1
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Suzuki R, Murakami C, Dilimulati K, Atsuta-Tsunoda K, Kawai T, Sakane F. Human sphingomyelin synthase 1 generates diacylglycerol in the presence and absence of ceramide via multiple enzymatic activities. FEBS Lett 2023; 597:2672-2686. [PMID: 37715942 DOI: 10.1002/1873-3468.14735] [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: 06/29/2023] [Revised: 08/24/2023] [Accepted: 09/01/2023] [Indexed: 09/18/2023]
Abstract
Sphingomyelin (SM) synthase 1 (SMS1), which is involved in lipodystrophy, deafness, and thrombasthenia, generates diacylglycerol (DG) and SM using phosphatidylcholine (PC) and ceramide as substrates. Here, we found that SMS1 possesses DG-generating activities via hydrolysis of PC and phosphatidylethanolamine (PE) in the absence of ceramide and ceramide phosphoethanolamine synthase (CPES) activity. In the presence of the same concentration (4.7 mol%) of PC and ceramide, the amounts of DG produced by SMS and PC-phospholipase C (PLC) activities of SMS1 were approximately 65% and 35% of total DG production, respectively. PC-PLC activity showed substrate selectivity for saturated and/or monounsaturated fatty acid-containing PC species. A PC-PLC/SMS inhibitor, D609, inhibited only SMS activity. Mn2+ inhibited only PC-PLC activity. Intriguingly, DG attenuated SMS/CPES activities. Our study indicates that SMS1 is a unique enzyme with PC-PLC/PE-PLC/SMS/CPES activities.
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Affiliation(s)
- Rika Suzuki
- Department of Chemistry, Graduate School of Science, Chiba University, Japan
| | - Chiaki Murakami
- Department of Chemistry, Graduate School of Science, Chiba University, Japan
- Institute for Advanced Academic Research, Chiba University, Japan
| | - Kamila Dilimulati
- Department of Chemistry, Graduate School of Science, Chiba University, Japan
| | | | - Takuma Kawai
- Department of Chemistry, Graduate School of Science, Chiba University, Japan
| | - Fumio Sakane
- Department of Chemistry, Graduate School of Science, Chiba University, Japan
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2
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Su P, Yan S, Yang J, Tong J, Samsom J, You F, Li Y, Chen Q, Jiang A, Zhai D, Chen J, Sun Z, Zhou J, Liu M, Lee FJS, Xu ZQD, Wang X, Vasdev N, Wong AHC, Liu F. Serum amyloid P component (SAP) modulates antidepressant effects through promoting membrane insertion of the serotonin transporter. Neuropsychopharmacology 2023; 48:508-517. [PMID: 36076020 PMCID: PMC9852251 DOI: 10.1038/s41386-022-01449-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 08/24/2022] [Accepted: 08/29/2022] [Indexed: 02/02/2023]
Abstract
Serum amyloid P component (SAP) is a universal constituent of human amyloid deposits including those in Alzheimer's disease. SAP has been observed to be elevated in patients with depression, and higher SAP levels are associated with better response to the antidepressant escitalopram. The mechanisms underlying these clinical observations remain unclear. We examined the effect of SAP on serotonin transporter (SERT) expression and localization using Western blot, confocal microscopy, and positron emission tomography with the radioligand [11C]DASB. We also investigated the effect of SAP on treatment response to escitalopram in mice with the forced swim test (FST), a classical behaviour paradigm to assess antidepressant effects. SAP reduced [11C]DASB binding as an index of SERT levels, consistent with Western blots showing decreased total SAP protein because of increased protein degradation. In conjunction with the global decrease in SERT levels, SAP also promotes VAMP-2 mediated SERT membrane insertion. SAP levels are correlated with behavioural despair and SSRI treatment response in mice with FST. In MDD patients, the SAP and membrane SERT levels are correlated with response to SSRI treatment. SAP has complex effects on SERT levels and localization, thereby modulating the effect of SSRIs, which could partially explain clinical variability in antidepressant treatment response. These results add to our understanding of the mechanism for antidepressant drug action, and with further work could be of clinical utility.
