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Kato R, Takenaka Y, Ohno Y, Kihara A. Catalytic mechanism of trans-2-enoyl-CoA reductases in the fatty acid elongation cycle and its cooperative action with fatty acid elongases. J Biol Chem 2024; 300:105656. [PMID: 38224948 PMCID: PMC10864336 DOI: 10.1016/j.jbc.2024.105656] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2023] [Revised: 01/06/2024] [Accepted: 01/08/2024] [Indexed: 01/17/2024] Open
Abstract
The fatty acid (FA) elongation cycle produces very-long-chain FAs with ≥C21, which have unique physiological functions. Trans-2-enoyl-CoA reductases (yeast, Tsc13; mammals, TECR) catalyze the reduction reactions in the fourth step of the FA elongation cycle and in the sphingosine degradation pathway. However, their catalytic residues and coordinated action in the FA elongation cycle complex are unknown. To reveal these, we generated and analyzed Ala-substituted mutants of 15 residues of Tsc13. An in vitro FA elongation assay showed that nine of these mutants were less active than WT protein, with E91A and Y256A being the least active. Growth complementation analysis, measurement of ceramide levels, and deuterium-sphingosine labeling revealed that the function of the E91A mutant was substantially impaired in vivo. In addition, we found that the activity of FA elongases, which catalyze the first step of the FA elongation cycle, were reduced in the absence of Tsc13. Similar results were observed in Tsc13 E91A-expressing cells, which is attributable to reduced interaction between the Tsc13 E91A mutant and the FA elongases Elo2/Elo3. Finally, we found that E94A and Y248A mutants of human TECR, which correspond to E91A and Y256A mutants of Tsc13, showed reduced and almost no activity, respectively. Based on these results and the predicted three-dimensional structure of Tsc13, we speculate that Tyr256/Tyr248 of Tsc13/TECR is the catalytic residue that supplies a proton to trans-2-enoyl-CoAs. Our findings provide a clue concerning the catalytic mechanism of Tsc13/TECR and the coordinated action in the FA elongation cycle complex.
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Affiliation(s)
- Ryoya Kato
- Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo, Japan
| | - Yuka Takenaka
- Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo, Japan
| | - Yusuke Ohno
- Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo, Japan.
| | - Akio Kihara
- Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo, Japan.
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Ushio M, Ishikawa T, Matsuura T, Mori IC, Kawai-Yamada M, Fukao Y, Nagano M. MHP1 and MHL generate odd-chain fatty acids from 2-hydroxy fatty acids in sphingolipids and are related to immunity in Arabidopsis thaliana. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2023; 336:111840. [PMID: 37619867 DOI: 10.1016/j.plantsci.2023.111840] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Revised: 07/02/2023] [Accepted: 08/21/2023] [Indexed: 08/26/2023]
Abstract
In plants, the 2-hydroxy fatty acids (HFAs) of sphingolipids are important for plant growth and stress responses. Although the synthetic pathway of HFAs is well understood, their degradation has not yet been elucidated. In Saccharomyces cerevisiae, Mpo1 has been identified as a dioxygenase that degrades HFAs. This study examined the functions of two homologs of yeast Mpo1, MHP1 and MHL, in Arabidopsis thaliana. The mhp1 and mhp1mhl mutants showed a dwarf phenotype compared to that of the wild type. Lipid analysis of the mutants revealed the involvement of MHP1 and MHL in synthesizing odd-chain fatty acids (OCFAs), possibly by the degradation of HFAs. OCFAs are present in trace amounts in plants; however, their physiological significance is largely unknown. RNA sequence analysis of the mhp1mhl mutant revealed that growth-related genes decreased, whereas genes involved in stress response increased. Additionally, the mhp1mhl mutant had increased expression of defense-related genes and increased resistance to infection by Pseudomonas syringae pv. tomato DC3000 (Pto), and Pto carrying the effector AvrRpt2. Phytohormone analysis demonstrated that jasmonic acid in mhp1mhl was higher than that in the wild type. These results indicate that MHP1 and MHL are involved in synthesizing OCFAs and immunity in Arabidopsis.
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Affiliation(s)
- Marina Ushio
- Graduate School of Life Sciences, Ritsumeikan University, 1-1-1 Nojihigashi, Kusatsu, Shiga 525-8577, Japan
| | - Toshiki Ishikawa
- Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Sakuraku, Saitama 338-8570, Japan
| | - Takakazu Matsuura
- Institute of Plant Science and Resources, Okayama University, 2-20-1 Chuo, Kurashiki 710-0046, Japan
| | - Izumi C Mori
- Institute of Plant Science and Resources, Okayama University, 2-20-1 Chuo, Kurashiki 710-0046, Japan
| | - Maki Kawai-Yamada
- Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Sakuraku, Saitama 338-8570, Japan
| | - Yoichiro Fukao
- Graduate School of Life Sciences, Ritsumeikan University, 1-1-1 Nojihigashi, Kusatsu, Shiga 525-8577, Japan; College of Life Sciences, Ritsumeikan University, 1-1-1 Nojihigashi, Kusatsu, Shiga 525-8577, Japan
| | - Minoru Nagano
- College of Life Sciences, Ritsumeikan University, 1-1-1 Nojihigashi, Kusatsu, Shiga 525-8577, Japan.
