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Yachida N, Hoshino F, Murakami C, Ebina M, Miura Y, Sakane F. Saturated fatty acid- and/or monounsaturated fatty acid-containing phosphatidic acids selectively interact with heat shock protein 27. J Biol Chem 2023; 299:103019. [PMID: 36791913 PMCID: PMC10023972 DOI: 10.1016/j.jbc.2023.103019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Revised: 01/30/2023] [Accepted: 02/06/2023] [Indexed: 02/17/2023] Open
Abstract
Diacylglycerol kinase (DGK) α, which is a key enzyme in the progression of cancer and, in contrast, in T-cell activity attenuation, preferentially produces saturated fatty acid (SFA)- and/or monounsaturated fatty acid (MUFA)-containing phosphatidic acids (PAs), such as 16:0/16:0-, 16:0/18:0-, and 16:1/16:1-PA, in melanoma cells. In the present study, we searched for the target proteins of 16:0/16:0-PA in melanoma cells and identified heat shock protein (HSP) 27, which acts as a molecular chaperone and contributes to cancer progression. HSP27 more strongly interacted with PA than other phospholipids, including phosphatidylcholine, phosphatidylserine, phosphatidylglycerol, cardiolipin, phosphatidylinositol, phosphatidylinositol 4-monophosphate, and phosphatidylinositol 4,5-bisphosphate. Moreover, HSP27 is more preferentially bound to SFA- and/or MUFA-containing PAs, including 16:0/16:0- and 16:0/18:1-PAs, than PUFA-containing PAs, including 18:0/20:4- and 18:0/22:6-PA. Furthermore, HSP27 and constitutively active DGKα expressed in COS-7 cells colocalized in a DGK activity-dependent manner. Notably, 16:0/16:0-PA, but not phosphatidylcholine or 16:0/16:0-phosphatidylserine, induced oligomer dissociation of HSP27, which enhances its chaperone activity. Intriguingly, HSP27 protein was barely detectable in Jurkat T cells, while the protein band was intensely detected in AKI melanoma cells. Taken together, these results strongly suggest that SFA- and/or MUFA-containing PAs produced by DGKα selectively target HSP27 and regulate its cancer-progressive function in melanoma cells but not in T cells.
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Affiliation(s)
- Naoto Yachida
- Department of Chemistry, Graduate School of Science, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba, Japan
| | - Fumi Hoshino
- Department of Chemistry, Graduate School of Science, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba, Japan
| | - Chiaki Murakami
- Department of Chemistry, Graduate School of Science, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba, Japan; Institute for Advanced Academic Research, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba, Japan
| | - Masayuki Ebina
- Department of Chemistry, Graduate School of Science, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba, Japan
| | - Yuri Miura
- Research Team for Mechanism of Aging, Tokyo Metropolitan Institute of Gerontology, Itabashi, Tokyo, Japan
| | - Fumio Sakane
- Department of Chemistry, Graduate School of Science, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba, Japan.
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2
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Velnati S, Centonze S, Rossino G, Purghè B, Antona A, Racca L, Mula S, Ruffo E, Malacarne V, Malerba M, Manfredi M, Graziani A, Baldanzi G. Wiskott-Aldrich syndrome protein interacts and inhibits diacylglycerol kinase alpha promoting IL-2 induction. Front Immunol 2023; 14:1043603. [PMID: 37138877 PMCID: PMC10149931 DOI: 10.3389/fimmu.2023.1043603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Accepted: 03/30/2023] [Indexed: 05/05/2023] Open
Abstract
Background Phosphorylation of diacylglycerol by diacylglycerol-kinases represents a major inhibitory event constraining T cell activation upon antigen engagement. Efficient TCR signalling requires the inhibition of the alpha isoform of diacylglycerol kinase, DGKα, by an unidentified signalling pathway triggered by the protein adaptor SAP. We previously demonstrated that, in SAP absence, excessive DGKα activity makes the T cells resistant to restimulation-induced cell death (RICD), an apoptotic program counteracting excessive T cell clonal expansion. Results Herein, we report that the Wiskott-Aldrich syndrome protein (WASp) inhibits DGKα through a specific interaction of the DGKα recoverin homology domain with the WH1 domain of WASp. Indeed, WASp is necessary and sufficient for DGKα inhibition, and this WASp function is independent of ARP2/3 activity. The adaptor protein NCK-1 and the small G protein CDC42 connect WASp-mediated DGKα inhibition to SAP and the TCR signalosome. In primary human T cells, this new signalling pathway is necessary for a full response in terms of IL-2 production, while minimally affecting TCR signalling and restimulation-induced cell death. Conversely, in T cells made resistant to RICD by SAP silencing, the enhanced DAG signalling due to DGKα inhibition is sufficient to restore apoptosis sensitivity. Conclusion We discover a novel signalling pathway where, upon strong TCR activation, the complex between WASp and DGKα blocks DGKα activity, allowing a full cytokine response.
