1
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Chen Y, Chen K, Zhu H, Qin H, Liu J, Cao X. Methyltransferase Setd2 prevents T cell-mediated autoimmune diseases via phospholipid remodeling. Proc Natl Acad Sci U S A 2024; 121:e2314561121. [PMID: 38359295 PMCID: PMC10895270 DOI: 10.1073/pnas.2314561121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Accepted: 12/16/2023] [Indexed: 02/17/2024] Open
Abstract
Coordinated metabolic reprogramming and epigenetic remodeling are critical for modulating T cell function and differentiation. However, how the epigenetic modification controls Th17/Treg cell balance via metabolic reprogramming remains obscure. Here, we find that Setd2, a histone H3K36 trimethyltransferase, suppresses Th17 development but promotes iTreg cell polarization via phospholipid remodeling. Mechanistically, Setd2 up-regulates transcriptional expression of lysophosphatidylcholine acyltransferase 4 (Lpcat4) via directly catalyzing H3K36me3 of Lpcat4 gene promoter in T cells. Lpcat4-mediated phosphatidylcholine PC(16:0,18:2) generation in turn limits endoplasmic reticulum stress and oxidative stress. These changes decrease HIF-1α transcriptional activity and thus suppress Th17 but enhance Treg development. Consistent with this regulatory paradigm, T cell deficiency of Setd2 aggravates neuroinflammation and demyelination in experimental autoimmune encephalomyelitis due to imbalanced Th17/Treg cell differentiation. Overall, our data reveal that Setd2 acts as an epigenetic brake for T cell-mediated autoimmunity through phospholipid remodeling, suggesting potential targets for treating neuroinflammatory diseases.
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Affiliation(s)
- Yali Chen
- Department of Immunology, Center for Immunotherapy, Institute of Basic Medical Sciences, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100005, China
- National Key Laboratory of Immunity and Inflammation, Institute of Immunology, Naval Medical University, Shanghai 200433, China
| | - Kun Chen
- Department of Immunology, Center for Immunotherapy, Institute of Basic Medical Sciences, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100005, China
- Translational Medical Center for Stem Cell Therapy, Shanghai East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai 200120, China
| | - Ha Zhu
- National Key Laboratory of Immunity and Inflammation, Institute of Immunology, Naval Medical University, Shanghai 200433, China
| | - Hua Qin
- Institute of Immunology, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Juan Liu
- National Key Laboratory of Immunity and Inflammation, Institute of Immunology, Naval Medical University, Shanghai 200433, China
| | - Xuetao Cao
- Department of Immunology, Center for Immunotherapy, Institute of Basic Medical Sciences, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100005, China
- National Key Laboratory of Immunity and Inflammation, Institute of Immunology, Naval Medical University, Shanghai 200433, China
- Institute of Immunology, College of Life Sciences, Nankai University, Tianjin 300071, China
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2
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Jang BG, Choi B, Kim S, Lee DS, Lee J, Koh YH, Jo SA, Kim JE, Kang TC, Kim MJ. 2,4-Diacetylphloroglucinol Reduces Beta-Amyloid Production and Secretion by Regulating ADAM10 and Intracellular Trafficking in Cellular and Animal Models of Alzheimer's Disease. Cells 2022; 11:cells11162585. [PMID: 36010661 PMCID: PMC9406471 DOI: 10.3390/cells11162585] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Revised: 08/14/2022] [Accepted: 08/17/2022] [Indexed: 11/26/2022] Open
Abstract
There is currently no effective treatment against Alzheimer’s disease (AD), although many strategies have been applied to reduce beta-amyloid (Aβ) levels. Here, we investigated 2,4-diacetylphloroglucinol (DAPG) effects on Aβ levels and mechanisms of action. DAPG was the most effective phloroglucinol derivative for reducing Aβ levels, without being toxic, in various models including HEK293 cells overexpressing Swedish mutant amyloid precursor protein (APP) (293sw), primary astrocytes isolated from APPsw/PS1dE9 transgenic mice, and after intrahippocampal injection of DAPG in APPsw/PS1dE9 transgenic mice. DAPG-mediated Aβ reduction was associated with increased soluble APPα (sAPPα) levels mediated by a disintegrin and metalloproteinase domain-containing protein 10 (ADAM10) but not ADAM17. ADAM10 inhibition in DAPG-treated cells prevented the effects on sAPPα but only partly on intracellular and secreted Aβ. To identify regulators of sAPPα and Aβ secretion, various inhibitors of intracellular trafficking were administered with DAPG. Brefeldin A (BFA) reversed DAPG-mediated changes in Aβ secretion in 293sw cells, whereas golgicide A (GCA) and BFA were effective in primary astrocytes, indicating a cell type-specific regulation of the trafficking. Moreover, GCA or BFA effects on sAPPα, but not Aβ, levels in primary astrocytes resembled those of ADAM10 inhibition, indicating at least partly independent trafficking pathways for sAPPα and Aβ. In conclusion, DAPG might be a promising drug candidate against AD regulating ADAM10 and intracellular trafficking, but optimizing DAPG ability to cross the BBB will be needed.
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Affiliation(s)
- Bong-Geum Jang
- Institute of Epilepsy Research, College of Medicine, Hallym University, Chuncheon 24252, Korea
| | - Boyoung Choi
- Institute of Epilepsy Research, College of Medicine, Hallym University, Chuncheon 24252, Korea
| | - Suyeon Kim
- Department of Anatomy and Neurobiology, College of Medicine, Hallym University, Chuncheon 24252, Korea
| | - Duk-Shin Lee
- Department of Anatomy and Neurobiology, College of Medicine, Hallym University, Chuncheon 24252, Korea
| | - Jisun Lee
- Department of Anatomy and Neurobiology, College of Medicine, Hallym University, Chuncheon 24252, Korea
| | - Young Ho Koh
- Division of Brain Disease Research, Department of Chronic Disease Convergence Research, Korea National Institute of Health, Cheongju 28159, Korea
| | - Sangmee Ahn Jo
- Department of Nanobiomedical Science & BK21 PLUS NBM Global Research Center for Regenerative Medicine, Dankook University, Cheonan 31116, Korea
- Department of Pharmacology, College of Pharmacy, Dankook University, Cheonan 31116, Korea
| | - Ji-Eun Kim
- Institute of Epilepsy Research, College of Medicine, Hallym University, Chuncheon 24252, Korea
- Department of Anatomy and Neurobiology, College of Medicine, Hallym University, Chuncheon 24252, Korea
| | - Tae-Cheon Kang
- Institute of Epilepsy Research, College of Medicine, Hallym University, Chuncheon 24252, Korea
- Department of Anatomy and Neurobiology, College of Medicine, Hallym University, Chuncheon 24252, Korea
| | - Min-Ju Kim
- Institute of Epilepsy Research, College of Medicine, Hallym University, Chuncheon 24252, Korea
- Department of Anatomy and Neurobiology, College of Medicine, Hallym University, Chuncheon 24252, Korea
- Correspondence: ; Tel.: +82-33-248-2523; Fax: +82-33-256-2525
