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Kundu S, Rohokale R, Lin C, Chen S, Biswas S, Guo Z. Bifunctional glycosphingolipid (GSL) probes to investigate GSL-interacting proteins in cell membranes. J Lipid Res 2024; 65:100570. [PMID: 38795858 DOI: 10.1016/j.jlr.2024.100570] [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: 03/19/2024] [Revised: 05/03/2024] [Accepted: 05/04/2024] [Indexed: 05/28/2024] Open
Abstract
Glycosphingolipids (GSLs) are abundant glycolipids on cells and essential for cell recognition, adhesion, signal transduction, and so on. However, their lipid anchors are not long enough to cross the membrane bilayer. To transduce transmembrane signals, GSLs must interact with other membrane components, whereas such interactions are difficult to investigate. To overcome this difficulty, bifunctional derivatives of II3-β-N-acetyl-D-galactosamine-GA2 (GalNAc-GA2) and β-N-acetyl-D-glucosamine-ceramide (GlcNAc-Cer) were synthesized as probes to explore GSL-interacting membrane proteins in live cells. Both probes contain photoreactive diazirine in the lipid moiety, which can crosslink with proximal membrane proteins upon photoactivation, and clickable alkyne in the glycan to facilitate affinity tag addition for crosslinked protein pull-down and characterization. The synthesis is highlighted by the efficient assembly of simple glycolipid precursors followed by on-site lipid remodeling. These probes were employed to profile GSL-interacting membrane proteins in HEK293 cells. The GalNAc-GA2 probe revealed 312 distinct proteins, with GlcNAc-Cer probe-crosslinked proteins as controls, suggesting the potential influence of the glycan on GSL functions. Many of the proteins identified with the GalNAc-GA2 probe are associated with GSLs, and some have been validated as being specific to this probe. The versatile probe design and experimental protocols are anticipated to be widely applicable to GSL research.
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Affiliation(s)
- Sayan Kundu
- Department of Chemistry, University of Florida, Gainesville, FL, USA
| | - Rajendra Rohokale
- Department of Chemistry, University of Florida, Gainesville, FL, USA
| | - Chuwei Lin
- Department of Biology, Genetics Institute, University of Florida, Gainesville, FL, USA
| | - Sixue Chen
- Department of Biology, Genetics Institute, University of Florida, Gainesville, FL, USA; Department of Biology, University of Mississippi, Oxford, MS, USA
| | - Shayak Biswas
- Department of Chemistry, University of Florida, Gainesville, FL, USA
| | - Zhongwu Guo
- Department of Chemistry, University of Florida, Gainesville, FL, USA.
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Total Chemical Synthesis of LC3A and LC3B Activity-Based Probes. Biomedicines 2023; 11:biomedicines11030884. [PMID: 36979862 PMCID: PMC10045837 DOI: 10.3390/biomedicines11030884] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 03/08/2023] [Accepted: 03/09/2023] [Indexed: 03/17/2023] Open
Abstract
Autophagy is a conserved cellular process involved in the degradation of intercellular materials. During this process, double-membrane vesicles called autophagosomes engulf cytoplasmic components ready for degradation. A key component in the formation of autophagosomes are the autophagy-related (Atg) proteins, including microtubule-associated protein light chain 3A (LC3A) and 3B (LC3B). After the C-terminus of LC3 is conjugated to a phospholipid, it promotes the elongation of the phagosome and provides a docking station for the delivery of proteins ready for degradation. Since dysregulation of the autophagy pathway has been associated with a variety of human diseases, components of this process have been considered as potential therapeutic targets. However, the mechanistic details of LC3-specific ligases and deconjugation enzymes are far from unraveled and chemical tools for activity profiling could aid in affording more insights into this process. Herein, we describe a native chemical ligation approach for the synthesis of two LC3 activity-based probes (ABPs). Initial studies show that the probes covalently interact with the cysteine protease ATG4B, showcasing the potential of these probes to unravel mechanistic and structural details.
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Nguyen TTM, Munkhzul C, Kim J, Kyoung Y, Vianney M, Shin S, Ju S, Pham-Bui HA, Kim J, Kim JS, Lee M. In vivo profiling of the Zucchini proximal proteome in the Drosophila ovary. Development 2023; 150:286990. [PMID: 36762624 DOI: 10.1242/dev.201220] [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: 08/23/2022] [Accepted: 01/24/2023] [Indexed: 02/11/2023]
Abstract
PIWI-interacting RNAs (piRNAs) are small RNAs that play a conserved role in genome defense. The piRNA processing pathway is dependent on the sequestration of RNA precursors and protein factors in specific subcellular compartments. Therefore, a highly resolved spatial proteomics approach can help identify the local interactions and elucidate the unknown aspects of piRNA biogenesis. Herein, we performed TurboID proximity labeling to investigate the interactome of Zucchini (Zuc), a key factor of piRNA biogenesis in germline cells and somatic follicle cells of the Drosophila ovary. Quantitative mass spectrometry analysis of biotinylated proteins defined the Zuc-proximal proteome, including the well-known partners of Zuc. Many of these were enriched in the outer mitochondrial membrane (OMM), where Zuc was specifically localized. The proximal proteome of Zuc showed a distinct set of proteins compared with that of Tom20, a representative OMM protein, indicating that chaperone function-related and endomembrane system/vesicle transport proteins are previously unreported interacting partners of Zuc. The functional relevance of several candidates in piRNA biogenesis was validated by derepression of transposable elements after knockdown. Our results present potential Zuc-interacting proteins, suggesting unrecognized biological processes.
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Affiliation(s)
- Thi Thanh My Nguyen
- Soonchunhyang Institute of Medi-bio Science, Soonchunhyang University, Cheonan 31151, Korea
| | - Choijamts Munkhzul
- Soonchunhyang Institute of Medi-bio Science, Soonchunhyang University, Cheonan 31151, Korea
- Department of Integrated Biomedical Science, Soonchunhyang University, Cheonan 31151, Korea
| | - Jeesoo Kim
- Center for RNA Research, Institute for Basic Science, Seoul 08826, Korea
- School of Biological Sciences, Seoul National University, Seoul 08826, Korea
| | - Yeonju Kyoung
- Center for RNA Research, Institute for Basic Science, Seoul 08826, Korea
- School of Biological Sciences, Seoul National University, Seoul 08826, Korea
| | - Michele Vianney
- Soonchunhyang Institute of Medi-bio Science, Soonchunhyang University, Cheonan 31151, Korea
- Department of Integrated Biomedical Science, Soonchunhyang University, Cheonan 31151, Korea
| | - Sanghee Shin
- Center for RNA Research, Institute for Basic Science, Seoul 08826, Korea
- School of Biological Sciences, Seoul National University, Seoul 08826, Korea
| | - Seonmin Ju
- Center for RNA Research, Institute for Basic Science, Seoul 08826, Korea
- School of Biological Sciences, Seoul National University, Seoul 08826, Korea
| | - Hoang-Anh Pham-Bui
- Soonchunhyang Institute of Medi-bio Science, Soonchunhyang University, Cheonan 31151, Korea
- Department of Integrated Biomedical Science, Soonchunhyang University, Cheonan 31151, Korea
| | - Junhyung Kim
- Soonchunhyang Institute of Medi-bio Science, Soonchunhyang University, Cheonan 31151, Korea
- Department of Integrated Biomedical Science, Soonchunhyang University, Cheonan 31151, Korea
| | - Jong-Seo Kim
- Center for RNA Research, Institute for Basic Science, Seoul 08826, Korea
- School of Biological Sciences, Seoul National University, Seoul 08826, Korea
| | - Mihye Lee
- Soonchunhyang Institute of Medi-bio Science, Soonchunhyang University, Cheonan 31151, Korea
- Department of Integrated Biomedical Science, Soonchunhyang University, Cheonan 31151, Korea
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Serrano-López EM, Coronado-Parra T, Marín-Vicente C, Szallasi Z, Gómez-Abellán V, López-Andreo MJ, Gragera M, Gómez-Fernández JC, López-Nicolás R, Corbalán-García S. Deciphering the Role and Signaling Pathways of PKCα in Luminal A Breast Cancer Cells. Int J Mol Sci 2022; 23:ijms232214023. [PMID: 36430510 PMCID: PMC9696894 DOI: 10.3390/ijms232214023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2022] [Revised: 10/11/2022] [Accepted: 10/26/2022] [Indexed: 11/16/2022] Open
Abstract
Protein kinase C (PKC) comprises a family of highly related serine/threonine protein kinases involved in multiple signaling pathways, which control cell proliferation, survival, and differentiation. The role of PKCα in cancer has been studied for many years. However, it has been impossible to establish whether PKCα acts as an oncogene or a tumor suppressor. Here, we analyzed the importance of PKCα in cellular processes such as proliferation, migration, or apoptosis by inhibiting its gene expression in a luminal A breast cancer cell line (MCF-7). Differential expression analysis and phospho-kinase arrays of PKCα-KD vs. PKCα-WT MCF-7 cells identified an essential set of proteins and oncogenic kinases of the JAK/STAT and PI3K/AKT pathways that were down-regulated, whereas IGF1R, ERK1/2, and p53 were up-regulated. In addition, unexpected genes related to the interferon pathway appeared down-regulated, while PLC, ERBB4, or PDGFA displayed up-regulated. The integration of this information clearly showed us the usefulness of inhibiting a multifunctional kinase-like PKCα in the first step to control the tumor phenotype. Then allowing us to design a possible selection of specific inhibitors for the unexpected up-regulated pathways to further provide a second step of treatment to inhibit the proliferation and migration of MCF-7 cells. The results of this study suggest that PKCα plays an oncogenic role in this type of breast cancer model. In addition, it reveals the signaling mode of PKCα at both gene expression and kinase activation. In this way, a wide range of proteins can implement a new strategy to fine-tune the control of crucial functions in these cells and pave the way for designing targeted cancer therapies.
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Affiliation(s)
- Emilio M. Serrano-López
- Department of Biochemistry and Molecular Biology A, Veterinary School, Universidad de Murcia, CEIR Campus Mare Nostrum (CMN), 30100 Murcia, Spain
- Instituto Murciano de Investigación Biosanitaria IMIB-Arrixaca, El Palmar, 30120 Murcia, Spain
| | - Teresa Coronado-Parra
- Department of Biochemistry and Molecular Biology A, Veterinary School, Universidad de Murcia, CEIR Campus Mare Nostrum (CMN), 30100 Murcia, Spain
- Microscopy Core Unit, Área Científica y Técnica de Investigación, Universidad de Murcia, 30100 Murcia, Spain
| | - Consuelo Marín-Vicente
- Department of Biochemistry and Molecular Biology A, Veterinary School, Universidad de Murcia, CEIR Campus Mare Nostrum (CMN), 30100 Murcia, Spain
- Cardiovascular Proteomics and Developmental Biology Program, Centro Nacional de Investigaciones Cardiovasculares (CNIC), 28029 Madrid, Spain
| | - Zoltan Szallasi
- Computational Health Informatics Program, Boston Children’s Hospital, Harvard Medical School, Boston, MA 02115, USA
- Department of Bioinformatics, Semmelweis University, H-1092 Budapest, Hungary
| | - Victoria Gómez-Abellán
- Department of Biochemistry and Molecular Biology A, Veterinary School, Universidad de Murcia, CEIR Campus Mare Nostrum (CMN), 30100 Murcia, Spain
- Department of Cellular Biology and Histology, Biology School, Universidad de Murcia, CEIR Campus Mare Nostrum (CMN), 30100 Murcia, Spain
| | - María José López-Andreo
- Department of Biochemistry and Molecular Biology A, Veterinary School, Universidad de Murcia, CEIR Campus Mare Nostrum (CMN), 30100 Murcia, Spain
- Molecular Biology Unit, Área Científica y Técnica de Investigación, Universidad de Murcia, 30100 Murcia, Spain
| | - Marcos Gragera
- Department of Biochemistry and Molecular Biology A, Veterinary School, Universidad de Murcia, CEIR Campus Mare Nostrum (CMN), 30100 Murcia, Spain
- Centro Nacional Biotecnología, Consejo Superior de Investigaciones Científicas, 28006 Madrid, Spain
| | - Juan C. Gómez-Fernández
- Department of Biochemistry and Molecular Biology A, Veterinary School, Universidad de Murcia, CEIR Campus Mare Nostrum (CMN), 30100 Murcia, Spain
- Instituto Murciano de Investigación Biosanitaria IMIB-Arrixaca, El Palmar, 30120 Murcia, Spain
| | - Rubén López-Nicolás
- Department of Biochemistry and Molecular Biology A, Veterinary School, Universidad de Murcia, CEIR Campus Mare Nostrum (CMN), 30100 Murcia, Spain
- Instituto Murciano de Investigación Biosanitaria IMIB-Arrixaca, El Palmar, 30120 Murcia, Spain
- Department of Bromatology and Nutrition, Veterinary School, Universidad de Murcia, CEIR Campus Mare Nostrum (CMN), 30100 Murcia, Spain
- Correspondence: (R.L.-N.); (S.C.-G.)
| | - Senena Corbalán-García
- Department of Biochemistry and Molecular Biology A, Veterinary School, Universidad de Murcia, CEIR Campus Mare Nostrum (CMN), 30100 Murcia, Spain
- Instituto Murciano de Investigación Biosanitaria IMIB-Arrixaca, El Palmar, 30120 Murcia, Spain
- Correspondence: (R.L.-N.); (S.C.-G.)
