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D'Agostino M, Simonetti A, Motta S, Wolff P, Romagnoli A, Piccinini A, Spinozzi F, Di Marino D, La Teana A, Ennifar E. Crystal structure of archaeal IF5A-DHS complex reveals insights into the hypusination mechanism. Structure 2024; 32:878-888.e4. [PMID: 38582076 DOI: 10.1016/j.str.2024.03.008] [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: 12/18/2023] [Revised: 02/12/2024] [Accepted: 03/12/2024] [Indexed: 04/08/2024]
Abstract
The translation factor IF5A is highly conserved in Eukarya and Archaea and undergoes a unique post-translational hypusine modification by the deoxyhypusine synthase (DHS) enzyme. DHS transfers the butylamine moiety from spermidine to IF5A using NAD as a cofactor, forming a deoxyhypusine intermediate. IF5A is a key player in protein synthesis, preventing ribosome stalling in proline-rich sequences during translation elongation and facilitating translation elongation and termination. Additionally, human eIF5A participates in various essential cellular processes and contributes to cancer metastasis, with inhibiting hypusination showing anti-proliferative effects. The hypusination pathway of IF5A is therefore an attractive new therapeutic target. We elucidated the 2.0 Å X-ray crystal structure of the archaeal DHS-IF5A complex, revealing hetero-octameric architecture and providing a detailed view of the complex active site including the hypusination loop. This structure, along with biophysical data and molecular dynamics simulations, provides new insights into the catalytic mechanism of the hypusination reaction.
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Affiliation(s)
- Mattia D'Agostino
- Department of Life and Environmental Sciences, Polytechnic University of Marche, Via Brecce Bianche, 60131 Ancona, Italy; Architecture et Réactivité de l'ARN, CNRS UPR 9002, Institut de Biologie Moléculaire et Cellulaire, Université de Strasbourg, Strasbourg, France
| | - Angelita Simonetti
- Architecture et Réactivité de l'ARN, CNRS UPR 9002, Institut de Biologie Moléculaire et Cellulaire, Université de Strasbourg, Strasbourg, France
| | - Stefano Motta
- Department of Earth and Environmental Sciences, University of Milano Bicocca, Piazza della Scienza 1, 20126 Milan, Italy
| | - Philippe Wolff
- Architecture et Réactivité de l'ARN, CNRS UPR 9002, Institut de Biologie Moléculaire et Cellulaire, Université de Strasbourg, Strasbourg, France
| | - Alice Romagnoli
- Department of Life and Environmental Sciences, Polytechnic University of Marche, Via Brecce Bianche, 60131 Ancona, Italy; New York-Marche Structural Biology Center (Ny-Masbic), Polytechnic University of Marche, Via Brecce Bianche, 60131 Ancona, Italy
| | - Astra Piccinini
- Department of Life and Environmental Sciences, Polytechnic University of Marche, Via Brecce Bianche, 60131 Ancona, Italy
| | - Francesco Spinozzi
- Department of Life and Environmental Sciences, Polytechnic University of Marche, Via Brecce Bianche, 60131 Ancona, Italy
| | - Daniele Di Marino
- Department of Life and Environmental Sciences, Polytechnic University of Marche, Via Brecce Bianche, 60131 Ancona, Italy; New York-Marche Structural Biology Center (Ny-Masbic), Polytechnic University of Marche, Via Brecce Bianche, 60131 Ancona, Italy; Neuronal Death and Neuroprotection Unit, Department of Neuroscience, Mario Negri Institute for Pharmacological Research-IRCCS, Via Mario Negri 2, 20156 Milano, Italy.
| | - Anna La Teana
- Department of Life and Environmental Sciences, Polytechnic University of Marche, Via Brecce Bianche, 60131 Ancona, Italy; New York-Marche Structural Biology Center (Ny-Masbic), Polytechnic University of Marche, Via Brecce Bianche, 60131 Ancona, Italy.
| | - Eric Ennifar
- Architecture et Réactivité de l'ARN, CNRS UPR 9002, Institut de Biologie Moléculaire et Cellulaire, Université de Strasbourg, Strasbourg, France.
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Wu B, Liu S. Structural Insights into the Mechanisms Underlying Polyaminopathies. Int J Mol Sci 2024; 25:6340. [PMID: 38928047 PMCID: PMC11203672 DOI: 10.3390/ijms25126340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2024] [Revised: 06/01/2024] [Accepted: 06/05/2024] [Indexed: 06/28/2024] Open
Abstract
Polyamines are ubiquitous in almost all biological entities and involved in various crucial physiological processes. They are also closely associated with the onset and progression of many diseases. Polyaminopathies are a group of rare genetic disorders caused by alterations in the function of proteins within the polyamine metabolism network. Although the identified polyaminopathies are all rare diseases at present, they are genetically heritable, rendering high risks not only to the carriers but also to their descendants. Meanwhile, more polyaminopathic patients might be discovered with the increasing accessibility of gene sequencing. This review aims to provide a comprehensive overview of the structural variations of mutated proteins in current polyaminopathies, in addition to their causative genes, types of mutations, clinical symptoms, and therapeutic approaches. We focus on analyzing how alterations in protein structure lead to protein dysfunction, thereby facilitating the onset of diseases. We hope this review will offer valuable insights and references for the future clinical diagnosis and precision treatment of polyaminopathies.