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3
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ISOBE M, SUZUKI Y, SUGIURA H, SHIBATA M, OHSAKI Y, KAMETAKA S. Novel cell-based system to assay cell-cell fusion during myotube formation. Biomed Res 2022; 43:107-114. [DOI: 10.2220/biomedres.43.107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Mari ISOBE
- Division of Biofunctional Sciences, Department of Integrated Health Sciences, Graduate School of Medicine, Nagoya University
| | - Yumika SUZUKI
- Division of Biofunctional Sciences, Department of Integrated Health Sciences, Graduate School of Medicine, Nagoya University
| | - Hideshi SUGIURA
- Division of Biofunctional Sciences, Department of Integrated Health Sciences, Graduate School of Medicine, Nagoya University
| | - Masahiro SHIBATA
- Division of Morphological Sciences, Kagoshima University Graduate School of Medical and Dental Sciences
| | - Yuki OHSAKI
- Department of Anatomy I, Sapporo Medical University School of Medicine
| | - Satoshi KAMETAKA
- Division of Biofunctional Sciences, Department of Integrated Health Sciences, Graduate School of Medicine, Nagoya University
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4
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Yoshioka K, Hirakawa Y, Kurano M, Ube Y, Ono Y, Kojima K, Iwama T, Kano K, Hasegawa S, Inoue T, Shimada T, Aoki J, Yatomi Y, Nangaku M, Inagi R. Lysophosphatidylcholine mediates fast decline in kidney function in diabetic kidney disease. Kidney Int 2021; 101:510-526. [PMID: 34856312 DOI: 10.1016/j.kint.2021.10.039] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 10/15/2021] [Accepted: 10/26/2021] [Indexed: 12/30/2022]
Abstract
Some patients with diabetic kidney disease (DKD) show a fast progression of kidney dysfunction and are known as a "fast decliner" (FD). Therefore, it is critical to understand pathomechanisms specific for fast decline. Here, we performed a comprehensive metabolomic analysis of patients with stage G3 DKD and identified increased urinary lysophosphatidylcholine (LPC) in fast decline. This was confirmed by quantification of urinary LPC using mass spectrometry and identified urinary LPC containing saturated fatty acids palmitic (16:0) and stearic (18:0) acids was increased in FDs. The upsurge in urinary LPC levels was correlated with a decline in estimated glomerular filtration rate after 2.5 years. To clarify a pathogenic role of LPC in FD, we studied an accelerated rat model of DKD and observed an increase in LPC (16:0) and (18:0) levels in the urine and kidney tubulointerstitium as the disease progressed. These findings suggested that local dysregulation of lipid metabolism resulted in excessive accumulation of this LPC species in the kidney. Our in vitro studies also confirmed LPC-mediated lipotoxicity in cultured proximal tubular cells. LPC induced accumulation of lipid droplets via activation of peroxisome proliferator-activated receptor-δ followed by upregulation of the lipid droplet membrane protein perilipin 2 and decreased autophagic flux, thereby inducing organelle stress and subsequent apoptosis. Thus, LPC (16:0) and (18:0) may mediate a fast progression of DKD and may serve as a target for novel therapeutic approaches.
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Affiliation(s)
- Kentaro Yoshioka
- Division of Nephrology and Endocrinology, The University of Tokyo Graduate School of Medicine, Tokyo, Japan; Division of CKD Pathophysiology, The University of Tokyo Graduate School of Medicine, Tokyo, Japan; R&D Division, Kyowa Kirin Co., Ltd., Tokyo, Japan
| | - Yosuke Hirakawa
- Division of Nephrology and Endocrinology, The University of Tokyo Graduate School of Medicine, Tokyo, Japan
| | - Makoto Kurano
- Department of Clinical Laboratory Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Yuko Ube
- R&D Division, Kyowa Kirin Co., Ltd., Tokyo, Japan
| | - Yoko Ono
- R&D Division, Kyowa Kirin Co., Ltd., Tokyo, Japan
| | | | - Taiga Iwama
- Department of Health Chemistry, The University of Tokyo Graduate School of Pharmaceutical Sciences, Tokyo, Japan
| | - Kuniyuki Kano
- Department of Health Chemistry, The University of Tokyo Graduate School of Pharmaceutical Sciences, Tokyo, Japan
| | - Sho Hasegawa
- Division of Nephrology and Endocrinology, The University of Tokyo Graduate School of Medicine, Tokyo, Japan; Division of CKD Pathophysiology, The University of Tokyo Graduate School of Medicine, Tokyo, Japan
| | - Tsuyoshi Inoue
- Division of CKD Pathophysiology, The University of Tokyo Graduate School of Medicine, Tokyo, Japan; Department of Physiology of Visceral Function and Body Fluid, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan
| | | | - Junken Aoki
- Department of Health Chemistry, The University of Tokyo Graduate School of Pharmaceutical Sciences, Tokyo, Japan
| | - Yutaka Yatomi
- Department of Clinical Laboratory Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Masaomi Nangaku
- Division of Nephrology and Endocrinology, The University of Tokyo Graduate School of Medicine, Tokyo, Japan.
| | - Reiko Inagi
- Division of CKD Pathophysiology, The University of Tokyo Graduate School of Medicine, Tokyo, Japan.
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5
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Ferrara PJ, Rong X, Maschek JA, Verkerke AR, Siripoksup P, Song H, Green TD, Krishnan KC, Johnson JM, Turk J, Houmard JA, Lusis AJ, Drummond MJ, McClung JM, Cox JE, Shaikh SR, Tontonoz P, Holland WL, Funai K. Lysophospholipid acylation modulates plasma membrane lipid organization and insulin sensitivity in skeletal muscle. J Clin Invest 2021; 131:135963. [PMID: 33591957 DOI: 10.1172/jci135963] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Accepted: 02/11/2021] [Indexed: 01/09/2023] Open
Abstract
Aberrant lipid metabolism promotes the development of skeletal muscle insulin resistance, but the exact identity of lipid-mediated mechanisms relevant to human obesity remains unclear. A comprehensive lipidomic analysis of primary myocytes from individuals who were insulin-sensitive and lean (LN) or insulin-resistant with obesity (OB) revealed several species of lysophospholipids (lyso-PLs) that were differentially abundant. These changes coincided with greater expression of lysophosphatidylcholine acyltransferase 3 (LPCAT3), an enzyme involved in phospholipid transacylation (Lands cycle). Strikingly, mice with skeletal muscle-specific knockout of LPCAT3 (LPCAT3-MKO) exhibited greater muscle lysophosphatidylcholine/phosphatidylcholine, concomitant with improved skeletal muscle insulin sensitivity. Conversely, skeletal muscle-specific overexpression of LPCAT3 (LPCAT3-MKI) promoted glucose intolerance. The absence of LPCAT3 reduced phospholipid packing of cellular membranes and increased plasma membrane lipid clustering, suggesting that LPCAT3 affects insulin receptor phosphorylation by modulating plasma membrane lipid organization. In conclusion, obesity accelerates the skeletal muscle Lands cycle, whose consequence might induce the disruption of plasma membrane organization that suppresses muscle insulin action.