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Glucose feeds the tricarboxylic acid cycle via excreted ethanol in fermenting yeast. Nat Chem Biol 2022; 18:1380-1387. [PMID: 35970997 DOI: 10.1038/s41589-022-01091-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2021] [Accepted: 06/22/2022] [Indexed: 01/08/2023]
Abstract
Ethanol and lactate are typical waste products of glucose fermentation. In mammals, glucose is catabolized by glycolysis into circulating lactate, which is broadly used throughout the body as a carbohydrate fuel. Individual cells can both uptake and excrete lactate, uncoupling glycolysis from glucose oxidation. Here we show that similar uncoupling occurs in budding yeast batch cultures of Saccharomyces cerevisiae and Issatchenkia orientalis. Even in fermenting S. cerevisiae that is net releasing ethanol, media 13C-ethanol rapidly enters and is oxidized to acetaldehyde and acetyl-CoA. This is evident in exogenous ethanol being a major source of both cytosolic and mitochondrial acetyl units. 2H-tracing reveals that ethanol is also a major source of both NADH and NADPH high-energy electrons, and this role is augmented under oxidative stress conditions. Thus, uncoupling of glycolysis from the oxidation of glucose-derived carbon via rapidly reversible reactions is a conserved feature of eukaryotic metabolism.
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Lloyd SM, Leon DB, Brady MO, Rodriguez D, McReynolds MP, Kweon J, Neely AE, Blumensaadt LA, Ho PJ, Bao X. CDK9 activity switch associated with AFF1 and HEXIM1 controls differentiation initiation from epidermal progenitors. Nat Commun 2022; 13:4408. [PMID: 35906225 PMCID: PMC9338292 DOI: 10.1038/s41467-022-32098-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Accepted: 07/15/2022] [Indexed: 11/24/2022] Open
Abstract
Progenitors in epithelial tissues, such as human skin epidermis, continuously make fate decisions between self-renewal and differentiation. Here we show that the Super Elongation Complex (SEC) controls progenitor fate decisions by directly suppressing a group of "rapid response" genes, which feature high enrichment of paused Pol II in the progenitor state and robust Pol II elongation in differentiation. SEC's repressive role is dependent on the AFF1 scaffold, but not AFF4. In the progenitor state, AFF1-SEC associates with the HEXIM1-containing inactive CDK9 to suppress these rapid-response genes. A key rapid-response SEC target is ATF3, which promotes the upregulation of differentiation-activating transcription factors (GRHL3, OVOL1, PRDM1, ZNF750) to advance terminal differentiation. SEC peptidomimetic inhibitors or PKC signaling activates CDK9 and rapidly induces these transcription factors within hours in keratinocytes. Thus, our data suggest that the activity switch of SEC-associated CDK9 underlies the initial processes bifurcating progenitor fates between self-renewal and differentiation.
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Affiliation(s)
- Sarah M Lloyd
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, 60208, USA
- Simpson Querrey Institute for Epigenetics, Northwestern University, Chicago, IL, 60611, USA
| | - Daniel B Leon
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, 60208, USA
| | - Mari O Brady
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, 60208, USA
| | - Deborah Rodriguez
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, 60208, USA
| | - Madison P McReynolds
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, 60208, USA
| | - Junghun Kweon
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, 60208, USA
| | - Amy E Neely
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, 60208, USA
| | - Laura A Blumensaadt
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, 60208, USA
| | - Patric J Ho
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, 60208, USA
| | - Xiaomin Bao
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, 60208, USA.
- Simpson Querrey Institute for Epigenetics, Northwestern University, Chicago, IL, 60611, USA.
- Robert H. Lurie Comprehensive Cancer Center, Northwestern University, Chicago, IL, 60611, USA.
- Department of Dermatology, Northwestern University, Chicago, IL, 60611, USA.
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Manochkumar J, Doss CGP, El-Seedi HR, Efferth T, Ramamoorthy S. The neuroprotective potential of carotenoids in vitro and in vivo. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2021; 91:153676. [PMID: 34339943 DOI: 10.1016/j.phymed.2021.153676] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Revised: 06/26/2021] [Accepted: 07/14/2021] [Indexed: 06/13/2023]
Abstract
BACKGROUND Despite advances in research on neurodegenerative diseases, the pathogenesis and treatment response of neurodegenerative diseases remain unclear. Recent studies revealed a significant role of carotenoids to treat neurodegenerative diseases. The aim of this study was to systematically review the neuroprotective potential of carotenoids in vivo and in vitro and the molecular mechanisms and pathological factors contributing to major neurodegenerative diseases (Alzheimer's disease, Huntington's disease, Parkinson's disease, amyotrophic lateral sclerosis, and stroke). HYPOTHESIS Carotenoids as therapeutic molecules to target neurodegenerative diseases. RESULTS Aggregation of toxic proteins, mitochondrial dysfunction, oxidative stress, the excitotoxic pathway, and neuroinflammation were the major pathological factors contributing to the progression of neurodegenerative diseases. Furthermore, in vitro and in vivo studies supported the beneficiary role of carotenoids, namely lycopene, β-carotene, crocin, crocetin, lutein, fucoxanthin and astaxanthin in alleviating disease progression. These carotenoids provide neuroprotection by inhibition of neuro-inflammation, microglial activation, excitotoxic pathway, modulation of autophagy, attenuation of oxidative damage and activation of defensive antioxidant enzymes. Additionally, studies conducted on humans also demonstrated that dietary intake of carotenoids lowers the risk of neurodegenerative diseases. CONCLUSION Carotenoids may be used as drugs to prevent and treat neurodegenerative diseases. Although, the in vitro and in vivo results are encouraging, further well conducted clinical studies on humans are required to conclude about the full potential of neurodegenerative diseases.
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Affiliation(s)
- Janani Manochkumar
- School of Bio Sciences and Technology, VIT University, Vellore 632014, Tamil Nadu, India
| | - C George Priya Doss
- School of Bio Sciences and Technology, VIT University, Vellore 632014, Tamil Nadu, India
| | - Hesham R El-Seedi
- Pharmacognosy, Department of Medicinal Chemistry, Uppsala University, Box 574, SE-75 123 Uppsala, Sweden; Department of Chemistry, Faculty of Science, Menoufia University, 32512 Shebin El-Koom, Egypt
| | - Thomas Efferth
- Department of Pharmaceutical Biology, Institute of Pharmaceutical and Biomedical Sciences, Johannes Gutenberg University Mainz, Germany
| | - Siva Ramamoorthy
- School of Bio Sciences and Technology, VIT University, Vellore 632014, Tamil Nadu, India.
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Jedrychowska J, Gasanov EV, Korzh V. Kcnb1 plays a role in development of the inner ear. Dev Biol 2020; 471:65-75. [PMID: 33316259 DOI: 10.1016/j.ydbio.2020.12.007] [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: 04/05/2020] [Revised: 12/03/2020] [Accepted: 12/07/2020] [Indexed: 10/22/2022]
Abstract
The function of the inner ear depends on the maintenance of high concentrations of K+ ions. The slow-inactivating delayed rectifier Kv2.1/KCNB1 channel works in the inner ear in mammals. The kcnb1 gene is expressed in the otic vesicle of developing zebrafish, suggesting its role in development of the inner ear. In the present study, we found that a Kcnb1 loss-of-function mutation affected development of the inner ear at multiple levels, including otic vesicle expansion, otolith formation, and the proliferation and differentiation of mechanosensory cells. This resulted in defects of kinocilia and stereocilia and abnormal function of the inner ear detected by behavioral assays. The quantitative transcriptional analysis of 75 genes demonstrated that the kcnb1 mutation affected the transcription of genes that are involved in K+ metabolism, cell proliferation, cilia development, and intracellular protein trafficking. These results demonstrate a role for Kv2.1/Kcnb1 channels in development of the inner ear in zebrafish.
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Affiliation(s)
- Justyna Jedrychowska
- International Institute of Molecular and Cell Biology in Warsaw, Poland; Postgraduate School of Molecular Medicine, Warsaw Medical University, Warsaw, Poland
| | - Eugene V Gasanov
- International Institute of Molecular and Cell Biology in Warsaw, Poland
| | - Vladimir Korzh
- International Institute of Molecular and Cell Biology in Warsaw, Poland.
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Pemberton JG, Kim YJ, Humpolickova J, Eisenreichova A, Sengupta N, Toth DJ, Boura E, Balla T. Defining the subcellular distribution and metabolic channeling of phosphatidylinositol. J Cell Biol 2020; 219:133809. [PMID: 32211894 PMCID: PMC7054996 DOI: 10.1083/jcb.201906130] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Revised: 11/08/2019] [Accepted: 12/23/2019] [Indexed: 02/06/2023] Open
Abstract
Phosphatidylinositol (PI) is an essential structural component of eukaryotic membranes that also serves as the common precursor for polyphosphoinositide (PPIn) lipids. Despite the recognized importance of PPIn species for signal transduction and membrane homeostasis, there is still a limited understanding of the relationship between PI availability and the turnover of subcellular PPIn pools. To address these shortcomings, we established a molecular toolbox for investigations of PI distribution within intact cells by exploiting the properties of a bacterial enzyme, PI-specific PLC (PI-PLC). Using these tools, we find a minor presence of PI in membranes of the ER, as well as a general enrichment within the cytosolic leaflets of the Golgi complex, peroxisomes, and outer mitochondrial membrane, but only detect very low steady-state levels of PI within the plasma membrane (PM) and endosomes. Kinetic studies also demonstrate the requirement for sustained PI supply from the ER for the maintenance of monophosphorylated PPIn species within the PM, Golgi complex, and endosomal compartments.