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Affiliation(s)
- Ping Su
- Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing, China, Beijing, China
- Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, ON, Canada
| | - Shuxin Yan
- Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing, China, Beijing, China
- Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, ON, Canada
| | - Jian Yang
- Beijing AnDing Hospital, Capital Medical University, Beijing, China, Beijing, China
| | - Junchao Tong
- Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, ON, Canada
| | - James Samsom
- Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, ON, Canada
| | - Fan You
- Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing, China, Beijing, China
| | - Yun Li
- Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing, China, Beijing, China
| | - Qiuyue Chen
- Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing, China, Beijing, China
| | - Anlong Jiang
- Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, ON, Canada
| | - Dongxu Zhai
- Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, ON, Canada
| | - Jiahao Chen
- Departments of Neurobiology and Pathology, Beijing Key Laboratory of Neural Regeneration and Repair, Capital Medical University, Beijing, 100069, China
| | - Zuoli Sun
- Beijing AnDing Hospital, Capital Medical University, Beijing, China, Beijing, China
| | - Jingjing Zhou
- Beijing AnDing Hospital, Capital Medical University, Beijing, China, Beijing, China
| | - Min Liu
- Beijing AnDing Hospital, Capital Medical University, Beijing, China, Beijing, China
| | - Frank J S Lee
- Faculty of Health Sciences, Simon Fraser University, Burnaby, BC, Canada
| | - Zhi-Qing David Xu
- Departments of Neurobiology and Pathology, Beijing Key Laboratory of Neural Regeneration and Repair, Capital Medical University, Beijing, 100069, China
| | - Xin Wang
- Department of Hematology, Shandong Provincial Hospital, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, 250021, China
| | - Neil Vasdev
- Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, ON, Canada
- Departments of Psychiatry, University of Toronto, Toronto, ON, Canada
| | - Albert H C Wong
- Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, ON, Canada
- Departments of Psychiatry, University of Toronto, Toronto, ON, Canada
- Departments of Pharmacology and Toxicology, University of Toronto, Toronto, ON, Canada
| | - Fang Liu
- Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing, China, Beijing, China.
- Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, ON, Canada.
- Departments of Psychiatry, University of Toronto, Toronto, ON, Canada.
- Departments of Physiology, University of Toronto, Toronto, ON, Canada.
- Institute of Medical Science, University of Toronto, Toronto, ON, Canada.
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3
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Nakamura M, Yoshimi A, Mouri A, Tokura T, Kimura H, Kishi S, Miyauchi T, Iwamoto K, Ito M, Sato-Boku A, Ozaki N, Nabeshima T, Noda Y. Duloxetine attenuates pain in association with downregulation of platelet serotonin transporter in patients with burning mouth syndrome and atypical odontalgia. Hum Psychopharmacol 2022; 37:e2818. [PMID: 34541697 DOI: 10.1002/hup.2818] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Accepted: 08/24/2021] [Indexed: 11/10/2022]
Abstract
OBJECTIVE The aim of this study was evaluation of the association between severity of pain and expression of total or ubiquitinated serotonin transporter (SERT) protein in patients with burning mouth syndrome and atypical odontalgia (BMS/AO), who were treated by duloxetine. METHODS Patients with BMS/AO were assessed for severity of pain using the visual analog scale (VAS), and expression of total and ubiquitinated SERT protein in platelets before (baseline) and 12 weeks after duloxetine-treatment. RESULTS The expression of total and ubiquitinated SERT protein at baseline in all patients (n = 33) were higher and lower, respectively, compared to those in healthy controls. 12 weeks after duloxetine-treatment, there was no difference in the total SERT protein levels between patients (n = 21) and healthy controls. In the 16 patients who could be measured, mean VAS scores and total SERT protein levels were significantly decreased after the treatment, compared to those at baseline. There was tendency for a positive correlation between total SERT protein levels and VAS scores in these patients. CONCLUSIONS Our findings indicate that duloxetine relieves pain in association with downregulation of platelet SERT expression in patients with BMS/AO.
