1
|
Wadhwa R, Hegde M, Zhang H, Kaul A, Wang J, Ishida Y, Terao K, Kunnumakkara AB, Kaul SC. Antistress and Antiaging Potentials of Alpha-Lipoic Acid: Insights from Cell Culture-Based Experiments. Appl Biochem Biotechnol 2024:10.1007/s12010-024-04994-4. [PMID: 38941028 DOI: 10.1007/s12010-024-04994-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/05/2024] [Indexed: 06/29/2024]
Abstract
Chronic stress has been linked to a large number of pathologies, including cancer, premature aging, and neurodegenerative diseases. The accumulation of molecular waste resulting from oxidative and heavy metal-induced stress has been ascribed as a major factor contributing to these diseases. With this in mind, we started by screening 13 small molecules to determine their antistress potential in heavy metal stress-exposed C6 glioblastoma and found that alpha-lipoic acid (ALA) (a natural antioxidant abundantly present in yeast, spinach, broccoli, and meat) was the most effective candidate. We then conducted molecular analyses to validate its mechanism of action. Dose-dependent toxicity assays of cells treated with two ALA enantiomers, R-ALA and S-ALA, showed that they are nontoxic and can be tolerated at relatively high doses. Cells exposed to heavy metal, heat, and oxidative stress showed better recovery when cultured in R-ALA-/S-ALA-supplemented medium, supported by reduction of reactive oxygen species (ROS), aggregated proteins, and mitochondrial and deoxyribonucleic acid (DNA) damage. Molecular analyses revealed protection against stress-induced apoptosis and induction of autophagy in R-ALA- and S-ALA-treated C6/U2OS cells. Consistent with these findings, normal human fibroblasts showed lifespan extension. Taken together, this study demonstrates that lipoic acid has antiaging and antistress potential and warrants further attention in laboratory and clinical studies.
Collapse
Affiliation(s)
- Renu Wadhwa
- AIST-INDIA DAILAB, National Institute of Advanced Industrial Science & Technology (AIST), Tsukuba, 305-8565, Japan
| | - Mangala Hegde
- Department of Biosciences and Bioengineering, Indian Institute of Technology (IIT), Guwahati, Assam, 781 039, India
| | - Huayue Zhang
- AIST-INDIA DAILAB, National Institute of Advanced Industrial Science & Technology (AIST), Tsukuba, 305-8565, Japan
| | - Ashish Kaul
- AIST-INDIA DAILAB, National Institute of Advanced Industrial Science & Technology (AIST), Tsukuba, 305-8565, Japan
| | - Jia Wang
- AIST-INDIA DAILAB, National Institute of Advanced Industrial Science & Technology (AIST), Tsukuba, 305-8565, Japan
| | - Yoshiyuki Ishida
- CycloChem Bio Co., Ltd., 7-4-5 Minatojima-Minamimachi, Chuo-Ku, Kobe, 650 0047, Japan
| | - Keiji Terao
- CycloChem Bio Co., Ltd., 7-4-5 Minatojima-Minamimachi, Chuo-Ku, Kobe, 650 0047, Japan
| | - Ajaikumar B Kunnumakkara
- Department of Biosciences and Bioengineering, Indian Institute of Technology (IIT), Guwahati, Assam, 781 039, India.
| | - Sunil C Kaul
- AIST-INDIA DAILAB, National Institute of Advanced Industrial Science & Technology (AIST), Tsukuba, 305-8565, Japan.
| |
Collapse
|
2
|
Dieckmann CL. A hub for regulation of mitochondrial metabolism: Fatty acid and lipoic acid biosynthesis. IUBMB Life 2024; 76:332-344. [PMID: 38088214 DOI: 10.1002/iub.2802] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Accepted: 11/21/2023] [Indexed: 05/28/2024]
Abstract
Having evolved from a prokaryotic origin, mitochondria retain pathways required for the catabolism of energy-rich molecules and for the biosynthesis of molecules that aid catabolism and/or participate in other cellular processes essential for life of the cell. Reviewed here are details of the mitochondrial fatty acid biosynthetic pathway (FAS II) and its role in building both the octanoic acid precursor for lipoic acid biosynthesis (LAS) and longer-chain fatty acids functioning in chaperoning the assembly of mitochondrial multisubunit complexes. Also covered are the details of mitochondrial lipoic acid biosynthesis, which is distinct from that of prokaryotes, and the attachment of lipoic acid to subunits of pyruvate dehydrogenase, α-ketoglutarate dehydrogenase, and glycine cleavage system complexes. Special emphasis has been placed on presenting what is currently known about the interconnected paths and loops linking the FAS II-LAS pathway and two other mitochondrial realms, the organellar translation machinery and Fe-S cluster biosynthesis and function.
