1
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Srinivasan S, Álvarez D, John Peter AT, Vanni S. Unbiased MD simulations identify lipid binding sites in lipid transfer proteins. J Cell Biol 2024; 223:e202312055. [PMID: 39105757 PMCID: PMC11303870 DOI: 10.1083/jcb.202312055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Revised: 05/29/2024] [Accepted: 07/16/2024] [Indexed: 08/07/2024] Open
Abstract
The characterization of lipid binding to lipid transfer proteins (LTPs) is fundamental to understand their molecular mechanism. However, several structures of LTPs, and notably those proposed to act as bridges between membranes, do not provide the precise location of their endogenous lipid ligands. To address this limitation, computational approaches are a powerful alternative methodology, but they are often limited by the high flexibility of lipid substrates. Here, we develop a protocol based on unbiased coarse-grain molecular dynamics simulations in which lipids placed away from the protein can spontaneously bind to LTPs. This approach accurately determines binding pockets in LTPs and provides a working hypothesis for the lipid entry pathway. We apply this approach to characterize lipid binding to bridge LTPs of the Vps13-Atg2 family, for which the lipid localization inside the protein is currently unknown. Overall, our work paves the way to determine binding pockets and entry pathways for several LTPs in an inexpensive, fast, and accurate manner.
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Affiliation(s)
| | - Daniel Álvarez
- Department of Biology, University of Fribourg, Fribourg, Switzerland
- Departamento de Química Física y Analítica, Universidad de Oviedo, Oviedo, España
| | - Arun T John Peter
- Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Stefano Vanni
- Department of Biology, University of Fribourg, Fribourg, Switzerland
- Swiss National Center for Competence in Research Bio-inspired Materials, University of Fribourg , Fribourg, Switzerland
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2
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Pathak A, Willis KG, Bankaitis VA, McDermott MI. Mammalian START-like phosphatidylinositol transfer proteins - Physiological perspectives and roles in cancer biology. Biochim Biophys Acta Mol Cell Biol Lipids 2024; 1869:159529. [PMID: 38945251 DOI: 10.1016/j.bbalip.2024.159529] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2024] [Revised: 06/09/2024] [Accepted: 06/25/2024] [Indexed: 07/02/2024]
Abstract
PtdIns and its phosphorylated derivatives, the phosphoinositides, are the biochemical components of a major pathway of intracellular signaling in all eukaryotic cells. These lipids are few in terms of cohort of unique positional isomers, and are quantitatively minor species of the bulk cellular lipidome. Nevertheless, phosphoinositides regulate an impressively diverse set of biological processes. It is from that perspective that perturbations in phosphoinositide-dependent signaling pathways are increasingly being recognized as causal foundations of many human diseases - including cancer. Although phosphatidylinositol transfer proteins (PITPs) are not enzymes, these proteins are physiologically significant regulators of phosphoinositide signaling. As such, PITPs are conserved throughout the eukaryotic kingdom. Their biological importance notwithstanding, PITPs remain understudied. Herein, we review current information regarding PITP biology primarily focusing on how derangements in PITP function disrupt key signaling/developmental pathways and are associated with a growing list of pathologies in mammals.
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Affiliation(s)
- Adrija Pathak
- Department of Cell Biology and Genetics, Texas A&M Health Science Center, College Station, Texas, 77843, USA; Department of Biochemistry & Biophysics, Texas A&M University, College Station, TX, 77843, USA
| | - Katelyn G Willis
- Department of Cell Biology and Genetics, Texas A&M Health Science Center, College Station, Texas, 77843, USA
| | - Vytas A Bankaitis
- Department of Cell Biology and Genetics, Texas A&M Health Science Center, College Station, Texas, 77843, USA; Department of Chemistry, Texas A&M University, College Station, Texas 77843 USA
| | - Mark I McDermott
- Department of Cell Biology and Genetics, Texas A&M Health Science Center, College Station, Texas, 77843, USA.
