABA is also found to regulate the activation of innate immune cells and glucose homeostasis in mammals. Therefore, this ‘stress hormone’ is of great importance to theoretical research and agricultural and medical applications. Botrytis cinerea is a well-known phytopathogenic ascomycete that synthesizes ABA via a pathway substantially different from higher plants. Identification of the functional genes involved in ABA biosynthesis in B. cinerea would be of special interest. We developed an ABA-overproducing mutant strain, B. cinerea TBC-A, previously and obtained a 41.5-Mb genome sequence of B. cinerea TBC-A. In this study, the transcriptomes of B. cinerea TBC-A and its ancestral strain TBC-6 were sequenced under identical fermentation conditions. A stringent comparative transcriptome analysis was performed to identify differentially expressed genes participating in the metabolic pathways related to ABA biosynthesis in B. cinerea. This study provides the first global view of the transcriptional changes underlying the very different ABA productivity of the B. cinerea strains and will expand our knowledge of the molecular basis for ABA biosynthesis in B. cinerea.
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Flipphi M, Oestreicher N, Nicolas V, Guitton A, Vélot C. The Aspergillus nidulans acuL gene encodes a mitochondrial carrier required for the utilization of carbon sources that are metabolized via the TCA cycle. Fungal Genet Biol 2014; 68:9-22. [DOI: 10.1016/j.fgb.2014.04.012] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2014] [Revised: 04/24/2014] [Accepted: 04/29/2014] [Indexed: 10/25/2022]
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Otzen C, Bardl B, Jacobsen ID, Nett M, Brock M. Candida albicans utilizes a modified β-oxidation pathway for the degradation of toxic propionyl-CoA. J Biol Chem 2014; 289:8151-69. [PMID: 24497638 DOI: 10.1074/jbc.m113.517672] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Propionyl-CoA arises as a metabolic intermediate from the degradation of propionate, odd-chain fatty acids, and some amino acids. Thus, pathways for catabolism of this intermediate have evolved in all kingdoms of life, preventing the accumulation of toxic propionyl-CoA concentrations. Previous studies have shown that fungi generally use the methyl citrate cycle for propionyl-CoA degradation. Here, we show that this is not the case for the pathogenic fungus Candida albicans despite its ability to use propionate and valerate as carbon sources. Comparative proteome analyses suggested the presence of a modified β-oxidation pathway with the key intermediate 3-hydroxypropionate. Gene deletion analyses confirmed that the enoyl-CoA hydratase/dehydrogenase Fox2p, the putative 3-hydroxypropionyl-CoA hydrolase Ehd3p, the 3-hydroxypropionate dehydrogenase Hpd1p, and the putative malonate semialdehyde dehydrogenase Ald6p essentially contribute to propionyl-CoA degradation and its conversion to acetyl-CoA. The function of Hpd1p was further supported by the detection of accumulating 3-hydroxypropionate in the hpd1 mutant on propionyl-CoA-generating nutrients. Substrate specificity of Hpd1p was determined from recombinant purified enzyme, which revealed a preference for 3-hydroxypropionate, although serine and 3-hydroxyisobutyrate could also serve as substrates. Finally, virulence studies in a murine sepsis model revealed attenuated virulence of the hpd1 mutant, which indicates generation of propionyl-CoA from host-provided nutrients during infection.