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Affiliation(s)
- Mariko Nakamura
- Division of Clinical Sciences and Neuropsychopharmacology, Graduate School of Pharmacy, Meijo University, Nagoya, Japan.,Clinical OMICs and Translation Research Center, Meijo University, Nagoya, Japan
| | - Akira Yoshimi
- Division of Clinical Sciences and Neuropsychopharmacology, Graduate School of Pharmacy, Meijo University, Nagoya, Japan.,Clinical OMICs and Translation Research Center, Meijo University, Nagoya, Japan.,Department of Psychiatry, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Akihiro Mouri
- Department of Regulatory Science for Evaluation & Development of Pharmaceuticals and Devices, Fujita Health University Graduate School of Health Science, Toyoake, Aichi, Japan
| | - Tatsuya Tokura
- Department of Psychiatry, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Hiroyuki Kimura
- Department of Psychiatry, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Shinichi Kishi
- Department of Psychiatry, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Tomoya Miyauchi
- Department of Psychiatry, Nagoya University Graduate School of Medicine, Nagoya, Japan.,Department of Psychiatry, KACHI Memorial Hospital, Toyohashi, Japan
| | - Kunihiro Iwamoto
- Department of Psychiatry, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Mikiko Ito
- Department of Oral and Maxillofacial Surgery, School of Dentistry, Aichi Gakuin University, Nagoya, Japan
| | - Aiji Sato-Boku
- Department of Anesthesiology, School of Dentistry, Aichi Gakuin University, Nagoya, Japan
| | - Norio Ozaki
- Department of Psychiatry, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Toshitaka Nabeshima
- Advanced Diagnostic System Research Laboratory, Graduate School of Health Sciences, Fujita Health University, Toyoake, Aichi, Japan.,Japanese Drug Organization of Appropriate Use and Research, Nagoya, Japan
| | - Yukihiro Noda
- Division of Clinical Sciences and Neuropsychopharmacology, Graduate School of Pharmacy, Meijo University, Nagoya, Japan.,Clinical OMICs and Translation Research Center, Meijo University, Nagoya, Japan.,Department of Psychiatry, Nagoya University Graduate School of Medicine, Nagoya, Japan.,Japanese Drug Organization of Appropriate Use and Research, Nagoya, Japan
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4
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The presynaptic glycine transporter GlyT2 is regulated by the Hedgehog pathway in vitro and in vivo. Commun Biol 2021; 4:1197. [PMID: 34663888 PMCID: PMC8523746 DOI: 10.1038/s42003-021-02718-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Accepted: 09/22/2021] [Indexed: 01/20/2023] Open
Abstract
The identity of a glycinergic synapse is maintained presynaptically by the activity of a surface glycine transporter, GlyT2, which recaptures glycine back to presynaptic terminals to preserve vesicular glycine content. GlyT2 loss-of-function mutations cause Hyperekplexia, a rare neurological disease in which loss of glycinergic neurotransmission causes generalized stiffness and strong motor alterations. However, the molecular underpinnings controlling GlyT2 activity remain poorly understood. In this work, we identify the Hedgehog pathway as a robust controller of GlyT2 expression and transport activity. Modulating the activation state of the Hedgehog pathway in vitro in rodent primary spinal cord neurons or in vivo in zebrafish embryos induced a selective control in GlyT2 expression, regulating GlyT2 transport activity. Our results indicate that activation of Hedgehog reduces GlyT2 expression by increasing its ubiquitination and degradation. This work describes a new molecular link between the Hedgehog signaling pathway and presynaptic glycine availability. By modulating the activation state of the Hedgehog pathway, de la Rocha-Muñoz et al demonstrate that Hedgehog signaling controls the expression and transport activity of the neuronal glycine transporter GlyT2. This work begins to reveal a potential link between the Hedgehog signaling pathway and presynaptic glycine availability.
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5
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Ngwa CJ, Farrukh A, Pradel G. Zinc finger proteins of Plasmodium falciparum. Cell Microbiol 2021; 23:e13387. [PMID: 34418264 DOI: 10.1111/cmi.13387] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 07/19/2021] [Accepted: 07/24/2021] [Indexed: 01/14/2023]
Abstract
Zinc finger proteins (ZFPs) are a large diverse family of proteins with one or more zinc finger domains in which zinc is important in stabilising the domain. ZFPs can interact with DNA, RNA, lipids or even other proteins and therefore contribute to diverse cellular processes including transcriptional regulation, ubiquitin-mediated protein degradation, mRNA decay and stability. In this review, we provide the first comprehensive classification of ZFPs of the malaria parasite Plasmodium falciparum and provide a state of knowledge on the main ZFPs in the parasite, which include the C2H2, CCCH, RING finger and the PHD finger proteins. TAKE AWAYS: The Plasmodium falciparum genome encodes 170 putative Zinc finger proteins (ZFPs). The C2H2, CCCH, RING finger and PHD finger subfamilies of ZFPs are most represented. Known ZFP functions include the regulation of mRNA metabolism and proteostasis.