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Affiliation(s)
- Patrick J Ferrara
- Diabetes and Metabolism Research Center and.,Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, Utah, USA.,East Carolina Diabetes and Obesity Institute and.,Human Performance Laboratory, East Carolina University, Greenville, North Carolina, USA.,Molecular Medicine Program, University of Utah, Salt Lake City, Utah, USA
| | - Xin Rong
- Department of Pathology and Laboratory Medicine, UCLA, Los Angeles, California, USA
| | - J Alan Maschek
- Diabetes and Metabolism Research Center and.,Metabolomics, Mass Spectrometry, and Proteomics Core and
| | - Anthony Rp Verkerke
- Diabetes and Metabolism Research Center and.,Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, Utah, USA.,East Carolina Diabetes and Obesity Institute and.,Human Performance Laboratory, East Carolina University, Greenville, North Carolina, USA
| | - Piyarat Siripoksup
- Diabetes and Metabolism Research Center and.,Department of Physical Therapy and Athletic Training, University of Utah, Salt Lake City, Utah, USA
| | - Haowei Song
- Division of Endocrinology Metabolism and Lipid Research, School of Medicine, Washington University in St. Louis, St. Louis, Missouri, USA
| | | | | | - Jordan M Johnson
- Diabetes and Metabolism Research Center and.,Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, Utah, USA.,East Carolina Diabetes and Obesity Institute and.,Human Performance Laboratory, East Carolina University, Greenville, North Carolina, USA
| | - John Turk
- Division of Endocrinology Metabolism and Lipid Research, School of Medicine, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Joseph A Houmard
- East Carolina Diabetes and Obesity Institute and.,Human Performance Laboratory, East Carolina University, Greenville, North Carolina, USA
| | - Aldons J Lusis
- Cardiology Division, Department of Medicine, UCLA, Los Angeles, California, USA
| | - Micah J Drummond
- Diabetes and Metabolism Research Center and.,Molecular Medicine Program, University of Utah, Salt Lake City, Utah, USA.,Department of Physical Therapy and Athletic Training, University of Utah, Salt Lake City, Utah, USA
| | | | - James E Cox
- Diabetes and Metabolism Research Center and.,Metabolomics, Mass Spectrometry, and Proteomics Core and.,Department of Biochemistry, University of Utah, Salt Lake City, Utah, USA
| | - Saame Raza Shaikh
- East Carolina Diabetes and Obesity Institute and.,Department of Nutrition, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Peter Tontonoz
- Department of Pathology and Laboratory Medicine, UCLA, Los Angeles, California, USA
| | - William L Holland
- Diabetes and Metabolism Research Center and.,Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, Utah, USA.,Molecular Medicine Program, University of Utah, Salt Lake City, Utah, USA
| | - Katsuhiko Funai
- Diabetes and Metabolism Research Center and.,Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, Utah, USA.,East Carolina Diabetes and Obesity Institute and.,Human Performance Laboratory, East Carolina University, Greenville, North Carolina, USA.,Molecular Medicine Program, University of Utah, Salt Lake City, Utah, USA.,Department of Physical Therapy and Athletic Training, University of Utah, Salt Lake City, Utah, USA
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6
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Mamode Cassim A, Gouguet P, Gronnier J, Laurent N, Germain V, Grison M, Boutté Y, Gerbeau-Pissot P, Simon-Plas F, Mongrand S. Plant lipids: Key players of plasma membrane organization and function. Prog Lipid Res 2018; 73:1-27. [PMID: 30465788 DOI: 10.1016/j.plipres.2018.11.002] [Citation(s) in RCA: 120] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Revised: 11/07/2018] [Accepted: 11/09/2018] [Indexed: 12/29/2022]
Abstract
The plasma membrane (PM) is the biological membrane that separates the interior of all cells from the outside. The PM is constituted of a huge diversity of proteins and lipids. In this review, we will update the diversity of molecular species of lipids found in plant PM. We will further discuss how lipids govern global properties of the plant PM, explaining that plant lipids are unevenly distributed and are able to organize PM in domains. From that observation, it emerges a complex picture showing a spatial and multiscale segregation of PM components. Finally, we will discuss how lipids are key players in the function of PM in plants, with a particular focus on plant-microbe interaction, transport and hormone signaling, abiotic stress responses, plasmodesmata function. The last chapter is dedicated to the methods that the plant membrane biology community needs to develop to get a comprehensive understanding of membrane organization in plants.
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Affiliation(s)
- Adiilah Mamode Cassim
- Laboratoire de Biogenèse Membranaire (LBM), CNRS, University of Bordeaux, UMR 5200, F-33882 Villenave d'Ornon, France
| | - Paul Gouguet
- Laboratoire de Biogenèse Membranaire (LBM), CNRS, University of Bordeaux, UMR 5200, F-33882 Villenave d'Ornon, France
| | - Julien Gronnier
- Laboratoire de Biogenèse Membranaire (LBM), CNRS, University of Bordeaux, UMR 5200, F-33882 Villenave d'Ornon, France
| | - Nelson Laurent
- Agroécologie, AgroSup Dijon, INRA, University of Bourgogne Franche-Comté, F-21000 Dijon, ERL 6003 CNRS, Dijon, France
| | - Véronique Germain
- Laboratoire de Biogenèse Membranaire (LBM), CNRS, University of Bordeaux, UMR 5200, F-33882 Villenave d'Ornon, France
| | - Magali Grison
- Laboratoire de Biogenèse Membranaire (LBM), CNRS, University of Bordeaux, UMR 5200, F-33882 Villenave d'Ornon, France
| | - Yohann Boutté
- Laboratoire de Biogenèse Membranaire (LBM), CNRS, University of Bordeaux, UMR 5200, F-33882 Villenave d'Ornon, France
| | - Patricia Gerbeau-Pissot
- Agroécologie, AgroSup Dijon, INRA, University of Bourgogne Franche-Comté, F-21000 Dijon, ERL 6003 CNRS, Dijon, France
| | - Françoise Simon-Plas
- Agroécologie, AgroSup Dijon, INRA, University of Bourgogne Franche-Comté, F-21000 Dijon, ERL 6003 CNRS, Dijon, France.
| | - Sébastien Mongrand
- Laboratoire de Biogenèse Membranaire (LBM), CNRS, University of Bordeaux, UMR 5200, F-33882 Villenave d'Ornon, France.
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7
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RIBEYE(B)-domain binds to lipid components of synaptic vesicles in an NAD(H)-dependent, redox-sensitive manner. Biochem J 2017; 474:1205-1220. [PMID: 28202712 DOI: 10.1042/bcj20160886] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2016] [Revised: 02/14/2017] [Accepted: 02/14/2017] [Indexed: 12/26/2022]
Abstract
Synaptic ribbons are needed for fast and continuous exocytosis in ribbon synapses. RIBEYE is a main protein component of synaptic ribbons and is necessary to build the synaptic ribbon. RIBEYE consists of a unique A-domain and a carboxyterminal B-domain, which binds NAD(H). Within the presynaptic terminal, the synaptic ribbons are in physical contact with large numbers of synaptic vesicle (SV)s. How this physical contact between ribbons and synaptic vesicles is established at a molecular level is not well understood. In the present study, we demonstrate that the RIBEYE(B)-domain can directly interact with lipid components of SVs using two different sedimentation assays with liposomes of defined chemical composition. Similar binding results were obtained with a SV-containing membrane fraction. The binding of liposomes to RIBEYE(B) depends upon the presence of a small amount of lysophospholipids present in the liposomes. Interestingly, binding of liposomes to RIBEYE(B) depends on NAD(H) in a redox-sensitive manner. The binding is enhanced by NADH, the reduced form, and is inhibited by NAD+, the oxidized form. Lipid-mediated attachment of vesicles is probably part of a multi-step process that also involves additional, protein-dependent processes.
