1
|
DGKB mediates radioresistance by regulating DGAT1-dependent lipotoxicity in glioblastoma. Cell Rep Med 2023; 4:100880. [PMID: 36603576 PMCID: PMC9873821 DOI: 10.1016/j.xcrm.2022.100880] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2022] [Revised: 08/08/2022] [Accepted: 12/08/2022] [Indexed: 01/06/2023]
Abstract
Glioblastoma (GBM) currently has a dismal prognosis. GBM cells that survive radiotherapy contribute to tumor progression and recurrence with metabolic advantages. Here, we show that diacylglycerol kinase B (DGKB), a regulator of the intracellular concentration of diacylglycerol (DAG), is significantly downregulated in radioresistant GBM cells. The downregulation of DGKB increases DAG accumulation and decreases fatty acid oxidation, contributing to radioresistance by reducing mitochondrial lipotoxicity. Diacylglycerol acyltransferase 1 (DGAT1), which catalyzes the formation of triglycerides from DAG, is increased after ionizing radiation. Genetic inhibition of DGAT1 using short hairpin RNA (shRNA) or microRNA-3918 (miR-3918) mimic suppresses radioresistance. We discover that cladribine, a clinical drug, activates DGKB, inhibits DGAT1, and sensitizes GBM cells to radiotherapy in vitro and in vivo. Together, our study demonstrates that DGKB downregulation and DGAT1 upregulation confer radioresistance by reducing mitochondrial lipotoxicity and suggests DGKB and DGAT1 as therapeutic targets to overcome GBM radioresistance.
Collapse
|
2
|
Koller D, Pathak GA, Wendt FR, Tylee DS, Levey DF, Overstreet C, Gelernter J, Taylor HS, Polimanti R. Epidemiologic and Genetic Associations of Endometriosis With Depression, Anxiety, and Eating Disorders. JAMA Netw Open 2023; 6:e2251214. [PMID: 36652249 PMCID: PMC9856929 DOI: 10.1001/jamanetworkopen.2022.51214] [Citation(s) in RCA: 24] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
IMPORTANCE Endometriosis is a common chronic gynecologic pathology with a large negative impact on women's health. Beyond severe physical symptoms, endometriosis is also associated with several psychiatric comorbidities, including depression and anxiety. OBJECTIVE To investigate whether pleiotropy contributes to the association of endometriosis with depression, anxiety, and eating disorders. DESIGN, SETTING, AND PARTICIPANTS This genetic association study was performed between September 13, 2021, and June 24, 2022, in 202 276 unrelated female participants. Genotypic and phenotypic information from the UK Biobank was combined with genome-wide association statistics available from the Psychiatric Genomics Consortium (11 countries), the Million Veteran Program (US), the FinnGen study (Finland), and the CHARGE (Cohorts for Heart and Aging Research in Genomic Epidemiology) consortium (5 countries). MAIN OUTCOMES AND MEASURES The main outcomes were the phenotypic and genetic associations of endometriosis with anxiety, depression, and eating disorders. RESULTS A total of 8276 women with endometriosis (mean [SD] age, 53.1 [7.9] years) and 194 000 female controls (mean [SD] age, 56.7 [7.9] years) were included in the study. In a multivariate regression analysis accounting for age, body mass index, socioeconomic status, chronic pain-related phenotypes, irritable bowel syndrome, and psychiatric comorbidities, endometriosis was associated with increased odds of depression (odds ratio [OR], 3.61; 95% CI, 3.32-3.92), eating disorders (OR, 2.94; 95% CI, 1.96-4.41), and anxiety (OR, 2.61; 95% CI, 2.30-2.97). These associations were supported by consistent genetic correlations (rg) (depression rg, 0.36, P = 1.5 × 10-9; anxiety rg, 0.33, P = 1.17 × 10-5; and eating disorders rg, 0.61, P = .02). With the application of a 1-sample mendelian randomization, the genetic liabilities to depression and anxiety were associated with increased odds of endometriosis (depression: OR, 1.09; 95% CI, 1.08-1.11; anxiety: OR, 1.39; 95% CI, 1.13-1.65). A genome-wide analysis of pleiotropic associations shared between endometriosis and psychiatric disorders identified 1 locus, DGKB rs12666606, with evidence of pleiotropy between endometriosis and depression after multiple testing correction (z = -9.46 for endometriosis, z = 8.10 for depression, P = 5.56 × 10-8; false discovery rate q = 4.95 × 10-4). CONCLUSIONS AND RELEVANCE These findings highlight that endometriosis is associated with women's mental health through pleiotropic mechanisms. To our knowledge, this is the first large-scale study to provide genetic and phenotypic evidence of the processes underlying the psychiatric comorbidities of endometriosis.
Collapse
Affiliation(s)
- Dora Koller
- Department of Psychiatry, Yale School of Medicine, West Haven, Connecticut
- Veterans Affairs Connecticut Healthcare Center, West Haven
- Department of Genetics, Microbiology, and Statistics, Faculty of Biology, University of Barcelona, Catalonia, Spain
| | - Gita A. Pathak
- Department of Psychiatry, Yale School of Medicine, West Haven, Connecticut
- Veterans Affairs Connecticut Healthcare Center, West Haven
| | - Frank R. Wendt
- Department of Psychiatry, Yale School of Medicine, West Haven, Connecticut
- Veterans Affairs Connecticut Healthcare Center, West Haven
| | - Daniel S. Tylee
- Department of Psychiatry, Yale School of Medicine, West Haven, Connecticut
- Veterans Affairs Connecticut Healthcare Center, West Haven
| | - Daniel F. Levey
- Department of Psychiatry, Yale School of Medicine, West Haven, Connecticut
- Veterans Affairs Connecticut Healthcare Center, West Haven
| | - Cassie Overstreet
- Department of Psychiatry, Yale School of Medicine, West Haven, Connecticut
- Veterans Affairs Connecticut Healthcare Center, West Haven
| | - Joel Gelernter
- Department of Psychiatry, Yale School of Medicine, West Haven, Connecticut
- Veterans Affairs Connecticut Healthcare Center, West Haven
| | - Hugh S. Taylor
- Department of Obstetrics, Gynecology, and Reproductive Sciences, Yale School of Medicine, New Haven, Connecticut
| | - Renato Polimanti
- Department of Psychiatry, Yale School of Medicine, West Haven, Connecticut
- Veterans Affairs Connecticut Healthcare Center, West Haven
| |
Collapse
|
3
|
Ma Y, Fa B, Yuan X, Zhang Y, Yu Z. STS-BN: An efficient Bayesian network method for detecting causal SNPs. Front Genet 2022; 13:942464. [PMID: 36186431 PMCID: PMC9520706 DOI: 10.3389/fgene.2022.942464] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Accepted: 08/16/2022] [Indexed: 11/16/2022] Open
Abstract
Background: The identification of the causal SNPs of complex diseases in large-scale genome-wide association analysis is beneficial to the studies of pathogenesis, prevention, diagnosis and treatment of these diseases. However, existing applicable methods for large-scale data suffer from low accuracy. Developing powerful and accurate methods for detecting SNPs associated with complex diseases is highly desired. Results: We propose a score-based two-stage Bayesian network method to identify causal SNPs of complex diseases for case-control designs. This method combines the ideas of constraint-based methods and score-and-search methods to learn the structure of the disease-centered local Bayesian network. Simulation experiments are conducted to compare this new algorithm with several common methods that can achieve the same function. The results show that our method improves the accuracy and stability compared to several common methods. Our method based on Bayesian network theory results in lower false-positive rates when all correct loci are detected. Besides, real-world data application suggests that our algorithm has good performance when handling genome-wide association data. Conclusion: The proposed method is designed to identify the SNPs related to complex diseases, and is more accurate than other methods which can also be adapted to large-scale genome-wide analysis studies data.
Collapse
Affiliation(s)
- Yanran Ma
- Department of Bioinformatics and Biostatistics, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Botao Fa
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Xi’an Jiaotong University, Xi’an, China
| | - Xin Yuan
- Department of Bioinformatics and Biostatistics, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Yue Zhang
- Department of Bioinformatics and Biostatistics, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
- *Correspondence: Yue Zhang, ; Zhangsheng Yu,
| | - Zhangsheng Yu
- Department of Bioinformatics and Biostatistics, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
- *Correspondence: Yue Zhang, ; Zhangsheng Yu,
| |
Collapse
|
4
|
Barber CN, Goldschmidt HL, Ma Q, Devine LR, Cole RN, Huganir RL, Raben DM. Identification of Synaptic DGKθ Interactors That Stimulate DGKθ Activity. Front Synaptic Neurosci 2022; 14:855673. [PMID: 35573662 PMCID: PMC9095502 DOI: 10.3389/fnsyn.2022.855673] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2022] [Accepted: 03/16/2022] [Indexed: 01/16/2023] Open
Abstract
Lipids and their metabolic enzymes are a critical point of regulation for the membrane curvature required to induce membrane fusion during synaptic vesicle recycling. One such enzyme is diacylglycerol kinase θ (DGKθ), which produces phosphatidic acid (PtdOH) that generates negative membrane curvature. Synapses lacking DGKθ have significantly slower rates of endocytosis, implicating DGKθ as an endocytic regulator. Importantly, DGKθ kinase activity is required for this function. However, protein regulators of DGKθ's kinase activity in neurons have never been identified. In this study, we employed APEX2 proximity labeling and mass spectrometry to identify endogenous interactors of DGKθ in neurons and assayed their ability to modulate its kinase activity. Seven endogenous DGKθ interactors were identified and notably, synaptotagmin-1 (Syt1) increased DGKθ kinase activity 10-fold. This study is the first to validate endogenous DGKθ interactors at the mammalian synapse and suggests a coordinated role between DGKθ-produced PtdOH and Syt1 in synaptic vesicle recycling.