Collapse
Affiliation(s)
- Carol L Dieckmann
- Department of Molecular and Cellular Biology, University of Arizona, Tucson, Arizona, USA
| |
Collapse
|
3
|
Norden PR, Wedan RJ, Longenecker JZ, Preston SEJ, Graber N, Ols O, Canfield M, McLaughlin E, Nowinski SM. Mitochondrial Phosphopantetheinylation is Required for Oxidative Function. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.09.592977. [PMID: 38766035 PMCID: PMC11100772 DOI: 10.1101/2024.05.09.592977] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2024]
Abstract
Sub-cellular compartmentalization of metabolism has important implications for the local production of metabolites and redox co-factors, as well as pathway regulation. 4'-phosphopantetheinyl (4'PP) groups are essential co-factors derived from coenzyme A and added to target proteins in both the cytoplasm and mitochondria by p hospho p antetheinyl transferase (PPTase) enzymes. Mammals express only one PPTase, thought to localize to the cytoplasm: aminoadipate semialdehyde dehydrogenase phosphopantetheinyl transferase (AASDHPPT); raising the question of how mitochondrial proteins are 4'PP-modified. We found that AASDHPPT is required for mitochondrial respiration and oxidative metabolism via the mitochondrial fatty acid synthesis (mtFAS) pathway. Moreover, we discovered that a pool of AASDHPPT localizes to the mitochondrial matrix via an N-terminal mitochondrial targeting sequence contained within the first 13 amino acids of the protein. Our data show that mitochondrial localization of AASDHPPT is required to support mtFAS function, and further identify two variants in Aasdhppt that are likely pathogenic in humans.
Collapse
|
4
|
Qi K, Lv Y, Xiong Y, Tian C, Liu C, Pan Y. Development of Transmission Ambient Pressure Laser Desorption Ionization/Postphotoionization Mass Spectrometry Imaging. Anal Chem 2024; 96:5489-5498. [PMID: 38527864 DOI: 10.1021/acs.analchem.3c05605] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/27/2024]
Abstract
Laser-based high-resolution mass spectrometry imaging at ambient conditions has promising applications in life science. However, the ion yield during laser desorption/ablation is poor. Here, transmission atmospheric pressure laser desorption ionization combined with a compact postphotoionization (t-AP-LDI/PI) assembly with a krypton discharge lamp was developed for the untargeted imaging of various biomolecules. The spatial distributions of numerous lipid classes, fatty acids, neurotransmitters, and amino acids in the subregions of mouse cerebellum tissue were obtained. Compared with single laser ablation, the sensitivities for most analytes were increased by 1 to 3 orders of magnitude by dopant-assisted postphotoionization. After careful optimization, a spatial resolution of 4 μm could be achieved for the metabolites in mouse hippocampus tissue. Finally, the melanoma tissue slices were analyzed using t-AP-LDI/PI MSI, which revealed the metabolic heterogeneity of the melanoma microenvironment and exhibited the phenomenon of abnormal proliferation and invasion trends in tumor cells.