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Affiliation(s)
- Bing Wu
- Cooperative Innovation Center of Industrial Fermentation (Ministry of Education & Hubei Province), Key Laboratory of Fermentation Engineering (Ministry of Education), Wuhan 430068, China
- Hubei Key Laboratory of Industrial Microbiology, National “111” Center for Cellular Regulation and Molecular Pharmaceutics, Hubei University of Technology, Wuhan 430068, China
| | - Sen Liu
- Cooperative Innovation Center of Industrial Fermentation (Ministry of Education & Hubei Province), Key Laboratory of Fermentation Engineering (Ministry of Education), Wuhan 430068, China
- Hubei Key Laboratory of Industrial Microbiology, National “111” Center for Cellular Regulation and Molecular Pharmaceutics, Hubei University of Technology, Wuhan 430068, China
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3
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Bachmann AS, VanSickle EA, Michael J, Vipond M, Bupp CP. Bachmann-Bupp syndrome and treatment. Dev Med Child Neurol 2024; 66:445-455. [PMID: 37469105 PMCID: PMC10796844 DOI: 10.1111/dmcn.15687] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 05/24/2023] [Accepted: 05/26/2023] [Indexed: 07/21/2023]
Abstract
Bachmann-Bupp syndrome (BABS) is a neurodevelopmental disorder characterized by developmental delay, hypotonia, and varying forms of non-congenital alopecia. The condition is caused by 3'-end mutations of the ornithine decarboxylase 1 (ODC1) gene, which produce carboxy (C)-terminally truncated variants of ODC, a pyridoxal 5'-phosphate-dependent enzyme. C-terminal truncation of ODC prevents its ubiquitin-independent proteasomal degradation and leads to cellular accumulation of ODC enzyme that remains catalytically active. ODC is the first rate-limiting enzyme that converts ornithine to putrescine in the polyamine pathway. Polyamines (putrescine, spermidine, spermine) are aliphatic molecules found in all forms of life and are important during embryogenesis, organogenesis, and tumorigenesis. BABS is an ultra-rare condition with few reported cases, but it serves as a convincing example for drug repurposing therapy. α-Difluoromethylornithine (DFMO, also known as eflornithine) is an ODC inhibitor with a strong safety profile in pediatric use for neuroblastoma and other cancers as well as West African sleeping sickness (trypanosomiasis). Patients with BABS have been treated with DFMO and have shown improvement in hair growth, muscle tone, and development.
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Affiliation(s)
- André S Bachmann
- Department of Pediatrics and Human Development, College of Human Medicine, Michigan State University, Grand Rapids, MI, USA
- International Center for Polyamine Disorders, Grand Rapids, MI, USA
| | - Elizabeth A VanSickle
- International Center for Polyamine Disorders, Grand Rapids, MI, USA
- Corewell Health, Helen DeVos Children's Hospital, Grand Rapids, MI, USA
| | - Julianne Michael
- International Center for Polyamine Disorders, Grand Rapids, MI, USA
- Corewell Health, Helen DeVos Children's Hospital, Grand Rapids, MI, USA
| | - Marlie Vipond
- International Center for Polyamine Disorders, Grand Rapids, MI, USA
- Corewell Health, Helen DeVos Children's Hospital, Grand Rapids, MI, USA
| | - Caleb P Bupp
- Department of Pediatrics and Human Development, College of Human Medicine, Michigan State University, Grand Rapids, MI, USA
- International Center for Polyamine Disorders, Grand Rapids, MI, USA
- Corewell Health, Helen DeVos Children's Hospital, Grand Rapids, MI, USA
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4
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Connors CT, Villaca CB, Anderson-Baucum EK, Rosario SR, Rutan CD, Childress PJ, Padgett LR, Robertson MA, Mastracci TL. A Translational Regulatory Mechanism Mediated by Hypusinated Eukaryotic Initiation Factor 5A Facilitates β-Cell Identity and Function. Diabetes 2024; 73:461-473. [PMID: 38055903 PMCID: PMC10882153 DOI: 10.2337/db23-0148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Accepted: 11/27/2023] [Indexed: 12/08/2023]
Abstract
As professional secretory cells, β-cells require adaptable mRNA translation to facilitate a rapid synthesis of proteins, including insulin, in response to changing metabolic cues. Specialized mRNA translation programs are essential drivers of cellular development and differentiation. However, in the pancreatic β-cell, the majority of factors identified to promote growth and development function primarily at the level of transcription. Therefore, despite its importance, the regulatory role of mRNA translation in the formation and maintenance of functional β-cells is not well defined. In this study, we have identified a translational regulatory mechanism mediated by the specialized mRNA translation factor eukaryotic initiation factor 5A (eIF5A), which facilitates the maintenance of β-cell identity and function. The mRNA translation function of eIF5A is only active when it is posttranslationally modified ("hypusinated") by the enzyme deoxyhypusine synthase (DHPS). We have discovered that the absence of β-cell DHPS in mice reduces the synthesis of proteins critical to β-cell identity and function at the stage of β-cell maturation, leading to a rapid and reproducible onset of diabetes. Therefore, our work has revealed a gatekeeper of specialized mRNA translation that permits the β-cell, a metabolically responsive secretory cell, to maintain the integrity of protein synthesis necessary during times of induced or increased demand. ARTICLE HIGHLIGHTS
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Affiliation(s)
- Craig T. Connors
- Department of Biology, Indiana University Indianapolis, Indianapolis, IN
| | | | | | - Spencer R. Rosario
- Department of Biostatistics and Bioinformatics, Roswell Park Comprehensive Cancer Center, Buffalo, NY
| | - Caleb D. Rutan
- Department of Biology, Indiana University Indianapolis, Indianapolis, IN
| | | | | | | | - Teresa L. Mastracci
- Department of Biology, Indiana University Indianapolis, Indianapolis, IN
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN
- Center for Diabetes and Metabolic Diseases, Indiana University School of Medicine, Indianapolis, IN
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5
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Barba-Aliaga M, Bernal V, Rong C, Zid BM, Alepuz P. eIF5A controls mitoprotein import by relieving ribosome stalling at the TIM50 translocase mRNA. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.19.572290. [PMID: 38187585 PMCID: PMC10769225 DOI: 10.1101/2023.12.19.572290] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2024]
Abstract
The efficient import of nuclear-encoded proteins into mitochondria is crucial for proper mitochondrial function. The conserved translation factor eIF5A is primarily known as an elongation factor which binds ribosomes to alleviate ribosome stalling at sequences encoding polyprolines or combinations of proline with glycine and charged amino acids. eIF5A is known to impact the mitochondrial function across a variety of species although the precise molecular mechanism underlying this impact remains unclear. We found that depletion of eIF5A in yeast drives reduced translation and levels of TCA cycle and oxidative phosphorylation proteins. We further found that loss of eIF5A leads to the accumulation of mitoprotein precursors in the cytosol as well as to the induction of a mitochondrial import stress response. Here we identify an essential polyproline-containing protein as a direct eIF5A target for translation: the mitochondrial inner membrane protein Tim50, which is the receptor subunit of the TIM23 translocase complex. We show how eIF5A directly controls mitochondrial protein import through the alleviation of ribosome stalling along TIM50 mRNA at the mitochondrial surface. Removal of the polyprolines from Tim50 rescues the mitochondrial import stress response, as well as the translation of oxidative phosphorylation reporter genes in an eIF5A loss of function. Overall, our findings elucidate how eIF5A impacts the mitochondrial function by reducing ribosome stalling and facilitating protein translation, thereby positively impacting the mitochondrial import process.