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8
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Wu H, Bogdanov M, Zhang Y, Sun K, Zhao S, Song A, Luo R, Parchim NF, Liu H, Huang A, Adebiyi MG, Jin J, Alexander DC, Milburn MV, Idowu M, Juneja HS, Kellems RE, Dowhan W, Xia Y. Hypoxia-mediated impaired erythrocyte Lands' Cycle is pathogenic for sickle cell disease. Sci Rep 2016; 6:29637. [PMID: 27436223 PMCID: PMC4951653 DOI: 10.1038/srep29637] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Accepted: 06/17/2016] [Indexed: 02/08/2023] Open
Abstract
Although Lands' cycle was discovered in 1958, its function and cellular regulation in membrane homeostasis under physiological and pathological conditions remain largely unknown. Nonbiased high throughput metabolomic profiling revealed that Lands' cycle was impaired leading to significantly elevated erythrocyte membrane lysophosphatidylcholine (LysoPC) content and circulating and erythrocyte arachidonic acid (AA) in mice with sickle cell disease (SCD), a prevalent hemolytic genetic disorder. Correcting imbalanced Lands' cycle by knockdown of phospholipase 2 (cPLA2) or overexpression of lysophosphatidycholine acyltransferase 1 (LPCAT1), two key enzymes of Lands' cycle in hematopoietic stem cells, reduced elevated erythrocyte membrane LysoPC content and circulating AA levels and attenuated sickling, inflammation and tissue damage in SCD chimeras. Human translational studies validated SCD mouse findings and further demonstrated that imbalanced Lands' cycle induced LysoPC production directly promotes sickling in cultured mouse and human SCD erythrocytes. Mechanistically, we revealed that hypoxia-mediated ERK activation underlies imbalanced Lands' cycle by preferentially inducing the activity of PLA2 but not LPCAT in human and mouse SCD erythrocytes. Overall, our studies have identified a pathological role of imbalanced Lands' cycle in SCD erythrocytes, novel molecular basis regulating Lands' cycle and therapeutic opportunities for the disease.
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Affiliation(s)
- Hongyu Wu
- Department of Biochemistry and Molecular Biology, University of Texas-Medical School, Houston, TX, USA
| | - Mikhail Bogdanov
- Department of Biochemistry and Molecular Biology, University of Texas-Medical School, Houston, TX, USA
| | - Yujin Zhang
- Department of Biochemistry and Molecular Biology, University of Texas-Medical School, Houston, TX, USA
| | - Kaiqi Sun
- Department of Biochemistry and Molecular Biology, University of Texas-Medical School, Houston, TX, USA.,Graduate School of Biomedical Science, University of Texas, Houston, TX, USA
| | - Shushan Zhao
- Department of Biochemistry and Molecular Biology, University of Texas-Medical School, Houston, TX, USA
| | - Anren Song
- Department of Biochemistry and Molecular Biology, University of Texas-Medical School, Houston, TX, USA
| | - Renna Luo
- Department of Biochemistry and Molecular Biology, University of Texas-Medical School, Houston, TX, USA
| | - Nicholas F Parchim
- Department of Biochemistry and Molecular Biology, University of Texas-Medical School, Houston, TX, USA.,Graduate School of Biomedical Science, University of Texas, Houston, TX, USA
| | - Hong Liu
- Department of Biochemistry and Molecular Biology, University of Texas-Medical School, Houston, TX, USA.,Graduate School of Biomedical Science, University of Texas, Houston, TX, USA
| | - Aji Huang
- Department of Biochemistry and Molecular Biology, University of Texas-Medical School, Houston, TX, USA
| | - Morayo G Adebiyi
- Department of Biochemistry and Molecular Biology, University of Texas-Medical School, Houston, TX, USA.,Graduate School of Biomedical Science, University of Texas, Houston, TX, USA
| | - Jianping Jin
- Department of Biochemistry and Molecular Biology, University of Texas-Medical School, Houston, TX, USA
| | | | | | - Modupe Idowu
- Department of Internal Medicine, University of Texas-Medical School, Houston, TX, USA
| | - Harinder S Juneja
- Department of Internal Medicine, University of Texas-Medical School, Houston, TX, USA
| | - Rodney E Kellems
- Department of Biochemistry and Molecular Biology, University of Texas-Medical School, Houston, TX, USA.,Graduate School of Biomedical Science, University of Texas, Houston, TX, USA
| | - William Dowhan
- Department of Biochemistry and Molecular Biology, University of Texas-Medical School, Houston, TX, USA
| | - Yang Xia
- Department of Biochemistry and Molecular Biology, University of Texas-Medical School, Houston, TX, USA.,Graduate School of Biomedical Science, University of Texas, Houston, TX, USA
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9
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Pagliuso A, Valente C, Giordano LL, Filograna A, Li G, Circolo D, Turacchio G, Marzullo VM, Mandrich L, Zhukovsky MA, Formiggini F, Polishchuk RS, Corda D, Luini A. Golgi membrane fission requires the CtBP1-S/BARS-induced activation of lysophosphatidic acid acyltransferase δ. Nat Commun 2016; 7:12148. [PMID: 27401954 PMCID: PMC4945875 DOI: 10.1038/ncomms12148] [Citation(s) in RCA: 214] [Impact Index Per Article: 26.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Accepted: 06/03/2016] [Indexed: 11/25/2022] Open
Abstract
Membrane fission is an essential cellular process by which continuous membranes split into separate parts. We have previously identified CtBP1-S/BARS (BARS) as a key component of a protein complex that is required for fission of several endomembranes, including basolateral post-Golgi transport carriers. Assembly of this complex occurs at the Golgi apparatus, where BARS binds to the phosphoinositide kinase PI4KIIIβ through a 14-3-3γ dimer, as well as to ARF and the PKD and PAK kinases. We now report that, when incorporated into this complex, BARS binds to and activates a trans-Golgi lysophosphatidic acid (LPA) acyltransferase type δ (LPAATδ) that converts LPA into phosphatidic acid (PA); and that this reaction is essential for fission of the carriers. LPA and PA have unique biophysical properties, and their interconversion might facilitate the fission process either directly or indirectly (via recruitment of proteins that bind to PA, including BARS itself).