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Affiliation(s)
- Suresh Velnati
- Department of Translational Medicine, Universitàdel Piemonte Orientale, Novara, Italy
- Center for Translational Research on Allergic and Autoimmune Diseases (CAAD), Università del Piemonte Orientale, Novara, Italy
| | - Sara Centonze
- Center for Translational Research on Allergic and Autoimmune Diseases (CAAD), Università del Piemonte Orientale, Novara, Italy
- Department of Heath Sciences, Università del Piemonte Orientale, Novara, Italy
- *Correspondence: Sara Centonze,
| | - Giulia Rossino
- Department of Molecular Biotechnology and Health Sciences, Molecular Biotechnology Center (MBC), University of Turin, Turin, Italy
| | - Beatrice Purghè
- Department of Translational Medicine, Universitàdel Piemonte Orientale, Novara, Italy
- Center for Translational Research on Allergic and Autoimmune Diseases (CAAD), Università del Piemonte Orientale, Novara, Italy
| | - Annamaria Antona
- Department of Translational Medicine, Universitàdel Piemonte Orientale, Novara, Italy
| | - Luisa Racca
- Department of Translational Medicine, Universitàdel Piemonte Orientale, Novara, Italy
- Center for Translational Research on Allergic and Autoimmune Diseases (CAAD), Università del Piemonte Orientale, Novara, Italy
| | - Sabrina Mula
- Department of Molecular Biotechnology and Health Sciences, Molecular Biotechnology Center (MBC), University of Turin, Turin, Italy
| | - Elisa Ruffo
- Department of Surgery and Immunology, University of Pittsburgh, Pittsburgh, PA, United States
| | - Valeria Malacarne
- Department of Translational Medicine, Universitàdel Piemonte Orientale, Novara, Italy
- Department of Molecular Biotechnology and Health Sciences, Molecular Biotechnology Center (MBC), University of Turin, Turin, Italy
| | - Mario Malerba
- Department of Translational Medicine, Universitàdel Piemonte Orientale, Novara, Italy
- Respiratory Unit, Sant’Andrea Hospital, Vercelli, Italy
| | - Marcello Manfredi
- Department of Translational Medicine, Universitàdel Piemonte Orientale, Novara, Italy
- Center for Translational Research on Allergic and Autoimmune Diseases (CAAD), Università del Piemonte Orientale, Novara, Italy
| | - Andrea Graziani
- Department of Translational Medicine, Universitàdel Piemonte Orientale, Novara, Italy
- Department of Molecular Biotechnology and Health Sciences, Molecular Biotechnology Center (MBC), University of Turin, Turin, Italy
| | - Gianluca Baldanzi
- Department of Translational Medicine, Universitàdel Piemonte Orientale, Novara, Italy
- Center for Translational Research on Allergic and Autoimmune Diseases (CAAD), Università del Piemonte Orientale, Novara, Italy
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3
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Takahashi D, Yonezawa K, Okizaki Y, Caaveiro JMM, Ueda T, Shimada A, Sakane F, Shimizu N. Ca 2+ -induced structural changes and intramolecular interactions in N-terminal region of diacylglycerol kinase alpha. Protein Sci 2022; 31:e4365. [PMID: 35762720 DOI: 10.1002/pro.4365] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Revised: 05/09/2022] [Accepted: 05/27/2022] [Indexed: 11/05/2022]
Abstract
Diacylglycerol kinases (DGKs) are multi-domain lipid kinases that modulate the levels of lipid messengers, diacylglycerol, and phosphatidic acid. Recently, increasing attention has been paid to its α isozyme (DGKα) as a potential target for cancer immunotherapy. However, little progress has been made on the structural biology of DGKs, and a detailed understanding of the Ca2+ -triggered activation of DGKα, for which the N-terminal domains likely play a critical role, remains unclear. We have recently shown that Ca2+ binding to DGKα-EF induces conformational changes from a protease-susceptible "open" conformation in the apo state to a well-folded one in its holo state. Here, we further studied the structural properties of DGKα N-terminal (RVH and EF) domains using a series of biophysical techniques. We first revealed that the N-terminal RVH domain is a novel Ca2+ -binding domain, but the Ca2+ -induced conformational changes mainly occur in the EF domain. This was corroborated by NMR experiments showing that the EF domain adopts a molten-globule like structure in the apo state. Further analyses using SEC-SAXS and NMR indicate that the partially unfolded EF domain interacts with RVH domain, likely via hydrophobic interactions in the absence of Ca2+ , and this interaction is modified in the presence of Ca2+ . Taken together, these results present novel insights into the structural rearrangement of DGKα N-terminal domains upon binding to Ca2+ , which is essential for the activation of the enzyme.