Collapse
Affiliation(s)
- Casey N. Barber
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD, United States,Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Hana L. Goldschmidt
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Qianqian Ma
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Lauren R. Devine
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Robert N. Cole
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Richard L. Huganir
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Daniel M. Raben
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD, United States,*Correspondence: Daniel M. Raben,
| |
Collapse
|
5
|
Ma Q, Srinivasan L, Gabelli SB, Raben DM. Elusive structure of mammalian DGKs. Adv Biol Regul 2022; 83:100847. [PMID: 34922895 PMCID: PMC8858910 DOI: 10.1016/j.jbior.2021.100847] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Revised: 11/29/2021] [Accepted: 11/30/2021] [Indexed: 01/03/2023]
Abstract
Mammalian diacylglycerol kinases (DGKs) are a group of enzymes that catalyze the ATP-dependent phosphorylation of diacylglycerol (DAG) to produce phosphatidic acid (PtdOH). In doing so, they modulate the levels of these two important signaling lipids. Currently, ten mammalian DGKs are organized into five classes that vary with respect to domain organization, regulation, and cellular/subcellular distribution. As lipids play critical roles in cells, it is not surprising that there is increasing interest in understanding the mechanism underlying the catalysis and regulation of lipid modulating enzymes such as DGKs. However, there are no solved 3D structures for any of the eukaryotic DGKs. In this review, we summarize what is known and the current challenges in determining the structures of these important enzymes. In addition to gain critical insights into their mechanisms of catalysis and regulation, DGK structures will provide a platform for the design of isoform specific inhibitors.
Collapse
Affiliation(s)
- Qianqian Ma
- Department of Biological Chemistry, The Johns Hopkins University School of Medicine, Baltimore Maryland
| | - Lakshmi Srinivasan
- Department of Biophysics and Biophysical Chemistry, The Johns Hopkins University School of Medicine, Baltimore Maryland
| | - Sandra B. Gabelli
- Department of Biophysics and Biophysical Chemistry, The Johns Hopkins University School of Medicine, Baltimore Maryland,Department of Oncology, The Johns Hopkins University School of Medicine, Baltimore Maryland,Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore Maryland,Corresponding author: Sandra B. Gabelli (), Daniel M. Raben ()
| | - Daniel M. Raben
- Department of Biological Chemistry, The Johns Hopkins University School of Medicine, Baltimore Maryland,Department of Oncology, The Johns Hopkins University School of Medicine, Baltimore Maryland,Corresponding author: Sandra B. Gabelli (), Daniel M. Raben ()
| |
Collapse
|
6
|
Barber CN, Raben DM. Roles of DGKs in neurons: Postsynaptic functions? Adv Biol Regul 2019; 75:100688. [PMID: 31836314 DOI: 10.1016/j.jbior.2019.100688] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2019] [Revised: 11/08/2019] [Accepted: 11/18/2019] [Indexed: 01/12/2023]
Abstract
Diacylglycerol kinases (DGKs) contribute to an important part of intracellular signaling because, in addition to reducing diacylglycerol levels, they generate phosphatidic acid (PtdOH) Recent research has led to the discovery of ten mammalian DGK isoforms, all of which are found in the mammalian brain. Many of these isoforms have studied functions within the brain, while others lack such understanding in regards to neuronal roles, regulation, and structural dynamics. However, while previously a neuronal function for DGKθ was unknown, it was recently found that DGKθ is required for the regulation of synaptic vesicle endocytosis and work is currently being conducted to elucidate the mechanism behind this regulation. Here we will review some of the roles of all mammalian DGKs and hypothesize additional roles. We will address the topic of redundancy among the ten DGK isoforms and discuss the possibility that DGKθ, among other DGKs, may have unstudied postsynaptic functions. We also hypothesize that in addition to DGKθ's presynaptic endocytic role, DGKθ might also regulate the endocytosis of AMPA receptors and other postsynaptic membrane proteins.
Collapse
Affiliation(s)
- Casey N Barber
- The Department of Biological Chemistry, The Johns Hopkins University School of Medicine, 725 North Wolfe Street, Baltimore, MD, 21205, USA
| | - Daniel M Raben
- The Department of Biological Chemistry, The Johns Hopkins University School of Medicine, 725 North Wolfe Street, Baltimore, MD, 21205, USA.
| |
Collapse
|
7
|
Massart J, Zierath JR. Role of Diacylglycerol Kinases in Glucose and Energy Homeostasis. Trends Endocrinol Metab 2019; 30:603-617. [PMID: 31331711 DOI: 10.1016/j.tem.2019.06.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Revised: 06/20/2019] [Accepted: 06/21/2019] [Indexed: 01/22/2023]
Abstract
Diacylglycerol kinases (DGKs) catalyze a reaction that converts diacylglycerol (DAG) to phosphatidic acid (PA). DAG and PA act as intermediates of de novo lipid synthesis, cellular membrane constituents, and signaling molecules. DGK isoforms regulate a variety of intracellular processes by terminating DAG signaling and activating PA-mediated pathways. The ten DGK isoforms are unique, not only structurally, but also in tissue-specific expression profiles, subcellular localization, regulatory mechanisms, and DAG preferences, suggesting isoform-specific functions. DAG accumulation has been associated with insulin resistance; however, this concept is challenged by opposing roles of DGK isoforms in the development of type 2 diabetes and obesity despite elevated DAG levels. This review focuses on the tissue- and isoform-specific role of DGK in glucose and energy homeostasis.
Collapse
Affiliation(s)
- Julie Massart
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
| | - Juleen R Zierath
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden; Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden; The Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Science, University of Copenhagen, Copenhagen, Denmark.
| |
Collapse
|
8
|
Merida I, Arranz-Nicolás J, Torres-Ayuso P, Ávila-Flores A. Diacylglycerol Kinase Malfunction in Human Disease and the Search for Specific Inhibitors. Handb Exp Pharmacol 2019; 259:133-162. [PMID: 31227890 DOI: 10.1007/164_2019_221] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The diacylglycerol kinases (DGKs) are master regulator kinases that control the switch from diacylglycerol (DAG) to phosphatidic acid (PA), two lipids with important structural and signaling properties. Mammalian DGKs distribute into five subfamilies that regulate local availability of DAG and PA pools in a tissue- and subcellular-restricted manner. Pharmacological manipulation of DGK activity holds great promise, given the critical contribution of specific DGK subtypes to the control of membrane structure, signaling complexes, and cell-cell communication. The latest advances in the DGK field have unveiled the differential contribution of selected isoforms to human disease. Defects in the expression/activity of individual DGK isoforms contribute substantially to cognitive impairment, mental disorders, insulin resistance, and vascular pathologies. Abnormal DGK overexpression, on the other hand, confers the acquisition of malignant traits including invasion, chemotherapy resistance, and inhibition of immune attack on tumors. Translation of these findings into therapeutic approaches will require development of methods to pharmacologically modulate DGK functions. In particular, inhibitors that target the DGKα isoform hold particular promise in the fight against cancer, on their own or in combination with immune-targeting therapies.
Collapse
Affiliation(s)
- Isabel Merida
- Department of Immunology and Oncology, National Center of Biotechnology (CNB-CSIC), Madrid, Spain.
| | - Javier Arranz-Nicolás
- Department of Immunology and Oncology, National Center of Biotechnology (CNB-CSIC), Madrid, Spain
| | - Pedro Torres-Ayuso
- Laboratory of Cell and Developmental Signaling, National Cancer Institute (NCI-NIH), Frederick, MD, USA
| | - Antonia Ávila-Flores
- Department of Immunology and Oncology, National Center of Biotechnology (CNB-CSIC), Madrid, Spain
| |
Collapse
|
9
|
Maeda Y, Shibata K, Akiyama R, Murakami Y, Takao S, Murakami C, Takahashi D, Sakai H, Sakane F. Diacylglycerol kinase β induces filopodium formation via its C1, catalytic and carboxy-terminal domains and interacts with the Rac1-GTPase-activating protein, β2-chimaerin. Biochem Biophys Res Commun 2018; 504:54-60. [DOI: 10.1016/j.bbrc.2018.08.119] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Accepted: 08/18/2018] [Indexed: 12/16/2022]
|
10
|
Gossmann A, Zille P, Calhoun V, Wang YP. FDR-Corrected Sparse Canonical Correlation Analysis With Applications to Imaging Genomics. IEEE TRANSACTIONS ON MEDICAL IMAGING 2018; 37:1761-1774. [PMID: 29993802 DOI: 10.1109/tmi.2018.2815583] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Reducing the number of false discoveries is presently one of the most pressing issues in the life sciences. It is of especially great importance for many applications in neuroimaging and genomics, where data sets are typically high-dimensional, which means that the number of explanatory variables exceeds the sample size. The false discovery rate (FDR) is a criterion that can be employed to address that issue. Thus it has gained great popularity as a tool for testing multiple hypotheses. Canonical correlation analysis (CCA) is a statistical technique that is used to make sense of the cross-correlation of two sets of measurements collected on the same set of samples (e.g., brain imaging and genomic data for the same mental illness patients), and sparse CCA extends the classical method to high-dimensional settings. Here, we propose a way of applying the FDR concept to sparse CCA, and a method to control the FDR. The proposed FDR correction directly influences the sparsity of the solution, adapting it to the unknown true sparsity level. Theoretical derivation as well as simulation studies show that our procedure indeed keeps the FDR of the canonical vectors below a user-specified target level. We apply the proposed method to an imaging genomics data set from the Philadelphia Neurodevelopmental Cohort. Our results link the brain connectivity profiles derived from brain activity during an emotion identification task, as measured by functional magnetic resonance imaging, to the corresponding subjects' genomic data.