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3
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Hamaï A, Drin G. Specificity of lipid transfer proteins: An in vitro story. Biochimie 2024:S0300-9084(24)00217-7. [PMID: 39304019 DOI: 10.1016/j.biochi.2024.09.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2024] [Revised: 09/06/2024] [Accepted: 09/17/2024] [Indexed: 09/22/2024]
Abstract
Lipids, which are highly diverse, are finely distributed between organelle membranes and the plasma membrane (PM) of eukaryotic cells. As a result, each compartment has its own lipid composition and molecular identity, which is essential for the functional fate of many proteins. This distribution of lipids depends on two main processes: lipid synthesis, which takes place in different subcellular regions, and the transfer of these lipids between and across membranes. This review will discuss the proteins that carry lipids throughout the cytosol, called LTPs (Lipid Transfer Proteins). More than the modes of action or biological roles of these proteins, we will focus on the in vitro strategies employed during the last 60 years to address a critical question: What are the lipid ligands of these LTPs? We will describe the extent to which these strategies, combined with structural data and investigations in cells, have made it possible to discover proteins, namely ORPs, Sec14, PITPs, STARDs, Ups/PRELIs, START-like, SMP-domain containing proteins, and bridge-like LTPs, which compose some of the main eukaryotic LTP families, and their lipid ligands. We will see how these approaches have played a central role in cell biology, showing that LTPs can connect distant metabolic branches, modulate the composition of cell membranes, and even create new subcellular compartments.
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Affiliation(s)
- Amazigh Hamaï
- Université Côte d'Azur, CNRS and Inserm, Institut de Pharmacologie Moléculaire et Cellulaire, UMR 7275, 660 route des lucioles, 06560, Valbonne Sophia Antipolis, France
| | - Guillaume Drin
- Université Côte d'Azur, CNRS and Inserm, Institut de Pharmacologie Moléculaire et Cellulaire, UMR 7275, 660 route des lucioles, 06560, Valbonne Sophia Antipolis, France.
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4
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Xu W, Peng X, Li Y, Zeng X, Yan W, Wang C, Wang CR, Chen S, Xu C, Tang X. OsSNDP4, a Sec14-nodulin Domain Protein, is Required for Pollen Development in Rice. RICE (NEW YORK, N.Y.) 2024; 17:54. [PMID: 39207611 PMCID: PMC11362464 DOI: 10.1186/s12284-024-00730-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/14/2024] [Accepted: 08/06/2024] [Indexed: 09/04/2024]
Abstract
Pollen is encased in a robust wall that shields the male gametophyte from various stresses and aids in pollination. The pollen wall consists of gametophyte-derived intine and sporophyte-derived exine. The exine is mainly composed of sporopollenin, which is biopolymers of aliphatic lipids and phenolics. The process of exine formation has been the subject of extensive research, yet the underlying molecular mechanisms remain elusive. In this study, we identified a rice mutant of the OsSNDP4 gene that is impaired in pollen development. We demonstrated that OsSNDP4, a putative Sec14-nodulin domain protein, exhibits a preference for binding to phosphatidylinositol (3)-phosphate [PI(3)P], a lipid primarily found in endosomal and vacuolar membranes. The OsSNDP4 protein was detected in association with the endoplasmic reticulum (ER), vacuolar membranes, and the nucleus. OsSNDP4 expression was detected in all tested organs but was notably higher in anthers during exine development. Loss of OsSNDP4 function led to abnormal vacuole dynamics, inhibition in Ubisch body development, and premature degradation of cellular contents and organelles in the tapetal cells. Microspores from the ossndp4 mutant plant displayed abnormal exine formation, abnormal vacuole enlargement, and ultimately, pollen abortion. RNA-seq assay revealed that genes involved in the biosynthesis of fatty acid and secondary metabolites, the biosynthesis of lipid polymers, and exosome formation were enriched among the down-regulated genes in the mutant anthers, which correlated with the morphological defects observed in the mutant anthers. Base on these findings, we propose that OsSNDP4 regulates pollen development by binding to PI(3)P and influencing the dynamics of membrane systems. The involvement of membrane systems in the regulation of sporopollenin biosynthesis, Ubisch body formation, and exine formation provides a novel mechanism regulating pollen wall development.