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Affiliation(s)
- Alessandro Pagliuso
- Institute of Protein Biochemistry, National Research Council, Via Pietro Castellino 111, 80131 Naples, Italy
- Telethon Institute of Genetics and Medicine (TIGEM), Via Campi Flegrei 34, Pozzuoli 80078, Italy
| | - Carmen Valente
- Institute of Protein Biochemistry, National Research Council, Via Pietro Castellino 111, 80131 Naples, Italy
| | - Lucia Laura Giordano
- Institute of Protein Biochemistry, National Research Council, Via Pietro Castellino 111, 80131 Naples, Italy
| | - Angela Filograna
- Institute of Protein Biochemistry, National Research Council, Via Pietro Castellino 111, 80131 Naples, Italy
| | - Guiling Li
- Institute of Protein Biochemistry, National Research Council, Via Pietro Castellino 111, 80131 Naples, Italy
| | - Diego Circolo
- Institute of Protein Biochemistry, National Research Council, Via Pietro Castellino 111, 80131 Naples, Italy
| | - Gabriele Turacchio
- Institute of Protein Biochemistry, National Research Council, Via Pietro Castellino 111, 80131 Naples, Italy
| | - Vincenzo Manuel Marzullo
- IRCCS SDN Istituto di Ricerca Diagnostica e Nucleare, Via Emanuele Gianturco 113, 80143 Naples, Italy
| | - Luigi Mandrich
- Institute of Protein Biochemistry, National Research Council, Via Pietro Castellino 111, 80131 Naples, Italy
| | - Mikhail A. Zhukovsky
- Institute of Protein Biochemistry, National Research Council, Via Pietro Castellino 111, 80131 Naples, Italy
| | - Fabio Formiggini
- Italian Institute of Technology, Centre for Advanced Biomaterials for Health Care at CRIB, Largo Barsanti e Matteucci 53, Naples 80125, Italy
| | - Roman S. Polishchuk
- Telethon Institute of Genetics and Medicine (TIGEM), Via Campi Flegrei 34, Pozzuoli 80078, Italy
| | - Daniela Corda
- Institute of Protein Biochemistry, National Research Council, Via Pietro Castellino 111, 80131 Naples, Italy
| | - Alberto Luini
- Institute of Protein Biochemistry, National Research Council, Via Pietro Castellino 111, 80131 Naples, Italy
- IRCCS SDN Istituto di Ricerca Diagnostica e Nucleare, Via Emanuele Gianturco 113, 80143 Naples, Italy
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10
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Henmi Y, Oe N, Kono N, Taguchi T, Takei K, Tanabe K. Phosphatidic acid induces EHD3-containing membrane tubulation and is required for receptor recycling. Exp Cell Res 2016; 342:1-10. [DOI: 10.1016/j.yexcr.2016.02.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Revised: 12/22/2015] [Accepted: 02/15/2016] [Indexed: 10/22/2022]
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11
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Differential inhibition of host cell cholesterol de novo biosynthesis and processing abrogates Eimeria bovis intracellular development. Parasitol Res 2014; 113:4165-76. [DOI: 10.1007/s00436-014-4092-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Accepted: 08/22/2014] [Indexed: 10/24/2022]
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12
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Acyltransferases and transacylases that determine the fatty acid composition of glycerolipids and the metabolism of bioactive lipid mediators in mammalian cells and model organisms. Prog Lipid Res 2014; 53:18-81. [DOI: 10.1016/j.plipres.2013.10.001] [Citation(s) in RCA: 160] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2012] [Revised: 07/20/2013] [Accepted: 10/01/2013] [Indexed: 12/21/2022]
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13
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Giridharan SSP, Cai B, Vitale N, Naslavsky N, Caplan S. Cooperation of MICAL-L1, syndapin2, and phosphatidic acid in tubular recycling endosome biogenesis. Mol Biol Cell 2013; 24:1776-90, S1-15. [PMID: 23596323 PMCID: PMC3667729 DOI: 10.1091/mbc.e13-01-0026] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
MICAL-L1 and the BAR-domain protein syndapin2 bind to phosphatidic acid (PA), a novel lipid component of recycling endosomes (REs). Interactions between these proteins stabilize their association with membranes and allow nucleation of tubules by syndapin2. A new role is highlighted for PA in recycling, suggesting a mechanism for tubular RE formation. Endocytic transport necessitates the generation of membrane tubules and their subsequent fission to transport vesicles for sorting of cargo molecules. The endocytic recycling compartment, an array of tubular and vesicular membranes decorated by the Eps15 homology domain protein, EHD1, is responsible for receptor and lipid recycling to the plasma membrane. It has been proposed that EHD dimers bind and bend membranes, thus generating recycling endosome (RE) tubules. However, recent studies show that molecules interacting with CasL-Like1 (MICAL-L1), a second, recently identified RE tubule marker, recruits EHD1 to preexisting tubules. The mechanisms and events supporting the generation of tubular recycling endosomes were unclear. Here, we propose a mechanism for the biogenesis of RE tubules. We demonstrate that MICAL-L1 and the BAR-domain protein syndapin2 bind to phosphatidic acid, which we identify as a novel lipid component of RE. Our studies demonstrate that direct interactions between these two proteins stabilize their association with membranes, allowing for nucleation of tubules by syndapin2. Indeed, the presence of phosphatidic acid in liposomes enhances the ability of syndapin2 to tubulate membranes in vitro. Overall our results highlight a new role for phosphatidic acid in endocytic recycling and provide new insights into the mechanisms by which tubular REs are generated.
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14
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Baba T, Yamamoto A, Tagaya M, Tani K. A lysophospholipid acyltransferase antagonist, CI-976, creates novel membrane tubules marked by intracellular phospholipase A1 KIAA0725p. Mol Cell Biochem 2013; 376:151-61. [PMID: 23378048 DOI: 10.1007/s11010-013-1563-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2012] [Accepted: 01/18/2013] [Indexed: 01/30/2023]
Abstract
CI-976 is a lysophospholipid acyltransferase antagonist that is known to affect secretory and endocytic membrane-trafficking pathways likely by increasing the lysophospholipid content in membranes. Our previous study suggested that lysophospholipids formed through the action of an intracellular phospholipase A(1), KIAA0725p (also known as DDHD2 and iPLA(1)γ), may be important for the association of this enzyme with membranes. In this study, we examined the effect of CI-976 on the membrane association of KIAA0725p. While in HeLa cells KIAA0725p is localized in the Golgi and cytosol, in mouse embryonic fibroblasts (MEFs), it was found to be principally localized in the cytosol with some on post-endoplasmic reticulum compartments including the cis-Golgi. Treatment of MEFs with CI-976 induced the redistribution of KIAA0725p to membrane tubules, which were in vicinity to fragmented mitochondria. These tubules were not decorated with canonical organelle markers including Golgi proteins. A human KIAA0725p mutant, which exhibits decreased membrane-binding ability, was also redistributed to membrane structures upon CI-976 treatment. Our data suggest that the association of KIAA0725p with membranes is regulated by lipid metabolism, and that CI-976 may create unique membrane structures that can be marked by KIAA0725p.
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Affiliation(s)
- Takashi Baba
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo, Japan
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15
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Modular organization of the mammalian Golgi apparatus. Curr Opin Cell Biol 2012; 24:467-74. [PMID: 22726585 DOI: 10.1016/j.ceb.2012.05.009] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2012] [Accepted: 05/29/2012] [Indexed: 02/07/2023]
Abstract
The Golgi apparatus is essential for post-translational modifications and sorting of proteins in the secretory pathway. In addition, it further performs a broad range of specialized functions. This functional diversity is achieved by combining basic morphological modules of cisternae into higher ordered structures. Linking cisternae into stacks that are further connected through tubules into a continuous Golgi ribbon greatly increases its efficiency and expands its repertoire of functions. During cell division, the different modules of the Golgi are inherited by different mechanisms to maintain its functional and morphological composition.
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16
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Regulation of the Golgi complex by phospholipid remodeling enzymes. Biochim Biophys Acta Mol Cell Biol Lipids 2012; 1821:1078-88. [PMID: 22562055 DOI: 10.1016/j.bbalip.2012.04.004] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2011] [Revised: 03/15/2012] [Accepted: 04/13/2012] [Indexed: 11/23/2022]
Abstract
The mammalian Golgi complex is a highly dynamic organelle consisting of stacks of flattened cisternae with associated coated vesicles and membrane tubules that contribute to cargo import and export, intra-cisternal trafficking, and overall Golgi architecture. At the morphological level, all of these structures are continuously remodeled to carry out these trafficking functions. Recent advances have shown that continual phospholipid remodeling by phospholipase A (PLA) and lysophospholipid acyltransferase (LPAT) enzymes, which deacylate and reacylate Golgi phospholipids, respectively, contributes to this morphological remodeling. Here we review the identification and characterization of four cytoplasmic PLA enzymes and one integral membrane LPAT that participate in the dynamic functional organization of the Golgi complex, and how some of these enzymes are integrated to determine the relative abundance of COPI vesicle and membrane tubule formation. This article is part of a Special Issue entitled Lipids and Vesicular Transport.