Collapse
|
11
|
de la Peña JB, Dela Peña IJ, Custodio RJ, Botanas CJ, Kim HJ, Cheong JH. Exploring the Validity of Proposed Transgenic Animal Models of Attention-Deficit Hyperactivity Disorder (ADHD). Mol Neurobiol 2017; 55:3739-3754. [PMID: 28534274 DOI: 10.1007/s12035-017-0608-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Accepted: 05/09/2017] [Indexed: 12/31/2022]
Abstract
Attention-deficit/hyperactivity disorder (ADHD) is a common, behavioral, and heterogeneous neurodevelopmental condition characterized by hyperactivity, impulsivity, and inattention. Symptoms of this disorder are managed by treatment with methylphenidate, amphetamine, and/or atomoxetine. The cause of ADHD is unknown, but substantial evidence indicates that this disorder has a significant genetic component. Transgenic animals have become an essential tool in uncovering the genetic factors underlying ADHD. Although they cannot accurately reflect the human condition, they can provide insights into the disorder that cannot be obtained from human studies due to various limitations. An ideal animal model of ADHD must have face (similarity in symptoms), predictive (similarity in response to treatment or medications), and construct (similarity in etiology or underlying pathophysiological mechanism) validity. As the exact etiology of ADHD remains unclear, the construct validity of animal models of ADHD would always be limited. The proposed transgenic animal models of ADHD have substantially increased and diversified over the years. In this paper, we compiled and explored the validity of proposed transgenic animal models of ADHD. Each of the reviewed transgenic animal models has strengths and limitations. Some fulfill most of the validity criteria of an animal model of ADHD and have been extensively used, while there are others that require further validation. Nevertheless, these transgenic animal models of ADHD have provided and will continue to provide valuable insights into the genetic underpinnings of this complex disorder.
Collapse
Affiliation(s)
- June Bryan de la Peña
- Uimyung Research Institute for Neuroscience, Department of Pharmacy, Sahmyook University, 815 Hwarang-ro, Nowon-gu, Seoul, 01795, Republic of Korea
| | - Irene Joy Dela Peña
- Uimyung Research Institute for Neuroscience, Department of Pharmacy, Sahmyook University, 815 Hwarang-ro, Nowon-gu, Seoul, 01795, Republic of Korea
| | - Raly James Custodio
- Uimyung Research Institute for Neuroscience, Department of Pharmacy, Sahmyook University, 815 Hwarang-ro, Nowon-gu, Seoul, 01795, Republic of Korea
| | - Chrislean Jun Botanas
- Uimyung Research Institute for Neuroscience, Department of Pharmacy, Sahmyook University, 815 Hwarang-ro, Nowon-gu, Seoul, 01795, Republic of Korea
| | - Hee Jin Kim
- Uimyung Research Institute for Neuroscience, Department of Pharmacy, Sahmyook University, 815 Hwarang-ro, Nowon-gu, Seoul, 01795, Republic of Korea
| | - Jae Hoon Cheong
- Uimyung Research Institute for Neuroscience, Department of Pharmacy, Sahmyook University, 815 Hwarang-ro, Nowon-gu, Seoul, 01795, Republic of Korea.
| |
Collapse
|
12
|
Lee D, Kim E, Tanaka-Yamamoto K. Diacylglycerol Kinases in the Coordination of Synaptic Plasticity. Front Cell Dev Biol 2016; 4:92. [PMID: 27630986 PMCID: PMC5005321 DOI: 10.3389/fcell.2016.00092] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Accepted: 08/17/2016] [Indexed: 01/07/2023] Open
Abstract
Synaptic plasticity is activity-dependent modification of the efficacy of synaptic transmission. Although, detailed mechanisms underlying synaptic plasticity are diverse and vary at different types of synapses, diacylglycerol (DAG)-associated signaling has been considered as an important regulator of many forms of synaptic plasticity, including long-term potentiation (LTP) and long-term depression (LTD). Recent evidences indicate that DAG kinases (DGKs), which phosphorylate DAG to phosphatidic acid to terminate DAG signaling, are important regulators of LTP and LTD, as supported by the results from mice lacking specific DGK isoforms. This review will summarize these studies and discuss how specific DGK isoforms distinctly regulate different forms of synaptic plasticity at pre- and postsynaptic sites. In addition, we propose a general role of DGKs as coordinators of synaptic plasticity that make local synaptic environments more permissive for synaptic plasticity by regulating DAG concentration and interacting with other synaptic proteins.
Collapse
Affiliation(s)
- Dongwon Lee
- Center for Synaptic Brain Dysfunctions, Institute for Basic Science Daejeon, South Korea
| | - Eunjoon Kim
- Center for Synaptic Brain Dysfunctions, Institute for Basic ScienceDaejeon, South Korea; Department of Biological Sciences, Korea Advanced Institute of Science and TechnologyDaejeon, South Korea
| | - Keiko Tanaka-Yamamoto
- Center for Functional Connectomics, Korea Institute of Science and Technology Seoul, South Korea
| |
Collapse
|
13
|
Memantine, an NMDA receptor antagonist, improves working memory deficits in DGKβ knockout mice. Neurosci Lett 2016; 630:228-232. [PMID: 27495014 DOI: 10.1016/j.neulet.2016.07.061] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2016] [Revised: 07/20/2016] [Accepted: 07/30/2016] [Indexed: 12/23/2022]
Abstract
Diacylglycerol kinase (DGK) β is a type 1 isozyme of the DGK family. We previously reported that DGKβ was deeply involved in neurite spine formation, and DGKβ knockout (KO) mice exhibited behavioral abnormalities concerning spine formation, such as cognitive, emotional, and attentional impairment. Moreover, some of these abnormalities were ameliorated by the administration of a mood stabilizer. However, there is no data about how memory-improving drugs used in the treatment of Alzheimer's disease affect DGKβ KO mice. In the present study, we evaluated the effect of an anti-Alzheimer's drug, memantine on the working memory deficit observed in DGKβ KO mice. In the Y-maze test, the administration of memantine significantly improved working memory of DGKβ KO mice. We also found that the expression levels of the NR2A and NR2B N-methyl-d-aspartate (NMDA) receptor subunits were increased in the prefrontal cortex, but decreased in the hippocampus of DGKβ KO mice. These altered expression levels of NR2 subunits might be related to the effect of an NMDA receptor antagonist, memantine. Taken together, these findings may support the hypothesis that DGKβ has a pivotal role in cognitive function.