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Affiliation(s)
- Weitao Xu
- Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Sciences, South China Normal University, Guangzhou, China
| | - Xiaoqun Peng
- Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Sciences, South China Normal University, Guangzhou, China
| | - Yiqi Li
- Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Sciences, South China Normal University, Guangzhou, China
| | - Xinhuang Zeng
- Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Sciences, South China Normal University, Guangzhou, China
| | - Wei Yan
- Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Sciences, South China Normal University, Guangzhou, China
- Shenzhen Institute of Molecular Crop Design, Shenzhen, China
| | - Changjian Wang
- Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Sciences, South China Normal University, Guangzhou, China
| | - Cheng Rui Wang
- Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Sciences, South China Normal University, Guangzhou, China
| | - Shunquan Chen
- Shenzhen Institute of Molecular Crop Design, Shenzhen, China
| | - Chunjue Xu
- Shenzhen Institute of Molecular Crop Design, Shenzhen, China.
| | - Xiaoyan Tang
- Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Sciences, South China Normal University, Guangzhou, China.
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, China.
- Shenzhen Institute of Molecular Crop Design, Shenzhen, China.
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5
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Moqadam M, Gartan P, Talandashti R, Chiapparino A, Titeca K, Gavin AC, Reuter N. A Membrane-Assisted Mechanism for the Release of Ceramide from the CERT START Domain. J Phys Chem B 2024; 128:6338-6351. [PMID: 38903016 PMCID: PMC11228987 DOI: 10.1021/acs.jpcb.4c02398] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2024] [Revised: 05/26/2024] [Accepted: 06/11/2024] [Indexed: 06/22/2024]
Abstract
Ceramide transfer protein CERT is the mediator of nonvesicular transfer of ceramide from the ER to Golgi. In CERT, START is the domain responsible for the binding and transport of ceramide. A wealth of structural data has revealed a helix-grip fold surrounding a large hydrophobic cavity holding the ceramide. Yet, little is known about the mechanisms by which START releases the ceramide through the polar region and into the packed environment of cellular membranes. As such events do not lend themselves easily to experimental investigations, we used multiple unbiased microsecond-long molecular simulations. We propose a membrane-assisted mechanism in which the membrane acts as an allosteric effector initiating the release of ceramide and where the passage of the ceramide acyl chains is facilitated by the intercalation of a single phosphatidylcholine lipid in the cavity, practically greasing the ceramide way out. We verify using free energy calculation and experimental lipidomics data that CERT forms stable complexes with phosphatidylcholine lipids, in addition to ceramide, thus providing validation for the proposed mechanism.
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Affiliation(s)
- Mahmoud Moqadam
- Department
of Chemistry, University of Bergen, Bergen 5020, Norway
- Computational
Biology Unit, Department of Informatics, University of Bergen, Bergen 5020, Norway
| | - Parveen Gartan
- Department
of Chemistry, University of Bergen, Bergen 5020, Norway
- Computational
Biology Unit, Department of Informatics, University of Bergen, Bergen 5020, Norway
| | - Reza Talandashti
- Department
of Chemistry, University of Bergen, Bergen 5020, Norway
- Computational
Biology Unit, Department of Informatics, University of Bergen, Bergen 5020, Norway
| | - Antonella Chiapparino
- European
Molecular Biology Laboratory, EMBL, Meyerhofstrasse 1, Heidelberg D-69117, Germany
| | - Kevin Titeca
- European
Molecular Biology Laboratory, EMBL, Meyerhofstrasse 1, Heidelberg D-69117, Germany
- Department
of Cell Physiology and Metabolism, University
of Geneva, CMU Rue Michel-Servet 1, Genève 4 1211, Switzerland
| | - Anne-Claude Gavin
- Department
of Cell Physiology and Metabolism, University
of Geneva, CMU Rue Michel-Servet 1, Genève 4 1211, Switzerland
| | - Nathalie Reuter
- Department
of Chemistry, University of Bergen, Bergen 5020, Norway
- Computational
Biology Unit, Department of Informatics, University of Bergen, Bergen 5020, Norway
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6
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Palamiuc L, Johnson JL, Haratipour Z, Loughran RM, Choi WJ, Arora GK, Tieu V, Ly K, Llorente A, Crabtree S, Wong JC, Ravi A, Wiederhold T, Murad R, Blind RD, Emerling BM. Hippo and PI5P4K signaling intersect to control the transcriptional activation of YAP. Sci Signal 2024; 17:eado6266. [PMID: 38805583 PMCID: PMC11283293 DOI: 10.1126/scisignal.ado6266] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2024] [Accepted: 05/09/2024] [Indexed: 05/30/2024]
Abstract
Phosphoinositides are essential signaling molecules. The PI5P4K family of phosphoinositide kinases and their substrates and products, PI5P and PI4,5P2, respectively, are emerging as intracellular metabolic and stress sensors. We performed an unbiased screen to investigate the signals that these kinases relay and the specific upstream regulators controlling this signaling node. We found that the core Hippo pathway kinases MST1/2 phosphorylated PI5P4Ks and inhibited their signaling in vitro and in cells. We further showed that PI5P4K activity regulated several Hippo- and YAP-related phenotypes, specifically decreasing the interaction between the key Hippo proteins MOB1 and LATS and stimulating the YAP-mediated genetic program governing epithelial-to-mesenchymal transition. Mechanistically, we showed that PI5P interacted with MOB1 and enhanced its interaction with LATS, thereby providing a signaling connection between the Hippo pathway and PI5P4Ks. These findings reveal how these two important evolutionarily conserved signaling pathways are integrated to regulate metazoan development and human disease.