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17
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Cai B, Caplan S, Naslavsky N. cPLA2α and EHD1 interact and regulate the vesiculation of cholesterol-rich, GPI-anchored, protein-containing endosomes. Mol Biol Cell 2012; 23:1874-88. [PMID: 22456504 PMCID: PMC3350552 DOI: 10.1091/mbc.e11-10-0881] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
cPLA2 hydrolyzes phospholipids and regulates membrane curvature and/or tubulation. Despite disparate roles for cPLA2 at the Golgi and early endosomes, its function in the regulation of membranes containing GPI-anchored proteins is not known. A role for cPLA2α and EHD1 is identified in the vesiculation of cholesterol-rich, GPI-AP–containing membranes. The lipid modifier phospholipase A2 catalyzes the hydrolysis of phospholipids to inverted-cone–shaped lysophospholipids that contribute to membrane curvature and/or tubulation. Conflicting findings exist regarding the function of cytosolic phospholipase A2 (cPLA2) and its role in membrane regulation at the Golgi and early endosomes. However, no studies addressed the role of cPLA2 in the regulation of cholesterol-rich membranes that contain glycosylphosphatidylinositol-anchored proteins (GPI-APs). Our studies support a role for cPLA2α in the vesiculation of GPI-AP–containing membranes, using endogenous CD59 as a model for GPI-APs. On cPLA2α depletion, CD59-containing endosomes became hypertubular. Moreover, accumulation of lysophospholipids induced by a lysophospholipid acyltransferase inhibitor extensively vesiculated CD59-containing endosomes. However, overexpression of cPLA2α did not increase the endosomal vesiculation, implying a requirement for additional factors. Indeed, depletion of the “pinchase” EHD1, a C-terminal Eps15 homology domain (EHD) ATPase, also induced hypertubulation of CD59-containing endosomes. Furthermore, EHD1 and cPLA2α demonstrated in situ proximity (<40 nm) and interacted in vivo. The results presented here provide evidence that the lipid modifier cPLA2α and EHD1 are involved in the vesiculation of CD59-containing endosomes. We speculate that cPLA2α induces membrane curvature and allows EHD1, possibly in the context of a complex, to sever the curved membranes into vesicles.
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Affiliation(s)
- Bishuang Cai
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE 68198, USA
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18
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Abstract
Ribbon synapses continuously transmit graded membrane potential changes into changes of synaptic vesicle exocytosis and rely on intense synaptic membrane trafficking. The synaptic ribbon is considered central to this process. In the present study we asked whether tonically active ribbon synapses are associated with the generation of certain lipids, specifically the highly active signaling phospholipid phosphatidic acid (PA). Using PA-sensor proteins, we demonstrate that PA is enriched at mouse retinal ribbon synapses in close vicinity to the synaptic ribbon in situ. As shown by heterologous expression, RIBEYE, a main component of synaptic ribbons, is responsible for PA binding at synaptic ribbons. Furthermore, RIBEYE is directly involved in the synthesis of PA. Using various independent substrate binding and enzyme assays, we demonstrate that the B domain of RIBEYE possesses lysophosphatidic acid (LPA) acyltransferase (LPAAT) activity, which leads to the generation of PA from LPA. Since an LPAAT-deficient RIBEYE mutant does not recruit PA-binding proteins to artificial synaptic ribbons, whereas wild-type RIBEYE supports PA binding, we conclude that the LPAAT activity of the RIBEYE(B) domain is a physiologically relevant source of PA generation at the synaptic ribbon. We propose that PA generated at synaptic ribbons likely facilitates synaptic vesicle trafficking.
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19
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COPI acts in both vesicular and tubular transport. Nat Cell Biol 2011; 13:996-1003. [PMID: 21725317 PMCID: PMC3149785 DOI: 10.1038/ncb2273] [Citation(s) in RCA: 93] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2010] [Accepted: 05/04/2011] [Indexed: 12/20/2022]
Abstract
Intracellular transport occurs through two general types of carrier, either vesicles or tubules. Coat proteins act as the core machinery that initiates vesicle formation, but the counterpart that initiates tubule formation has been unclear. Here, we find that the coat protein I (COPI) complex initially drives the formation of Golgi buds. Subsequently, a set of opposing lipid enzymatic activities determines whether these buds become vesicles or tubules. Lysophosphatidic acid acyltransferase-γ (LPAATγ) promotes COPI vesicle fission for retrograde vesicular transport. In contrast, cytosolic phospholipase A2-α (cPLA2α) inhibits this fission event to induce COPI tubules, which act in anterograde intra-Golgi transport and Golgi ribbon formation. These findings not only advance a molecular understanding of how COPI vesicle fission is achieved, but also provide insight into how COPI acts in intra-Golgi transport and reveal an unexpected mechanistic relationship between vesicular and tubular transport.
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20
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Lee SH, Schneider C, Higdon AN, Darley-Usmar VM, Chung CY. Role of iPLA(2) in the regulation of Src trafficking and microglia chemotaxis. Traffic 2011; 12:878-89. [PMID: 21438970 DOI: 10.1111/j.1600-0854.2011.01195.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Microglia are immune effector cells in the central nervous system (CNS) and their activation, migration and proliferation play crucial roles in brain injuries and diseases. We examined the role of intracellular Ca(2+) -independent phospholipase A(2) (iPLA(2)) in the regulation of microglia chemotaxis toward ADP. Inhibition of iPLA(2) by 4-bromoenol lactone (BEL) or iPLA(2) knockdown exerted a significant inhibition on phosphatidylinositol-3-kinase (PI3K) activation and chemotaxis. Further examination revealed that iPLA(2) knockdown abrogated Src activation, which is required for PI3K activation and chemotaxis. Colocalization studies showed that cSrc-GFP was retained in the endosomal recycling compartment (ERC) in iPLA(2) knockdown cells, but the addition of arachidonic acid (AA) could restore cSrc trafficking to the plasma membrane by allowing the formation/release of recycling endosomes associated with cSrc-GFP. Using BODIPY-AA, we showed that AA is selectively enriched in recycling endosomes. These results suggest that AA is required for the cSrc trafficking to the plasma membrane by controlling the formation/release of recycling endosomes from the ERC.
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Affiliation(s)
- Sang-Hyun Lee
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37232-6600, USA
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21
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Ouellette SP, Carabeo RA. A Functional Slow Recycling Pathway of Transferrin is Required for Growth of Chlamydia. Front Microbiol 2010; 1:112. [PMID: 21607082 PMCID: PMC3095398 DOI: 10.3389/fmicb.2010.00112] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2010] [Accepted: 09/10/2010] [Indexed: 01/11/2023] Open
Abstract
An inhibitor of host cell lysophospholipid acyltransferase, an enzyme involved in lipid metabolism blocked growth of the obligate intracellular pathogen Chlamydia through its action on the transport of transferrin (Tf) via the slow pathway of recycling. A detailed characterization of this inhibition revealed that Tf accumulated in vesicles positive for Rab11, with a concomitant reduction in the level of Tf found within the transport intermediate Rab4/11 hybrid vesicles. The net result was the failure to be recycled to the plasma membrane. In chlamydiae-infected cells, the Tf-containing Rab11-positive vesicles were typically found intimately associated with the inclusion, and treatment with the inhibitor caused their accumulation, suggesting that the timely progression and completion of Tf recycling was necessary for proper chlamydial growth. Growth inhibition by the compound could be negated by the simple removal of the Tf-containing fraction of the serum, a further indication that accumulation of Tf around the chlamydial inclusion was deleterious to the pathogen. Thus, it appears that manipulating the slow recycling pathway can have biological consequences for Chlamydia and implies the need to regulate carefully the interaction of the inclusion with this host trafficking pathway.