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Affiliation(s)
- Joshua G Pemberton
- Section on Molecular Signal Transduction, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD
| | - Yeun Ju Kim
- Section on Molecular Signal Transduction, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD
| | - Jana Humpolickova
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Prague, Czech Republic
| | - Andrea Eisenreichova
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Prague, Czech Republic
| | - Nivedita Sengupta
- Section on Molecular Signal Transduction, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD
| | - Daniel J Toth
- Section on Molecular Signal Transduction, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD
| | - Evzen Boura
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Prague, Czech Republic
| | - Tamas Balla
- Section on Molecular Signal Transduction, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD
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Li D, Yang SG, He CW, Zhang ZT, Liang Y, Li H, Zhu J, Su X, Gong Q, Xie Z. Excess diacylglycerol at the endoplasmic reticulum disrupts endomembrane homeostasis and autophagy. BMC Biol 2020; 18:107. [PMID: 32859196 PMCID: PMC7453538 DOI: 10.1186/s12915-020-00837-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Accepted: 07/24/2020] [Indexed: 01/22/2023] Open
Abstract
Background When stressed, eukaryotic cells produce triacylglycerol (TAG) to store nutrients and mobilize autophagy to combat internal damage. We and others previously reported that in yeast, elimination of TAG synthesizing enzymes inhibits autophagy under nitrogen starvation, yet the underlying mechanism has remained elusive. Results Here, we show that disruption of TAG synthesis led to diacylglycerol (DAG) accumulation and its relocation from the vacuolar membrane to the endoplasmic reticulum (ER). We further show that, beyond autophagy, ER-accumulated DAG caused severe defects in the endomembrane system, including disturbing the balance of ER-Golgi protein trafficking, manifesting in bulging of ER and loss of the Golgi apparatus. Genetic or chemical manipulations that increase consumption or decrease supply of DAG reversed these defects. In contrast, increased amounts of precursors of glycerolipid synthesis, including phosphatidic acid and free fatty acids, did not replicate the effects of excess DAG. We also provide evidence that the observed endomembrane defects do not rely on Golgi-produced DAG, Pkc1 signaling, or the unfolded protein response. Conclusions This work identifies DAG as the critical lipid molecule responsible for autophagy inhibition under condition of defective TAG synthesis and demonstrates the disruption of ER and Golgi function by excess DAG as the potential cause of the autophagy defect.
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Affiliation(s)
- Dan Li
- State Key Laboratory of Microbial Metabolism & Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, #800 Dong-Chuan Road, Shanghai, 200240, People's Republic of China
| | - Shu-Gao Yang
- School of Biology and Basic Medical Sciences, Soochow University, Suzhou, Jiangsu, People's Republic of China
| | - Cheng-Wen He
- State Key Laboratory of Microbial Metabolism & Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, #800 Dong-Chuan Road, Shanghai, 200240, People's Republic of China
| | - Zheng-Tan Zhang
- State Key Laboratory of Microbial Metabolism & Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, #800 Dong-Chuan Road, Shanghai, 200240, People's Republic of China
| | - Yongheng Liang
- College of Life Sciences, Nanjing Agricultural University, Nanjing, Jiangsu, People's Republic of China
| | - Hui Li
- State Key Laboratory of Microbial Metabolism & Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, #800 Dong-Chuan Road, Shanghai, 200240, People's Republic of China
| | - Jing Zhu
- State Key Laboratory of Microbial Metabolism & Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, #800 Dong-Chuan Road, Shanghai, 200240, People's Republic of China
| | - Xiong Su
- School of Biology and Basic Medical Sciences, Soochow University, Suzhou, Jiangsu, People's Republic of China.
| | - Qingqiu Gong
- State Key Laboratory of Microbial Metabolism & Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, #800 Dong-Chuan Road, Shanghai, 200240, People's Republic of China.
| | - Zhiping Xie
- State Key Laboratory of Microbial Metabolism & Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, #800 Dong-Chuan Road, Shanghai, 200240, People's Republic of China.
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11
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Capaci V, Bascetta L, Fantuz M, Beznoussenko GV, Sommaggio R, Cancila V, Bisso A, Campaner E, Mironov AA, Wiśniewski JR, Ulloa Severino L, Scaini D, Bossi F, Lees J, Alon N, Brunga L, Malkin D, Piazza S, Collavin L, Rosato A, Bicciato S, Tripodo C, Mantovani F, Del Sal G. Mutant p53 induces Golgi tubulo-vesiculation driving a prometastatic secretome. Nat Commun 2020; 11:3945. [PMID: 32770028 PMCID: PMC7414119 DOI: 10.1038/s41467-020-17596-5] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2019] [Accepted: 07/03/2020] [Indexed: 12/16/2022] Open
Abstract
TP53 missense mutations leading to the expression of mutant p53 oncoproteins are frequent driver events during tumorigenesis. p53 mutants promote tumor growth, metastasis and chemoresistance by affecting fundamental cellular pathways and functions. Here, we demonstrate that p53 mutants modify structure and function of the Golgi apparatus, culminating in the increased release of a pro-malignant secretome by tumor cells and primary fibroblasts from patients with Li-Fraumeni cancer predisposition syndrome. Mechanistically, interacting with the hypoxia responsive factor HIF1α, mutant p53 induces the expression of miR-30d, which in turn causes tubulo-vesiculation of the Golgi apparatus, leading to enhanced vesicular trafficking and secretion. The mut-p53/HIF1α/miR-30d axis potentiates the release of soluble factors and the deposition and remodeling of the ECM, affecting mechano-signaling and stromal cells activation within the tumor microenvironment, thereby enhancing tumor growth and metastatic colonization.
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Affiliation(s)
- Valeria Capaci
- Laboratorio Nazionale CIB (LNCIB), 34149, Trieste, Italy
| | - Lorenzo Bascetta
- Laboratorio Nazionale CIB (LNCIB), 34149, Trieste, Italy
- International School for Advanced Studies (SISSA), 34146, Trieste, Italy
| | - Marco Fantuz
- Laboratorio Nazionale CIB (LNCIB), 34149, Trieste, Italy
- International School for Advanced Studies (SISSA), 34146, Trieste, Italy
| | | | | | - Valeria Cancila
- Tumor Immunology Unit, Department of Health Science, Human Pathology Section, University of Palermo, School of Medicine, 90133, Palermo, Italy
| | - Andrea Bisso
- Laboratorio Nazionale CIB (LNCIB), 34149, Trieste, Italy
- Department of Experimental Oncology, IEO, European Institute of Oncology IRCCS, 20141, Milan, Italy
| | - Elena Campaner
- Laboratorio Nazionale CIB (LNCIB), 34149, Trieste, Italy
- Dipartimento di Scienze della Vita, Università degli Studi di Trieste, 34127, Trieste, Italy
| | - Alexander A Mironov
- Fondazione Istituto FIRC di Oncologia Molecolare (IFOM), 20139, Milan, Italy
| | - Jacek R Wiśniewski
- Department of Proteomics and Signal Transduction, Max Planck Institute of Biochemistry, 85152, Martinsried, Germany
| | - Luisa Ulloa Severino
- Dipartimento di Scienze della Vita, Università degli Studi di Trieste, 34127, Trieste, Italy
| | - Denis Scaini
- International School for Advanced Studies (SISSA), 34146, Trieste, Italy
| | - Fleur Bossi
- Dipartimento di Scienze della Vita, Università degli Studi di Trieste, 34127, Trieste, Italy
| | - Jodi Lees
- Genetics and Genome Biology Program, The Hospital for Sick Children, Toronto, ON, Canada
| | - Noa Alon
- Genetics and Genome Biology Program, The Hospital for Sick Children, Toronto, ON, Canada
| | - Ledia Brunga
- Genetics and Genome Biology Program, The Hospital for Sick Children, Toronto, ON, Canada
| | - David Malkin
- Genetics and Genome Biology Program, The Hospital for Sick Children, Toronto, ON, Canada
- Department of Pediatrics, University of Toronto, Toronto, ON, Canada
| | - Silvano Piazza
- Laboratorio Nazionale CIB (LNCIB), 34149, Trieste, Italy
| | - Licio Collavin
- Laboratorio Nazionale CIB (LNCIB), 34149, Trieste, Italy
- Dipartimento di Scienze della Vita, Università degli Studi di Trieste, 34127, Trieste, Italy
| | - Antonio Rosato
- Veneto Institute of Oncology IOV-IRCCS, 35128, Padua, Italy
- Department of Surgery, Oncology and Gastroenterology, University of Padova, 35128, Padova, Italy
| | - Silvio Bicciato
- Center for Genome Research, University of Modena and Reggio Emilia, 41125, Modena, Italy
| | - Claudio Tripodo
- Tumor Immunology Unit, Department of Health Science, Human Pathology Section, University of Palermo, School of Medicine, 90133, Palermo, Italy
| | - Fiamma Mantovani
- Laboratorio Nazionale CIB (LNCIB), 34149, Trieste, Italy
- Dipartimento di Scienze della Vita, Università degli Studi di Trieste, 34127, Trieste, Italy
| | - Giannino Del Sal
- Laboratorio Nazionale CIB (LNCIB), 34149, Trieste, Italy.
- Fondazione Istituto FIRC di Oncologia Molecolare (IFOM), 20139, Milan, Italy.
- Dipartimento di Scienze della Vita, Università degli Studi di Trieste, 34127, Trieste, Italy.
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12
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Ólafsson G, Thorpe PH. Polo kinase recruitment via the constitutive centromere-associated network at the kinetochore elevates centromeric RNA. PLoS Genet 2020; 16:e1008990. [PMID: 32810142 PMCID: PMC7455000 DOI: 10.1371/journal.pgen.1008990] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 08/28/2020] [Accepted: 07/13/2020] [Indexed: 12/23/2022] Open
Abstract
The kinetochore, a multi-protein complex assembled on centromeres, is essential to segregate chromosomes during cell division. Deficiencies in kinetochore function can lead to chromosomal instability and aneuploidy-a hallmark of cancer cells. Kinetochore function is controlled by recruitment of regulatory proteins, many of which have been documented, however their function often remains uncharacterized and many are yet to be identified. To identify candidates of kinetochore regulation we used a proteome-wide protein association strategy in budding yeast and detected many proteins that are involved in post-translational modifications such as kinases, phosphatases and histone modifiers. We focused on the Polo-like kinase, Cdc5, and interrogated which cellular components were sensitive to constitutive Cdc5 localization. The kinetochore is particularly sensitive to constitutive Cdc5 kinase activity. Targeting Cdc5 to different kinetochore subcomplexes produced diverse phenotypes, consistent with multiple distinct functions at the kinetochore. We show that targeting Cdc5 to the inner kinetochore, the constitutive centromere-associated network (CCAN), increases the levels of centromeric RNA via an SPT4 dependent mechanism.
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Affiliation(s)
- Guðjón Ólafsson
- School of Biological and Chemical Sciences, Queen Mary, University of London, London, United Kingdom
| | - Peter H. Thorpe
- School of Biological and Chemical Sciences, Queen Mary, University of London, London, United Kingdom
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13
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Lipp NF, Ikhlef S, Milanini J, Drin G. Lipid Exchangers: Cellular Functions and Mechanistic Links With Phosphoinositide Metabolism. Front Cell Dev Biol 2020; 8:663. [PMID: 32793602 PMCID: PMC7385082 DOI: 10.3389/fcell.2020.00663] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Accepted: 07/01/2020] [Indexed: 12/28/2022] Open
Abstract
Lipids are amphiphilic molecules that self-assemble to form biological membranes. Thousands of lipid species coexist in the cell and, once combined, define organelle identity. Due to recent progress in lipidomic analysis, we now know how lipid composition is finely tuned in different subcellular regions. Along with lipid synthesis, remodeling and flip-flop, lipid transfer is one of the active processes that regulates this intracellular lipid distribution. It is mediated by Lipid Transfer Proteins (LTPs) that precisely move certain lipid species across the cytosol and between the organelles. A particular subset of LTPs from three families (Sec14, PITP, OSBP/ORP/Osh) act as lipid exchangers. A striking feature of these exchangers is that they use phosphatidylinositol or phosphoinositides (PIPs) as a lipid ligand and thereby have specific links with PIP metabolism and are thus able to both control the lipid composition of cellular membranes and their signaling capacity. As a result, they play pivotal roles in cellular processes such as vesicular trafficking and signal transduction at the plasma membrane. Recent data have shown that some PIPs are used as energy by lipid exchangers to generate lipid gradients between organelles. Here we describe the importance of lipid counter-exchange in the cell, its structural basis, and presumed links with pathologies.