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Mori K, Naganuma T, Kihara A. Role of 2-hydroxy acyl-CoA lyase HACL2 in odd-chain fatty acid production via α-oxidation in vivo. Mol Biol Cell 2023; 34:ar85. [PMID: 37285239 PMCID: PMC10398889 DOI: 10.1091/mbc.e23-02-0042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Revised: 05/22/2023] [Accepted: 05/30/2023] [Indexed: 06/09/2023] Open
Abstract
Although most fatty acids (FAs) are even chain, certain tissues, including brain, contain relatively large quantities of odd-chain FAs in their sphingolipids. One of the pathways producing odd-chain FAs is the α-oxidation of 2-hydroxy (2-OH) FAs, where 2-OH acyl-CoA lyases (HACL1 and HACL2) catalyze the key cleavage reaction. However, the contribution of each HACL to odd-chain FA production in vivo remains unknown. Here, we found that HACL2 and HACL1 play major roles in the α-oxidation of 2-OH FAs (especially very-long-chain types) and 3-methyl FAs (other α-oxidation substrates), respectively, using ectopic expression systems of human HACL2 and HACL1 in yeast and analyzing Hacl1 and/or Hacl2 knockout (KO) CHO-K1 cells. We then generated Hacl2 KO mice and measured the quantities of odd-chain and 2-OH lipids (free FAs and sphingolipids [ceramides, sphingomyelins, and monohexosylceramides]) in 17 tissues. We observed fewer odd-chain lipids and more 2-OH lipids in many tissues of Hacl2 KO mice than in wild-type mice, and of these differences the reductions were most prominent for odd-chain monohexosylceramides in the brain and ceramides in the stomach. These results indicate that HACL2-involved α-oxidation of 2-OH FAs is mainly responsible for odd-chain FA production in the brain and stomach.
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Affiliation(s)
- Keisuke Mori
- Laboratory of Biochemistry, Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo 060-0812, Japan
| | - Tatsuro Naganuma
- Laboratory of Biochemistry, Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo 060-0812, Japan
| | - Akio Kihara
- Laboratory of Biochemistry, Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo 060-0812, Japan
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Yang W, Gutbrod P, Gutbrod K, Peisker H, Song X, Falz AL, Meyer AJ, Dörmann P. 2-Hydroxy-phytanoyl-CoA lyase (AtHPCL) is involved in phytol metabolism in Arabidopsis. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2022; 109:1290-1304. [PMID: 34902195 DOI: 10.1111/tpj.15632] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Revised: 12/03/2021] [Accepted: 12/07/2021] [Indexed: 06/14/2023]
Abstract
During chlorophyll degradation, large amounts of the isoprenoid alcohol phytol are released. The pathway of phytol catabolism has been studied in humans, because chlorophyll is part of the human diet, but little is known for plants. In humans, phytanoyl-CoA derived from phytol is degraded via α-oxidation by phytanoyl-CoA hydroxylase (PAHX) and 2-hydroxy-phytanoyl-CoA lyase (HPCL). Arabidopsis contains two sequences homologous to the human proteins AtPAHX and AtHPCL. Insertional mutants of Arabidopsis (pahx, hpcl) were grown under N deprivation to stimulate chlorophyll breakdown or supplemented with phytol to increase the endogenous amount of phytol. During N deprivation, chlorophyll, phytol, phytenal, upstream metabolites of phytol breakdown, and tocopherol and fatty acid phytyl esters, alternative phytol-derived lipids, accumulated in pahx and hpcl mutants, in line with the scenario that the mutations interfere with phytol degradation. AtHPCL was localized to the peroxisomes. Expression analysis of the AtHPCL sequence in the yeast Δpxp1 or Δmpo1 mutants followed by supplementation with 2-hydroxy-palmitic acid and enzyme assays of peroxisomal proteins from Col-0 and hpcl plants with 2-hydroxy-stearoyl-CoA revealed that AtHPCL harbors 2-hydroxy-acyl-CoA lyase activity. The α-dioxygenases αDOX1 and αDOX2 are involved in α-oxidation of fatty acids and could be involved in an alternative pathway of phytol degradation. However, phytol-related lipids in the αdox1, αdox2, or αdox1 αdox2 mutants were not altered compared with Col-0, indicating that αDOX1 and αDOX2 are not involved in phytol degradation. These results demonstrate that phytol degradation in Arabidopsis involves α-oxidation by AtPAHX and AtHPCL, but that it is independent of αDOX1/αDOX2.
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Affiliation(s)
- Wentao Yang
- Institute of Molecular Physiology and Biotechnology of Plants (IMBIO), University of Bonn, Karlrobert-Kreiten-Straße 13, 53115, Bonn, Germany
| | - Philipp Gutbrod
- Institute of Molecular Physiology and Biotechnology of Plants (IMBIO), University of Bonn, Karlrobert-Kreiten-Straße 13, 53115, Bonn, Germany
| | - Katharina Gutbrod
- Institute of Molecular Physiology and Biotechnology of Plants (IMBIO), University of Bonn, Karlrobert-Kreiten-Straße 13, 53115, Bonn, Germany
| | - Helga Peisker
- Institute of Molecular Physiology and Biotechnology of Plants (IMBIO), University of Bonn, Karlrobert-Kreiten-Straße 13, 53115, Bonn, Germany
| | - Xiaoning Song
- Institute of Molecular Physiology and Biotechnology of Plants (IMBIO), University of Bonn, Karlrobert-Kreiten-Straße 13, 53115, Bonn, Germany
| | - Anna-Lena Falz
- Institute of Crop Science and Resource Conservation (INRES), University of Bonn, Friedrich-Ebert-Allee 144, 53113, Bonn, Germany
| | - Andreas J Meyer
- Institute of Crop Science and Resource Conservation (INRES), University of Bonn, Friedrich-Ebert-Allee 144, 53113, Bonn, Germany
| | - Peter Dörmann
- Institute of Molecular Physiology and Biotechnology of Plants (IMBIO), University of Bonn, Karlrobert-Kreiten-Straße 13, 53115, Bonn, Germany
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