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Affiliation(s)
- Marina Barba-Aliaga
- Instituto de Biotecnología y Biomedicina (Biotecmed), Universitat de València, 46100 València, Spain
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Biológicas, Universitat de València, 46100 València, Spain
| | - Vanessa Bernal
- Instituto de Biotecnología y Biomedicina (Biotecmed), Universitat de València, 46100 València, Spain
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Biológicas, Universitat de València, 46100 València, Spain
| | - Cynthia Rong
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, United States
| | - Brian M Zid
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, United States
| | - Paula Alepuz
- Instituto de Biotecnología y Biomedicina (Biotecmed), Universitat de València, 46100 València, Spain
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Biológicas, Universitat de València, 46100 València, Spain
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6
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Guo JS, Liu KL, Qin YX, Hou L, Jian LY, Yang YH, Li XY. Hypusination-induced DHPS/eIF5A pathway as a new therapeutic strategy for human diseases: A mechanistic review and structural classification of DHPS inhibitors. Biomed Pharmacother 2023; 167:115440. [PMID: 37683595 DOI: 10.1016/j.biopha.2023.115440] [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: 07/04/2023] [Revised: 08/30/2023] [Accepted: 09/04/2023] [Indexed: 09/10/2023] Open
Abstract
The discovery of new therapeutic strategies for diseases is essential for drug research. Deoxyhypusine synthase (DHPS) is a critical enzyme that modifies the conversion of the eukaryotic translation initiation factor 5A (eIF5A) precursor into physiologically active eIF5A (eIF5A-Hyp). Recent studies have revealed that the hypusine modifying of DHPS on eIF5A has an essential regulatory role in human diseases. The hypusination-induced DHPS/eIF5A pathway has been shown to play an essential role in various cancers, and it could regulate immune-related diseases, glucose metabolism-related diseases, neurological-related diseases, and aging. In addition, DHPS has a more defined substrate and a well-defined structure within the active pocket than eIF5A. More and more researchers are focusing on the prospect of advanced development of DHPS inhibitors. This review summarizes the regulatory mechanisms of the hypusination-induced DHPS/eIF5A pathway in a variety of diseases in addition to the inhibitors related to this pathway; it highlights and analyzes the structural features and mechanisms of action of DHPS inhibitors and expands the prospects of future drug development using DHPS as an anticancer target.
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Affiliation(s)
- Jing-Si Guo
- Department of Pharmacy, Shengjing Hospital of China Medical University, No. 36 Sanhao Street, Shenyang 110004, PR China
| | - Kai-Li Liu
- School of Pharmacy, China Medical University, No. 77 Puhe, Shenyang 110122, PR China
| | - Yu-Xi Qin
- Department of Pharmacy, Shengjing Hospital of China Medical University, No. 36 Sanhao Street, Shenyang 110004, PR China
| | - Lin Hou
- Department of Pharmacy, Shengjing Hospital of China Medical University, No. 36 Sanhao Street, Shenyang 110004, PR China
| | - Ling-Yan Jian
- Department of Pharmacy, Shengjing Hospital of China Medical University, No. 36 Sanhao Street, Shenyang 110004, PR China
| | - Yue-Hui Yang
- Department of Pharmacy, Shengjing Hospital of China Medical University, No. 36 Sanhao Street, Shenyang 110004, PR China
| | - Xin-Yang Li
- Department of Pharmacy, Shengjing Hospital of China Medical University, No. 36 Sanhao Street, Shenyang 110004, PR China.
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Xu Q, He L, Zhang S, Di X, Jiang H. Deubiquitinase OTUD3: a double-edged sword in immunity and disease. Front Cell Dev Biol 2023; 11:1237530. [PMID: 37829187 PMCID: PMC10566363 DOI: 10.3389/fcell.2023.1237530] [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: 06/09/2023] [Accepted: 08/28/2023] [Indexed: 10/14/2023] Open
Abstract
Deubiquitination is an important form of post-translational modification that regulates protein homeostasis. Ovarian tumor domain-containing proteins (OTUDs) subfamily member OTUD3 was identified as a deubiquitinating enzyme involved in the regulation of various physiological processes such as immunity and inflammation. Disturbances in these physiological processes trigger diseases in humans and animals, such as cancer, neurodegenerative diseases, diabetes, mastitis, etc. OTUD3 is aberrantly expressed in tumors and is a double-edged sword, exerting tumor-promoting or anti-tumor effects in different types of tumors affecting cancer cell proliferation, metastasis, and metabolism. OTUD3 is regulated at the transcriptional level by a number of MicroRNAs, such as miR-520h, miR-32, and miR101-3p. In addition, OTUD3 is regulated by a number of post-translational modifications, such as acetylation and ubiquitination. Therefore, understanding the regulatory mechanisms of OTUD3 expression can help provide insight into its function in human immunity and disease, offering the possibility of its use as a therapeutic target to diagnose or treat disease.