Collapse
Affiliation(s)
- Keke Qi
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029, China
- High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei, Anhui 230031, China
| | - Yongmei Lv
- Department of Dermatology, The Second Affiliated Hospital of Anhui Medical University, Hefei 230601, China
| | - Ying Xiong
- Hefei National Laboratory for Physical Sciences at the Microscale, School of Life Sciences, University of Science and Technology of China, Hefei 230026, China
| | - Changlin Tian
- High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei, Anhui 230031, China
- Hefei National Laboratory for Physical Sciences at the Microscale, School of Life Sciences, University of Science and Technology of China, Hefei 230026, China
| | - Chengyuan Liu
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029, China
| | - Yang Pan
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029, China
| |
Collapse
|
5
|
Nataraj J, MacLean JA, Davies J, Kurtz J, Salisbury A, Liker MA, Sanger TD, Olaya J. Application of deep brain stimulation for the treatment of childhood-onset dystonia in patients with MEPAN syndrome. Front Neurol 2024; 14:1307595. [PMID: 38328756 PMCID: PMC10847241 DOI: 10.3389/fneur.2023.1307595] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Accepted: 12/27/2023] [Indexed: 02/09/2024] Open
Abstract
Introduction Mitochondrial Enoyl CoA Reductase Protein-Associated Neurodegeneration (MEPAN) syndrome is a rare inherited metabolic condition caused by MECR gene mutations. This gene encodes a protein essential for fatty acid synthesis, and defects cause progressively worsening childhood-onset dystonia, optic atrophy, and basal ganglia abnormalities. Deep brain stimulation (DBS) has shown mixed improvement in other childhood-onset dystonia conditions. To the best of our knowledge, DBS has not been investigated as a treatment for dystonia in patients with MEPAN syndrome. Methods Two children with MEPAN were identified as possible DBS candidates due to severe generalized dystonia unresponsive to pharmacotherapy. Temporary depth electrodes were placed in six locations bilaterally and tested during a 6-day hospitalization to determine the best locations for permanent electrode placement. The Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS) and Barry-Albright Dystonia Scale (BADS) were used for preoperative and postoperative testing to quantitatively assess dystonia severity changes. Patient 1 had permanent electrodes placed at the globus pallidus internus (GPi) and pedunculopontine nucleus (PPN). Patient 2 had permanent electrodes placed at the GPi and ventralis intermedius nucleus of the thalamus (VIM). Results Both patients successfully underwent DBS placement with no perioperative complications and significant improvement in their BFMDRS score. Patient 2 also demonstrated improvement in the BADS. Discussion We demonstrated a novel application of DBS in MEPAN syndrome patients with childhood-onset dystonia. These patients showed clinically significant improvements in dystonia following DBS, indicating that DBS can be considered for dystonia in patients with rare metabolic disorders that currently have no other proven treatment options.
Collapse
Affiliation(s)
- Jaya Nataraj
- Samueli School of Engineering, University of California Irvine, Irvine, CA, United States
- Research Institute, Children’s Hospital of Orange County, Orange, CA, United States
| | - Jennifer A. MacLean
- Research Institute, Children’s Hospital of Orange County, Orange, CA, United States
- Department of Neurology, Children’s Hospital of Orange County, Orange, CA, United States
| | - Jordan Davies
- Division of Neurosurgery, Children’s Hospital of Orange County, Orange, CA, United States
- Department of Neurological Surgery, School of Medicine, University of California Irvine, Irvine, CA, United States
| | - Joshua Kurtz
- School of Medicine, University of California Irvine, Irvine, CA, United States
| | - Amanda Salisbury
- Research Institute, Children’s Hospital of Orange County, Orange, CA, United States
| | - Mark A. Liker
- Division of Neurosurgery, Children’s Hospital of Orange County, Orange, CA, United States
- Department of Neurological Surgery, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
| | - Terence D. Sanger
- Samueli School of Engineering, University of California Irvine, Irvine, CA, United States
- Research Institute, Children’s Hospital of Orange County, Orange, CA, United States
- Department of Neurology, Children’s Hospital of Orange County, Orange, CA, United States
- Department of Pediatrics, School of Medicine, University of California Irvine, Irvine, CA, United States
| | - Joffre Olaya
- Division of Neurosurgery, Children’s Hospital of Orange County, Orange, CA, United States
- Department of Neurological Surgery, School of Medicine, University of California Irvine, Irvine, CA, United States
| |
Collapse
|
6
|
Dutta D, Kanca O, Byeon SK, Marcogliese PC, Zuo Z, Shridharan RV, Park JH, Lin G, Ge M, Heimer G, Kohler JN, Wheeler MT, Kaipparettu BA, Pandey A, Bellen HJ. A defect in mitochondrial fatty acid synthesis impairs iron metabolism and causes elevated ceramide levels. Nat Metab 2023; 5:1595-1614. [PMID: 37653044 PMCID: PMC11151872 DOI: 10.1038/s42255-023-00873-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2022] [Accepted: 07/21/2023] [Indexed: 09/02/2023]
Abstract
In most eukaryotic cells, fatty acid synthesis (FAS) occurs in the cytoplasm and in mitochondria. However, the relative contribution of mitochondrial FAS (mtFAS) to the cellular lipidome is not well defined. Here we show that loss of function of Drosophila mitochondrial enoyl coenzyme A reductase (Mecr), which is the enzyme required for the last step of mtFAS, causes lethality, while neuronal loss of Mecr leads to progressive neurodegeneration. We observe a defect in Fe-S cluster biogenesis and increased iron levels in flies lacking mecr, leading to elevated ceramide levels. Reducing the levels of either iron or ceramide suppresses the neurodegenerative phenotypes, indicating an interplay between ceramide and iron metabolism. Mutations in human MECR cause pediatric-onset neurodegeneration, and we show that human-derived fibroblasts display similar elevated ceramide levels and impaired iron homeostasis. In summary, this study identifies a role of mecr/MECR in ceramide and iron metabolism, providing a mechanistic link between mtFAS and neurodegeneration.