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Affiliation(s)
- Scot P Ouellette
- Centre for Molecular Microbiology and Infection, Division of Cell and Molecular Biology, Imperial College London London, UK
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22
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Membrane topology of human AGPAT3 (LPAAT3). Biochem Biophys Res Commun 2010; 397:661-7. [PMID: 20537980 DOI: 10.1016/j.bbrc.2010.05.149] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2010] [Accepted: 05/27/2010] [Indexed: 11/21/2022]
Abstract
Integral membrane lysophospholipid acyltransferases (AT) are involved in many reactions that produce phospholipids and triglycerides. Enzymes that utilize lysophosphatidic acid (LPA) as an acceptor substrate have been termed LPAATs, and several are members of the 1-acylglycerol-3-phosphate O-acyltransferase (AGPAT) gene family. Amino acid sequence comparisons with other acyltransferases reveal that AGPATs contain four conserved motifs (I-IV), whose invariant residues appear to be important for catalysis and/or substrate recognition. Although the enzymatic activities of many AGPATs are known, for many members their structural organization within membranes and their exact biological functions are unclear. Recently, a new function for AGPATs was discovered when it was determined that human AGPAT3/LPAAT3 is involved in the structure and function of the Golgi complex. Here we have determined the topological orientation of human AGPAT3/LPAAT3. AGPAT3/LPAAT3 possesses two transmembrane domains, one of which separates motifs I and II, which are thought to form a functional unit that is critical for enzymatic activity. This is a surprising result but similar to a recent study on the topology of human LPAAT 1. The data is consistent with a structural arrangement in which motif I is located in the cytoplasm and motif II is in the endoplasmic reticulum and Golgi lumen, suggesting a different model for AGPAT3/LPAAT3's enzymatic mechanism.
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23
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Abstract
The role of lipid metabolic enzymes in Golgi membrane remodeling is a subject of intense interest. Now, in this issue, Schmidt and Brown (2009. J. Cell Biol. doi:10.1083/jcb.200904147) report that lysophosphatidic acid-specific acyltransferase, LPAAT3, contributes to Golgi membrane dynamics by suppressing tubule formation.
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Affiliation(s)
- Vytas A Bankaitis
- Department of Cell and Developmental Biology, Lineberger Comprehensive Cancer Center, University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA.
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24
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Schmidt JA, Brown WJ. Lysophosphatidic acid acyltransferase 3 regulates Golgi complex structure and function. ACTA ACUST UNITED AC 2009; 186:211-8. [PMID: 19635840 PMCID: PMC2717635 DOI: 10.1083/jcb.200904147] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Recent studies have suggested that the functional organization of the Golgi complex is dependent on phospholipid remodeling enzymes. Here, we report the identification of an integral membrane lysophosphatidic acid–specific acyltransferase, LPAAT3, which regulates Golgi membrane tubule formation, trafficking, and structure by altering phospholipids and lysophospholipids. Overexpression of LPAAT3 significantly inhibited the formation of Golgi membrane tubules in vivo and in vitro. Anterograde and retrograde protein trafficking was slower in cells overexpressing LPAAT3 and accelerated in cells with reduced expression (by siRNA). Golgi morphology was also dependent on LPAAT3 because its knockdown caused the Golgi to become fragmented. These data are the first to show a direct role for a specific phospholipid acyltransferase in regulating membrane trafficking and organelle structure.
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Affiliation(s)
- John A Schmidt
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA
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25
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Morikawa RK, Aoki J, Kano F, Murata M, Yamamoto A, Tsujimoto M, Arai H. Intracellular phospholipase A1gamma (iPLA1gamma) is a novel factor involved in coat protein complex I- and Rab6-independent retrograde transport between the endoplasmic reticulum and the Golgi complex. J Biol Chem 2009; 284:26620-30. [PMID: 19632984 DOI: 10.1074/jbc.m109.038869] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The mammalian intracellular phospholipase A(1) (iPLA(1)) family consists of three members, iPLA(1)alpha/PA-PLA(1), iPLA(1)beta/p125, and iPLA(1)gamma/KIAA0725p. Although iPLA(1)beta has been implicated in organization of the ER-Golgi compartments, little is known about the physiological role of its closest paralog, iPLA(1)gamma. Here we show that iPLA(1)gamma mediates a specific retrograde membrane transport pathway between the endoplasmic reticulum (ER) and the Golgi complex. iPLA(1)gamma appeared to be localized to the cytosol, the cis-Golgi, and the ER-Golgi intermediate compartment (ERGIC). Time-lapse microscopy revealed that a population of GFP-iPLA(1)gamma was associated with transport carriers moving out from the Golgi complex. Knockdown of iPLA(1)gamma expression by RNAi did not affect the anterograde transport of VSVGts045 but dramatically delayed two types of Golgi-to-ER retrograde membrane transport; that is, transfer of the Golgi membrane into the ER in the presence of brefeldin A and delivery of cholera toxin B subunit from the Golgi complex to the ER. Notably, knockdown of iPLA(1)gamma did not impair COPI- and Rab6-dependent retrograde transports represented by ERGIC-53 recycling and ER delivery of Shiga toxin, respectively. Thus, iPLA(1)gamma is a novel membrane transport factor that contributes to a specific Golgi-to-ER retrograde pathway distinct from presently characterized COPI- and Rab6-dependent pathways.
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Affiliation(s)
- Rei K Morikawa
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
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26
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Geiser DL, Shen MC, Mayo JJ, Winzerling JJ. Iron loaded ferritin secretion and inhibition by CI-976 in Aedes aegypti larval cells. Comp Biochem Physiol B Biochem Mol Biol 2009; 152:352-63. [PMID: 19168145 PMCID: PMC2649984 DOI: 10.1016/j.cbpb.2009.01.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2008] [Revised: 01/01/2009] [Accepted: 01/03/2009] [Indexed: 12/26/2022]
Abstract
Ferritin is a multimer of 24 subunits of heavy and light chains. In mammals, iron taken into cells is stored in ferritin or incorporated into iron-containing proteins. Very little ferritin is found circulating in mammalian serum; most is retained in the cytoplasm. Female mosquitoes, such as Aedes aegypti (yellow fever mosquito, Diptera), require a blood meal for oogenesis. Mosquitoes receive a potentially toxic level of iron in the blood meal which must be processed and stored. We demonstrate by (59)Fe pulse-chase experiments that cultured A. aegypti larval CCL-125 cells take up iron from culture media and store it in ferritin found mainly in the membrane fraction and secrete iron-loaded ferritin. We observe that in these larval cells ferritin co-localizes with ceramide-containing membranes in the absence of iron. With iron treatment, ferritin is found associated with ceramide-containing membranes as well as in cytoplasmic non-ceramide vesicles. Treatment of CCL-125 cells with iron and CI-976, an inhibitor of lysophospholipid acyl transferases, disrupts ferritin secretion with a concomitant decrease in cell viability. Interfering with ferritin secretion may limit the ability of mosquitoes to adjust to the high iron load of the blood meal and decrease iron delivery to the ovaries reducing egg numbers.