Collapse
|
14
|
Brain membrane lipids in major depression and anxiety disorders. Biochim Biophys Acta Mol Cell Biol Lipids 2015; 1851:1052-65. [DOI: 10.1016/j.bbalip.2014.12.014] [Citation(s) in RCA: 188] [Impact Index Per Article: 20.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2014] [Revised: 12/06/2014] [Accepted: 12/16/2014] [Indexed: 11/13/2022]
|
15
|
Komenoi S, Takemura F, Sakai H, Sakane F. Diacylglycerol kinase η1 is a high affinity isozyme for diacylglycerol. FEBS Lett 2015; 589:1272-7. [DOI: 10.1016/j.febslet.2015.03.032] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2014] [Revised: 03/26/2015] [Accepted: 03/27/2015] [Indexed: 12/13/2022]
|
16
|
Ishisaka M, Tsujii S, Mizoguchi T, Tsuruma K, Shimazawa M, Hara H. The effects of valproate and olanzapine on the abnormal behavior of diacylglycerol kinase β knockout mice. Pharmacol Rep 2015; 67:275-80. [DOI: 10.1016/j.pharep.2014.10.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2014] [Revised: 10/09/2014] [Accepted: 10/15/2014] [Indexed: 11/29/2022]
|
17
|
Involvement of diacylglycerol kinase β in the spine formation at distal dendrites of striatal medium spiny neurons. Brain Res 2015; 1594:36-45. [DOI: 10.1016/j.brainres.2014.11.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Revised: 10/23/2014] [Accepted: 11/06/2014] [Indexed: 01/15/2023]
|
18
|
Tu-Sekine B, Goldschmidt H, Raben DM. Diacylglycerol, phosphatidic acid, and their metabolic enzymes in synaptic vesicle recycling. Adv Biol Regul 2014; 57:147-52. [PMID: 25446883 DOI: 10.1016/j.jbior.2014.09.010] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2014] [Revised: 09/03/2014] [Accepted: 09/03/2014] [Indexed: 01/10/2023]
Abstract
The synaptic vesicle (SV) cycle includes exocytosis of vesicles loaded with a neurotransmitter such as glutamate, coordinated recovery of SVs by endocytosis, refilling of vesicles, and subsequent release of the refilled vesicles from the presynaptic bouton. SV exocytosis is tightly linked with endocytosis, and variations in the number of vesicles, and/or defects in the refilling of SVs, will affect the amount of neurotransmitter available for release (Sudhof, 2004). There is increasing interest in the roles synaptic vesicle lipids and lipid metabolizing enzymes play in this recycling. Initial emphasis was placed on the role of polyphosphoinositides in SV cycling as outlined in a number of reviews (Lim and Wenk, 2009; Martin, 2012; Puchkov and Haucke, 2013; Rohrbough and Broadie, 2005). Other lipids are now recognized to also play critical roles. For example, PLD1 (Humeau et al., 2001; Rohrbough and Broadie, 2005) and some DGKs (Miller et al., 1999; Nurrish et al., 1999) play roles in neurotransmission which is consistent with the critical roles for phosphatidic acid (PtdOH) and diacylglycerol (DAG) in the regulation of SV exo/endocytosis (Cremona et al., 1999; Exton, 1994; Huttner and Schmidt, 2000; Lim and Wenk, 2009; Puchkov and Haucke, 2013; Rohrbough and Broadie, 2005). PLD generates phosphatidic acid by catalyzing the hydrolysis of phosphatidylcholine (PtdCho) and in some systems this PtdOH is de-phosphorylated to generate DAG. In contrast, DGK catalyzes the phosphorylation of DAG thereby converting it into PtdOH. While both enzymes are poised to regulate the levels of DAG and PtdOH, therefore, they both lead to the generation of PtdOH and could have opposite effects on DAG levels. This is particularly important for SV cycling as PtdOH and DAG are both needed for evoked exocytosis (Lim and Wenk, 2009; Puchkov and Haucke, 2013; Rohrbough and Broadie, 2005). Two lipids and their involved metabolic enzymes, two sphingolipids have also been implicated in exocytosis: sphingosine (Camoletto et al., 2009; Chan et al., 2012; Chan and Sieburth, 2012; Darios et al., 2009; Kanno et al., 2010; Rohrbough et al., 2004) and sphingosine-1-phosphate (Chan, Hu, 2012; Chan and Sieburth, 2012; Kanno et al., 2010). Finally a number of reports have focused on the somewhat less well studies roles of sphingolipids and cholesterol in SV cycling. In this report, we review the recent understanding of the roles PLDs, DGKs, and DAG lipases, as well as sphingolipids and cholesterol play in synaptic vesicle cycling.
Collapse
Affiliation(s)
- Becky Tu-Sekine
- The Department of Biological Chemistry, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Hana Goldschmidt
- The Department of Biological Chemistry, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Daniel M Raben
- The Department of Biological Chemistry, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
| |
Collapse
|
19
|
Chew SK, Lu D, Campos LS, Scott KL, Saci A, Wang J, Collinson A, Raine K, Hinton J, Teague JW, Jones D, Menzies A, Butler AP, Gamble J, O'Meara S, McLaren S, Chin L, Liu P, Futreal PA. Polygenic in vivo validation of cancer mutations using transposons. Genome Biol 2014; 15:455. [PMID: 25260652 PMCID: PMC4210617 DOI: 10.1186/s13059-014-0455-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2014] [Accepted: 08/27/2014] [Indexed: 01/22/2023] Open
Abstract
The in vivo validation of cancer mutations and genes identified in cancer genomics is resource-intensive because of the low throughput of animal experiments. We describe a mouse model that allows multiple cancer mutations to be validated in each animal line. Animal lines are generated with multiple candidate cancer mutations using transposons. The candidate cancer genes are tagged and randomly expressed in somatic cells, allowing easy identification of the cancer genes involved in the generated tumours. This system presents a useful, generalised and efficient means for animal validation of cancer genes.
Collapse
|
20
|
Natalini PM, Mateos MV, Ilincheta de Boschero MG, Giusto NM. A novel light-dependent activation of DAGK and PKC in bovine photoreceptor nuclei. Exp Eye Res 2014; 125:142-55. [PMID: 24950064 DOI: 10.1016/j.exer.2014.06.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2014] [Revised: 06/06/2014] [Accepted: 06/07/2014] [Indexed: 10/25/2022]
Abstract
In this work, we describe a selective light-dependent distribution of the lipid kinase 1,2-diacylglycerol kinase (EC 2.7.1.107, DAGK) and the phosphorylated protein kinase C alpha (pPKCα) in a nuclear fraction of photoreceptor cells from bovine retinas. A nuclear fraction enriched in small nuclei from photoreceptor cells (PNF), was obtained when a modified nuclear isolation protocol developed by our laboratory was used. We measured and compared DAGK activity as phosphatidic acid (PA) formation in PNF obtained from retinas exposed to light and in retinas kept in darkness using [γ-(32)P]ATP or [(3)H]DAG. In the absence of exogenous substrates and detergents, no changes in DAGK activity were observed. However, when DAGK activity assays were performed in the presence of exogenous substrates, such as stearoyl arachidonoyl glycerol (SAG) or dioleoyl glycerol (DOG), and different detergents (used to make different DAGK isoforms evident), we observed significant light effects on DAGK activity, suggesting the presence of several DAGK isoforms in PNF. Under conditions favoring DAGKζ activity (DOG, Triton X-100, dioleoyl phosphatidylserine and R59022) we observed an increase in PA formation in PNF from retinas exposed to light with respect to those exposed to darkness. In contrast, under conditions favoring DAGKɛ (SAG, octylglucoside and R59022) we observed a decrease in its activity. These results suggest different physiological roles of the above-mentioned DAGK isoforms. Western blot analysis showed that whereas light stimulation of bovine retinas increases DAGKζ nuclear content, it decreases DAGKɛ and DAGKβ content in PNF. The role of PIP2-phospholipase C in light-stimulated DAGK activity was demonstrated using U73122. Light was also observed to induce enhanced pPKCα content in PNF. The selective distribution of DAGKζ and ɛ in PNF could be a light-dependent mechanism that in vertebrate retina promotes selective DAG removal and PKC regulation.
Collapse
Affiliation(s)
- Paola M Natalini
- Instituto de Investigaciones Bioquímicas de Bahía Blanca (INIBIBB), Universidad Nacional del Sur (UNS) and Consejo Nacional de Investigaciones Científicas y Técnicas, 8000 Bahía Blanca, Buenos Aires, Argentina
| | - Melina V Mateos
- Instituto de Investigaciones Bioquímicas de Bahía Blanca (INIBIBB), Universidad Nacional del Sur (UNS) and Consejo Nacional de Investigaciones Científicas y Técnicas, 8000 Bahía Blanca, Buenos Aires, Argentina
| | - Mónica G Ilincheta de Boschero
- Instituto de Investigaciones Bioquímicas de Bahía Blanca (INIBIBB), Universidad Nacional del Sur (UNS) and Consejo Nacional de Investigaciones Científicas y Técnicas, 8000 Bahía Blanca, Buenos Aires, Argentina.
| | - Norma M Giusto
- Instituto de Investigaciones Bioquímicas de Bahía Blanca (INIBIBB), Universidad Nacional del Sur (UNS) and Consejo Nacional de Investigaciones Científicas y Técnicas, 8000 Bahía Blanca, Buenos Aires, Argentina
| |
Collapse
|
21
|
Shirai Y, Saito N. Diacylglycerol kinase as a possible therapeutic target for neuronal diseases. J Biomed Sci 2014; 21:28. [PMID: 24708409 PMCID: PMC4005014 DOI: 10.1186/1423-0127-21-28] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2014] [Accepted: 03/05/2014] [Indexed: 02/02/2023] Open
Abstract
Diacylglycerol kinase (DGK) is a lipid kinase converting diacylglycerol to phosphatidic acid, and regulates many enzymes including protein kinase C, phosphatidylinositol 4-phosphate 5-kinase, and mTOR. To date, ten mammalian DGK subtypes have been cloned and divided into five groups, and they show subtype-specific tissue distribution. Therefore, each DGK subtype is thought to be involved in respective cellular responses by regulating balance of the two lipid messengers, diacylglycerol and phosphatidic acid. Indeed, the recent researches using DGK knockout mice have clearly demonstrated the importance of DGK in the immune system and its pathophysiological roles in heart and insulin resistance in diabetes. Especially, most subtypes show high expression in brain with subtype specific regional distribution, suggesting that each subtype has important and unique functions in brain. Recently, neuronal functions of some DGK subtypes have accumulated. Here, we introduce DGKs with their structural motifs, summarize the enzymatic properties and neuronal functions, and discuss the possibility of DGKs as a therapeutic target of the neuronal diseases.