Collapse
Affiliation(s)
- Debdeep Dutta
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA
| | - Oguz Kanca
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA
| | - Seul Kee Byeon
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, USA
| | - Paul C Marcogliese
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA
- Department of Biochemistry & Medical Genetics, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Zhongyuan Zuo
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA
| | - Rishi V Shridharan
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA
| | - Jun Hyoung Park
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Guang Lin
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA
| | - Ming Ge
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA
| | - Gali Heimer
- Pediatric Neurology Unit, Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Ramat Gan, Israel
- The Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Jennefer N Kohler
- Division of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, CA, USA
| | - Matthew T Wheeler
- Division of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, CA, USA
| | - Benny A Kaipparettu
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Akhilesh Pandey
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, USA
- Manipal Academy of Higher Education, Manipal, India
| | - Hugo J Bellen
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA.
| |
Collapse
|
7
|
Hayflick SJ, Jeong SY, Sibon OCM. PKAN pathogenesis and treatment. Mol Genet Metab 2022; 137:283-291. [PMID: 36240582 PMCID: PMC9970616 DOI: 10.1016/j.ymgme.2022.09.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Revised: 09/28/2022] [Accepted: 09/30/2022] [Indexed: 11/30/2022]
Abstract
Studies aimed at supporting different treatment approaches for pantothenate kinase-associated neurodegeneration (PKAN) have revealed the complexity of coenzyme A (CoA) metabolism and the limits of our current knowledge about disease pathogenesis. Here we offer a foundation for critically evaluating the myriad approaches, argue for the importance of unbiased disease models, and highlight some of the outstanding questions that are central to our understanding and treating PKAN.
Collapse
Affiliation(s)
- Susan J Hayflick
- Departments of Molecular & Medical Genetics, Pediatrics, and Neurology, Oregon Health & Science University, Portland, OR 97239, USA.
| | - Suh Young Jeong
- Department of Molecular & Medical Genetics, Oregon Health & Science University, Portland, OR 97239, USA
| | - Ody C M Sibon
- Department of Biomedical Sciences of Cells and Systems, University Medical Center Groningen, University of Groningen, 9713 AV, the Netherlands
| |
Collapse
|
8
|
Angelova PR. Sources and triggers of oxidative damage in neurodegeneration. Free Radic Biol Med 2021; 173:52-63. [PMID: 34224816 DOI: 10.1016/j.freeradbiomed.2021.07.003] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 06/19/2021] [Accepted: 07/01/2021] [Indexed: 02/07/2023]
Abstract
Neurodegeneration describes a group of more than 300 neurological diseases, characterised by neuronal loss and intra- or extracellular protein depositions, as key neuropathological features. Multiple factors play role in the pathogenesis of these group of disorders: mitochondrial dysfunction, membrane damage, calcium dyshomeostasis, metallostasis, defect clearance and renewal mechanisms, to name a few. All these factors, without exceptions, have in common the involvement of immensely increased generation of free radicals and occurrence of oxidative stress, and as a result - exhaustion of the scavenging potency of the cellular redox defence mechanisms. Besides genetic predisposition and environmental exposure to toxins, the main risk factor for developing neurodegeneration is age. And although the "Free radical theory of ageing" was declared dead, it is undisputable that accumulation of damage occurs with age, especially in systems that are regulated by free radical messengers and those that oppose oxidative stress, protein oxidation and the accuracy in protein synthesis and degradation machinery has difficulties to be maintained. This brief review provides a comprehensive summary on the main sources of free radical damage, occurring in the setting of neurodegeneration.