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Affiliation(s)
- Dawn L Geiser
- Department of Nutritional Sciences, The University of Arizona, Tucson, 85721, USA.
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27
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Jackson SK, Abate W, Tonks AJ. Lysophospholipid acyltransferases: novel potential regulators of the inflammatory response and target for new drug discovery. Pharmacol Ther 2008; 119:104-14. [PMID: 18538854 DOI: 10.1016/j.pharmthera.2008.04.001] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Molecular and biochemical analyses of membrane phospholipids have revealed that, in addition to their physico-chemical properties, the metabolites of phospholipids play a crucial role in the recognition, signalling and responses of cells to a variety of stimuli. Such responses are mediated in large part by the removal and/or addition of different acyl chains to provide different phospholipid molecular species. The reacylation reactions, catalysed by specific acyltransferases control phospholipid composition and the availability of the important mediators free arachidonic acid and lysophospholipids. Lysophospholipid acyltransferases are therefore key control points for cellular responses to a variety of stimuli including inflammation. Regulation or manipulation of lysophospholipid acyltransferases may thus provide important mechanisms for novel anti-inflammatory therapies. This review will highlight mammalian lysophospholipid acyltransferases with particular reference to the potential role of lysophosphatidylcholine acyltransferase and its substrates in sepsis and other inflammatory conditions and as a potential target for novel anti-inflammatory therapies.
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Affiliation(s)
- Simon K Jackson
- Centre for Research in Biomedicine, Faculty of Health and Life Sciences, Frenchay Campus, University of the West of England, Bristol, UK.
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28
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Jackson SK, Abate W, Parton J, Jones S, Harwood JL. Lysophospholipid metabolism facilitates Toll-like receptor 4 membrane translocation to regulate the inflammatory response. J Leukoc Biol 2008; 84:86-92. [PMID: 18403647 DOI: 10.1189/jlb.0907601] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Sepsis, an overwhelming inflammatory response to infection, is a major cause of morbidity and mortality worldwide and has no specific therapy. Phospholipid metabolites, such as lysophospholipids, have been shown to regulate inflammatory responses in sepsis, although their mechanism of action is not well understood. The phospholipid-metabolizing enzymes, lysophospholipid acyltransferases, control membrane phospholipid composition, function, and the inflammatory responses of innate immune cells. Here, we show that lysophosphatidylcholine acyltransferase (LPCAT) regulates inflammatory responses to LPS and other microbial stimuli. Specific inhibition of LPCAT down-regulated inflammatory cytokine production in monocytes and epithelial cells by preventing translocation of TLR4 into membrane lipid raft domains. Our observations demonstrate a new regulatory mechanism that facilitates the innate immune responses to microbial molecular patterns and provide a basis for the anti-inflammatory activity observed in many phospholipid metabolites. This provides the possibility of the development of new classes of anti-inflammatory and antisepsis agents.
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Affiliation(s)
- Simon K Jackson
- Centre for Research in Biomedicine, University of the West of England, Bristol, BS16 1QY, UK.
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29
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Larsen MK, Tuck S, Færgeman NJ, Knudsen J. MAA-1, a novel acyl-CoA-binding protein involved in endosomal vesicle transport in Caenorhabditis elegans. Mol Biol Cell 2006; 17:4318-29. [PMID: 16870706 PMCID: PMC1635345 DOI: 10.1091/mbc.e06-01-0035] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
The budding and fission of vesicles during membrane trafficking requires many proteins, including those that coat the vesicles, adaptor proteins that recruit components of the coat, and small GTPases that initiate vesicle formation. In addition, vesicle formation in vitro is promoted by the hydrolysis of acyl-CoA lipid esters. The mechanisms by which these lipid esters are directed to the appropriate membranes in vivo, and their precise roles in vesicle biogenesis, are not yet understood. Here, we present the first report on membrane associated ACBP domain-containing protein-1 (MAA-1), a novel membrane-associated member of the acyl-CoA-binding protein family. We show that in Caenorhabditis elegans, MAA-1 localizes to intracellular membrane organelles in the secretory and endocytic pathway and that mutations in maa-1 reduce the rate of endosomal recycling. A lack of maa-1 activity causes a change in endosomal morphology. Although in wild type, many endosomal organelles have long tubular protrusions, loss of MAA-1 activity results in loss of the tubular domains, suggesting the maa-1 is required for the generation or maintenance of these domains. Furthermore, we demonstrate that MAA-1 binds fatty acyl-CoA in vitro and that this ligand-binding ability is important for its function in vivo. Our results are consistent with a role for MAA-1 in an acyl-CoA-dependent process during vesicle formation.
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Affiliation(s)
- Morten K. Larsen
- *Department of Biochemistry and Molecular Biology, University of Southern Denmark, 5230 Odense M, Denmark; and
- Umeå Center for Molecular Pathogenesis, Umeå University, Umeå, SE-90187, Sweden
| | - Simon Tuck
- Umeå Center for Molecular Pathogenesis, Umeå University, Umeå, SE-90187, Sweden
| | - Nils J. Færgeman
- *Department of Biochemistry and Molecular Biology, University of Southern Denmark, 5230 Odense M, Denmark; and
| | - Jens Knudsen
- *Department of Biochemistry and Molecular Biology, University of Southern Denmark, 5230 Odense M, Denmark; and
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Brown WJ, Schmidt JA. Use of Acyltransferase Inhibitors to Block Vesicular Traffic Between the ER and Golgi Complex. Methods Enzymol 2005; 404:115-25. [PMID: 16413263 DOI: 10.1016/s0076-6879(05)04012-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
This article describes the use of acyltransferase inhibitors as probes for studying the potential role of lysophospholipid acyltransferases (LPAT) in intracellular membrane trafficking in the secretory and endocytic pathways. The small molecule inhibitors that are described here were originally found as acyl-CoA:cholesterol acyltransferase (ACAT) inhibitors. One of these, CI-976 (2,2-methyl-N-(2,4,6,-trimethoxyphenyl)dodecanamide), was also found to be a potent LPAT inhibitor. CI-976 is a small, hydrophobic, membrane-permeant compound and both in vivo and in vitro studies have shown that it, but not other ACAT inhibitors, has a profound effect on multiple membrane trafficking pathways in eukaryotic cells including: (1) inhibition of COPII vesicle budding from the endoplasmic reticulum (ER), (2) inhibition of transferrin and transferrin receptor export from the endocytic recycling compartment, and (3) stimulation of tubule-mediated retrograde trafficking of Golgi membranes to the ER. Here we describe the use of CI-976 and other ACAT inhibitors for studies with both cultured mammalian cells and in vitro reconstitution assays, with a particular emphasis on COPII vesicle budding from the ER. All of these studies strongly suggest that CI-976-sensitive LPATs play a role in coated vesicle fission, and therefore, CI-976 is a valuable addition to the arsenal of small molecule inhibitors that can be used to study secretory and endocytic membrane trafficking pathways.
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Affiliation(s)
- William J Brown
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York, USA
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