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Affiliation(s)
- Qiao Xu
- Department of Cell Biology, School of Life Sciences, Central South University, Changsha, Hunan, China
| | - Lan He
- School of Biomedical Science, Hunan University, Changsha, Hunan, China
| | - Shubing Zhang
- Department of Cell Biology, School of Life Sciences, Central South University, Changsha, Hunan, China
| | - Xiaotang Di
- Department of Cell Biology, School of Life Sciences, Central South University, Changsha, Hunan, China
| | - Hao Jiang
- Department of Biomedical Informatics, School of Life Sciences, Central South University, Changsha, Hunan, China
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Tamborlin L, Pereira KD, Guimarães DSPSF, Silveira LR, Luchessi AD. The first evidence of biological activity for free Hypusine, an enigmatic amino acid discovered in the '70s. Amino Acids 2023:10.1007/s00726-023-03283-4. [PMID: 37258638 DOI: 10.1007/s00726-023-03283-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Accepted: 05/19/2023] [Indexed: 06/02/2023]
Abstract
Hypusine amino acid [Nε-(4-amino-2-hydroxybutyl)-lysine] was first isolated in 1971 from bovine brain extracts. Hypusine originates from a post-translational modification at the eukaryotic translation initiation factor 5A (eIF5A), a protein produced by archaebacteria and eukaryotes. The eIF5A protein is the only one described containing the hypusine residue, which is essential for its activity. Hypusine as a free amino acid is a consequence of proteolytic degradation of eIF5A. Herein, we showed, for the first time, evidence of biological activity for the free hypusine. C6 rat glioma cells were treated with hypusine, and different cellular parameters were evaluated. Hypusine treatment significantly reduced C6 cell proliferation and potently suppressed their clonogenic capacity without leading to apoptosis. Hypusine also decreased the Eif5A transcript content and the global protein synthesis profile that may occur due to negative feedback in response to high hypusine concentration, controlling the content of newly synthesized eIF5A, which can affect the translation process. Besides, hypusine treatment also altered cellular metabolism by changing the pathways for energy production, reducing cellular respiration coupled with oxidative phosphorylation, and increasing the anaerobic metabolism. These observed results and the relationship between eIF5A and tumor processes led us to test the combination of hypusine with the chemotherapeutic drug temozolomide. Combining temozolomide with hypusine reduced the MTT conversion to the same levels as those observed using double temozolomide dosage alone, demonstrating a synergetic action between the compounds. Thus, since 1971, this is the first study showing evidence of biological activity for hypusine not associated with being an essential component of the eiF5A protein. Finding out the molecular targets of hypusine are the following efforts to completely characterize its biological activity.
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Affiliation(s)
- Leticia Tamborlin
- Laboratory of Biotechnology, School of Applied Sciences, State University of Campinas (UNICAMP), Rua Pedro Zaccaria, 1300, Jardim Santa Luiza, Limeira, São Paulo, 13484-350, Brazil
- Institute of Biosciences, São Paulo State University (UNESP), Rio Claro, São Paulo, Brazil
| | - Karina Danielle Pereira
- Laboratory of Biotechnology, School of Applied Sciences, State University of Campinas (UNICAMP), Rua Pedro Zaccaria, 1300, Jardim Santa Luiza, Limeira, São Paulo, 13484-350, Brazil
| | | | - Leonardo Reis Silveira
- Obesity and Comorbidities Research Center, Department of Structural and Functional Biology, State University of Campinas (UNICAMP), Limeira, São Paulo, Brazil
| | - Augusto Ducati Luchessi
- Laboratory of Biotechnology, School of Applied Sciences, State University of Campinas (UNICAMP), Rua Pedro Zaccaria, 1300, Jardim Santa Luiza, Limeira, São Paulo, 13484-350, Brazil.
- Institute of Biosciences, São Paulo State University (UNESP), Rio Claro, São Paulo, Brazil.
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Connors CT, Anderson-Baucum EK, Rosario S, Villaca CBP, Rutan CD, Childress PJ, Padgett LR, Robertson MA, Mastracci TL. Deoxyhypusine synthase is required for the translational regulation of pancreatic beta cell maturation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.24.537996. [PMID: 37162889 PMCID: PMC10168283 DOI: 10.1101/2023.04.24.537996] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
As professional secretory cells, beta cells require adaptable mRNA translation to facilitate a rapid synthesis of proteins, including insulin, in response to changing metabolic cues. Specialized mRNA translation programs are essential drivers of cellular development and differentiation. However, in the pancreatic beta cell, the majority of factors identified to promote growth and development function primarily at the level of transcription. Therefore, despite its importance, the regulatory role of mRNA translation in the formation and maintenance of functional beta cells is not well defined. In this study, we have identified a translational regulatory mechanism in the beta cell driven by the specialized mRNA translation factor, eukaryotic initiation factor 5A (eIF5A), which facilitates beta cell maturation. The mRNA translation function of eIF5A is only active when it is post-translationally modified ("hypusinated") by the enzyme deoxyhypusine synthase (DHPS). We have discovered that the absence of beta cell DHPS in mice reduces the synthesis of proteins critical to beta cell identity and function at the stage of beta cell maturation, leading to a rapid and reproducible onset of diabetes. Therefore, our work has revealed a gatekeeper of specialized mRNA translation that permits the beta cell, a metabolically responsive secretory cell, to maintain the integrity of protein synthesis necessary during times of induced or increased demand. ARTICLE HIGHLIGHTS Pancreatic beta cells are professional secretory cells that require adaptable mRNA translation for the rapid, inducible synthesis of proteins, including insulin, in response to changing metabolic cues. Our previous work in the exocrine pancreas showed that development and function of the acinar cells, which are also professional secretory cells, is regulated at the level of mRNA translation by a specialized mRNA translation factor, eIF5A HYP . We hypothesized that this translational regulation, which can be a response to stress such as changes in growth or metabolism, may also occur in beta cells. Given that the mRNA translation function of eIF5A is only active when the factor is post-translationally modified ("hypusinated") by the enzyme deoxyhypusine synthase (DHPS), we asked the question: does DHPS/eIF5A HYP regulate the formation and maintenance of functional beta cells? We discovered that in the absence of beta cell DHPS in mice, eIF5A is not hypusinated (activated), which leads to a reduction in the synthesis of critical beta cell proteins that interrupts pathways critical for identity and function. This translational regulation occurs at weaning age, which is a stage of cellular stress and maturation for the beta cell. Therefore without DHPS/eIF5A HYP , beta cells do not mature and mice progress to hyperglycemia and diabetes. Our findings suggest that secretory cells have a mechanism to regulate mRNA translation during times of cellular stress. Our work also implies that driving an increase in mRNA translation in the beta cell might overcome or possibly reverse the beta cell defects that contribute to early dysfunction and the progression to diabetes.