Collapse
Affiliation(s)
- Yasuhito Shirai
- Laboratory of Chemistry and Utilization of Animal Production Resources, Applied Chemistry in Bioscience Division, Graduate School of Agricultural Science, Kobe University, Rokkodai-cho 1-1, Nada-ku, 657-8501 Kobe, Japan.
| | | |
Collapse
|
22
|
Kano T, Kouzuki T, Mizuno S, Ueda S, Yamanoue M, Sakane F, Saito N, Shirai Y. Both the C1 domain and a basic amino acid cluster at the C-terminus are important for the neurite and branch induction ability of DGKβ. Biochem Biophys Res Commun 2014; 447:89-94. [DOI: 10.1016/j.bbrc.2014.03.113] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2014] [Accepted: 03/22/2014] [Indexed: 01/14/2023]
|
23
|
Shirai Y. [Function of diacylglycerol kinase β in neurons]. Nihon Yakurigaku Zasshi 2014; 143:131-6. [PMID: 24614636 DOI: 10.1254/fpj.143.131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
24
|
Ishisaka M, Hara H. The Roles of Diacylglycerol Kinases in the Central Nervous System: Review of Genetic Studies in Mice. J Pharmacol Sci 2014; 124:336-43. [DOI: 10.1254/jphs.13r07cr] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
|
25
|
Mines MA. Hyperactivity: glycogen synthase kinase-3 as a therapeutic target. Eur J Pharmacol 2013; 708:56-9. [PMID: 23500205 DOI: 10.1016/j.ejphar.2013.02.055] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2012] [Revised: 02/15/2013] [Accepted: 02/24/2013] [Indexed: 11/19/2022]
Abstract
The diagnosis of hyperactivity-associated disorders has increased within the past few years. The prevalence of hyperactivity-associated disorders is indicative of the need to more fully understand the underlying causes and to develop improved therapeutic interventions. There is increasing evidence that glycogen synthase kinase-3 (GSK3) mediates locomotor hyperactivity in a number of animal models, and therefore may be a potential target for therapeutic intervention in hyperactivity-associated behaviors. In this review, we discuss 1) the effect of manipulations of GSK3 in the absence of drugs and disorders on locomotor activity, 2) the role of GSK3 in drug-induced hyperactivity in rodents, and 3) regulation of locomotor activity by GSK3 in transgenic mouse models related to specific disorders. These studies link GSK3 regulation and activity to hyperactivity-associated behaviors and disease pathologies.
Collapse
Affiliation(s)
- Marjelo A Mines
- Department of Psychiatry and Behavioral Sciences, Miller School of Medicine, University of Miami, Miami, FL 33136, USA.
| |
Collapse
|
26
|
Ishisaka M, Tsuruma K, Shimazawa M, Shirai Y, Saito N, Hara H. Increased Seizure Susceptibility in a Mouse with Diacylglycerol Kinase <i>β</i> Deficiency. ACTA ACUST UNITED AC 2013. [DOI: 10.4236/nm.2013.42019] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
27
|
Matsutomo D, Isozaki T, Sakai H, Sakane F. Osmotic shock-dependent redistribution of diacylglycerol kinase η1 to non-ionic detergent-resistant membrane via pleckstrin homology and C1 domains. ACTA ACUST UNITED AC 2012; 153:179-90. [DOI: 10.1093/jb/mvs130] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
|
28
|
Induction of filopodia-like protrusions in N1E-115 neuroblastoma cells by diacylglycerol kinase γ independent of its enzymatic activity: potential novel function of the C-terminal region containing the catalytic domain of diacylglycerol kinase γ. Mol Cell Biochem 2012; 373:85-93. [PMID: 23054194 DOI: 10.1007/s11010-012-1477-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2012] [Accepted: 09/26/2012] [Indexed: 10/27/2022]
Abstract
Type I diacylglycerol kinase (DGK) isozymes (α, β, and γ) contain recoverin homology domains and calcium-binding EF-hand motifs at their N-termini. The γ-isoform of DGK is abundantly expressed in retinal and Purkinje cells; however, its function in neuronal cells remains unknown. Here, we report that the mRNA and protein levels of DGKγ, but not DGKα or β, were markedly increased in N1E-115 neuroblastoma cells upon cellular differentiation by serum starvation. Interestingly, overexpression of wild-type DGKγ, which was partially located at the plasma membrane, considerably induced the formation of slender, filopodia-like cytoplasmic projections from N1E-115 cell bodies. Deletion of the recoverin homology domain and the EF-hand motifs, which potentiated the plasma membrane localization of the isozyme, significantly enhanced the formation of the filopodia-like protrusions. Intriguingly, the catalytic activity of the isozyme is not essential for the protrusion formation. The N-terminal half of the catalytic domain and a short stretch of amino acid residues at the C-terminus are responsible for plasma membrane localization and filopodia-like process formation. Taken together, we have described a potentially novel morphological function of the C-terminal DGKγ catalytic region that is independent of its enzymatic activity.
Collapse
|
29
|
Ishisaka M, Kakefuda K, Oyagi A, Ono Y, Tsuruma K, Shimazawa M, Kitaichi K, Hara H. Diacylglycerol kinase β knockout mice exhibit attention-deficit behavior and an abnormal response on methylphenidate-induced hyperactivity. PLoS One 2012; 7:e37058. [PMID: 22590645 PMCID: PMC3349656 DOI: 10.1371/journal.pone.0037058] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2012] [Accepted: 04/12/2012] [Indexed: 01/22/2023] Open
Abstract
Background Diacylglycerol kinase (DGK) is an enzyme that phosphorylates diacylglycerol to produce phosphatidic acid. DGKβ is one of the subtypes of the DGK family and regulates many intracellular signaling pathways in the central nervous system. Previously, we demonstrated that DGKβ knockout (KO) mice showed various dysfunctions of higher brain function, such as cognitive impairment (with lower spine density), hyperactivity, reduced anxiety, and careless behavior. In the present study, we conducted further tests on DGKβ KO mice in order to investigate the function of DGKβ in the central nervous system, especially in the pathophysiology of attention deficit hyperactivity disorder (ADHD). Methodology/Principal Findings DGKβ KO mice showed attention-deficit behavior in the object-based attention test and it was ameliorated by methylphenidate (MPH, 30 mg/kg, i.p.). In the open field test, DGKβ KO mice displayed a decreased response to the locomotor stimulating effects of MPH (30 mg/kg, i.p.), but showed a similar response to an N-methyl-d-aspartate (NMDA) receptor antagonist, MK-801 (0.3 mg/kg, i.p.), when compared to WT mice. Examination of the phosphorylation of extracellular signal-regulated kinase (ERK), which is involved in regulation of locomotor activity, indicated that ERK1/2 activation induced by MPH treatment was defective in the striatum of DGKβ KO mice. Conclusions/Significance These findings suggest that DGKβ KO mice showed attention-deficit and hyperactive phenotype, similar to ADHD. Furthermore, the hyporesponsiveness of DGKβ KO mice to MPH was due to dysregulation of ERK phosphorylation, and that DGKβ has a pivotal involvement in ERK regulation in the striatum.
Collapse
Affiliation(s)
- Mitsue Ishisaka
- Molecular Pharmacology, Department of Biofunctional Evaluation, Gifu Pharmaceutical University, Gifu, Japan
| | | | | | | | | | | | | | | |
Collapse
|
30
|
Orangutan Alu quiescence reveals possible source element: support for ancient backseat drivers. Mob DNA 2012; 3:8. [PMID: 22541534 PMCID: PMC3357318 DOI: 10.1186/1759-8753-3-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2011] [Accepted: 04/30/2012] [Indexed: 01/25/2023] Open
Abstract
Background Sequence analysis of the orangutan genome revealed that recent proliferative activity of Alu elements has been uncharacteristically quiescent in the Pongo (orangutan) lineage, compared with all previously studied primate genomes. With relatively few young polymorphic insertions, the genomic landscape of the orangutan seemed like the ideal place to search for a driver, or source element, of Alu retrotransposition. Results Here we report the identification of a nearly pristine insertion possessing all the known putative hallmarks of a retrotranspositionally competent Alu element. It is located in an intronic sequence of the DGKB gene on chromosome 7 and is highly conserved in Hominidae (the great apes), but absent from Hylobatidae (gibbon and siamang). We provide evidence for the evolution of a lineage-specific subfamily of this shared Alu insertion in orangutans and possibly the lineage leading to humans. In the orangutan genome, this insertion contains three orangutan-specific diagnostic mutations which are characteristic of the youngest polymorphic Alu subfamily, AluYe5b5_Pongo. In the Homininae lineage (human, chimpanzee and gorilla), this insertion has acquired three different mutations which are also found in a single human-specific Alu insertion. Conclusions This seemingly stealth-like amplification, ongoing at a very low rate over millions of years of evolution, suggests that this shared insertion may represent an ancient backseat driver of Alu element expansion.