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Affiliation(s)
- Che Julius Ngwa
- Division of Cellular and Applied Infection Biology, Institute of Zoology, RWTH Aachen University, Aachen, Germany
| | - Afia Farrukh
- Division of Cellular and Applied Infection Biology, Institute of Zoology, RWTH Aachen University, Aachen, Germany
| | - Gabriele Pradel
- Division of Cellular and Applied Infection Biology, Institute of Zoology, RWTH Aachen University, Aachen, Germany
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6
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Zhang Y, Zhang X, Liu N, Ren S, Xia C, Yang X, Lou Y, Wang H, Zhang N, Yan X, Zhang Z, Zhang Y, Wang Z, Chen N. Comparative Proteomic Characterization of Ventral Hippocampus in Susceptible and Resilient Rats Subjected to Chronic Unpredictable Stress. Front Neurosci 2021; 15:675430. [PMID: 34220431 PMCID: PMC8249003 DOI: 10.3389/fnins.2021.675430] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Accepted: 05/10/2021] [Indexed: 12/19/2022] Open
Abstract
Chronic stress is an essential factor leading to depression. However, there exist individual differences in people exposed to the same stressful stimuli. Some people display negative psychology and behavior, while others are normal. Given the importance of individual difference, finding differentially expressed proteins in stress-resistant and stress-susceptible groups has great significance for the study of pathogenesis and treatment of depression. In this study, stress-susceptible rats and stress-resilient rats were first distinguished by sucrose preference test. These stress-susceptible rats also displayed depression-like behaviors in forced swimming test and open field test. Then, we employed label-free quantitative proteomics to analyze proteins in the ventral hippocampus. There were 4,848 proteins totally identified. Based on statistical analysis, we found 276 differentially expressed proteins. Bioinformatics analysis revealed that the biological processes of these differential proteins were related to mitochondrion organization, protein localization, coenzyme metabolic process, cerebral cortex tangential migration, vesicle-mediated transport, and so on. The KEGG pathways were mainly involved in metabolic pathways, axon guidance, autophagy, and tight junction. Furthermore, we ultimately found 20 stress-susceptible proteins and two stress-resilient proteins. These stress-related proteins could not only be potential biomarkers for depression diagnosis but also contribute to finding new therapeutic targets and providing personalized medicine.
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Affiliation(s)
- Yani Zhang
- State Key Laboratory of Bioactive Substances and Function of Natural Medicines, Institute of Materia Medica and Neuroscience Center, Chinese Academy Medical Sciences and Peking Union Medical College, Beijing, China.,Institute of Clinical Pharmacology and Science and Technology Innovation Center, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Xiaoling Zhang
- State Key Laboratory of Bioactive Substances and Function of Natural Medicines, Institute of Materia Medica and Neuroscience Center, Chinese Academy Medical Sciences and Peking Union Medical College, Beijing, China
| | - Nuo Liu
- State Key Laboratory of Bioactive Substances and Function of Natural Medicines, Institute of Materia Medica and Neuroscience Center, Chinese Academy Medical Sciences and Peking Union Medical College, Beijing, China
| | - Siyu Ren
- State Key Laboratory of Bioactive Substances and Function of Natural Medicines, Institute of Materia Medica and Neuroscience Center, Chinese Academy Medical Sciences and Peking Union Medical College, Beijing, China
| | - Congyuan Xia
- State Key Laboratory of Bioactive Substances and Function of Natural Medicines, Institute of Materia Medica and Neuroscience Center, Chinese Academy Medical Sciences and Peking Union Medical College, Beijing, China
| | - Xiong Yang
- State Key Laboratory of Bioactive Substances and Function of Natural Medicines, Institute of Materia Medica and Neuroscience Center, Chinese Academy Medical Sciences and Peking Union Medical College, Beijing, China
| | - Yuxia Lou
- State Key Laboratory of Bioactive Substances and Function of Natural Medicines, Institute of Materia Medica and Neuroscience Center, Chinese Academy Medical Sciences and Peking Union Medical College, Beijing, China
| | - Huiqin Wang
- State Key Laboratory of Bioactive Substances and Function of Natural Medicines, Institute of Materia Medica and Neuroscience Center, Chinese Academy Medical Sciences and Peking Union Medical College, Beijing, China
| | - Ningning Zhang
- State Key Laboratory of Bioactive Substances and Function of Natural Medicines, Institute of Materia Medica and Neuroscience Center, Chinese Academy Medical Sciences and Peking Union Medical College, Beijing, China
| | - Xu Yan