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Michael J, VanSickle E, Vipond M, Dalman A, Prokop J, Schwartz CE, Rajasekaran S, Bachmann AS, Barth M, Prouteau C, Almagor Y, Berkun L, Alterescu G, Bupp CP. Two New Cases of Bachmann-Bupp Syndrome Identified through the International Center for Polyamine Disorders. Med Sci (Basel) 2023; 11:29. [PMID: 37092498 PMCID: PMC10123676 DOI: 10.3390/medsci11020029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Revised: 03/29/2023] [Accepted: 03/29/2023] [Indexed: 04/07/2023] Open
Abstract
Recent identification of four additional polyaminopathies, including Bachmann-Bupp syndrome, have benefited from previous research on Snyder-Robinson syndrome in order to advance from research to treatment more quickly. As a result of the discovery of these conditions, the potential for treatment within this pathway, and for other possible unidentified polyaminopathies, the International Center for Polyamine Disorders (ICPD) was created to help promote understanding of these conditions, research opportunities, and appropriate care for families. This case study provides insights from two new patients diagnosed with Bachmann-Bupp syndrome, further expanding our understanding of this ultra-rare condition, as well as a general discussion about other known polyaminopathies. This work also presents considerations for collaborative research efforts across these conditions, along with others that are likely to be identified in time, and outlines the role that the ICPD hopes to fill as more patients with these polyaminopathies continue to be identified and diagnosed.
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Affiliation(s)
- Julianne Michael
- Corewell Health and Helen DeVos Children’s Hospital, Grand Rapids, MI 49503, USA
- International Center for Polyamine Disorders, Grand Rapids, MI 49503, USA
- Department of Pediatrics and Human Development, College of Human Medicine, Michigan State University, Grand Rapids, MI 49503, USA
| | - Elizabeth VanSickle
- Corewell Health and Helen DeVos Children’s Hospital, Grand Rapids, MI 49503, USA
- International Center for Polyamine Disorders, Grand Rapids, MI 49503, USA
| | - Marlie Vipond
- Corewell Health and Helen DeVos Children’s Hospital, Grand Rapids, MI 49503, USA
- International Center for Polyamine Disorders, Grand Rapids, MI 49503, USA
| | - Abby Dalman
- Corewell Health and Helen DeVos Children’s Hospital, Grand Rapids, MI 49503, USA
| | - Jeremy Prokop
- Corewell Health and Helen DeVos Children’s Hospital, Grand Rapids, MI 49503, USA
| | - Charles E. Schwartz
- International Center for Polyamine Disorders, Grand Rapids, MI 49503, USA
- Department of Pediatrics and Human Development, College of Human Medicine, Michigan State University, Grand Rapids, MI 49503, USA
| | - Surender Rajasekaran
- Corewell Health and Helen DeVos Children’s Hospital, Grand Rapids, MI 49503, USA
- International Center for Polyamine Disorders, Grand Rapids, MI 49503, USA
- Department of Pediatrics and Human Development, College of Human Medicine, Michigan State University, Grand Rapids, MI 49503, USA
| | - André S. Bachmann
- International Center for Polyamine Disorders, Grand Rapids, MI 49503, USA
- Department of Pediatrics and Human Development, College of Human Medicine, Michigan State University, Grand Rapids, MI 49503, USA
| | - Magalie Barth
- Department of Biochemistry and Genetics, Angers University Hospital Center, 49100 Angers, France
| | - Clément Prouteau
- Department of Biochemistry and Genetics, Angers University Hospital Center, 49100 Angers, France
| | | | - Lina Berkun
- Shaare Zedek Medical Center, Medical Genetics Institute, Jerusalem 9103102, Israel
| | - Gheona Alterescu
- Shaare Zedek Medical Center, Medical Genetics Institute, Jerusalem 9103102, Israel
| | - Caleb P. Bupp
- Corewell Health and Helen DeVos Children’s Hospital, Grand Rapids, MI 49503, USA
- International Center for Polyamine Disorders, Grand Rapids, MI 49503, USA
- Department of Pediatrics and Human Development, College of Human Medicine, Michigan State University, Grand Rapids, MI 49503, USA
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Schultz CR, Sheldon RD, Xie H, Demireva EY, Uhl KL, Agnew DW, Geerts D, Bachmann AS. New K50R mutant mouse models reveal impaired hypusination of eif5a2 with alterations in cell metabolite landscape. Biol Open 2023; 12:290754. [PMID: 36848144 PMCID: PMC10084858 DOI: 10.1242/bio.059647] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Accepted: 02/21/2023] [Indexed: 03/01/2023] Open
Abstract
The eukaryotic translation initiation factor 5A1 (eIF5A1) and 5A2 (eIF5A2) are important proteins in a variety of physiological and pathophysiological processes and their function has been linked to neurodevelopmental disorders, cancer, and viral infections. Here, we report two new genome-edited mouse models, generated using a CRISPR-Cas9 approach, in which the amino acid residue lysine 50 is replaced with arginine 50 (K50R) in eIF5A1 or in the closely related eIF5A2 protein. This mutation prevents the spermidine-dependent post-translational formation of hypusine, a unique lysine derivative that is necessary for activation of eIF5A1 and eIF5A2. Mouse brain lysates from homozygous eif5a2-K50R mutant mice (eif5a2K50R/K50R) confirmed the absence of hypusine formation of eIF5A2, and metabolomic analysis of primary mouse dermal fibroblasts revealed significant alterations in the metabolite landscape compared to controls including increased levels of tryptophan, kyrunenine, pyridoxine, nicotinamide adenine dinucleotide, riboflavin, flavin adenine dinucleotide, pantothenate, and coenzyme A. Further supported by new publicly available bioinformatics data, these new mouse models represent excellent in vivo models to study hypusine-dependent biological processes, hypusination-related disorders caused by eIF5A1 and eIF5A2 gene aberrations or mRNA expression dysregulation, as well as several major human cancer types and potential therapies.