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Affiliation(s)
- Nicolas-Frédéric Lipp
- Institut de Pharmacologie Moléculaire et Cellulaire, CNRS, Université Côte d'Azur, Valbonne, France
| | - Souade Ikhlef
- Institut de Pharmacologie Moléculaire et Cellulaire, CNRS, Université Côte d'Azur, Valbonne, France
| | - Julie Milanini
- Institut de Pharmacologie Moléculaire et Cellulaire, CNRS, Université Côte d'Azur, Valbonne, France
| | - Guillaume Drin
- Institut de Pharmacologie Moléculaire et Cellulaire, CNRS, Université Côte d'Azur, Valbonne, France
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14
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Castro V, Calvo G, Ávila-Pérez G, Dreux M, Gastaminza P. Differential Roles of Lipin1 and Lipin2 in the Hepatitis C Virus Replication Cycle. Cells 2019; 8:cells8111456. [PMID: 31752156 PMCID: PMC6912735 DOI: 10.3390/cells8111456] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Revised: 11/09/2019] [Accepted: 11/13/2019] [Indexed: 02/06/2023] Open
Abstract
Although their origin, nature and structure are not identical, a common feature of positive-strand RNA viruses is their ability to subvert host lipids and intracellular membranes to generate replication and assembly complexes. Recently, lipin1, a cellular enzyme that converts phosphatidic acid into diacylglycerol, has been implicated in the formation of the membranous web that hosts hepatitis C virus (HCV) replicase. In the liver, lipin1 cooperates with lipin2 to maintain glycerolipid homeostasis. We extended our previous study of the lipin family on HCV infection, by determining the impact of the lipin2 silencing on viral replication. Our data reveal that lipin2 silencing interferes with HCV virion secretion at late stages of the infection, without significantly affecting viral replication or assembly. Moreover, uninfected lipin2-, but not lipin1-deficient cells display alterations in mitochondrial and Golgi apparatus morphology, suggesting that lipin2 contributes to the maintenance of the overall organelle architecture. Finally, our data suggest a broader function of lipin2 for replication of HCV and other RNA viruses, in contrast with the specific impact of lipin1 silencing on HCV replication. Overall, this study reveals distinctive functions of lipin1 and lipin2 in cells of hepatic origin, a context in which they are often considered functionally redundant.
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Affiliation(s)
- Victoria Castro
- Department of Cellular and Molecular Biology Centro Nacional de Biotecnología-Consejo Superior de Investigaciones Científicas, Centro Nacional de Biotecnología-C.S.I.C., Calle Darwin 3, 28049 Madrid, Spain; (V.C.); (G.C.); (G.Á.-P.)
| | - Gema Calvo
- Department of Cellular and Molecular Biology Centro Nacional de Biotecnología-Consejo Superior de Investigaciones Científicas, Centro Nacional de Biotecnología-C.S.I.C., Calle Darwin 3, 28049 Madrid, Spain; (V.C.); (G.C.); (G.Á.-P.)
| | - Ginés Ávila-Pérez
- Department of Cellular and Molecular Biology Centro Nacional de Biotecnología-Consejo Superior de Investigaciones Científicas, Centro Nacional de Biotecnología-C.S.I.C., Calle Darwin 3, 28049 Madrid, Spain; (V.C.); (G.C.); (G.Á.-P.)
| | - Marlène Dreux
- CIRI, Inserm, U1111, Université Claude Bernard Lyon 1, CNRS, UMR5308, École Normale Supérieure de Lyon, Univ Lyon, F-69007 Lyon, France;
| | - Pablo Gastaminza
- Department of Cellular and Molecular Biology Centro Nacional de Biotecnología-Consejo Superior de Investigaciones Científicas, Centro Nacional de Biotecnología-C.S.I.C., Calle Darwin 3, 28049 Madrid, Spain; (V.C.); (G.C.); (G.Á.-P.)
- Correspondence: ; Tel.: +34-91-585-4678; Fax: +34-91-585-4506
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15
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Zhukovsky MA, Filograna A, Luini A, Corda D, Valente C. Phosphatidic acid in membrane rearrangements. FEBS Lett 2019; 593:2428-2451. [PMID: 31365767 DOI: 10.1002/1873-3468.13563] [Citation(s) in RCA: 99] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Revised: 07/25/2019] [Accepted: 07/26/2019] [Indexed: 12/16/2022]
Abstract
Phosphatidic acid (PA) is the simplest cellular glycerophospholipid characterized by unique biophysical properties: a small headgroup; negative charge; and a phosphomonoester group. Upon interaction with lysine or arginine, PA charge increases from -1 to -2 and this change stabilizes protein-lipid interactions. The biochemical properties of PA also allow interactions with lipids in several subcellular compartments. Based on this feature, PA is involved in the regulation and amplification of many cellular signalling pathways and functions, as well as in membrane rearrangements. Thereby, PA can influence membrane fusion and fission through four main mechanisms: it is a substrate for enzymes producing lipids (lysophosphatidic acid and diacylglycerol) that are involved in fission or fusion; it contributes to membrane rearrangements by generating negative membrane curvature; it interacts with proteins required for membrane fusion and fission; and it activates enzymes whose products are involved in membrane rearrangements. Here, we discuss the biophysical properties of PA in the context of the above four roles of PA in membrane fusion and fission.
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Affiliation(s)
- Mikhail A Zhukovsky
- Institute of Protein Biochemistry and Institute of Biochemistry and Cell Biology, National Research Council, Naples, Italy
| | - Angela Filograna
- Institute of Protein Biochemistry and Institute of Biochemistry and Cell Biology, National Research Council, Naples, Italy
| | - Alberto Luini
- Institute of Protein Biochemistry and Institute of Biochemistry and Cell Biology, National Research Council, Naples, Italy
| | - Daniela Corda
- Institute of Protein Biochemistry and Institute of Biochemistry and Cell Biology, National Research Council, Naples, Italy
| | - Carmen Valente
- Institute of Protein Biochemistry and Institute of Biochemistry and Cell Biology, National Research Council, Naples, Italy
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16
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The late stage of COPI vesicle fission requires shorter forms of phosphatidic acid and diacylglycerol. Nat Commun 2019; 10:3409. [PMID: 31363100 PMCID: PMC6667475 DOI: 10.1038/s41467-019-11324-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Accepted: 06/21/2019] [Indexed: 12/19/2022] Open
Abstract
Studies on vesicle formation by the Coat Protein I (COPI) complex have contributed to a basic understanding of how vesicular transport is initiated. Phosphatidic acid (PA) and diacylglycerol (DAG) have been found previously to be required for the fission stage of COPI vesicle formation. Here, we find that PA with varying lipid geometry can all promote early fission, but only PA with shortened acyl chains promotes late fission. Moreover, diacylglycerol (DAG) acts after PA in late fission, with this role of DAG also requiring shorter acyl chains. Further highlighting the importance of the short-chain lipid geometry for late fission, we find that shorter forms of PA and DAG promote the vesiculation ability of COPI fission factors. These findings advance a general understanding of how lipid geometry contributes to membrane deformation for vesicle fission, and also how proteins and lipids coordinate their actions in driving this process.
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17
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Romani P, Brian I, Santinon G, Pocaterra A, Audano M, Pedretti S, Mathieu S, Forcato M, Bicciato S, Manneville JB, Mitro N, Dupont S. Extracellular matrix mechanical cues regulate lipid metabolism through Lipin-1 and SREBP. Nat Cell Biol 2019; 21:338-347. [DOI: 10.1038/s41556-018-0270-5] [Citation(s) in RCA: 92] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Accepted: 12/20/2018] [Indexed: 12/15/2022]
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18
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Quartino PY, Fidelio GD, Manneville JB, Goud B, Ambroggio EE. Detecting phospholipase activity with the amphipathic lipid packing sensor motif of ArfGAP1. Biochem Biophys Res Commun 2018; 505:290-294. [DOI: 10.1016/j.bbrc.2018.09.116] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2018] [Accepted: 09/18/2018] [Indexed: 11/25/2022]
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19
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The Inner Nuclear Membrane Is a Metabolically Active Territory that Generates Nuclear Lipid Droplets. Cell 2018; 174:700-715.e18. [PMID: 29937227 PMCID: PMC6371920 DOI: 10.1016/j.cell.2018.05.047] [Citation(s) in RCA: 166] [Impact Index Per Article: 27.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Revised: 03/01/2018] [Accepted: 05/22/2018] [Indexed: 11/24/2022]
Abstract
The inner nuclear membrane (INM) encases the genome and is fused with the outer nuclear membrane (ONM) to form the nuclear envelope. The ONM is contiguous with the endoplasmic reticulum (ER), the main site of phospholipid synthesis. In contrast to the ER and ONM, evidence for a metabolic activity of the INM has been lacking. Here, we show that the INM is an adaptable membrane territory capable of lipid metabolism. S. cerevisiae cells target enzymes to the INM that can promote lipid storage. Lipid storage involves the synthesis of nuclear lipid droplets from the INM and is characterized by lipid exchange through Seipin-dependent membrane bridges. We identify the genetic circuit for nuclear lipid droplet synthesis and a role of these organelles in regulating this circuit by sequestration of a transcription factor. Our findings suggest a link between INM metabolism and genome regulation and have potential relevance for human lipodystrophy. INM is metabolically active and stores lipids via nuclear lipid droplets (nLDs) Intranuclear lipid sensors detect DAG enrichment at INM and PA/DAG on nLDs Nutrients and Opi1 transcriptional circuit regulate nLD synthesis Lipodystrophy-related Seipin promotes formation of INM-nLD membrane bridges
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20
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Abstract
The coat protein complex I (COPI) allows the precise sorting of lipids and proteins between Golgi cisternae and retrieval from the Golgi to the ER. This essential role maintains the identity of the early secretory pathway and impinges on key cellular processes, such as protein quality control. In this Cell Science at a Glance and accompanying poster, we illustrate the different stages of COPI-coated vesicle formation and revisit decades of research in the context of recent advances in the elucidation of COPI coat structure. By calling attention to an array of questions that have remained unresolved, this review attempts to refocus the perspectives of the field.
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Affiliation(s)
- Eric C Arakel
- Department of Molecular Biology, Universitätsmedizin Göttingen, Humboldtallee 23, 37073 Göttingen, Germany
| | - Blanche Schwappach
- Department of Molecular Biology, Universitätsmedizin Göttingen, Humboldtallee 23, 37073 Göttingen, Germany .,Max-Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany
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21
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Kavaliauskiene S, Torgersen ML, Lingelem ABD, Klokk TI, Lintonen T, Simolin H, Ekroos K, Skotland T, Sandvig K. Cellular effects of fluorodeoxyglucose: Global changes in the lipidome and alteration in intracellular transport. Oncotarget 2018; 7:79885-79900. [PMID: 27829218 PMCID: PMC5346758 DOI: 10.18632/oncotarget.13089] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Accepted: 10/21/2016] [Indexed: 11/29/2022] Open
Abstract
2-fluoro-2-deoxy-D-glucose (FDG), labeled with 18F radioisotope, is the most common imaging agent used for positron emission tomography (PET) in oncology. However, little is known about the cellular effects of FDG. Another glucose analogue, 2-deoxy-D-glucose (2DG), has been shown to affect many cellular functions, including intracellular transport and lipid metabolism, and has been found to improve the efficacy of cancer chemotherapeutic agents in vivo. Thus, in the present study, we have investigated cellular effects of FDG with the focus on changes in cellular lipids and intracellular transport. By quantifying more than 200 lipids from 17 different lipid classes in HEp-2 cells and by analyzing glycosphingolipids from MCF-7, HT-29 and HBMEC cells, we have discovered that FDG treatment inhibits glucosylceramide synthesis and thus reduces cellular levels of glycosphingolipids. In addition, in HEp-2 cells the levels and/or species composition of other lipid classes, namely diacylglycerols, phosphatidic acids and phosphatidylinositols, were found to change upon treatment with FDG. Furthermore, we show here that FDG inhibits retrograde Shiga toxin transport and is much more efficient in protecting cells against the toxin than 2DG. In summary, our data reveal novel effects of FDG on cellular transport and glycosphingolipid metabolism, which suggest a potential clinical application of FDG as an adjuvant for cancer chemotherapy.