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Yang J, Kong L, Chen X, Wang D, Qi L, Zhao W, Zhang Y, Liu X, Peng YL. A carnitine–acylcarnitine carrier protein, MoCrc1, is essential for pathogenicity in Magnaporthe oryzae. Curr Genet 2012; 58:139-48. [DOI: 10.1007/s00294-012-0372-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2012] [Revised: 02/26/2012] [Accepted: 03/12/2012] [Indexed: 11/29/2022]
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Role of carnitine acetyltransferases in acetyl coenzyme A metabolism in Aspergillus nidulans. EUKARYOTIC CELL 2011; 10:547-55. [PMID: 21296915 DOI: 10.1128/ec.00295-10] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The flow of carbon metabolites between cellular compartments is an essential feature of fungal metabolism. During growth on ethanol, acetate, or fatty acids, acetyl units must enter the mitochondrion for metabolism via the tricarboxylic acid cycle, and acetyl coenzyme A (acetyl-CoA) in the cytoplasm is essential for the biosynthetic reactions and for protein acetylation. Acetyl-CoA is produced in the cytoplasm by acetyl-CoA synthetase during growth on acetate and ethanol while β-oxidation of fatty acids generates acetyl-CoA in peroxisomes. The acetyl-carnitine shuttle in which acetyl-CoA is reversibly converted to acetyl-carnitine by carnitine acetyltransferase (CAT) enzymes is important for intracellular transport of acetyl units. In the filamentous ascomycete Aspergillus nidulans, a cytoplasmic CAT, encoded by facC, is essential for growth on sources of cytoplasmic acetyl-CoA while a second CAT, encoded by the acuJ gene, is essential for growth on fatty acids as well as acetate. We have shown that AcuJ contains an N-terminal mitochondrial targeting sequence and a C-terminal peroxisomal targeting sequence (PTS) and is localized to both peroxisomes and mitochondria, independent of the carbon source. Mislocalization of AcuJ to the cytoplasm does not result in loss of growth on acetate but prevents growth on fatty acids. Therefore, while mitochondrial AcuJ is essential for the transfer of acetyl units to mitochondria, peroxisomal localization is required only for transfer from peroxisomes to mitochondria. Peroxisomal AcuJ was not required for the import of acetyl-CoA into peroxisomes for conversion to malate by malate synthase (MLS), and export of acetyl-CoA from peroxisomes to the cytoplasm was found to be independent of FacC when MLS was mislocalized to the cytoplasm.
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ATP-citrate lyase is required for production of cytosolic acetyl coenzyme A and development in Aspergillus nidulans. EUKARYOTIC CELL 2010; 9:1039-48. [PMID: 20495057 DOI: 10.1128/ec.00080-10] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Acetyl coenzyme A (CoA) is a central metabolite in carbon and energy metabolism and in the biosynthesis of cellular molecules. A source of cytoplasmic acetyl-CoA is essential for the production of fatty acids and sterols and for protein acetylation, including histone acetylation in the nucleus. In Saccharomyces cerevisiae and Candida albicans acetyl-CoA is produced from acetate by cytoplasmic acetyl-CoA synthetase, while in plants and animals acetyl-CoA is derived from citrate via ATP-citrate lyase. In the filamentous ascomycete Aspergillus nidulans, tandem divergently transcribed genes (aclA and aclB) encode the subunits of ATP-citrate lyase, and we have deleted these genes. Growth is greatly diminished on carbon sources that do not result in cytoplasmic acetyl-CoA, such as glucose and proline, while growth is not affected on carbon sources that result in the production of cytoplasmic acetyl-CoA, such as acetate and ethanol. Addition of acetate restores growth on glucose or proline, and this is dependent on facA, which encodes cytoplasmic acetyl-CoA synthetase, but not on the regulatory gene facB. Transcription of aclA and aclB is repressed by growth on acetate or ethanol. Loss of ATP-citrate lyase results in severe developmental effects, with the production of asexual spores (conidia) being greatly reduced and a complete absence of sexual development. This is in contrast to Sordaria macrospora, in which fruiting body formation is initiated but maturation is defective in an ATP-citrate lyase mutant. Addition of acetate does not repair these defects, indicating a specific requirement for high levels of cytoplasmic acetyl-CoA during differentiation. Complementation in heterokaryons between aclA and aclB deletions for all phenotypes indicates that the tandem gene arrangement is not essential.