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Affiliation(s)
- Daisuke Takahashi
- Department of Protein Structure, Function, and Design, Graduate School of Pharmaceutical Science, Kyushu University, Fukuoka, Japan
| | - Kento Yonezawa
- Photon Factory, Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), Tsukuba, Japan.,Center for Digital Green-Innovation (CDG), Nara Institute of Science and Technology (NAIST), Ikoma, Japan
| | - Yuki Okizaki
- Department of Protein Structure, Function, and Design, Graduate School of Pharmaceutical Science, Kyushu University, Fukuoka, Japan
| | - Jose M M Caaveiro
- Department of Global Healthcare, Graduate School of Pharmaceutical Science, Kyushu University, Fukuoka, Japan
| | - Tadashi Ueda
- Department of Protein Structure, Function, and Design, Graduate School of Pharmaceutical Science, Kyushu University, Fukuoka, Japan
| | - Atsushi Shimada
- Division of Structural Biology, Medical Institute of Bioregulation, Kyushu University, Fukuoka, Japan
| | - Fumio Sakane
- Department of Chemistry, Graduate School of Science, Chiba University, Chiba, Japan
| | - Nobutaka Shimizu
- Photon Factory, Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), Tsukuba, Japan
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4
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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.
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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 ()
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5
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Sakane F, Hoshino F, Ebina M, Sakai H, Takahashi D. The Roles of Diacylglycerol Kinase α in Cancer Cell Proliferation and Apoptosis. Cancers (Basel) 2021; 13:cancers13205190. [PMID: 34680338 PMCID: PMC8534027 DOI: 10.3390/cancers13205190] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2021] [Revised: 10/14/2021] [Accepted: 10/14/2021] [Indexed: 02/02/2023] Open
Abstract
Simple Summary Diacylglycerol (DG) kinase (DGK) phosphorylates DG to generate phosphatidic acid (PA). DGKα is highly expressed in several refractory cancer cells, including melanoma, hepatocellular carcinoma, and glioblastoma cells, attenuates apoptosis, and promotes proliferation. In cancer cells, PA produced by DGKα plays an important role in proliferation/antiapoptosis. In addition to cancer cells, DGKα is highly abundant in T cells and induces a nonresponsive state (anergy), representing the main mechanism by which advanced cancers avoid immune action. In T cells, DGKα induces anergy through DG consumption. Therefore, a DGKα-specific inhibitor is expected to be a dual effective anticancer treatment that inhibits cancer cell proliferation and simultaneously activates T cell function. Moreover, the inhibition of DGKα synergistically enhances the anticancer effects of programmed cell death-1/programmed cell death ligand 1 blockade. Taken together, DGKα inhibition provides a promising new treatment strategy for refractory cancers. Abstract Diacylglycerol (DG) kinase (DGK) phosphorylates DG to generate phosphatidic acid (PA). The α isozyme is activated by Ca2+ through its EF-hand motifs and tyrosine phosphorylation. DGKα is highly expressed in several refractory cancer cells including melanoma, hepatocellular carcinoma, and glioblastoma cells. In melanoma cells, DGKα is an antiapoptotic factor that activates nuclear factor-κB (NF-κB) through the atypical protein kinase C (PKC) ζ-mediated phosphorylation of NF-κB. DGKα acts as an enhancer of proliferative activity through the Raf–MEK–ERK pathway and consequently exacerbates hepatocellular carcinoma progression. In glioblastoma and melanoma cells, DGKα attenuates apoptosis by enhancing the phosphodiesterase (PDE)-4A1–mammalian target of the rapamycin pathway. As PA activates PKCζ, Raf, and PDE, it is likely that PA generated by DGKα plays an important role in the proliferation/antiapoptosis of cancer cells. In addition to cancer cells, DGKα is highly abundant in T cells and induces a nonresponsive state (anergy), which represents the main mechanism by which advanced cancers escape immune action. In T cells, DGKα attenuates the activity of Ras-guanyl nucleotide-releasing protein, which is activated by DG and avoids anergy through DG consumption. Therefore, a DGKα-specific inhibitor is expected to be a dual effective anticancer treatment that inhibits cancer cell proliferation and simultaneously enhances T cell functions. Moreover, the inhibition of DGKα synergistically enhances the anticancer effects of programmed cell death-1/programmed cell death ligand 1 blockade. Taken together, DGKα inhibition provides a promising new treatment strategy for refractory cancers.