Collapse
|
31
|
Hozumi Y, Goto K. Diacylglycerol kinase β in neurons: functional implications at the synapse and in disease. Adv Biol Regul 2012; 52:315-25. [PMID: 22781745 DOI: 10.1016/j.jbior.2012.03.003] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2012] [Accepted: 03/23/2012] [Indexed: 11/18/2022]
Abstract
Phosphoinositide cycle plays a pivotal role in neuronal signal transduction. In this cycle, diacylglycerol kinase (DGK) phosphorylates diacylglycerol (DG) to yield phosphatidic acid (PA). DG and PA acts as important second messengers that regulate distinct cascade of cellular events. Previous studies have disclosed that DGK consists of a family of isozymes that differ in their structure, enzymatic property, gene expression, subcellular localization, and binding partner. Intriguingly, most if not all DGK isozymes are abundantly expressed in the brain, suggesting important roles of this enzyme family in brain function. Of DGKs, DGKβ was the first enzyme identified as being expressed in a neuronal population in the brain. This review focuses on recent findings of DGKβ at the molecular, cellular, and organismal levels together with pathological implications in brain function and disease.
Collapse
Affiliation(s)
- Yasukazu Hozumi
- Department of Anatomy and Cell Biology, Yamagata University School of Medicine, Iida-nishi 2-2-2, Yamagata 990-9585, Japan.
| | | |
Collapse
|
32
|
Sumiyoshi M, Sato S, Takeda Y, Sumida K, Koga K, Itoh T, Nakagawa H, Shimohigashi Y, Shimohigashi M. A circadian neuropeptide PDF in the honeybee, Apis mellifera: cDNA cloning and expression of mRNA. Zoolog Sci 2012; 28:897-909. [PMID: 22132787 DOI: 10.2108/zsj.28.897] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Pigment-dispersing factor (PDF) is a pacemaker hormone regulating the locomotor rhythm in insects. In the present study, we cloned the cDNAs encoding the Apis PDF precursor protein, and found that there are at least seven different pdf mRNAs yielded by an alternative splicing site and five alternative polyadenylation sites in the 5'UTR and 3'UTR regions. The amino acid sequence of Apis PDF peptide has a characteristic novel amino acid residue, aspargine (Asn), at position 17. Quantitative real-time PCR of total and 5'UTR insertion-type pdf mRNAs revealed, for the first time, that the expression levels change in a circadian manner with a distinct trough at the beginning of night in LD conditions, and at the subjective night under DD conditions. In contrast, the expression level of 5'UTR deletion-type pdf mRNAs was about half of that of the insertion type, and the expression profile failed to show a circadian rhythm. As the expression profile of the total pdf mRNA exhibited a circadian rhythm, transcription regulated at the promoter region was supposed to be controlled by some of the clock components. Whole mount in situ hybridization revealed that 14 lateral neurons at the frontal margin of the optic lobe express these mRNA isoforms. PDF expressing cells examined with a newly produced antibody raised against Apis PDF were also found to have a dense supply of axon terminals in the optic lobes and the central brain.
Collapse
Affiliation(s)
- Miho Sumiyoshi
- Division of Biology, Department of Earth System of Science, Faculty of Science, Fukuoka University, Fukuoka 814-0180, Japan
| | | | | | | | | | | | | | | | | |
Collapse
|
33
|
Shulga YV, Topham MK, Epand RM. Regulation and functions of diacylglycerol kinases. Chem Rev 2011; 111:6186-208. [PMID: 21800853 DOI: 10.1021/cr1004106] [Citation(s) in RCA: 158] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Yulia V Shulga
- Department of Biochemistry and Biomedical Sciences, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4K1, Canada
| | | | | |
Collapse
|
34
|
Tu-Sekine B, Raben DM. Regulation and roles of neuronal diacylglycerol kinases: a lipid perspective. Crit Rev Biochem Mol Biol 2011; 46:353-64. [PMID: 21539478 DOI: 10.3109/10409238.2011.577761] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Diacylglycerol kinases (DGKs) are a class of enzymes that catalyze the ATP-dependent conversion of diacylglycerol (DAG) to phosphatidic acid (PtdOH), resulting in the coordinate regulation of these two lipid second messengers. This regulation is particularly important in the nervous system where it is now well-established that DAG and PtdOH serve very important roles in modulating a variety of neurological functions. There are currently 10 identified mammalian DGKs, organized into five classes or "Types" based upon similarities in their primary sequences. A number of studies have identified eight of these isoforms in various regions of the mammalian central nervous system (CNS): DGK-α, DGK-β, DGK-γ, DGK-η, DGK-ζ, DGK-ι, DGK-ϵ, and DGK-θ. Further studies have provided compelling evidence supporting roles for these enzymes in neuronal spine density, myelination, synaptic activity, neuronal plasticity, epileptogenesis and neurotransmitter release. The physiological regulation of these enzymes is less clear. Like all interfacial enzymes, DGKs metabolize their hydrophobic substrate (DAG) at a membrane-aqueous interface. Therefore, these enzymes can be regulated by alterations in their subcellular localization, enzymatic activity, and/or membrane association. In this review, we summarize what is currently understood about the localization and regulation of the neuronal DGKs in the mammalian CNS.
Collapse
Affiliation(s)
- Becky Tu-Sekine
- Department of Biological Chemistry, The Johns Hopkins University School of Medicine, Baltimore, 21205 MD, USA
| | | |
Collapse
|
35
|
Kakefuda K, Oyagi A, Ishisaka M, Tsuruma K, Shimazawa M, Yokota K, Shirai Y, Horie K, Saito N, Takeda J, Hara H. Diacylglycerol kinase β knockout mice exhibit lithium-sensitive behavioral abnormalities. PLoS One 2010; 5:e13447. [PMID: 20976192 PMCID: PMC2956634 DOI: 10.1371/journal.pone.0013447] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2010] [Accepted: 09/22/2010] [Indexed: 12/27/2022] Open
Abstract
Background Diacylglycerol kinase (DGK) is an enzyme that phosphorylates diacylglycerol (DG) to produce phosphatidic acid (PA). DGKβ is widely distributed in the central nervous system, such as the olfactory bulb, cerebral cortex, striatum, and hippocampus. Recent studies reported that the splice variant at the COOH-terminal of DGKβ was related to bipolar disorder, but its detailed mechanism is still unknown. Methodology/Principal Findings In the present study, we performed behavioral tests using DGKβ knockout (KO) mice to investigate the effects of DGKβ deficits on psychomotor behavior. DGKβ KO mice exhibited some behavioral abnormalities, such as hyperactivity, reduced anxiety, and reduced depression. Additionally, hyperactivity and reduced anxiety were attenuated by the administration of the mood stabilizer, lithium, but not haloperidol, diazepam, or imipramine. Moreover, DGKβ KO mice showed impairment in Akt-glycogen synthesis kinase (GSK) 3β signaling and cortical spine formation. Conclusions/Significance These findings suggest that DGKβ KO mice exhibit lithium-sensitive behavioral abnormalities that are, at least in part, due to the impairment of Akt-GSK3β signaling and cortical spine formation.
Collapse
Affiliation(s)
- Kenichi Kakefuda
- Molecular Pharmacology, Department of Biofunctional Evaluation, Gifu Pharmaceutical University, Gifu, Japan
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
36
|
Abstract
The elucidation of several genetic etiologies of both monogenic and polygenic type 2 diabetes (T2D) has revealed several key regulators of glucose homeostasis and insulin secretion in humans. Genome-wide association studies (GWAS) have been instrumental in most of these recent discoveries. The T2D susceptibility genes identified so far are mainly involved in pancreatic beta-cell maturation or function. However, common DNA variants in those genes only explain approximately 10% of T2D heritability. The resequencing of whole exomes and whole genomes with next-generation technologies should identify additional genetic changes that contribute to the monogenic forms of diabetes and possibly provide novel clues to the genetic architecture of common adult T2D.
Collapse
|
37
|
Shirai Y, Kouzuki T, Kakefuda K, Moriguchi S, Oyagi A, Horie K, Morita SY, Shimazawa M, Fukunaga K, Takeda J, Saito N, Hara H. Essential role of neuron-enriched diacylglycerol kinase (DGK), DGKbeta in neurite spine formation, contributing to cognitive function. PLoS One 2010; 5:e11602. [PMID: 20657643 PMCID: PMC2904696 DOI: 10.1371/journal.pone.0011602] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2010] [Accepted: 06/20/2010] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Diacylglycerol (DG) kinase (DGK) phosphorylates DG to produce phosphatidic acid (PA). Of the 10 subtypes of mammalian DGKs, DGKbeta is a membrane-localized subtype and abundantly expressed in the cerebral cortex, hippocampus, and caudate-putamen. However, its physiological roles in neurons and higher brain function have not been elucidated. METHODOLOGY/PRINCIPAL FINDINGS We, therefore, developed DGKbeta KO mice using the Sleeping Beauty transposon system, and found that its long-term potentiation in the hippocampal CA1 region was reduced, causing impairment of cognitive functions including spatial and long-term memories in Y-maze and Morris water-maze tests. The primary cultured hippocampal neurons from KO mice had less branches and spines compared to the wild type. This morphological impairment was rescued by overexpression of DGKbeta. In addition, overexpression of DGKbeta in SH-SY5Y cells or primary cultured mouse hippocampal neurons resulted in branch- and spine-formation, while a splice variant form of DGKbeta, which has kinase activity but loses membrane localization, did not induce branches and spines. In the cells overexpressing DGKbeta but not the splice variant form, DGK product, PA, was increased and the substrate, DG, was decreased on the plasma membrane. Importantly, lower spine density and abnormality of PA and DG contents in the CA1 region of the KO mice were confirmed. CONCLUSIONS/SIGNIFICANCE These results demonstrate that membrane-localized DGKbeta regulates spine formation by regulation of lipids, contributing to the maintenance of neural networks in synaptic transmission of cognitive processes including memory.