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Affiliation(s)
- Chad R Schultz
- Department of Pediatrics and Human Development, College of Human Medicine, Michigan State University, Grand Rapids, MI 49503, USA
| | - Ryan D Sheldon
- Core Technologies and Services, Mass Spectrometry Core, Van Andel Institute, Grand Rapids, MI 49503, USA
| | - Huirong Xie
- Transgenic and Genome Editing Facility, Institute for Quantitative Health Science and Engineering, Research Technology Support Facility, Michigan State University, East Lansing, MI 48824, USA
| | - Elena Y Demireva
- Transgenic and Genome Editing Facility, Institute for Quantitative Health Science and Engineering, Research Technology Support Facility, Michigan State University, East Lansing, MI 48824, USA
| | - Katie L Uhl
- Department of Pediatrics and Human Development, College of Human Medicine, Michigan State University, Grand Rapids, MI 49503, USA
| | - Dalen W Agnew
- Department of Pathobiology & Diagnostic Investigation, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824, USA
| | - Dirk Geerts
- Department of Hematology, Amsterdam University Medical Center, Location VUMC, 1081 HV Amsterdam, The Netherlands
| | - André S Bachmann
- Department of Pediatrics and Human Development, College of Human Medicine, Michigan State University, Grand Rapids, MI 49503, USA
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12
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Wang P, Yang L, Yang R, Chen Z, Ren X, Wang F, Jiao Y, Ding Y, Yang F, Sun T, Ma H. Predicted molecules and signaling pathways for regulating seizures in the hippocampus in lithium-pilocarpine induced acute epileptic rats: A proteomics study. Front Cell Neurosci 2022; 16:947732. [DOI: 10.3389/fncel.2022.947732] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Accepted: 11/14/2022] [Indexed: 12/02/2022] Open
Abstract
Seizures in rodent models that are induced by lithium-pilocarpine mimic human seizures in a highly isomorphic manner. The hippocampus is a brain region that generates and spreads seizures. In order to understand the early phases of seizure events occurring in the hippocampus, global protein expression levels in the hippocampus on day 1 and day 3 were analyzed in lithium-pilocarpine induced acute epileptic rat models using a tandem mass tag-based proteomic approach. Our results showed that differentially expressed proteins were likely to be enhanced rather than prohibited in modulating seizure activity on days 1 and 3 in lithium-pilocarpine induced seizure rats. The differentially regulated proteins differed on days 1 and 3 in the seizure rats, indicating that different molecules and pathways are involved in seizure events occurring from day 1 to day 3 following lithium-pilocarpine administration. In regard to subcellular distribution, the results suggest that post-seizure cellular function in the hippocampus is possibly regulated in a differential manner on seizure progression. Gene ontology annotation results showed that, on day 1 following lithium-pilocarpine administration, it is likely necessary to regulate macromolecular complex assembly, and cell death, while on day 3, it may be necessary to modulate protein metabolic process, cytoplasm, and protein binding. Protein metabolic process rather than macromolecular complex assembly and cell death were affected on day 3 following lithium-pilocarpine administration. The extracellular matrix, receptors, and the constitution of plasma membranes were altered most strongly in the development of seizure events. In a KEGG pathway enrichment cluster analysis, the signaling pathways identified were relevant to sustained angiogenesis and evading apoptosis, and complement and coagulation cascades. On day 3, pathways relevant to Huntington’s disease, and tumor necrosis factor signaling were most prevalent. These results suggest that seizure events occurring in day 1 modulate macromolecular complex assembly and cell death, and in day 3 modulate biological protein metabolic process. In summary, our study found limited evidence for ongoing seizure events in the hippocampus of lithium-pilocarpine induced animal models; nevertheless, evaluating the global differential expression of proteins and their impacts on bio-function may offer new perspectives for studying epileptogenesis in the future.
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13
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Ziegler A, Steindl K, Hanner AS, Kumar Kar R, Prouteau C, Boland A, Deleuze JF, Coubes C, Bézieau S, Küry S, Maystadt I, Le Mao M, Lenaers G, Navet B, Faivre L, Tran Mau-Them F, Zanoni P, Chung WK, Rauch A, Bonneau D, Park MH. Bi-allelic variants in DOHH, catalyzing the last step of hypusine biosynthesis, are associated with a neurodevelopmental disorder. Am J Hum Genet 2022; 109:1549-1558. [PMID: 35858628 PMCID: PMC9388783 DOI: 10.1016/j.ajhg.2022.06.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Accepted: 06/21/2022] [Indexed: 02/06/2023] Open
Abstract
Deoxyhypusine hydroxylase (DOHH) is the enzyme catalyzing the second step in the post-translational synthesis of hypusine [Nε-(4-amino-2-hydroxybutyl)lysine] in the eukaryotic initiation factor 5A (eIF5A). Hypusine is formed exclusively in eIF5A by two sequential enzymatic steps catalyzed by deoxyhypusine synthase (DHPS) and deoxyhypusine hydroxylase (DOHH). Hypusinated eIF5A is essential for translation and cell proliferation in eukaryotes, and all three genes encoding eIF5A, DHPS, and DOHH are highly conserved throughout eukaryotes. Pathogenic variants affecting either DHPS or EIF5A have been previously associated with neurodevelopmental disorders. Using trio exome sequencing, we identified rare bi-allelic pathogenic missense and truncating DOHH variants segregating with disease in five affected individuals from four unrelated families. The DOHH variants are associated with a neurodevelopmental phenotype that is similar to phenotypes caused by DHPS or EIF5A variants and includes global developmental delay, intellectual disability, facial dysmorphism, and microcephaly. A two-dimensional gel analyses revealed the accumulation of deoxyhypusine-containing eIF5A [eIF5A(Dhp)] and a reduction in the hypusinated eIF5A in fibroblasts derived from affected individuals, providing biochemical evidence for deficiency of DOHH activity in cells carrying the bi-allelic DOHH variants. Our data suggest that rare bi-allelic variants in DOHH result in reduced enzyme activity, limit the hypusination of eIF5A, and thereby lead to a neurodevelopmental disorder.