- State Key Laboratory of Bioactive Substances and Function of Natural Medicines, Institute of Materia Medica and Neuroscience Center, Chinese Academy Medical Sciences and Peking Union Medical College, Beijing, China
| | - Zhao Zhang
- State Key Laboratory of Bioactive Substances and Function of Natural Medicines, Institute of Materia Medica and Neuroscience Center, Chinese Academy Medical Sciences and Peking Union Medical College, Beijing, China
| | - Yi Zhang
- Department of Anatomy, School of Chinese Medicine, Beijing University of Chinese Medicine, Beijing, China
| | - Zhenzhen Wang
- State Key Laboratory of Bioactive Substances and Function of Natural Medicines, Institute of Materia Medica and Neuroscience Center, Chinese Academy Medical Sciences and Peking Union Medical College, Beijing, China
| | - Naihong Chen
- State Key Laboratory of Bioactive Substances and Function of Natural Medicines, Institute of Materia Medica and Neuroscience Center, Chinese Academy Medical Sciences and Peking Union Medical College, Beijing, China.,Institute of Clinical Pharmacology and Science and Technology Innovation Center, Guangzhou University of Chinese Medicine, Guangzhou, China
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7
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Asami M, Suzuki Y, Sakane F. Dopamine and the phosphorylated dopamine transporter are increased in the diacylglycerol kinase η-knockout mouse brain. FEBS Lett 2021; 595:1313-1321. [PMID: 33599293 DOI: 10.1002/1873-3468.14059] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Revised: 01/26/2021] [Accepted: 02/09/2021] [Indexed: 12/19/2022]
Abstract
The molecular mechanisms generating the mania-like abnormal behaviors caused by diacylglycerol (DG) kinase (DGK) η deficiency remain unclear. Here, we found that DGKη knockout markedly increased dopamine (DA) levels in the midbrain (DA-producing region, 2.8-fold) and cerebral cortex (DA projection region, 1.2-fold). Moreover, DGKη deficiency significantly augmented phosphorylated DA transporter (DAT) levels (1.4-fold increase), which induce DA efflux to the synaptic cleft, in the cerebral cortex. Moreover, phosphorylation levels of protein kinase C-β, which is activated by DG and involved in DAT phosphorylation, were also increased. DAT expressed in Neuro-2a cells recruited DGKη to the plasma membrane and colocalized with it. These results strongly suggest that dopaminergic hyperfunction caused by DGKη deficiency in the brain leads to mania-like behaviors.
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Affiliation(s)
- Maho Asami
- Department of Chemistry, Graduate School of Science, Chiba University, Japan
| | - Yuji Suzuki
- Department of Chemistry, Graduate School of Science, Chiba University, Japan
| | - Fumio Sakane
- Department of Chemistry, Graduate School of Science, Chiba University, Japan
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8
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New Era of Diacylglycerol Kinase, Phosphatidic Acid and Phosphatidic Acid-Binding Protein. Int J Mol Sci 2020; 21:ijms21186794. [PMID: 32947951 PMCID: PMC7555651 DOI: 10.3390/ijms21186794] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Revised: 09/11/2020] [Accepted: 09/14/2020] [Indexed: 12/12/2022] Open
Abstract
Diacylglycerol kinase (DGK) phosphorylates diacylglycerol (DG) to generate phosphatidic acid (PA). Mammalian DGK consists of ten isozymes (α–κ) and governs a wide range of physiological and pathological events, including immune responses, neuronal networking, bipolar disorder, obsessive-compulsive disorder, fragile X syndrome, cancer, and type 2 diabetes. DG and PA comprise diverse molecular species that have different acyl chains at the sn-1 and sn-2 positions. Because the DGK activity is essential for phosphatidylinositol turnover, which exclusively produces 1-stearoyl-2-arachidonoyl-DG, it has been generally thought that all DGK isozymes utilize the DG species derived from the turnover. However, it was recently revealed that DGK isozymes, except for DGKε, phosphorylate diverse DG species, which are not derived from phosphatidylinositol turnover. In addition, various PA-binding proteins (PABPs), which have different selectivities for PA species, were recently found. These results suggest that DGK–PA–PABP axes can potentially construct a large and complex signaling network and play physiologically and pathologically important roles in addition to DGK-dependent attenuation of DG–DG-binding protein axes. For example, 1-stearoyl-2-docosahexaenoyl-PA produced by DGKδ interacts with and activates Praja-1, the E3 ubiquitin ligase acting on the serotonin transporter, which is a target of drugs for obsessive-compulsive and major depressive disorders, in the brain. This article reviews recent research progress on PA species produced by DGK isozymes, the selective binding of PABPs to PA species and a phosphatidylinositol turnover-independent DG supply pathway.