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Martínez O, Marco E, Gago F, Laborda F, Ramón De Lucas J. Suppression of the acuH13 and acuH31 nonsense mutations in the carnitine/acylcarnitine translocase (acuH) gene of Aspergillus nidulans by the G265S substitution in the domain 2 of the release factor eRF1. Fungal Genet Biol 2007; 44:139-51. [PMID: 16971148 DOI: 10.1016/j.fgb.2006.07.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2006] [Revised: 06/28/2006] [Accepted: 07/24/2006] [Indexed: 11/15/2022]
Abstract
A search for suppressors of the carnitine/acylcarnitine translocase (CACT) deficiency in Aspergillus nidulans permitted the identification of the suaE7 mutation, mapping at a new translational suppressor (suaE) gene. The suaE gene is essential in A. nidulans and encodes the eukaryotic release factor 1 (eRF1). The suaE7 mutation suppresses two acuH alleles (acuH13 and acuH31), both carrying nonsense mutations in the CACT encoding gene that involve the replacement of a CAG (Gln) codon with a premature TAG stop codon. In contrast, the suaE7 gene does not suppress the acuH20 amber nonsense mutation involving a TGG-->TAG change. The phenotype associated to the suaE7 mutation strictly resembles that of mutants at the suaA and suaC genes, two translational suppressor genes previously identified, suggesting that their gene products might functionally interact in translation termination. Sequencing of the suaE7 gene allowed the identification of a mutation in the domain 2 of the omnipotent class-1 eukaryotic release factor involving the Gly265Ser substitution in the A. nidulans eRF1. This mutation creates a structural context unfavourable for normal eRF binding that allows the misreading of stop codons by natural suppressor tRNAs, such as the tRNAs(Gln). Structural analysis using molecular modelling of A. nidulans eRF1 domain 2 bearing the G265S substitution and computer simulation results suggest that this mutation might impair the necessary conformational changes in the eRF1 to optimally recognize the stop codon and simultaneously interact with the peptidyl transferase centre of the 60S ribosomal subunit.
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Affiliation(s)
- Oscar Martínez
- Departamento de Microbiología y Parasitología, Facultad de Farmacia, Campus Universitario, Universidad de Alcalá, Carretera Madrid-Barcelona Km 33, Alcalá de Henares ES-28871, Madrid, Spain
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Rottensteiner H, Theodoulou FL. The ins and outs of peroxisomes: Co-ordination of membrane transport and peroxisomal metabolism. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2006; 1763:1527-40. [PMID: 17010456 DOI: 10.1016/j.bbamcr.2006.08.012] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2006] [Revised: 08/15/2006] [Accepted: 08/18/2006] [Indexed: 11/28/2022]
Abstract
Peroxisomes perform a range of metabolic functions which require the movement of substrates, co-substrates, cofactors and metabolites across the peroxisomal membrane. In this review, we discuss the evidence for and against specific transport systems involved in peroxisomal metabolism and how these operate to co-ordinate biochemical reactions within the peroxisome with those in other compartments of the cell.
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Affiliation(s)
- Hanspeter Rottensteiner
- Medical Faculty of the Ruhr-University of Bochum, Department of Physiological Chemistry, Section of Systems Biochemistry, 44780 Bochum, Germany.
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Pérez P, Martínez O, Romero B, Olivas I, Pedregosa AM, Palmieri F, Laborda F, Ramón De Lucas J. Functional analysis of mutations in the human carnitine/acylcarnitine translocase in Aspergillus nidulans. Fungal Genet Biol 2003; 39:211-20. [PMID: 12892634 DOI: 10.1016/s1087-1845(03)00049-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Deficiency of the carnitine/acylcarnitine translocase (CACT), the most severe disorder of fatty acid beta-oxidation, is usually lethal in both humans and animals, precluding the development of animal models of the disease. In contrast, CACT deficiency is conditionally lethal in the fungus Aspergillus nidulans, since loss-of-function mutations in acuH, the translocase structural gene, do not prevent growth on carbon sources other than ketogenic compounds, such as fatty acids. Here, we describe the molecular characterization of extant acuH alleles and the development of a fungal model for CACT deficiency based on the ability of human CACT to fully complement, when expressed at physiological levels, the growth defect of an A. nidulans DeltaacuH strain on acetate and long-chain fatty acids. By using growth tests and in vitro assays this model enabled us to carry out a functional characterization of human CACT mutations showing that it may be useful for distinguishing potentially pathogenic human CACT missense mutations from neutral, single residue substitution-causing polymorphisms.
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Affiliation(s)
- Patricia Pérez
- Departamento de Microbiología y Parasitología, Universidad de Alcalá, Carretera Madrid-Barcelona Km, 33.600, Alcalá de Henares ES-28871, Madrid, Spain
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