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Affiliation(s)
- Simona Kavaliauskiene
- Department of Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital, Oslo, Norway.,Center for Cancer Biomedicine, Oslo University Hospital, Oslo, Norway.,Department of Biosciences, University of Oslo, Oslo, Norway
| | - Maria Lyngaas Torgersen
- Department of Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital, Oslo, Norway.,Center for Cancer Biomedicine, Oslo University Hospital, Oslo, Norway
| | - Anne Berit Dyve Lingelem
- Department of Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital, Oslo, Norway.,Center for Cancer Biomedicine, Oslo University Hospital, Oslo, Norway
| | - Tove Irene Klokk
- Department of Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital, Oslo, Norway.,Center for Cancer Biomedicine, Oslo University Hospital, Oslo, Norway
| | | | | | | | - Tore Skotland
- Department of Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital, Oslo, Norway.,Center for Cancer Biomedicine, Oslo University Hospital, Oslo, Norway
| | - Kirsten Sandvig
- Department of Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital, Oslo, Norway.,Center for Cancer Biomedicine, Oslo University Hospital, Oslo, Norway.,Department of Biosciences, University of Oslo, Oslo, Norway
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22
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Krčková Z, Kocourková D, Daněk M, Brouzdová J, Pejchar P, Janda M, Pokotylo I, Ott PG, Valentová O, Martinec J. The Arabidopsis thaliana non-specific phospholipase C2 is involved in the response to Pseudomonas syringae attack. ANNALS OF BOTANY 2018; 121:297-310. [PMID: 29300825 PMCID: PMC5808806 DOI: 10.1093/aob/mcx160] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Accepted: 10/24/2017] [Indexed: 05/20/2023]
Abstract
Background and Aims The non-specific phospholipase C (NPC) is a new member of the plant phospholipase family that reacts to abiotic environmental stresses, such as phosphate deficiency, high salinity, heat and aluminium toxicity, and is involved in root development, silicon distribution and brassinolide signalling. Six NPC genes (NPC1-NPC6) are found in the Arabidopsis genome. The NPC2 isoform has not been experimentally characterized so far. Methods The Arabidopsis NPC2 isoform was cloned and heterologously expressed in Escherichia coli. NPC2 enzyme activity was determined using fluorescent phosphatidylcholine as a substrate. Tissue expression and subcellular localization were analysed using GUS- and GFP-tagged NPC2. The expression patterns of NPC2 were analysed via quantitative real-time PCR. Independent homozygous transgenic plant lines overexpressing NPC2 under the control of a 35S promoter were generated, and reactive oxygen species were measured using a luminol-based assay. Key Results The heterologously expressed protein possessed phospholipase C activity, being able to hydrolyse phosphatidylcholine to diacylglycerol. NPC2 tagged with GFP was predominantly localized to the Golgi apparatus in Arabidopsis roots. The level of NPC2 transcript is rapidly altered during plant immune responses and correlates with the activation of multiple layers of the plant defence system. Transcription of NPC2 decreased substantially after plant infiltration with Pseudomonas syringae, flagellin peptide flg22 and salicylic acid treatments and expression of the effector molecule AvrRpm1. The decrease in NPC2 transcript levels correlated with a decrease in NPC2 enzyme activity. NPC2-overexpressing mutants showed higher reactive oxygen species production triggered by flg22. Conclusions This first experimental characterization of NPC2 provides new insights into the role of the non-specific phospholipase C protein family. The results suggest that NPC2 is involved in the response of Arabidopsis to P. syringae attack.
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Affiliation(s)
- Zuzana Krčková
- Institute of Experimental Botany of the Czech Academy of Sciences, Czech Republic
| | - Daniela Kocourková
- Institute of Experimental Botany of the Czech Academy of Sciences, Czech Republic
| | - Michal Daněk
- Institute of Experimental Botany of the Czech Academy of Sciences, Czech Republic
| | - Jitka Brouzdová
- Institute of Experimental Botany of the Czech Academy of Sciences, Czech Republic
| | - Přemysl Pejchar
- Institute of Experimental Botany of the Czech Academy of Sciences, Czech Republic
| | - Martin Janda
- Institute of Experimental Botany of the Czech Academy of Sciences, Czech Republic
- Department of Biochemistry and Microbiology, University of Chemistry and Technology, Prague, Czech Republic
| | - Igor Pokotylo
- The Institute of Bioorganic Chemistry and Petrochemistry, National Academy of Sciences of Ukraine, Ukraine
| | - Peter G Ott
- Plant Protection Institute, Centre for Agricultural Research, Hungarian Academy of Sciences, Hungary
| | - Olga Valentová
- Department of Biochemistry and Microbiology, University of Chemistry and Technology, Prague, Czech Republic
| | - Jan Martinec
- Institute of Experimental Botany of the Czech Academy of Sciences, Czech Republic
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23
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Campelo F, van Galen J, Turacchio G, Parashuraman S, Kozlov MM, García-Parajo MF, Malhotra V. Sphingomyelin metabolism controls the shape and function of the Golgi cisternae. eLife 2017; 6. [PMID: 28500756 PMCID: PMC5462544 DOI: 10.7554/elife.24603] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Accepted: 05/04/2017] [Indexed: 12/11/2022] Open
Abstract
The flat Golgi cisterna is a highly conserved feature of eukaryotic cells, but how is this morphology achieved and is it related to its function in cargo sorting and export? A physical model of cisterna morphology led us to propose that sphingomyelin (SM) metabolism at the trans-Golgi membranes in mammalian cells essentially controls the structural features of a Golgi cisterna by regulating its association to curvature-generating proteins. An experimental test of this hypothesis revealed that affecting SM homeostasis converted flat cisternae into highly curled membranes with a concomitant dissociation of membrane curvature-generating proteins. These data lend support to our hypothesis that SM metabolism controls the structural organization of a Golgi cisterna. Together with our previously presented role of SM in controlling the location of proteins involved in glycosylation and vesicle formation, our data reveal the significance of SM metabolism in the structural organization and function of Golgi cisternae. DOI:http://dx.doi.org/10.7554/eLife.24603.001 The Golgi complex is a hub inside cells that transports many proteins to various parts of the cell. It also receives freshly made proteins and modifies them to help them mature into their final active forms. The complex is made up of a stack of disc-like membrane structures called cisternae. Are the shapes of the cisternae important for the Golgi complex to work properly? Membranes are made of mixtures of molecules known as lipids and proteins. Previous experiments show that when the mixture of lipids in the Golgi membranes changes in a specific manner, the cisternae curl into an onion-like shape and the Golgi cannot process or send out proteins anymore. Campelo et al. used mathematics and experimental approaches to investigate what causes the Golgi to change shape when the lipid mixture of the cisternae changes. A mathematical description of the shape of the Golgi predicted that some proteins keep the cisternae flat by holding the membrane rim that connects the two faces of a cisterna. To test this prediction, Campelo et al. performed experiments in human cells, which showed that when the mixture of lipids in the Golgi membranes changes, certain proteins jump from the rim, causing the cisternae to curl. These same proteins are also needed to transport cargo proteins out of the Golgi, meaning that there is a connection between the shape of the Golgi and the tasks it carries out. The shape of the Golgi complex is altered in Alzheimer’s disease and many other neurodegenerative diseases. The next challenges are to understand how these shape changes happen, how this affects cells, and if it could be possible to develop drugs that prevent these changes from occurring in patients. DOI:http://dx.doi.org/10.7554/eLife.24603.002
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Affiliation(s)
- Felix Campelo
- ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Josse van Galen
- Centre for Genomic Regulation, The Barcelona Institute of Science and Technology, Barcelona, Spain.,Universitat Pompeu Fabra, Barcelona, Spain
| | - Gabriele Turacchio
- Institute of Protein Biochemistry, National Research Council of Italy, Naples, Italy
| | | | - Michael M Kozlov
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - María F García-Parajo
- ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Barcelona, Spain.,Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Spain
| | - Vivek Malhotra
- Centre for Genomic Regulation, The Barcelona Institute of Science and Technology, Barcelona, Spain.,Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Spain.,Universitat Pompeu Fabra, Barcelona, Spain
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24
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Bustos-Morán E, Blas-Rus N, Martín-Cófreces NB, Sánchez-Madrid F. Orchestrating Lymphocyte Polarity in Cognate Immune Cell-Cell Interactions. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2016; 327:195-261. [PMID: 27692176 DOI: 10.1016/bs.ircmb.2016.06.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The immune synapse (IS) is a specialized structure established between different immune cells that fulfills several functions, including a role as a communication bridge. This intimate contact between a T cell and an antigen-presenting cell promotes the proliferation and differentiation of lymphocytes involved in the contact. T-cell activation requires the specific triggering of the T-cell receptor (TCR), which promotes the activation of different signaling pathways inducing the polarization of the T cell. During this process, different adhesion and signaling receptors reorganize at specialized membrane domains, concomitantly to the polarization of the tubulin and actin cytoskeletons, forming stable polarization platforms. The centrosome also moves toward the IS, driving the movement of different organelles, such as the biosynthetic, secretory, degrading machinery, and mitochondria, to sustain T-cell activation. A proper orchestration of all these events is essential for T-cell effector functions and the accomplishment of a complete immune response.
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Affiliation(s)
- Eugenio Bustos-Morán
- Vascular Pathophysiology Area, Spanish National Center of Cardiovascular Research (CNIC), Madrid, Spain
| | - Noelia Blas-Rus
- Department of Immunology, La Princesa Hospital, Autonomus University of Madrid (UAM), Health Research Institute of Princesa Hospital (ISS-IP), Madrid, Spain
| | - Noa Beatriz Martín-Cófreces
- Vascular Pathophysiology Area, Spanish National Center of Cardiovascular Research (CNIC), Madrid, Spain.,Department of Immunology, La Princesa Hospital, Autonomus University of Madrid (UAM), Health Research Institute of Princesa Hospital (ISS-IP), Madrid, Spain
| | - Francisco Sánchez-Madrid
- Vascular Pathophysiology Area, Spanish National Center of Cardiovascular Research (CNIC), Madrid, Spain.,Department of Immunology, La Princesa Hospital, Autonomus University of Madrid (UAM), Health Research Institute of Princesa Hospital (ISS-IP), Madrid, Spain
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25
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Starr ML, Hurst LR, Fratti RA. Phosphatidic Acid Sequesters Sec18p from cis-SNARE Complexes to Inhibit Priming. Traffic 2016; 17:1091-109. [PMID: 27364524 DOI: 10.1111/tra.12423] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Revised: 06/28/2016] [Accepted: 06/28/2016] [Indexed: 01/08/2023]
Abstract
Yeast vacuole fusion requires the activation of cis-SNARE complexes through priming carried out by Sec18p/N-ethylmaleimide sensitive factor and Sec17p/α-SNAP. The association of Sec18p with vacuolar cis-SNAREs is regulated in part by phosphatidic acid (PA) phosphatase production of diacylglycerol (DAG). Inhibition of PA phosphatase activity blocks the transfer of membrane-associated Sec18p to SNAREs. Thus, we hypothesized that Sec18p associates with PA-rich membrane microdomains before transferring to cis-SNARE complexes upon PA phosphatase activity. Here, we examined the direct binding of Sec18p to liposomes containing PA or DAG. We found that Sec18p preferentially bound to liposomes containing PA compared with those containing DAG by approximately fivefold. Additionally, using a specific PA-binding domain blocked Sec18p binding to PA-liposomes and displaced endogenous Sec18p from isolated vacuoles. Moreover, the direct addition of excess PA blocked the priming activity of isolated vacuoles in a manner similar to chemically inhibiting PA phosphatase activity. These data suggest that the conversion of PA to DAG facilitates the recruitment of Sec18p to cis-SNAREs. Purified vacuoles from yeast lacking the PA phosphatase Pah1p showed reduced Sec18p association with cis-SNAREs and complementation with plasmid-encoded PAH1 or recombinant Pah1p restored the interaction. Taken together, this demonstrates that regulating PA concentrations by Pah1p activity controls SNARE priming by Sec18p.