Collapse
Affiliation(s)
- Yasuhito Shirai
- Laboratory of Molecular Pharmacology, Biosignal Research Center, Kobe University, Kobe, Japan
| | - Takeshi Kouzuki
- Laboratory of Molecular Pharmacology, Biosignal Research Center, Kobe University, Kobe, Japan
| | - Kenichi Kakefuda
- Molecular Pharmacology, Department of Biofunctional Evaluation, Gifu Pharmaceutical University, Gifu, Japan
| | - Shigeki Moriguchi
- Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan
| | - Atsushi Oyagi
- Molecular Pharmacology, Department of Biofunctional Evaluation, Gifu Pharmaceutical University, Gifu, Japan
| | - Kyoji Horie
- Department of Social and Environmental Medicine, Graduate School of Medicine, Osaka University, Suita, Japan
| | - Shin-ya Morita
- Laboratory of Pharmaceutical Technology, Kobe Pharmaceutical University, Kobe, Japan
| | - Masamitsu Shimazawa
- Molecular Pharmacology, Department of Biofunctional Evaluation, Gifu Pharmaceutical University, Gifu, Japan
| | - Kohji Fukunaga
- Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan
| | - Junji Takeda
- Department of Social and Environmental Medicine, Graduate School of Medicine, Osaka University, Suita, Japan
| | - Naoaki Saito
- Laboratory of Molecular Pharmacology, Biosignal Research Center, Kobe University, Kobe, Japan
| | - Hideaki Hara
- Molecular Pharmacology, Department of Biofunctional Evaluation, Gifu Pharmaceutical University, Gifu, Japan
| |
Collapse
|
38
|
|
39
|
Mérida I, Avila-Flores A, García J, Merino E, Almena M, Torres-Ayuso P. Diacylglycerol kinase alpha, from negative modulation of T cell activation to control of cancer progression. ACTA ACUST UNITED AC 2009; 49:174-88. [PMID: 19534031 DOI: 10.1016/j.advenzreg.2009.01.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- Isabel Mérida
- Department of Immunology and Oncology, Centro Nacional de Biotecnología/CSIC, Darwin 3, Campus de Cantoblanco, E-28049 Madrid, Spain.
| | | | | | | | | | | |
Collapse
|
40
|
Hozumi Y, Watanabe M, Otani K, Goto K. Diacylglycerol kinase beta promotes dendritic outgrowth and spine maturation in developing hippocampal neurons. BMC Neurosci 2009; 10:99. [PMID: 19691842 PMCID: PMC3224667 DOI: 10.1186/1471-2202-10-99] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2009] [Accepted: 08/19/2009] [Indexed: 12/15/2022] Open
Abstract
Background Diacylglycerol kinase (DGK) is an enzyme that phosphorylates diacylglycerol to phosphatidic acid and comprises multiple isozymes of distinct properties. Of DGKs, mRNA signal for DGKβ is strongly detected in the striatum, and one of the transcripts derived from the human DGKβ locus is annotated in GenBank as being differentially expressed in bipolar disorder patients. Recently, we have reported that DGKβ is expressed in medium spiny neurons of the striatum and is highly concentrated at the perisynapse of dendritic spines. However, it remains elusive how DGKβ is implicated in pathophysiological role in neurons at the cellular level. Results In the present study, we investigated the expression and subcellular localization of DGKβ in the hippocampus, together with its functional implication using transfected hippocampal neurons. DGKβ is expressed not only in projection neurons but also in interneurons and is concentrated at perisynaptic sites of asymmetrical synapses. Overexpression of wild-type DGKβ promotes dendrite outgrowth at 7 d in vitro (DIV) and spine maturation at 14 DIV in transfected hippocampal neurons, although its kinase-dead mutant has no effect. Conclusion In the hippocampus, DGKβ is expressed in both projection neurons and interneurons and is accumulated at the perisynapse of dendritic spines in asymmetrical synapses. Transfection experiments suggest that DGKβ may be involved in the molecular machineries of dendrite outgrowth and spinogenesis through its kinase activity.
Collapse
Affiliation(s)
- Yasukazu Hozumi
- Department of Anatomy and Cell Biology, Yamagata University School of Medicine, Yamagata 990-9585, Japan.
| | | | | | | |
Collapse
|
41
|
Hozumi Y, Fukaya M, Adachi N, Saito N, Otani K, Kondo H, Watanabe M, Goto K. Diacylglycerol kinaseβaccumulates on the perisynaptic site of medium spiny neurons in the striatum. Eur J Neurosci 2008; 28:2409-22. [DOI: 10.1111/j.1460-9568.2008.06547.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
42
|
Gaviraghi M, Caricasole A, Costanzo C, Diamanti D, Dandrea M, Donadelli M, Scarpa A, Palmieri M. Identification of a candidate alternative promoter region of the human Bcl2L11 (Bim) gene. BMC Mol Biol 2008; 9:56. [PMID: 18549468 PMCID: PMC2442123 DOI: 10.1186/1471-2199-9-56] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2007] [Accepted: 06/12/2008] [Indexed: 01/31/2023] Open
Abstract
Background Despite the importance of the BCL2L11 (BIM) protein in various apoptotic processes in development and disease, little is known of the promoter structure of the human BCL2L11 locus and of the cis-acting elements regulating expression of the human gene. Results In the search for novel promoter sequences in the human BCL2L11 locus, we have identified previously unrecognized genomic sequences displaying promoter activity and E2F responsiveness, and driving the expression of BCL2L11 coding transcripts. In man, transcripts originating from this novel putative promoter contribute significantly to total BCL2L11 mRNA expression in testis, heart and liver. In HEK293 cells, this novel candidate promoter originates BCL2L11 transcripts whose expression can be modulated by a known modulator of BCL2L11 expression (Trichostatin A) and by E2F, a characterized transcriptional regulator of BCL2L11 expression. Conclusion The identification of a novel putative human BCL2L11 promoter provides new insights into the structure and regulation of the BCL2L11 locus.
Collapse
Affiliation(s)
- Margherita Gaviraghi
- Department of Pathology, Section of Pathological Anatomy, University of Verona, Verona, Italy.
| | | | | | | | | | | | | | | |
Collapse
|
43
|
Abstract
DGKs (diacylglycerol kinases) are members of a unique and conserved family of intracellular lipid kinases that phosphorylate DAG (diacylglycerol), catalysing its conversion into PA (phosphatidic acid). This reaction leads to attenuation of DAG levels in the cell membrane, regulating a host of intracellular signalling proteins that have evolved the ability to bind this lipid. The product of the DGK reaction, PA, is also linked to the regulation of diverse functions, including cell growth, membrane trafficking, differentiation and migration. In multicellular eukaryotes, DGKs provide a link between lipid metabolism and signalling. Genetic experiments in Caenorhabditis elegans, Drosophila melanogaster and mice have started to unveil the role of members of this protein family as modulators of receptor-dependent responses in processes such as synaptic transmission and photoreceptor transduction, as well as acquired and innate immune responses. Recent discoveries provide new insights into the complex mechanisms controlling DGK activation and their participation in receptor-regulated processes. After more than 50 years of intense research, the DGK pathway emerges as a key player in the regulation of cell responses, offering new possibilities of therapeutic intervention in human pathologies, including cancer, heart disease, diabetes, brain afflictions and immune dysfunctions.
Collapse
|
44
|
Goto K, Hozumi Y, Nakano T, Saino-Saito S, Martelli AM. Lipid Messenger, Diacylglycerol, and its Regulator, Diacylglycerol Kinase, in Cells, Organs, and Animals: History and Perspective. TOHOKU J EXP MED 2008; 214:199-212. [DOI: 10.1620/tjem.214.199] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Affiliation(s)
- Kaoru Goto
- Department of Anatomy and Cell Biology, Yamagata University School of Medicine
| | - Yasukazu Hozumi
- Department of Anatomy and Cell Biology, Yamagata University School of Medicine
| | - Tomoyuki Nakano
- Department of Anatomy and Cell Biology, Yamagata University School of Medicine
| | - Sachiko Saino-Saito
- Department of Anatomy and Cell Biology, Yamagata University School of Medicine
| | | |
Collapse
|
45
|
Merino E, Sanjuán MA, Moraga I, Ciprés A, Mérida I. Role of the diacylglycerol kinase alpha-conserved domains in membrane targeting in intact T cells. J Biol Chem 2007; 282:35396-404. [PMID: 17911109 DOI: 10.1074/jbc.m702085200] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Diacylglycerol kinase (DGK) phosphorylates diacylglycerol to phosphatidic acid, modifying the cellular levels of these two lipid mediators. Ten DGK isoforms, grouped into five subtypes, are found in higher organisms. All contain a conserved C-terminal domain and at least two cysteine-rich motifs of unknown function. DGKalpha is a type I enzyme that acts as a negative modulator of diacylglycerol-based signals during T cell activation. Here we studied the functional role of the DGKalpha domains using mutational analysis to investigate membrane binding in intact cells. We show that the two atypical C1 domains are essential for plasma membrane targeting of the protein in intact cells but unnecessary for catalytic activity. We also identify the C-terminal sequence of the protein as essential for membrane binding in a phosphatidic acid-dependent manner. Finally we demonstrate that, in the absence of the calcium binding domain, receptor-dependent translocation of the truncated protein is regulated by phosphorylation of Tyr(335). This functional study provides new insight into the role of the so-called conserved domains of this lipid kinase family and demonstrates the existence of additional domains that confer specific plasma membrane localization to this particular isoform.