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Affiliation(s)
- Fumio Sakane
- Department of Chemistry, Graduate School of Science, Chiba University, Chiba 263-8522, Japan; (F.H.); (M.E.)
- Correspondence: ; Tel.: +81-43-290-3695
| | - Fumi Hoshino
- Department of Chemistry, Graduate School of Science, Chiba University, Chiba 263-8522, Japan; (F.H.); (M.E.)
| | - Masayuki Ebina
- Department of Chemistry, Graduate School of Science, Chiba University, Chiba 263-8522, Japan; (F.H.); (M.E.)
| | - Hiromichi Sakai
- Department of Biosignaling and Radioisotope Experiment, Interdisciplinary Center for Science Research, Organization for Research and Academic Information, Shimane University, Izumo 693-8501, Japan;
| | - Daisuke Takahashi
- Department of Pharmaceutical Health Care and Sciences, Kyushu University, Fukuoka 812-8582, Japan;
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Beyond Lipid Signaling: Pleiotropic Effects of Diacylglycerol Kinases in Cellular Signaling. Int J Mol Sci 2020; 21:ijms21186861. [PMID: 32962151 PMCID: PMC7554708 DOI: 10.3390/ijms21186861] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [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: 09/16/2020] [Indexed: 12/13/2022] Open
Abstract
The diacylglycerol kinase family, which can attenuate diacylglycerol signaling and activate phosphatidic acid signaling, regulates various signaling transductions in the mammalian cells. Studies on the regulation of diacylglycerol and phosphatidic acid levels by various enzymes, the identification and characterization of various diacylglycerol and phosphatidic acid-regulated proteins, and the overlap of different diacylglycerol and phosphatidic acid metabolic and signaling processes have revealed the complex and non-redundant roles of diacylglycerol kinases in regulating multiple biochemical and biological networks. In this review article, we summarized recent progress in the complex and non-redundant roles of diacylglycerol kinases, which is expected to aid in restoring dysregulated biochemical and biological networks in various pathological conditions at the bed side.
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7
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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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8
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DGKα in Neutrophil Biology and Its Implications for Respiratory Diseases. Int J Mol Sci 2019; 20:ijms20225673. [PMID: 31766109 PMCID: PMC6887790 DOI: 10.3390/ijms20225673] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Revised: 11/08/2019] [Accepted: 11/11/2019] [Indexed: 12/21/2022] Open
Abstract
Diacylglycerol kinases (DGKs) play a key role in phosphoinositide signaling by removing diacylglycerol and generating phosphatidic acid. Besides the well-documented role of DGKα and DGKζ as negative regulators of lymphocyte responses, a robust body of literature points to those enzymes, and specifically DGKα, as crucial regulators of leukocyte function. Upon neutrophil stimulation, DGKα activation is necessary for migration and a productive response. The role of DGKα in neutrophils is evidenced by its aberrant behavior in juvenile periodontitis patients, which express an inactive DGKα transcript. Together with in vitro experiments, this suggests that DGKs may represent potential therapeutic targets for disorders where inflammation, and neutrophils in particular, plays a major role. In this paper we focus on obstructive respiratory diseases, including asthma and chronic obstructive pulmonary disease (COPD), but also rare genetic diseases such as alpha-1-antitrypsin deficiency. Indeed, the biological role of DGKα is understudied outside the T lymphocyte field. The recent wave of research aiming to develop novel and specific inhibitors as well as KO mice will allow a better understanding of DGK's role in neutrophilic inflammation. Better knowledge and pharmacologic tools may also allow DGK to move from the laboratory bench to clinical trials.