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Affiliation(s)
- Matthew L Starr
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Logan R Hurst
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Rutilio A Fratti
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
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26
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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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27
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Smulan LJ, Ding W, Freinkman E, Gujja S, Edwards YJK, Walker AK. Cholesterol-Independent SREBP-1 Maturation Is Linked to ARF1 Inactivation. Cell Rep 2016; 16:9-18. [PMID: 27320911 DOI: 10.1016/j.celrep.2016.05.086] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Revised: 04/29/2016] [Accepted: 05/22/2016] [Indexed: 11/19/2022] Open
Abstract
Lipogenesis requires coordinated expression of genes for fatty acid, phospholipid, and triglyceride synthesis. Transcription factors, such as SREBP-1 (Sterol regulatory element binding protein), may be activated in response to feedback mechanisms linking gene activation to levels of metabolites in the pathways. SREBPs can be regulated in response to membrane cholesterol and we also found that low levels of phosphatidylcholine (a methylated phospholipid) led to SBP-1/SREBP-1 maturation in C. elegans or mammalian models. To identify additional regulatory components, we performed a targeted RNAi screen in C. elegans, finding that both lpin-1/Lipin 1 (which converts phosphatidic acid to diacylglycerol) and arf-1.2/ARF1 (a GTPase regulating Golgi function) were important for low-PC activation of SBP-1/SREBP-1. Mechanistically linking the major hits of our screen, we find that limiting PC synthesis or LPIN1 knockdown in mammalian cells reduces the levels of active GTP-bound ARF1. Thus, changes in distinct lipid ratios may converge on ARF1 to increase SBP-1/SREBP-1 activity.
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Affiliation(s)
- Lorissa J Smulan
- Program in Molecular Medicine, UMASS Medical School, 373 Plantation Street, Worcester, MA 01605, USA
| | - Wei Ding
- Program in Molecular Medicine, UMASS Medical School, 373 Plantation Street, Worcester, MA 01605, USA
| | - Elizaveta Freinkman
- Metabolite Profiling Facility, Whitehead Institute for Biomedical Research, 9 Cambridge Center, Cambridge, MA 02142, USA
| | - Sharvari Gujja
- Program in Molecular Medicine, UMASS Medical School, 373 Plantation Street, Worcester, MA 01605, USA
| | - Yvonne J K Edwards
- Program in Molecular Medicine, UMASS Medical School, 373 Plantation Street, Worcester, MA 01605, USA
| | - Amy K Walker
- Program in Molecular Medicine, UMASS Medical School, 373 Plantation Street, Worcester, MA 01605, USA.
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28
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Ganesan S, Shabits BN, Zaremberg V. Tracking Diacylglycerol and Phosphatidic Acid Pools in Budding Yeast. Lipid Insights 2016; 8:75-85. [PMID: 27081314 PMCID: PMC4824325 DOI: 10.4137/lpi.s31781] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2015] [Revised: 02/24/2016] [Accepted: 03/05/2016] [Indexed: 02/07/2023] Open
Abstract
Phosphatidic acid (PA) and diacylglycerol (DAG) are key signaling molecules and important precursors for the biosynthesis of all glycerolipids found in eukaryotes. Research conducted in the model organism Saccharomyces cerevisiae has been at the forefront of the identification of the enzymes involved in the metabolism and transport of PA and DAG. Both these lipids can alter the local physical properties of membranes by introducing negative curvature, but the anionic nature of the phosphomonoester headgroup in PA sets it apart from DAG. As a result, the mechanisms underlying PA and DAG interaction with other lipids and proteins are notoriously different. This is apparent from the analysis of the protein domains responsible for recognition and binding to each of these lipids. We review the current evidence obtained using the PA-binding proteins and domains fused to fluorescent proteins for in vivo tracking of PA pools in yeast. In addition, we present original results for visualization of DAG pools in yeast using the C1 domain from mammalian PKCδ. An emerging first cellular map of the distribution of PA and DAG pools in actively growing yeast is discussed.
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Affiliation(s)
| | - Brittney N Shabits
- Department of Biological Sciences, University of Calgary, Calgary, AB, Canada
| | - Vanina Zaremberg
- Department of Biological Sciences, University of Calgary, Calgary, AB, Canada
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29
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Xie S, Naslavsky N, Caplan S. Diacylglycerol kinases in membrane trafficking. CELLULAR LOGISTICS 2015; 5:e1078431. [PMID: 27057419 DOI: 10.1080/21592799.2015.1078431] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2015] [Revised: 07/22/2015] [Accepted: 07/24/2015] [Indexed: 10/23/2022]
Abstract
Diacylglycerol kinases (DGKs) belong to a family of cytosolic kinases that regulate the phosphorylation of diacylglycerol (DAG), converting it into phosphatidic acid (PA). There are 10 known mammalian DGK isoforms, each with a different tissue distribution and substrate specificity. These differences allow regulation of cellular responses by fine-tuning the delicate balance of cellular DAG and PA. DGK isoforms are best characterized as mediators of signal transduction and immune function. However, since recent studies reveal that DAG and PA are also involved in the regulation of endocytic trafficking, it is therefore anticipated that DGKs also plays an important role in membrane trafficking. In this review, we summarize the literature discussing the role of DGK isoforms at different stages of endocytic trafficking, including endocytosis, exocytosis, endocytic recycling, and transport from/to the Golgi apparatus. Overall, these studies contribute to our understanding of the involvement of PA and DAG in endocytic trafficking, an area of research that is drawing increasing attention in recent years.
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Affiliation(s)
- Shuwei Xie
- Department of Biochemistry and Molecular Biology and the Fred and Pamela Buffett Cancer Center; University of Nebraska Medical Center ; Omaha, NE USA
| | - Naava Naslavsky
- Department of Biochemistry and Molecular Biology and the Fred and Pamela Buffett Cancer Center; University of Nebraska Medical Center ; Omaha, NE USA
| | - Steve Caplan
- Department of Biochemistry and Molecular Biology and the Fred and Pamela Buffett Cancer Center; University of Nebraska Medical Center ; Omaha, NE USA
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30
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Adiko AC, Babdor J, Gutiérrez-Martínez E, Guermonprez P, Saveanu L. Intracellular Transport Routes for MHC I and Their Relevance for Antigen Cross-Presentation. Front Immunol 2015; 6:335. [PMID: 26191062 PMCID: PMC4489332 DOI: 10.3389/fimmu.2015.00335] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2015] [Accepted: 06/15/2015] [Indexed: 01/22/2023] Open
Abstract
Cross-presentation, in which exogenous antigens are presented via MHC I complexes, is involved both in the generation of anti-infectious and anti-tumoral cytotoxic CD8+ T cells and in the maintenance of immune tolerance. While cross-presentation was described almost four decades ago and while it is now established that some dendritic cell (DC) subsets are better than others in processing and cross-presenting internalized antigens, the involved molecular mechanisms remain only partially understood. Some of the least explored molecular mechanisms in cross-presentation concern the origin of cross-presenting MHC I molecules and the cellular compartments where antigenic peptide loading occurs. This review focuses on MHC I molecules and their intracellular trafficking. We discuss the source of cross-presenting MHC I in DCs as well as the role of the endocytic pathway in their recycling from the cell surface. Next, we describe the importance of the TAP peptide transporter for delivering peptides to MHC I during cross-presentation. Finally, we highlight the impact of innate immunity mechanisms on specific antigen cross-presentation mechanisms in which TLR activation modulates MHC I trafficking and TAP localization.
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Affiliation(s)
- Aimé Cézaire Adiko
- INSERM U1149, Faculté Bichat Medical School, ELR8252 CNRS, Center for Research on Inflammation , Paris , France ; Université Paris Diderot, Sorbonne Paris Cité , Paris , France
| | - Joel Babdor
- INSERM UMR 1163, Laboratory of Cellular and Molecular Mechanisms of Hematological Disorders and Therapeutic Implications , Paris , France ; Université Paris Descartes, Sorbonne Paris Cité , Paris , France ; Imagine Institute , Paris , France
| | - Enric Gutiérrez-Martínez
- Laboratory of Phagocyte Immunobiology, Peter Gorer Department of Immunobiology, King's College London , London , UK
| | - Pierre Guermonprez
- Laboratory of Phagocyte Immunobiology, Peter Gorer Department of Immunobiology, King's College London , London , UK
| | - Loredana Saveanu
- INSERM U1149, Faculté Bichat Medical School, ELR8252 CNRS, Center for Research on Inflammation , Paris , France ; Université Paris Diderot, Sorbonne Paris Cité , Paris , France
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31
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Ruelland E, Kravets V, Derevyanchuk M, Martinec J, Zachowski A, Pokotylo I. Role of phospholipid signalling in plant environmental responses. ENVIRONMENTAL AND EXPERIMENTAL BOTANY 2015; 114:129-143. [PMID: 0 DOI: 10.1016/j.envexpbot.2014.08.009] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
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32
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Galea G, Bexiga MG, Panarella A, O'Neill ED, Simpson JC. A high-content screening microscopy approach to dissect the role of Rab proteins in Golgi-to-ER retrograde trafficking. J Cell Sci 2015; 128:2339-49. [PMID: 25999475 DOI: 10.1242/jcs.167973] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Accepted: 05/18/2015] [Indexed: 12/24/2022] Open
Abstract
Here, we describe a high-content microscopy-based screen that allowed us to systematically assess and rank proteins involved in Golgi-to-endoplasmic reticulum (ER) retrograde transport in mammalian cells. Using a cell line stably expressing a GFP-tagged Golgi enzyme, we used brefeldin A treatment to stimulate the production of Golgi-to-ER carriers and then quantitatively analysed populations of cells for changes in this trafficking event. Systematic RNA interference (RNAi)-based depletion of 58 Rab GTPase proteins and 12 Rab accessory proteins of the PRAF, YIPF and YIF protein families revealed that nine of these were strong regulators. In addition to demonstrating roles for Rab1a, Rab1b, Rab2a, and Rab6a or Rab6a' in this transport step, we also identified Rab10 and Rab11a as playing a role and being physically present on a proportion of the Golgi-to-ER tubular intermediates. Combinatorial depletions of Rab proteins also revealed previously undescribed functional co-operation and physical co-occurrence between several Rab proteins. Our approach therefore provides a novel and robust strategy for a more complete investigation of the molecular components required to regulate Golgi-to-ER transport in mammalian cells.
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Affiliation(s)
- George Galea
- School of Biology and Environmental Science and UCD Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Dublin 4, Ireland
| | - Mariana G Bexiga
- School of Biology and Environmental Science and UCD Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Dublin 4, Ireland
| | - Angela Panarella
- School of Biology and Environmental Science and UCD Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Dublin 4, Ireland
| | - Elaine D O'Neill
- School of Biology and Environmental Science and UCD Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Dublin 4, Ireland
| | - Jeremy C Simpson
- School of Biology and Environmental Science and UCD Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Dublin 4, Ireland
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33
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Sicart A, Katan M, Egea G, Sarri E. PLCγ1 participates in protein transport and diacylglycerol production triggered by cargo arrival at the Golgi. Traffic 2015; 16:250-66. [PMID: 25491205 DOI: 10.1111/tra.12246] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Revised: 11/26/2014] [Accepted: 11/26/2014] [Indexed: 02/02/2023]
Abstract
Diacylglycerol (DAG) is required for membrane traffic and structural organization at the Golgi. DAG is a lipid metabolite of several enzymatic reactions present at this organelle, but the mechanisms by which they are regulated are still unknown. Here, we show that cargo arrival at the Golgi increases the recruitment of the DAG-sensing constructs C1-PKCθ-GFP and the PKD-wt-GFP. The recruitment of both constructs was reduced by PLCγ1 silencing. Post-Golgi trafficking of transmembrane and soluble proteins was impaired in PLCγ1-silenced cells. Under basal conditions, PLCγ1 contributed to the maintenance of the pool of DAG associated with the Golgi and to the structural organization of the organelle. Finally, we show that cytosolic phospholipase C (PLC) can hydrolyse phosphatidylinositol 4-phosphate in isolated Golgi membranes. Our results indicate that PLCγ1 is part of the molecular mechanism that couples cargo arrival at the Golgi with DAG production to co-ordinate the formation of transport carriers for post-Golgi traffic.