Collapse
Affiliation(s)
- Ernesto Merino
- Department of Immunology and Oncology, Centro Nacional de Biotecnología/Consejo Superior de Investigaciones Científicas, Cantoblanco, E-28049 Madrid, Spain
| | | | | | | | | |
Collapse
|
46
|
Sakane F, Imai SI, Kai M, Yasuda S, Kanoh H. Diacylglycerol kinases: Why so many of them? Biochim Biophys Acta Mol Cell Biol Lipids 2007; 1771:793-806. [PMID: 17512245 DOI: 10.1016/j.bbalip.2007.04.006] [Citation(s) in RCA: 247] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2007] [Revised: 03/28/2007] [Accepted: 04/06/2007] [Indexed: 11/17/2022]
Abstract
Diacylglycerol (DAG) kinase (DGK) modulates the balance between the two signaling lipids, DAG and phosphatidic acid (PA), by phosphorylating DAG to yield PA. To date, ten mammalian DGK isozymes have been identified. In addition to the C1 domains (protein kinase C-like zinc finger structures) conserved commonly in all DGKs, these isoforms possess a variety of regulatory domains of known and/or predicted functions, such as a pair of EF-hand motifs, a pleckstrin homology domain, a sterile alpha motif domain and ankyrin repeats. Beyond our expectations, recent studies have revealed that DGK isozymes play pivotal roles in a wide variety of signal transduction pathways conducting development, neural and immune responses, cytoskeleton reorganization and carcinogenesis. Moreover, there has been rapidly growing evidence indicating that individual DGK isoforms exert their specific roles through interactions with unique partner proteins such as protein kinase Cs, Ras guanyl nucleotide-releasing protein, chimaerins and phosphatidylinositol-4-phosphate 5-kinase. Therefore, an emerging paradigm for DGK is that the individual DGK isoforms assembled in their own signaling complexes should carry out spatio-temporally segregated tasks for a wide range of biological processes via regulating local, but not global, concentrations of DAG and/or PA.
Collapse
Affiliation(s)
- Fumio Sakane
- Department of Biochemistry, Sapporo Medical University School of Medicine, South-1, West-17, Chuo-ku, Sapporo 060-8556, Japan.
| | | | | | | | | |
Collapse
|
47
|
Kobayashi N, Hozumi Y, Ito T, Hosoya T, Kondo H, Goto K. Differential subcellular targeting and activity-dependent subcellular localization of diacylglycerol kinase isozymes in transfected cells. Eur J Cell Biol 2007; 86:433-44. [PMID: 17599647 DOI: 10.1016/j.ejcb.2007.05.002] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2006] [Revised: 04/28/2007] [Accepted: 05/15/2007] [Indexed: 11/22/2022] Open
Abstract
Diacylglycerol kinase (DGK) plays a pivotal role in cellular signal transduction through regulating levels of the second messenger diacylglycerol (DG). Previous studies have revealed that DGK is composed of a family of isozymes that show remarkable heterogeneity in terms of molecular structure, functional domains, tissue and cellular gene expression. Recently, it has been shown that DG is produced in various subcellular compartments including the plasma membrane, internal membranes, cytoskeleton, and nucleus. However, it remains unclear how DG is regulated at distinct subcellular sites. To address this point, we have used an epitope-tag expression system in cultured cells and investigated the subcellular localization of DGK isozymes under the same experimental conditions. We show here that DGK isozymes are targeted differentially to unique subcellular sites in transfected COS7 cells, including the cytoplasm, actin stress fibers, Golgi complex, endoplasmic reticulum, and nucleus. It is also shown that among the isozymes overexpression of DGKbeta causes fragmentation of actin stress fibers while a kinase-dead mutant of DGKbeta abolishes its colocalization with actin stress fibers. These data strongly suggest that each isozyme may be responsible for the metabolism of DG that is produced upon stimulation at a different and specific subcellular site and that DGKbeta activity might have effects on the reorganization of actin stress fibers in transfected COS7 cells.
Collapse
Affiliation(s)
- Naoki Kobayashi
- Department of Anatomy and Cell Biology, Yamagata University School of Medicine, Iida-nishi 2-2-2, Yamagata 990-9585, Japan
| | | | | | | | | | | |
Collapse
|
48
|
Yanagisawa K, Yasuda S, Kai M, Imai SI, Yamada K, Yamashita T, Jimbow K, Kanoh H, Sakane F. Diacylglycerol kinase α suppresses tumor necrosis factor-α-induced apoptosis of human melanoma cells through NF-κB activation. Biochim Biophys Acta Mol Cell Biol Lipids 2007; 1771:462-74. [PMID: 17276726 DOI: 10.1016/j.bbalip.2006.12.008] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2006] [Revised: 11/15/2006] [Accepted: 12/18/2006] [Indexed: 10/23/2022]
Abstract
We investigated the implication of diacylglycerol kinase (DGK) alpha (type I isoform) in melanoma cells because we found that this DGK isoform was expressed in several human melanoma cell lines but not in noncancerous melanocytes. Intriguingly, the overexpression of wild-type (WT) DGKalpha, but not of its kinase-dead (KD) mutant, markedly suppressed tumor necrosis factor (TNF)-alpha-induced apoptosis of AKI human melanoma cells. In the reverse experiment, siRNA-mediated knockdown of DGKalpha significantly enhanced the apoptosis. The overexpression of other type I isoforms (DGKbeta and DGKgamma) had, on the other hand, no detectable effects on the apoptosis. These results indicate that DGKalpha specifically suppresses the TNF-alpha-induced apoptosis through its catalytic action. We found that the overexpression of DGKalpha-WT, but not of DGKalpha-KD, further enhanced the TNF-alpha-stimulated transcriptional activity of an anti-apoptotic factor, NF-kappaB. Conversely, DGKalpha-knockdown considerably inhibited the NF-kappaB activity. Moreover, an NF-kappaB inhibitor blunted the anti-apoptotic effect of DGKalpha overexpression. Together, these results strongly suggest that DGKalpha is a novel positive regulator of NF-kappaB, which suppresses TNF-alpha-induced melanoma cell apoptosis.
Collapse
Affiliation(s)
- Kenji Yanagisawa
- Department of Dermatology, Sapporo Medical University School of Medicine, Sapporo, Japan
| | | | | | | | | | | | | | | | | |
Collapse
|
49
|
Goto K, Hozumi Y, Nakano T, Saino SS, Kondo H. Cell Biology and Pathophysiology of the Diacylglycerol Kinase Family: Morphological Aspects in Tissues and Organs. INTERNATIONAL REVIEW OF CYTOLOGY 2007; 264:25-63. [DOI: 10.1016/s0074-7696(07)64002-9] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
|
50
|
Scali C, Caraci F, Gianfriddo M, Diodato E, Roncarati R, Pollio G, Gaviraghi G, Copani A, Nicoletti F, Terstappen GC, Caricasole A. Inhibition of Wnt signaling, modulation of Tau phosphorylation and induction of neuronal cell death by DKK1. Neurobiol Dis 2006; 24:254-65. [PMID: 16919965 DOI: 10.1016/j.nbd.2006.06.016] [Citation(s) in RCA: 98] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2006] [Revised: 06/12/2006] [Accepted: 06/30/2006] [Indexed: 11/30/2022] Open
Abstract
Expression of the Wnt antagonist Dickkopf-1 (DKK1) is induced during neurodegenerative processes associated with Alzheimer's Disease and brain ischemia. However, little is known about DKK1-mediated effects on neurons. We now describe that, in cultured neurons, DKK1 is able to inhibit canonical Wnt signaling, as assessed by TCF reporter assay and analysis of beta-catenin levels, and to elicit cell death associated with loss of BCL-2 expression, induction of BAX, and TAU hyperphosphorylation. Local infusion of DKK1 in rats caused neuronal cell death and astrocytosis in the CA1 region of the hippocampus and death of cholinergic neurons in the nucleus basalis magnocellularis. Both effects were reversed by systemic administration of lithium ions, which rescue the Wnt pathway by inhibiting glycogen synthase kinase-3beta. The demonstration that DKK1 inhibits Wnt signaling in neurons and causes neuronal death supports the hypothesis that inhibition of the canonical Wnt pathway contributes to the pathophysiology of neurodegenerative disorders.
Collapse
|