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9
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Takahashi D, Suzuki K, Sakamoto T, Iwamoto T, Murata T, Sakane F. Crystal structure and calcium-induced conformational changes of diacylglycerol kinase α EF-hand domains. Protein Sci 2019; 28:694-706. [PMID: 30653270 DOI: 10.1002/pro.3572] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Revised: 01/10/2019] [Accepted: 01/10/2019] [Indexed: 01/07/2023]
Abstract
Diacylglycerol kinases (DGKs) are multi-domain lipid kinases that phosphorylate diacylglycerol into phosphatidic acid, modulating the levels of these key signaling lipids. Recently, increasing attention has been paid to DGKα isozyme as a potential target for cancer immunotherapy. We have previously shown that DGKα is positively regulated by Ca2+ binding to its N-terminal EF-hand domains (DGKα-EF). However, little progress has been made for the structural biology of mammalian DGKs and the molecular mechanism underlying the Ca2+ -triggered activation remains unclear. Here we report the first crystal structure of Ca2+ -bound DGKα-EF and analyze the structural changes upon binding to Ca2+ . DGKα-EF adopts a canonical EF-hand fold, but unexpectedly, has an additional α-helix (often called a ligand mimic [LM] helix), which is packed into the hydrophobic core. Biophysical and biochemical analyses reveal that DGKα-EF adopts a protease-susceptible "open" conformation without Ca2+ that tends to form a dimer. Cooperative binding of two Ca2+ ions dissociates the dimer into a well-folded monomer, which resists to proteolysis. Taken together, our results provide experimental evidence that Ca2+ binding induces substantial conformational changes in DGKα-EF, which likely regulates intra-molecular interactions responsible for the activation of DGKα and suggest a possible role of the LM helix for the Ca2+ -induced conformational changes. SIGNIFICANCE STATEMENT: Diacylglycerol kinases (DGKs), which modulates the levels of two lipid second messengers, diacylglycerol and phosphatidic acid, is still structurally enigmatic enzymes since its first identification in 1959. We here present the first crystal structure of EF-hand domains of diacylglycerol kinase α in its Ca2+ bound form and characterize Ca2+ -induced conformational changes, which likely regulates intra-molecular interactions. Our study paves the way for future studies to understand the structural basis of DGK isozymes.
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Affiliation(s)
- Daisuke Takahashi
- Department of Chemistry, Graduate School of Science, Chiba University, Chiba, Japan
| | - Kano Suzuki
- Department of Chemistry, Graduate School of Science, Chiba University, Chiba, Japan
| | - Taiichi Sakamoto
- Department of Life Science, Faculty of Advanced Engineering, Chiba Institute of Technology, Chiba, Japan
| | - Takeo Iwamoto
- Division of Molecular Cell Biology, Core Research Facilities for Basic Science, Research Center for Medical Sciences, The Jikei University School of Medicine, Chiba, Japan
| | - Takeshi Murata
- Department of Chemistry, Graduate School of Science, Chiba University, Chiba, Japan.,Molecular Chirality Research Center, Chiba University, Chiba, Japan
| | - Fumio Sakane
- Department of Chemistry, Graduate School of Science, Chiba University, Chiba, Japan
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10
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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]
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11
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Takahashi D, Sakane F. Expression and purification of human diacylglycerol kinase α from baculovirus-infected insect cells for structural studies. PeerJ 2018; 6:e5449. [PMID: 30128205 PMCID: PMC6089211 DOI: 10.7717/peerj.5449] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Accepted: 07/26/2018] [Indexed: 02/02/2023] Open
Abstract
Diacylglycerol kinases (DGKs) are lipid kinases that modulate the levels of lipid second messengers, diacylglycerol and phosphatidic acid. Recently, increasing attention has been paid to its α isozyme (DGKα) as a potential target for cancer immunotherapy. DGKα consists of the N-terminal regulatory domains including EF-hand motifs and C1 domains, and the C-terminal catalytic domain (DGKα-CD). To date, however, no structures of mammalian DGKs including their CDs have yet been reported, impeding our understanding on the catalytic mechanism of DGKs and the rational structure-based drug design. Here we attempted to produce DGKα-CD or a full-length DGKα using bacterial and baculovirus-insect cell expression system for structural studies. While several DGKα-CD constructs produced using both bacterial and insect cells formed insoluble or soluble aggregates, the full-length DGKα expressed in insect cells remained soluble and was purified to near homogeneity as a monomer with yields (1.3 mg/mL per one L cell culture) feasible for protein crystallization. Following enzymatic characterization showed that the purified DGKα is in fully functional state. We further demonstrated that the purified enzyme could be concentrated without any significant aggregation, and characterized its secondary structure by circular dichroism. Taken together, these results suggest that the presence of N-terminal regulatory domains suppress protein aggregation likely via their intramolecular interactions with DGKα-CD, and demonstrate that the baculovirus-insect cell expression of the full-length form of DGKα, not DGKα-CD alone, represents a promising approach to produce protein sample for structural studies of DGKα. Thus, our study will encourage future efforts to determine the crystal structure of DGK, which has not been determined since it was first identified in 1959.