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Affiliation(s)
- Adrià Sicart
- Departament de Biologia Cel·lular, Immunologia i Neurociències, Facultat de Medicina, Universitat de Barcelona, C/ Casanova, 143, 08036, Barcelona, Spain; Current address: Vlaams Instituut voor Biotechnologie (VIB), Centre for the Biology of Disease and KU Leuven, Department of Human Genetics, Campus Gasthuisberg, 3000 Leuven, Belgium
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34
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Edens LJ, Levy DL. cPKC regulates interphase nuclear size during Xenopus development. ACTA ACUST UNITED AC 2014; 206:473-83. [PMID: 25135933 PMCID: PMC4137061 DOI: 10.1083/jcb.201406004] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
During Xenopus development, increased nuclear cPKC activity and decreased nuclear association of lamins mediate nuclear scaling. Dramatic changes in cell and nuclear size occur during development and differentiation, and aberrant nuclear size is associated with many disease states. However, the mechanisms that regulate nuclear size are largely unknown. A robust system for investigating nuclear size is early Xenopus laevis development, during which reductions in nuclear size occur without changes in DNA content. To identify cellular factors that regulate nuclear size during development, we developed a novel nuclear resizing assay wherein nuclei assembled in Xenopus egg extract become smaller in the presence of cytoplasmic interphase extract isolated from post-gastrula Xenopus embryos. We show that nuclear shrinkage depends on conventional protein kinase C (cPKC). Increased nuclear cPKC localization and activity and decreased nuclear association of lamins mediate nuclear size reductions during development, and manipulating cPKC activity in vivo during interphase alters nuclear size in the embryo. We propose a model of steady-state nuclear size regulation whereby nuclear expansion is balanced by an active cPKC-dependent mechanism that reduces nuclear size.
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Affiliation(s)
- Lisa J Edens
- Department of Molecular Biology, University of Wyoming, Laramie, WY 82071
| | - Daniel L Levy
- Department of Molecular Biology, University of Wyoming, Laramie, WY 82071
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35
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ARFGAP1 is dynamically associated with lipid droplets in hepatocytes. PLoS One 2014; 9:e111309. [PMID: 25397679 PMCID: PMC4232254 DOI: 10.1371/journal.pone.0111309] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2013] [Accepted: 09/30/2014] [Indexed: 12/18/2022] Open
Abstract
The ARF GTPase Activating Protein 1 (ARFGAP1) associates mainly with the cytosolic side of Golgi cisternal membranes where it participates in the formation of both COPI and clathrin-coated vesicles. In this study, we show that ARFGAP1 associates transiently with lipid droplets upon addition of oleate in cultured cells. Also, that addition of cyclic AMP shifts ARFGAP1 from lipid droplets to the Golgi apparatus and that overexpression and knockdown of ARFGAP1 affect lipid droplet formation. Examination of human liver tissue reveals that ARFGAP1 is found associated with lipid droplets at steady state in some but not all hepatocytes.
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36
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Martínez-Martínez N, Martínez-Alonso E, Ballesta J, Martínez-Menárguez JA. Phospholipase D2 is involved in the formation of Golgi tubules and ArfGAP1 recruitment. PLoS One 2014; 9:e111685. [PMID: 25354038 PMCID: PMC4213061 DOI: 10.1371/journal.pone.0111685] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2014] [Accepted: 10/03/2014] [Indexed: 11/19/2022] Open
Abstract
Lipids and lipid-modifying enzymes play a key role in the biogenesis, maintenance and fission of transport carriers in the secretory and endocytic pathways. In the present study we demonstrate that phosphatidic acid generated by phospholipase D2 (PLD2) is involved in the formation of Golgi tubules. The main evidence to support this is: 1) inhibitors of phosphatidic acid formation and PLD2 depletion inhibit the formation of tubules containing resident enzymes and regulators of intra-Golgi transport in a low temperature (15°C) model of Golgi tubulation but do not affect brefeldin A-induced tubules, 2) inhibition of PLD2 enzymatic activity and PLD2 depletion in cells cultured under physiological conditions (37°C) induce the formation of tubules specifically containing Golgi matrix proteins, and, 3) over-expression of PLD2 induces the formation of a tubular network. In addition, it was found that the generation of this lipid by the isoenzyme is necessary for ArfGAP1 recruitment to Golgi membranes. These results suggest that both proteins are involved in the molecular mechanisms which drive the formation of different types of Golgi tubules.
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Affiliation(s)
- Narcisa Martínez-Martínez
- Department of Cell Biology and Histology, Medical School, IMIB-Arrixaca, University of Murcia, Murcia, Spain
| | - Emma Martínez-Alonso
- Department of Cell Biology and Histology, Medical School, IMIB-Arrixaca, University of Murcia, Murcia, Spain
| | - José Ballesta
- Department of Cell Biology and Histology, Medical School, IMIB-Arrixaca, University of Murcia, Murcia, Spain
| | - José A. Martínez-Menárguez
- Department of Cell Biology and Histology, Medical School, IMIB-Arrixaca, University of Murcia, Murcia, Spain
- * E-mail:
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Zhang P, Verity MA, Reue K. Lipin-1 regulates autophagy clearance and intersects with statin drug effects in skeletal muscle. Cell Metab 2014; 20:267-79. [PMID: 24930972 PMCID: PMC4170588 DOI: 10.1016/j.cmet.2014.05.003] [Citation(s) in RCA: 121] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2013] [Revised: 03/03/2014] [Accepted: 04/21/2014] [Indexed: 02/04/2023]
Abstract
LPIN1 encodes lipin-1, a phosphatidic acid phosphatase (PAP) enzyme that catalyzes the dephosphorylation of phosphatidic acid to form diacylglycerol. Homozygous LPIN1 gene mutations cause severe rhabdomyolysis, and heterozygous LPIN1 missense mutations may promote statin-induced myopathy. We demonstrate that lipin-1-related myopathy in the mouse is associated with a blockade in autophagic flux and accumulation of aberrant mitochondria. Lipin-1 PAP activity is required for maturation of autolysosomes, through its activation of the protein kinase D (PKD)-Vps34 phosphatidylinositol 3-kinase signaling cascade. Statin treatment also reduces PKD activation and autophagic flux, which are compounded by diminished mammalian target of rapamycin (mTOR) abundance in lipin-1-haploinsufficent and -deficient muscle. Lipin-1 restoration in skeletal muscle prevents myonecrosis and statin toxicity in vivo, and activated PKD rescues autophagic flux in lipin-1-deficient cells. Our findings identify lipin-1 PAP activity as a component of the macroautophagy pathway and define the basis for lipin-1-related myopathies.
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Affiliation(s)
- Peixiang Zhang
- Department of Human Genetics, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | - M Anthony Verity
- Division of Neuropathology, Department of Pathology and Laboratory Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | - Karen Reue
- Department of Human Genetics, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA; Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA; Molecular Biology Institute, University of California, Los Angeles, Los Angeles, CA 90095, USA.
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38
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Egea-Jiménez AL, Corbalán-García S, Gómez-Fernández JC. The C1B domains of novel PKCε and PKCη have a higher membrane binding affinity than those of the also novel PKCδ and PKCθ. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2014; 1838:1898-909. [DOI: 10.1016/j.bbamem.2014.04.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2014] [Revised: 03/28/2014] [Accepted: 04/02/2014] [Indexed: 10/25/2022]
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Abstract
Lipids are unevenly distributed within and between cell membranes, thus defining organelle identity. Such distribution relies on local metabolic branches and mechanisms that move lipids. These processes are regulated by feedback mechanisms that decipher topographical information in organelle membranes and then regulate lipid levels or flows. In the endoplasmic reticulum, the major lipid source, transcriptional regulators and enzymes sense changes in membrane features to modulate lipid production. At the Golgi apparatus, lipid-synthesizing, lipid-flippase, and lipid-transport proteins (LTPs) collaborate to control lipid balance and distribution within the membrane to guarantee remodeling processes crucial for vesicular trafficking. Open questions exist regarding LTPs, which are thought to be lipid sensors that regulate lipid synthesis or carriers that transfer lipids between organelles across long distances or in contact sites. A novel model is that LTPs, by exchanging two different lipids, exploit one lipid gradient between two distinct membranes to build a second lipid gradient.
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Affiliation(s)
- Guillaume Drin
- Institut de Pharmacologie Moléculaire et Cellulaire, Université de Nice Sophia-Antipolis and CNRS, 06560 Valbonne, France;
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Kavaliauskiene S, Nymark CM, Bergan J, Simm R, Sylvänne T, Simolin H, Ekroos K, Skotland T, Sandvig K. Cell density-induced changes in lipid composition and intracellular trafficking. Cell Mol Life Sci 2014; 71:1097-116. [PMID: 23921715 PMCID: PMC11113877 DOI: 10.1007/s00018-013-1441-y] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2013] [Revised: 07/24/2013] [Accepted: 07/25/2013] [Indexed: 12/11/2022]
Abstract
Cell density is one of the extrinsic factors to which cells adapt their physiology when grown in culture. However, little is known about the molecular changes which occur during cell growth and how cellular responses are then modulated. In many cases, inhibitors, drugs or growth factors used for in vitro studies change the rate of cell proliferation, resulting in different cell densities in control and treated samples. Therefore, for a comprehensive data analysis, it is essential to understand the implications of cell density on the molecular level. In this study, we have investigated how lipid composition changes during cell growth, and the consequences it has for transport of Shiga toxin. By quantifying 308 individual lipid species from 17 different lipid classes, we have found that the levels and species distribution of several lipids change during cell growth, with the major changes observed for diacylglycerols, phosphatidic acids, cholesterol esters, and lysophosphatidylethanolamines. In addition, there is a reduced binding and retrograde transport of Shiga toxin in high density cells which lead to reduced intoxication by the toxin. In conclusion, our data provide novel information on how lipid composition changes during cell growth in culture, and how these changes can modulate intracellular trafficking.
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Affiliation(s)
- Simona Kavaliauskiene
- Department of Biochemistry, Institute for Cancer Research, Oslo University Hospital, The Norwegian Radium Hospital, Montebello, 0379 Oslo, Norway
- Center for Cancer Biomedicine, Oslo University Hospital, Oslo, Norway
- Department of Biosciences, University of Oslo, Oslo, Norway
| | - Carl-Martin Nymark
- Department of Biochemistry, Institute for Cancer Research, Oslo University Hospital, The Norwegian Radium Hospital, Montebello, 0379 Oslo, Norway
- Center for Cancer Biomedicine, Oslo University Hospital, Oslo, Norway
| | - Jonas Bergan
- Department of Biochemistry, Institute for Cancer Research, Oslo University Hospital, The Norwegian Radium Hospital, Montebello, 0379 Oslo, Norway
- Center for Cancer Biomedicine, Oslo University Hospital, Oslo, Norway
- Department of Biosciences, University of Oslo, Oslo, Norway
| | - Roger Simm
- Department of Biochemistry, Institute for Cancer Research, Oslo University Hospital, The Norwegian Radium Hospital, Montebello, 0379 Oslo, Norway
- Center for Cancer Biomedicine, Oslo University Hospital, Oslo, Norway
| | | | | | | | - Tore Skotland
- Department of Biochemistry, Institute for Cancer Research, Oslo University Hospital, The Norwegian Radium Hospital, Montebello, 0379 Oslo, Norway
- Center for Cancer Biomedicine, Oslo University Hospital, Oslo, Norway
| | - Kirsten Sandvig
- Department of Biochemistry, Institute for Cancer Research, Oslo University Hospital, The Norwegian Radium Hospital, Montebello, 0379 Oslo, Norway
- Center for Cancer Biomedicine, Oslo University Hospital, Oslo, Norway
- Department of Biosciences, University of Oslo, Oslo, Norway
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Sandvig K, Bergan J, Kavaliauskiene S, Skotland T. Lipid requirements for entry of protein toxins into cells. Prog Lipid Res 2014; 54:1-13. [PMID: 24462587 DOI: 10.1016/j.plipres.2014.01.001] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2013] [Revised: 01/15/2014] [Accepted: 01/15/2014] [Indexed: 01/05/2023]
Abstract
The plant toxin ricin and the bacterial toxin Shiga toxin both belong to a group of protein toxins having one moiety that binds to the cell surface, and another, enzymatically active moiety, that enters the cytosol and inhibits protein synthesis by inactivating ribosomes. Both toxins travel all the way from the cell surface to endosomes, the Golgi apparatus and the ER before the ribosome-inactivating moiety enters the cytosol. Shiga toxin binds to the neutral glycosphingolipid Gb3 at the cell surface and is therefore dependent on this lipid for transport into the cells, whereas ricin binds both glycoproteins and glycolipids with terminal galactose. The different steps of transport used by these toxins have specific requirements for lipid species, and with the recent developments in mass spectrometry analysis of lipids and microscopical and biochemical dissection of transport in cells, we are starting to see the complexity of endocytosis and intracellular transport. In this article we describe lipid requirements and the consequences of lipid changes for the entry and intoxication with ricin and Shiga toxin. These toxins can be a threat to human health, but can also be exploited for diagnosis and therapy, and have proven valuable as tools to study intracellular transport.