Collapse
|
9
|
Garcia Corrales AV, Haidar M, Bogie JFJ, Hendriks JJA. Fatty Acid Synthesis in Glial Cells of the CNS. Int J Mol Sci 2021; 22:ijms22158159. [PMID: 34360931 PMCID: PMC8348209 DOI: 10.3390/ijms22158159] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 07/22/2021] [Accepted: 07/26/2021] [Indexed: 12/12/2022] Open
Abstract
Fatty acids (FAs) are of crucial importance for brain homeostasis and neural function. Glia cells support the high demand of FAs that the central nervous system (CNS) needs for its proper functioning. Additionally, FAs can modulate inflammation and direct CNS repair, thereby contributing to brain pathologies such Alzheimer’s disease or multiple sclerosis. Intervention strategies targeting FA synthesis in glia represents a potential therapeutic opportunity for several CNS diseases.
Collapse
Affiliation(s)
- Aida V Garcia Corrales
- Department of Immunology and Infection, Biomedical Research Institute, Hasselt University, 3590 Diepenbeek, Belgium
| | - Mansour Haidar
- Department of Immunology and Infection, Biomedical Research Institute, Hasselt University, 3590 Diepenbeek, Belgium
| | - Jeroen F J Bogie
- Department of Immunology and Infection, Biomedical Research Institute, Hasselt University, 3590 Diepenbeek, Belgium
| | - Jerome J A Hendriks
- Department of Immunology and Infection, Biomedical Research Institute, Hasselt University, 3590 Diepenbeek, Belgium
| |
Collapse
|
10
|
Pietikäinen LP, Rahman MT, Hiltunen JK, Dieckmann CL, Kastaniotis AJ. Genetic dissection of the mitochondrial lipoylation pathway in yeast. BMC Biol 2021; 19:14. [PMID: 33487163 PMCID: PMC7831266 DOI: 10.1186/s12915-021-00951-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Accepted: 01/06/2021] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND Lipoylation of 2-ketoacid dehydrogenases is essential for mitochondrial function in eukaryotes. While the basic principles of the lipoylation processes have been worked out, we still lack a thorough understanding of the details of this important post-translational modification pathway. Here we used yeast as a model organism to characterize substrate usage by the highly conserved eukaryotic octanoyl/lipoyl transferases in vivo and queried how amenable the lipoylation system is to supplementation with exogenous substrate. RESULTS We show that the requirement for mitochondrial fatty acid synthesis to provide substrates for lipoylation of the 2-ketoacid dehydrogenases can be bypassed by supplying the cells with free lipoic acid (LA) or octanoic acid (C8) and a mitochondrially targeted fatty acyl/lipoyl activating enzyme. We also provide evidence that the S. cerevisiae lipoyl transferase Lip3, in addition to transferring LA from the glycine cleavage system H protein to the pyruvate dehydrogenase (PDH) and α-ketoglutarate dehydrogenase (KGD) E2 subunits, can transfer this cofactor from the PDH complex to the KGD complex. In support of yeast as a model system for human metabolism, we demonstrate that the human octanoyl/lipoyl transferases can substitute for their counterparts in yeast to support respiratory growth and protein lipoylation. Like the wild-type yeast enzyme, the human lipoyl transferase LIPT1 responds to LA supplementation in the presence of the activating enzyme LplA. CONCLUSIONS In the yeast model system, the eukaryotic lipoylation pathway can use free LA and C8 as substrates when fatty/lipoic acid activating enzymes are targeted to mitochondria. Lip3 LA transferase has a wider substrate specificity than previously recognized. We show that these features of the lipoylation mechanism in yeast are conserved in mammalian mitochondria. Our findings have important implications for the development of effective therapies for the treatment of LA or mtFAS deficiency-related disorders.
Collapse
Affiliation(s)
- Laura P Pietikäinen
- Faculty of Biochemistry and Molecular Medicine and Biocenter Oulu, University of Oulu, PO Box 5400, FI-90014, Oulu, Finland
| | - M Tanvir Rahman
- Faculty of Biochemistry and Molecular Medicine and Biocenter Oulu, University of Oulu, PO Box 5400, FI-90014, Oulu, Finland
| | - J Kalervo Hiltunen
- Faculty of Biochemistry and Molecular Medicine and Biocenter Oulu, University of Oulu, PO Box 5400, FI-90014, Oulu, Finland
| | - Carol L Dieckmann
- Department of Molecular and Cellular Biology, University of Arizona, Tucson, AZ, 85721, USA
| | - Alexander J Kastaniotis
- Faculty of Biochemistry and Molecular Medicine and Biocenter Oulu, University of Oulu, PO Box 5400, FI-90014, Oulu, Finland.
| |
Collapse
|