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Affiliation(s)
- Daisuke Takahashi
- Department of Chemistry, Graduate School of Science, Chiba University, Chiba, Japan
| | - Fumio Sakane
- Department of Chemistry, Graduate School of Science, Chiba University, Chiba, Japan
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12
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Yamamoto T, Sakai H, Sakane F. EF-hand motifs of diacylglycerol kinase α interact intra-molecularly with its C1 domains. FEBS Open Bio 2014; 4:387-92. [PMID: 24918053 PMCID: PMC4050180 DOI: 10.1016/j.fob.2014.04.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Revised: 04/14/2014] [Accepted: 04/15/2014] [Indexed: 02/02/2023] Open
Abstract
We revealed the intra-molecular interaction of DGKα. The EF-hand motifs of DGKα directly binds to its C1 domains. The intra-molecular interaction was negatively regulated by Ca2+. The intra-molecular interaction is important for the activation mechanism of DGKα.
Diacylglycerol kinase (DGK) α, which is activated by Ca2+, contains a recoverin homology (RVH) domain, tandem repeats of two Ca2+-binding EF-hand motifs, two cysteine-rich C1 domains and the catalytic domain. We previously found that a DGKα mutant lacking the RVH domain and EF-hands was constitutively active and that the N-terminal region of DGKα, consisting of the RVH domain and EF-hand motifs, interacted intra-molecularly with the C-terminal region containing the C1 and catalytic domains. In this study, we narrowed down the interaction regions of DGKα. At the C-terminal region, the C1 domains are responsible for the intra-molecular interaction. At the N-terminal region, the EF-hand motifs mainly contribute to the interaction. Moreover, using highly purified EF-hand motifs and C1 domains, we demonstrate that they directly bind to each other. The co-precipitation of these two domains was clearly attenuated by the addition of Ca2+. These results indicate that the Ca2+-induced dissociation of the intra-molecular interaction between the EF-hand motifs and the C1 domains of DGKα is the key event that regulates the activity of the enzyme.
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Key Words
- C1 domain
- C1Ds, C1 domains
- CR, catalytic region
- Calcium
- DG, diacylglycerol
- DGK, diacylglycerol kinase
- Diacylglycerol kinase
- EF-hand
- EFHs, EF-hand motifs
- EGFP, enhanced green fluorescence protein
- EGTA, ethylene glycol tetraacetic acid
- GST, glutathione S-transferase
- Intra-molecular interaction
- RVH, recoverin homology
- RVHD, RVH domain
- TF, trigger factor
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Affiliation(s)
- Tatsuya Yamamoto
- Department of Chemistry, Graduate School of Science, Chiba University, Chiba, Japan
| | - Hiromichi Sakai
- Department of Chemistry, Graduate School of Science, Chiba University, Chiba, Japan
| | - Fumio Sakane
- Department of Chemistry, Graduate School of Science, Chiba University, Chiba, Japan
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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.
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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.