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9
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Sakai H, Murakami C, Usuki T, Lu Q, Matsumoto KI, Urano T, Sakane F. Diacylglycerol kinase η regulates C2C12 myoblast proliferation through the mTOR signaling pathway. Biochimie 2020; 177:13-24. [PMID: 32791090 DOI: 10.1016/j.biochi.2020.07.018] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 06/16/2020] [Accepted: 07/27/2020] [Indexed: 02/08/2023]
Abstract
Diacylglycerol kinase (DGK) phosphorylates diacylglycerol to produce phosphatidic acid (PA). The η isozyme of DGK is abundantly expressed in C2C12 myoblasts. However, the role of DGKη in skeletal muscle cells remains unknown. In the present study, we showed that DGKη was downregulated at an early stage of myogenic differentiation. The knockdown of DGKη by siRNAs significantly inhibited C2C12 myoblast proliferation but did not inhibit differentiation. Moreover, the suppression of DGKη expression decreased the expression levels of mammalian target of rapamycin (mTOR), which is a key regulator of cell proliferation, and fatty acid synthase (FASN), which catalyzes the de novo synthesis of fatty acids for cell proliferation and is transcriptionally regulated via mTOR signaling. Furthermore, the knockdown of mTOR or raptor, which is a component of mTOR complex 1 (mTORC1), decreased the amount of FASN. These results indicate that DGKη regulates myoblast proliferation through the mTOR (mTORC1)-FASN pathway. Interestingly, the knockdown of mTOR reduced the expression levels of DGKη, implying mutual regulation between DGKη and mTOR. In DGKη-knockdown myoblasts, C30-C36-PA species, mTOR activators, were decreased, suggesting that the modulation of mTOR activity through these PA species also plays an important role in myoblast proliferation.
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Affiliation(s)
- Hiromichi Sakai
- Department of Biosignaling and Radioisotope Experiment, Interdisciplinary Center for Science Research, Organization for Research and Academic Information, Shimane University, Izumo, Japan.
| | - Chiaki Murakami
- Department of Chemistry, Graduate School of Science, Chiba University, Chiba, Japan
| | - Takako Usuki
- Department of Chemistry, Graduate School of Science, Chiba University, Chiba, Japan
| | - Qiang Lu
- Department of Chemistry, Graduate School of Science, Chiba University, Chiba, Japan
| | - Ken-Ichi Matsumoto
- Department of Biosignaling and Radioisotope Experiment, Interdisciplinary Center for Science Research, Organization for Research and Academic Information, Shimane University, Izumo, Japan
| | - Takeshi Urano
- Department of Biosignaling and Radioisotope Experiment, Interdisciplinary Center for Science Research, Organization for Research and Academic Information, Shimane University, Izumo, Japan; Department of Biochemistry, Shimane University School of Medicine, Izumo, Japan
| | - Fumio Sakane
- Department of Chemistry, Graduate School of Science, Chiba University, Chiba, Japan.
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10
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Lu Q, Murakami C, Murakami Y, Hoshino F, Asami M, Usuki T, Sakai H, Sakane F. 1‐Stearoyl‐2‐docosahexaenoyl‐phosphatidic acid interacts with and activates Praja‐1, the E3 ubiquitin ligase acting on the serotonin transporter in the brain. FEBS Lett 2020; 594:1787-1796. [DOI: 10.1002/1873-3468.13765] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Revised: 02/15/2020] [Accepted: 02/21/2020] [Indexed: 12/28/2022]
Affiliation(s)
- Qiang Lu
- Department of Chemistry Graduate School of Science Chiba University Chiba Japan
| | - Chiaki Murakami
- Department of Chemistry Graduate School of Science Chiba University Chiba Japan
| | - Yuki Murakami
- Department of Chemistry Graduate School of Science Chiba University Chiba Japan
| | - Fumi Hoshino
- Department of Chemistry Graduate School of Science Chiba University Chiba Japan
| | - Maho Asami
- Department of Chemistry Graduate School of Science Chiba University Chiba Japan
| | - Takako Usuki
- Department of Chemistry Graduate School of Science Chiba University Chiba Japan
| | - Hiromichi Sakai
- Department of Biosignaling and Radioisotope Experiment Interdisciplinary Center for Science Research Organization for Research and Academic Information Shimane University Izumo Japan
| | - Fumio Sakane
- Department of Chemistry Graduate School of Science Chiba University Chiba Japan
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