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Affiliation(s)
| | - Jared L. Johnson
- Weill Cornell Medicine, Meyer Cancer Center, New York, NY 10021
- Weill Cornell Medicine, Department of Medicine, New York, NY 10021
| | - Zeinab Haratipour
- Vanderbilt University Medical Center, Department of Medicine, Division of Diabetes, Endocrinology and Metabolism, Nashville, TN 37232
- Austin Peay State University, Clarksville, TN, 37044
| | | | - Woong Jae Choi
- Vanderbilt University Medical Center, Department of Medicine, Division of Diabetes, Endocrinology and Metabolism, Nashville, TN 37232
| | | | | | - Kyanh Ly
- Sanford Burnham Prebys, La Jolla, CA 92037
| | | | | | - Jenny C.Y. Wong
- Weill Cornell Medicine, Meyer Cancer Center, New York, NY 10021
- New York University Grossman School of Medicine, Department of Cell Biology, New York, NY 10016, USA
| | | | | | - Rabi Murad
- Sanford Burnham Prebys, La Jolla, CA 92037
| | - Raymond D. Blind
- Vanderbilt University Medical Center, Department of Medicine, Division of Diabetes, Endocrinology and Metabolism, Nashville, TN 37232
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7
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Kim YJ, Pemberton JG, Eisenreichova A, Mandal A, Koukalova A, Rohilla P, Sohn M, Konradi AW, Tang TT, Boura E, Balla T. Non-vesicular phosphatidylinositol transfer plays critical roles in defining organelle lipid composition. EMBO J 2024; 43:2035-2061. [PMID: 38627600 PMCID: PMC11099152 DOI: 10.1038/s44318-024-00096-3] [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: 09/11/2023] [Revised: 03/12/2024] [Accepted: 03/21/2024] [Indexed: 05/18/2024] Open
Abstract
Phosphatidylinositol (PI) is the precursor lipid for the minor phosphoinositides (PPIns), which are critical for multiple functions in all eukaryotic cells. It is poorly understood how phosphatidylinositol, which is synthesized in the ER, reaches those membranes where PPIns are formed. Here, we used VT01454, a recently identified inhibitor of class I PI transfer proteins (PITPs), to unravel their roles in lipid metabolism, and solved the structure of inhibitor-bound PITPNA to gain insight into the mode of inhibition. We found that class I PITPs not only distribute PI for PPIns production in various organelles such as the plasma membrane (PM) and late endosomes/lysosomes, but that their inhibition also significantly reduced the levels of phosphatidylserine, di- and triacylglycerols, and other lipids, and caused prominent increases in phosphatidic acid. While VT01454 did not inhibit Golgi PI4P formation nor reduce resting PM PI(4,5)P2 levels, the recovery of the PM pool of PI(4,5)P2 after receptor-mediated hydrolysis required both class I and class II PITPs. Overall, these studies show that class I PITPs differentially regulate phosphoinositide pools and affect the overall cellular lipid landscape.