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14
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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]
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15
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Joshi RP, Schmidt AM, Das J, Pytel D, Riese MJ, Lester M, Diehl JA, Behrens EM, Kambayashi T, Koretzky GA. The ζ isoform of diacylglycerol kinase plays a predominant role in regulatory T cell development and TCR-mediated ras signaling. Sci Signal 2013; 6:ra102. [PMID: 24280043 DOI: 10.1126/scisignal.2004373] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Diacylglycerol (DAG) is a critical second messenger that mediates T cell receptor (TCR)-stimulated signaling. The abundance of DAG is reduced by the diacylglycerol kinases (DGKs), which catalyze the conversion of DAG to phosphatidic acid (PA) and thus inhibit DAG-mediated signaling. In T cells, the predominant DGK isoforms are DGKα and DGKζ, and deletion of the genes encoding either isoform enhances DAG-mediated signaling. We found that DGKζ, but not DGKα, suppressed the development of natural regulatory T (T(reg)) cells and predominantly mediated Ras and Akt signaling downstream of the TCR. The differential functions of DGKα and DGKζ were not attributable to differences in protein abundance in T cells or in their localization to the contact sites between T cells and antigen-presenting cells. RasGRP1, a key DAG-mediated activator of Ras signaling, associated to a greater extent with DGKζ than with DGKα; however, in silico modeling of TCR-stimulated Ras activation suggested that a difference in RasGRP1 binding affinity was not sufficient to cause differences in the functions of each DGK isoform. Rather, the model suggested that a greater catalytic rate for DGKζ than for DGKα might lead to DGKζ exhibiting increased suppression of Ras-mediated signals compared to DGKα. Consistent with this notion, experimental studies demonstrated that DGKζ was more effective than DGKα at catalyzing the metabolism of DAG to PA after TCR stimulation. The enhanced effective enzymatic production of PA by DGKζ is therefore one possible mechanism underlying the dominant functions of DGKζ in modulating T(reg) cell development.
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Affiliation(s)
- Rohan P Joshi
- 1Abramson Family Cancer Research Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
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16
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Joshi RP, Koretzky GA. Diacylglycerol kinases: regulated controllers of T cell activation, function, and development. Int J Mol Sci 2013; 14:6649-73. [PMID: 23531532 PMCID: PMC3645659 DOI: 10.3390/ijms14046649] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2013] [Revised: 03/07/2013] [Accepted: 03/14/2013] [Indexed: 01/22/2023] Open
Abstract
Diacylglycerol kinases (DGKs) are a diverse family of enzymes that catalyze the conversion of diacylglycerol (DAG), a crucial second messenger of receptor-mediated signaling, to phosphatidic acid (PA). Both DAG and PA are bioactive molecules that regulate a wide set of intracellular signaling proteins involved in innate and adaptive immunity. Clear evidence points to a critical role for DGKs in modulating T cell activation, function, and development. More recently, studies have elucidated factors that control DGK function, suggesting an added complexity to how DGKs act during signaling. This review summarizes the available knowledge of the function and regulation of DGK isoforms in signal transduction with a particular focus on T lymphocytes.
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Affiliation(s)
- Rohan P. Joshi
- Abramson Family Cancer Research Institute, University of Pennsylvania, Philadelphia, PA 19104, USA; E-Mail:
| | - Gary A. Koretzky
- Abramson Family Cancer Research Institute, University of Pennsylvania, Philadelphia, PA 19104, USA; E-Mail:
- Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +1-215-746-5522; Fax: +1-215-746-5525
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Petro EJ, Raben DM. Bacterial expression strategies for several Sus scrofa diacylglycerol kinase alpha constructs: solubility challenges. Sci Rep 2013; 3:1609. [PMID: 23558375 PMCID: PMC3617429 DOI: 10.1038/srep01609] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2013] [Accepted: 03/19/2013] [Indexed: 01/27/2023] Open
Abstract
We pursued several strategies for expressing either full-length Sus scrofa diacylglycerol kinase (DGK) alpha or the catalytic domain (alphacat) in Escherichia coli. Alphacat could be extracted, refolded, and purified from inclusion bodies, but when subjected to analytical gel filtration chromatography, it elutes in the void volume, in what we conclude are microscopic aggregates unsuitable for x-ray crystallography. Adding glutathione S-transferase, thioredoxin, or maltose binding protein as N-terminal fusion tags did not improve alphacat's solubility. Coexpressing with bacterial chaperones increased the yield of alphacat in the supernatant after high-speed centrifugation, but the protein still elutes in the void upon analytical gel filtration chromatography. We believe our work will be of interest to those interested in the structure of eukaryotic DGKs, so that they know which expression strategies have already been tried, as well as to those interested in protein folding and those interested in chaperone/target-protein interactions.
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Affiliation(s)
- Elizabeth J. Petro
- Department of Biological Chemistry, The Johns Hopkins University School of Medicine, Baltimore, MD
| | - Daniel M. Raben
- Department of Biological Chemistry, The Johns Hopkins University School of Medicine, Baltimore, MD
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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.
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