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Affiliation(s)
- Alban Ziegler
- Département de Génétique Médicale, Centre Hospitalier Universitaire d’Angers, 49933, Angers France,Université d’Angers, MitoVasc Unit, UMR Centre National de la Recherche Scientifique 6015, INSERM 1083, 49000 Angers, France,Corresponding author
| | - Katharina Steindl
- Institute of Medical Genetics, University of Zurich, 8952 Schlieren-Zurich, Switzerland
| | - Ashleigh S. Hanner
- National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD 20892-4340, USA
| | - Rajesh Kumar Kar
- National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD 20892-4340, USA
| | - Clément Prouteau
- Département de Génétique Médicale, Centre Hospitalier Universitaire d’Angers, 49933, Angers France
| | - Anne Boland
- Université Paris-Saclay, CEA, Centre National de Recherche en Génomique Humaine, 91057, Evry, France
| | - Jean Francois Deleuze
- Université Paris-Saclay, CEA, Centre National de Recherche en Génomique Humaine, 91057, Evry, France
| | - Christine Coubes
- Département de Génétique Médicale, Hôpital Arnaud de Villeneuve, Centre Hospitalier-Universitaire de Montpellier, 34295 Montpellier, France
| | - Stéphane Bézieau
- Nantes Université, Centre Hospitalier Universitaire Nantes, Service de Génétique Médicale, 44000 Nantes, France,Nantes Université, Centre Hospitalier Universitaire Nantes, Centre National de la Recherche Scientifique, INSERM, l’institut du thorax, 44000 Nantes, France
| | - Sébastien Küry
- Nantes Université, Centre Hospitalier Universitaire Nantes, Service de Génétique Médicale, 44000 Nantes, France,Nantes Université, Centre Hospitalier Universitaire Nantes, Centre National de la Recherche Scientifique, INSERM, l’institut du thorax, 44000 Nantes, France
| | - Isabelle Maystadt
- Centre de Génétique Humaine, Institut de Pathologie et de Génétique, 6041 Gosselies, Belgique
| | - Morgane Le Mao
- Université d’Angers, MitoVasc Unit, UMR Centre National de la Recherche Scientifique 6015, INSERM 1083, 49000 Angers, France
| | - Guy Lenaers
- Université d’Angers, MitoVasc Unit, UMR Centre National de la Recherche Scientifique 6015, INSERM 1083, 49000 Angers, France,Service de Neurologie, Centre Hospitalier Universitaire d’Angers, 49933, Angers France
| | - Benjamin Navet
- Département de Génétique Médicale, Centre Hospitalier Universitaire d’Angers, 49933, Angers France
| | - Laurence Faivre
- Unité de Formation et de Recherche des Sciences de Santé, INSERM-Université de Bourgogne, UMR 1231, Genetics of Developmental Disorders, FHU-TRANSLAD, 21000, Dijon, France,Centre de Référence Anomalies du Développement et Syndromes Malformatifs, FHU-TRANSLAD, Hôpital d'Enfants, Centre Hospitalier Universitaire Dijon, 21000, Dijon, France
| | - Frédéric Tran Mau-Them
- Unité de Formation et de Recherche des Sciences de Santé, INSERM-Université de Bourgogne, UMR 1231, Genetics of Developmental Disorders, FHU-TRANSLAD, 21000, Dijon, France,Unité Fonctionnelle d’Innovation Diagnostique des Maladies Rares, FHU-TRANSLAD, Centre Hospitalier Universitaire Dijon Bourgogne, Dijon, France
| | - Paolo Zanoni
- Institute of Medical Genetics, University of Zurich, 8952 Schlieren-Zurich, Switzerland
| | - Wendy K. Chung
- Department of Pediatrics, Columbia University, New York, NY 10032, USA,Department of Medicine, Columbia University, New York, NY 10032, USA
| | - Anita Rauch
- Institute of Medical Genetics, University of Zurich, 8952 Schlieren-Zurich, Switzerland,University Children's Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Dominique Bonneau
- Département de Génétique Médicale, Centre Hospitalier Universitaire d’Angers, 49933, Angers France,Université d’Angers, MitoVasc Unit, UMR Centre National de la Recherche Scientifique 6015, INSERM 1083, 49000 Angers, France
| | - Myung Hee Park
- National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD 20892-4340, USA,Corresponding author
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Polyamines and Their Metabolism: From the Maintenance of Physiological Homeostasis to the Mediation of Disease. MEDICAL SCIENCES (BASEL, SWITZERLAND) 2022; 10:medsci10030038. [PMID: 35893120 PMCID: PMC9326668 DOI: 10.3390/medsci10030038] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 07/08/2022] [Accepted: 07/11/2022] [Indexed: 12/13/2022]
Abstract
The polyamines spermidine and spermine are positively charged aliphatic molecules. They are critical in the regulation of nucleic acid and protein structures, protein synthesis, protein and nucleic acid interactions, oxidative balance, and cell proliferation. Cellular polyamine levels are tightly controlled through their import, export, de novo synthesis, and catabolism. Enzymes and enzymatic cascades involved in polyamine metabolism have been well characterized. This knowledge has been used for the development of novel compounds for research and medical applications. Furthermore, studies have shown that disturbances in polyamine levels and their metabolic pathways, as a result of spontaneous mutations in patients, genetic engineering in mice or experimentally induced injuries in rodents, are associated with multiple maladaptive changes. The adverse effects of altered polyamine metabolism have also been demonstrated in in vitro models. These observations highlight the important role these molecules and their metabolism play in the maintenance of physiological normalcy and the mediation of injury. This review will attempt to cover the extensive and diverse knowledge of the biological role of polyamines and their metabolism in the maintenance of physiological homeostasis and the mediation of tissue injury.
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15
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16
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Specific and sensitive GC-MS analysis of hypusine, N ε-(4-amino-2-hydroxybutyl)lysine, a biomarker of hypusinated eukaryotic initiation factor eIF5A, and its application to the bi-ethnic ASOS study. Amino Acids 2022; 54:1083-1099. [PMID: 35243537 PMCID: PMC9217869 DOI: 10.1007/s00726-022-03142-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Accepted: 02/15/2022] [Indexed: 12/12/2022]
Abstract
Hypusination is a unique two-step enzymatic post-translational modification of the Nε-amino group of lysine-50 of the eukaryotic initiation factor 5A (eIF5A). We developed a specific and sensitive gas chromatography–mass spectrometry (GC–MS) method for the measurement of biological hypusine (Hyp), i.e., Nε-(4-amino-2-hydroxybutyl)lysine. The method includes a two-step derivatization of Hyp: first esterification with 2 M HCl in CH3OH (60 min, 80 °C) to the methyl ester (Me) and then acylation with penta-fluoro-propionic (PFP) anhydride in ethyl acetate (30 min, 65 °C). Esterification with 2 M HCl in CD3OD was used to prepare the internal standard. The major derivatization product was identified as the un-labelled (d0Me) and the deuterium-labelled methyl esters (d3Me) derivatives: d0Me-Hyp-(PFP)5 and d3Me-Hyp-(PFP)5, respectively. Negative-ion chemical ionization generated the most intense ions with m/z 811 for d0Me-Hyp-(PFP)5 and m/z 814 for the internal standard d3Me-Hyp-(PFP)5. Selected-ion monitoring of m/z 811 and m/z 814 was used in quantitative analyses. Free Hyp was found in spot urine samples (10 µL) of two healthy subjects at 0.60 µM (0.29 µmol Hyp/mmol creatinine) in the female and 1.80 µM (0.19 µmol Hyp/mmol creatinine) in the male subject. The mean accuracy of the method in these urine samples spiked with 1–5 µM Hyp was 91–94%. The limit of detection (LOD) of the method is 1.4 fmol Hyp. The method was applied to measure the urinary excretion rates of Hyp in healthy black (n = 38, age 7.8 ± 0.7 years) and white (n = 41, age 7.7 ± 1.0 years) boys of the Arterial Stiffness in Offspring Study (ASOS). The Hyp concentrations were 3.55 [2.68–5.31] µM (range 0.54–9.84 µM) in the black boys and 3.87 [2.95–5.06] µM (range 1.0–11.7 µM) in the white boys (P = 0.64). The creatinine-corrected excretion rates were 0.25 [0.20–0.29] µmol/mmol (range 0.11–0.36 µmol/mmol) in the black boys and 0.26 [0.21–0.30] µmol/mmol (range 0.10–0.45 µmol/mmol) in the white boys (P = 0.82). These results suggest that there is no ethnic-related difference in the ASOS population in the eIF5A modification. Remarkable differences were found between black and white boys with respect to correlations of urinary Hyp with amino acids and advanced glycation end-products of Lys, Arg and Cys. Deoxyhypusine, formally the direct precursor of Hyp, seems not to be excreted in the urine by healthy subjects.