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Affiliation(s)
- Kirsten Sandvig
- Centre for Cancer Biomedicine, Faculty of Medicine, University of Oslo, Oslo, Norway; Department of Biochemistry, Institute for Cancer Research, The Norwegian Radium Hospital, Oslo University Hospital, Oslo, Norway; Department of Biosciences, University of Oslo, Oslo, Norway.
| | - Jonas Bergan
- Centre for Cancer Biomedicine, Faculty of Medicine, University of Oslo, Oslo, Norway; Department of Biochemistry, Institute for Cancer Research, The Norwegian Radium Hospital, Oslo University Hospital, Oslo, Norway.
| | - Simona Kavaliauskiene
- Centre for Cancer Biomedicine, Faculty of Medicine, University of Oslo, Oslo, Norway; Department of Biochemistry, Institute for Cancer Research, The Norwegian Radium Hospital, Oslo University Hospital, Oslo, Norway; Department of Biosciences, University of Oslo, Oslo, Norway.
| | - Tore Skotland
- Centre for Cancer Biomedicine, Faculty of Medicine, University of Oslo, Oslo, Norway; Department of Biochemistry, Institute for Cancer Research, The Norwegian Radium Hospital, Oslo University Hospital, Oslo, Norway.
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Abstract
Phosphatidic acid (PA) is recognized as an important class of lipid messengers. The cellular PA levels are dynamic; PA is produced and metabolized by several enzymatic reactions, including different phospholipases, lipid kinases, and phosphatases. PA interacts with various proteins and the interactions may modulate enzyme catalytic activities and/or tether proteins to membranes. The PA-protein interactions are impacted by changes in cellular pH and other effectors, such as cations. PA is involved in a wide range of cellular processes, including vesicular trafficking, cytoskeletal organization, secretion, cell proliferation, and survival. Manipulations of different PA production reactions alter cellular and organismal response to a wide range of abiotic and biotic stresses. Further investigations of PA's function and mechanisms of action will advance not only the understanding of cell signaling networks but also may lead to biotechnological and pharmacological applications.
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Abstract
Lipid droplets are intracellular organelles that are found in most cells, where they have fundamental roles in metabolism. They function prominently in storing oil-based reserves of metabolic energy and components of membrane lipids. Lipid droplets are the dispersed phase of an oil-in-water emulsion in the aqueous cytosol of cells, and the importance of basic biophysical principles of emulsions for lipid droplet biology is now being appreciated. Because of their unique architecture, with an interface between the dispersed oil phase and the aqueous cytosol, specific mechanisms underlie their formation, growth and shrinkage. Such mechanisms enable cells to use emulsified oil when the demands for metabolic energy or membrane synthesis change. The regulation of the composition of the phospholipid surfactants at the surface of lipid droplets is crucial for lipid droplet homeostasis and protein targeting to their surfaces.
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Martínez-Alonso E, Tomás M, Martínez-Menárguez JA. Golgi tubules: their structure, formation and role in intra-Golgi transport. Histochem Cell Biol 2013; 140:327-39. [PMID: 23812035 DOI: 10.1007/s00418-013-1114-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/16/2013] [Indexed: 11/28/2022]
Abstract
Tubules are common Golgi elements that can form extensive networks associated with the cis-, lateral and trans-Golgi sides, but despite this, they have almost been forgotten for decades. The molecular mechanisms involved in their formation, elongation and fission are only just beginning to be understood. However, the role of these membranes is not well understood. In the present review, we analyze the mechanisms that induce Golgi tubulation or, conversely, disrupt tubules in order to throw some lights on the nature of these elements. The putative role of these elements in the framework of current models for intra-Golgi transport is also discussed.
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Affiliation(s)
- Emma Martínez-Alonso
- Department of Cell Biology and Histology, Medical School, University of Murcia, 30100 Murcia, Spain
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Gutiérrez-Martínez E, Fernández-Ulibarri I, Lázaro-Diéguez F, Johannes L, Pyne S, Sarri E, Egea G. Lipid phosphate phosphatase 3 participates in transport carrier formation and protein trafficking in the early secretory pathway. J Cell Sci 2013; 126:2641-55. [PMID: 23591818 DOI: 10.1242/jcs.117705] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The inhibition of phosphatidic acid phosphatase (PAP) activity by propanolol indicates that diacylglycerol (DAG) is required for the formation of transport carriers at the Golgi and for retrograde trafficking to the ER. Here we report that the PAP2 family member lipid phosphate phosphatase 3 (LPP3, also known as PAP2b) localizes in compartments of the secretory pathway from ER export sites to the Golgi complex. The depletion of human LPP3: (i) reduces the number of tubules generated from the ER-Golgi intermediate compartment and the Golgi, with those formed from the Golgi being longer in LPP3-silenced cells than in control cells; (ii) impairs the Rab6-dependent retrograde transport of Shiga toxin subunit B from the Golgi to the ER, but not the anterograde transport of VSV-G or ssDsRed; and (iii) induces a high accumulation of Golgi-associated membrane buds. LPP3 depletion also reduces levels of de novo synthesized DAG and the Golgi-associated DAG contents. Remarkably, overexpression of a catalytically inactive form of LPP3 mimics the effects of LPP3 knockdown on Rab6-dependent retrograde transport. We conclude that LPP3 participates in the formation of retrograde transport carriers at the ER-Golgi interface, where it transitorily cycles, and during its route to the plasma membrane.
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Affiliation(s)
- Enric Gutiérrez-Martínez
- Departament de Biologia Cel·lular, Immunologia i Neurociències, Facultat de Medicina, Universitat de Barcelona, 08036 Barcelona, Spain
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46
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Abstract
The Golgi complex is considered the central station of the secretory pathway where cargo proteins and lipids are properly modified, classified, packed into specific carriers and delivered to their final destinations. Early electron microscope studies showed the extraordinary structural complexity of this organelle. However, despite the large volume of incoming and outgoing traffic, it is able to maintain its architecture, although it is also flexible enough to adapt to the functional status of the cell. Many components of the molecular machinery involved in membrane traffic and other Golgi functions have been identified. However, some basic aspects of Golgi functioning remain unsolved. For instance, how cargo moves through the stack remains controversial and two classical models have been proposed: vesicular transport and cisternal maturation. Since neither of these models explains all the experimental data, a combination of these models as well as new models have been proposed. In this context, the specific role of the cisternae, vesicles and tubules needs to be clarified. In this review, we summarize our current knowledge of the Golgi organization and function, focusing on the mechanisms of intra-Golgi transport.
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Martínez-Alonso E, Tomás M, Martínez-Menárguez JA. Morpho-functional architecture of the Golgi complex of neuroendocrine cells. Front Endocrinol (Lausanne) 2013; 4:41. [PMID: 23543640 PMCID: PMC3610015 DOI: 10.3389/fendo.2013.00041] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2013] [Accepted: 03/14/2013] [Indexed: 12/22/2022] Open
Abstract
In neuroendocrine cells, prohormones move from the endoplasmic reticulum to the Golgi complex (GC), where they are sorted and packed into secretory granules. The GC is considered the central station of the secretory pathway of proteins and lipids en route to their final destination. In most mammalian cells, it is formed by several stacks of cisternae connected by tubules, forming a continuous ribbon. This organelle shows an extraordinary structural and functional complexity, which is exacerbated by the fact that its architecture is cell type specific and also tuned by the functional status of the cell. It is, indeed, one the most beautiful cellular organelles and, for that reason, perhaps the most extensively photographed by electron microscopists. In recent decades, an exhaustive dissection of the molecular machinery involved in membrane traffic and other Golgi functions has been carried out. Concomitantly, detailed morphological studies have been performed, including 3D analysis by electron tomography, and the precise location of key proteins has been identified by immunoelectron microscopy. Despite all this effort, some basic aspects of Golgi functioning remain unsolved. For instance, the mode of intra-Golgi transport is not known, and two opposing theories (vesicular transport and cisternal maturation models) have polarized the field for many years. Neither of these theories explains all the experimental data so that new theories and combinations thereof have recently been proposed. Moreover, the specific role of the small vesicles and tubules which surround the stacks needs to be clarified. In this review, we summarize our current knowledge of the Golgi architecture in relation with its function and the mechanisms of intra-Golgi transport. Within the same framework, the characteristics of the GC of neuroendocrine cells are analyzed.
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Affiliation(s)
- Emma Martínez-Alonso
- Department of Cell Biology and Histology, Medical School, University of MurciaMurcia, Spain
| | - Mónica Tomás
- Department of Human Anatomy and Embryology, Medical School, Valencia UniversityValencia, Spain
| | - José A. Martínez-Menárguez
- Department of Cell Biology and Histology, Medical School, University of MurciaMurcia, Spain
- *Correspondence: José A. Martínez-Menárguez, Department of Cell Biology and Histology, Medical School, University of Murcia, 30100 Murcia, Spain. e-mail:
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48
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Cancino J, Luini A. Signaling Circuits on the Golgi Complex. Traffic 2012; 14:121-34. [DOI: 10.1111/tra.12022] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2012] [Revised: 10/12/2012] [Accepted: 10/12/2012] [Indexed: 01/21/2023]
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Cottam NP, Ungar D. Retrograde vesicle transport in the Golgi. PROTOPLASMA 2012; 249:943-55. [PMID: 22160157 DOI: 10.1007/s00709-011-0361-7] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2011] [Accepted: 11/29/2011] [Indexed: 05/23/2023]
Abstract
The Golgi apparatus is the central sorting and biosynthesis hub of the secretory pathway, and uses vesicle transport for the recycling of its resident enzymes. This system must operate with high fidelity and efficiency for the correct modification of secretory glycoconjugates. In this review, we discuss recent advances on how coats, tethers, Rabs and SNAREs cooperate at the Golgi to achieve vesicle transport. We cover the well understood vesicle formation process orchestrated by the COPI coat, and the comprehensively documented fusion process governed by a set of Golgi localised SNAREs. Much less clear are the steps in-between formation and fusion of vesicles, and we therefore provide a much needed update of the latest findings about vesicle tethering. The interplay between Rab GTPases, golgin family coiled-coil tethers and the conserved oligomeric Golgi (COG) complex at the Golgi are thoroughly evaluated.
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Affiliation(s)
- Nathanael P Cottam
- Department of Biology (Area 9), University of York, Heslington, York, YO10 5DD, UK
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50
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Abstract
The striking morphology of the Golgi complex has fascinated cell biologists since its discovery over 100 years ago. Yet, despite intense efforts to understand how membrane flow relates to Golgi form and function, this organelle continues to baffle cell biologists and biochemists alike. Fundamental questions regarding Golgi function, while hotly debated, remain unresolved. Historically, Golgi function has been described from a protein-centric point of view, but we now appreciate that conceptual frameworks for how lipid metabolism is integrated with Golgi biogenesis and function are essential for a mechanistic understanding of this fascinating organelle. It is from a lipid-centric perspective that we discuss the larger question of Golgi dynamics and membrane trafficking. We review the growing body of evidence for how lipid metabolism is integrally written into the engineering of the Golgi system and highlight questions for future study.
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Affiliation(s)
- Vytas A Bankaitis
- Department of Cell and Developmental Biology, University of North Carolina School of Medicine, Chapel Hill, NC 27599-7090, USA.
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