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17
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Barba-Aliaga M, Alepuz P. Role of eIF5A in Mitochondrial Function. Int J Mol Sci 2022; 23:1284. [PMID: 35163207 PMCID: PMC8835957 DOI: 10.3390/ijms23031284] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 01/19/2022] [Accepted: 01/21/2022] [Indexed: 12/17/2022] Open
Abstract
The eukaryotic translation initiation factor 5A (eIF5A) is an evolutionarily conserved protein that binds ribosomes to facilitate the translation of peptide motifs with consecutive prolines or combinations of prolines with glycine and charged amino acids. It has also been linked to other molecular functions and cellular processes, such as nuclear mRNA export and mRNA decay, proliferation, differentiation, autophagy, and apoptosis. The growing interest in eIF5A relates to its association with the pathogenesis of several diseases, including cancer, viral infection, and diabetes. It has also been proposed as an anti-aging factor: its levels decay in aged cells, whereas increasing levels of active eIF5A result in the rejuvenation of the immune and vascular systems and improved brain cognition. Recent data have linked the role of eIF5A in some pathologies with its function in maintaining healthy mitochondria. The eukaryotic translation initiation factor 5A is upregulated under respiratory metabolism and its deficiency reduces oxygen consumption, ATP production, and the levels of several mitochondrial metabolic enzymes, as well as altering mitochondria dynamics. However, although all the accumulated data strongly link eIF5A to mitochondrial function, the precise molecular role and mechanisms involved are still unknown. In this review, we discuss the findings linking eIF5A and mitochondria, speculate about its role in regulating mitochondrial homeostasis, and highlight its potential as a target in diseases related to energy metabolism.
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Affiliation(s)
- Marina Barba-Aliaga
- Instituto de Biotecnología y Biomedicina (Biotecmed), Universitat de València, 46100 València, Spain
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Biológicas, Universitat de València, 46100 València, Spain
| | - Paula Alepuz
- Instituto de Biotecnología y Biomedicina (Biotecmed), Universitat de València, 46100 València, Spain
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Biológicas, Universitat de València, 46100 València, Spain
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18
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Kar RK, Hanner AS, Starost MF, Springer D, Mastracci TL, Mirmira RG, Park MH. Neuron-specific ablation of eIF5A or deoxyhypusine synthase leads to impairments in growth, viability, neurodevelopment, and cognitive functions in mice. J Biol Chem 2021; 297:101333. [PMID: 34688659 PMCID: PMC8605248 DOI: 10.1016/j.jbc.2021.101333] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Revised: 10/13/2021] [Accepted: 10/19/2021] [Indexed: 12/05/2022] Open
Abstract
Eukaryotic initiation factor 5A (eIF5A)†,‡ is an essential protein that requires a unique amino acid, hypusine, for its activity. Hypusine is formed exclusively in eIF5A post-translationally via two enzymes, deoxyhypusine synthase (DHPS) and deoxyhypusine hydroxylase. Each of the genes encoding these proteins, Eif5a, Dhps, and Dohh, is required for mouse embryonic development. Variants in EIF5A or DHPS were recently identified as the genetic basis underlying certain rare neurodevelopmental disorders in humans. To investigate the roles of eIF5A and DHPS in brain development, we generated four conditional KO mouse strains using the Emx1-Cre or Camk2a-Cre strains and examined the effects of temporal- and region-specific deletion of Eif5a or Dhps. The conditional deletion of Dhps or Eif5a by Emx1 promotor-driven Cre expression (E9.5, in the cortex and hippocampus) led to gross defects in forebrain development, reduced growth, and premature death. On the other hand, the conditional deletion of Dhps or Eif5a by Camk2a promoter-driven Cre expression (postnatal, mainly in the CA1 region of the hippocampus) did not lead to global developmental defects; rather, these KO animals exhibited severe impairment in spatial learning, contextual learning, and memory when subjected to the Morris water maze and a contextual learning test. In both models, the Dhps-KO mice displayed more severe impairment than their Eif5a-KO counterparts. The observed defects in the brain, global development, or cognitive functions most likely result from translation errors due to a deficiency in active, hypusinated eIF5A. Our study underscores the important roles of eIF5A and DHPS in neurodevelopment.
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Affiliation(s)
- Rajesh Kumar Kar
- Molecular and Cellular Biochemistry Section, NIDCR, National Institutes of Health, Bethesda, Maryland, USA
| | - Ashleigh S Hanner
- Molecular and Cellular Biochemistry Section, NIDCR, National Institutes of Health, Bethesda, Maryland, USA
| | - Matthew F Starost
- Division of Veterinary Resources, Diagnostic and Research Services Branch, National Institutes of Health, Bethesda, Maryland, USA
| | - Danielle Springer
- NHLBI Murine Phenotyping Core, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Teresa L Mastracci
- Department of Biology, Indiana University-Purdue University-Indianapolis, Indianapolis, Indiana, USA
| | | | - Myung Hee Park
- Molecular and Cellular Biochemistry Section, NIDCR, National Institutes of Health, Bethesda, Maryland, USA.
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