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Affiliation(s)
- 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, 20892, USA
| | - 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, 20892, USA
| | - Andrea Eisenreichova
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo nam. 2., 166 10, Prague 6, Czech Republic
| | - Amrita Mandal
- Section on Molecular Signal Transduction, Eunice Kennedy Shriver, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Alena Koukalova
- Section on Molecular Signal Transduction, Eunice Kennedy Shriver, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Pooja Rohilla
- Section on Molecular Signal Transduction, Eunice Kennedy Shriver, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Mira Sohn
- Section on Molecular Signal Transduction, Eunice Kennedy Shriver, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, 20892, USA
| | | | | | - Evzen Boura
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo nam. 2., 166 10, Prague 6, 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, 20892, USA.
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8
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Diep DTV, Collado J, Hugenroth M, Fausten RM, Percifull L, Wälte M, Schuberth C, Schmidt O, Fernández-Busnadiego R, Bohnert M. A metabolically controlled contact site between vacuoles and lipid droplets in yeast. Dev Cell 2024; 59:740-758.e10. [PMID: 38367622 DOI: 10.1016/j.devcel.2024.01.016] [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: 04/26/2023] [Revised: 11/17/2023] [Accepted: 01/18/2024] [Indexed: 02/19/2024]
Abstract
The lipid droplet (LD) organization proteins Ldo16 and Ldo45 affect multiple aspects of LD biology in yeast. They are linked to the LD biogenesis machinery seipin, and their loss causes defects in LD positioning, protein targeting, and breakdown. However, their molecular roles remained enigmatic. Here, we report that Ldo16/45 form a tether complex with Vac8 to create vacuole lipid droplet (vCLIP) contact sites, which can form in the absence of seipin. The phosphatidylinositol transfer protein (PITP) Pdr16 is a further vCLIP-resident recruited specifically by Ldo45. While only an LD subpopulation is engaged in vCLIPs at glucose-replete conditions, nutrient deprivation results in vCLIP expansion, and vCLIP defects impair lipophagy upon prolonged starvation. In summary, Ldo16/45 are multifunctional proteins that control the formation of a metabolically regulated contact site. Our studies suggest a link between LD biogenesis and breakdown and contribute to a deeper understanding of how lipid homeostasis is maintained during metabolic challenges.
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Affiliation(s)
- Duy Trong Vien Diep
- Institute of Cell Dynamics and Imaging, University of Münster, Von-Esmarch-Strasse 56, 48149 Münster, Germany; Cells in Motion Interfaculty Centre (CiM), University of Münster, Münster, Germany
| | - Javier Collado
- Institute of Neuropathology, University Medical Center Göttingen, 37099 Göttingen, Germany
| | - Marie Hugenroth
- Institute of Cell Dynamics and Imaging, University of Münster, Von-Esmarch-Strasse 56, 48149 Münster, Germany; Cells in Motion Interfaculty Centre (CiM), University of Münster, Münster, Germany
| | - Rebecca Martina Fausten
- Institute of Cell Dynamics and Imaging, University of Münster, Von-Esmarch-Strasse 56, 48149 Münster, Germany; Cells in Motion Interfaculty Centre (CiM), University of Münster, Münster, Germany
| | - Louis Percifull
- Institute of Cell Dynamics and Imaging, University of Münster, Von-Esmarch-Strasse 56, 48149 Münster, Germany; Cells in Motion Interfaculty Centre (CiM), University of Münster, Münster, Germany
| | - Mike Wälte
- Institute of Cell Dynamics and Imaging, University of Münster, Von-Esmarch-Strasse 56, 48149 Münster, Germany
| | - Christian Schuberth
- Institute of Cell Dynamics and Imaging, University of Münster, Von-Esmarch-Strasse 56, 48149 Münster, Germany; Cells in Motion Interfaculty Centre (CiM), University of Münster, Münster, Germany
| | - Oliver Schmidt
- Institute of Cell Biology, Biocenter Innsbruck, Medical University of Innsbruck, 6020 Innsbruck, Austria
| | - Rubén Fernández-Busnadiego
- Institute of Neuropathology, University Medical Center Göttingen, 37099 Göttingen, Germany; Cluster of Excellence "Multiscale Imaging: from Molecular Machines to Networks of Excitable Cells" (MBExC), University of Göttingen, Göttingen, Germany; Faculty of Physics, University of Göttingen, Göttingen 37077, Germany
| | - Maria Bohnert
- Institute of Cell Dynamics and Imaging, University of Münster, Von-Esmarch-Strasse 56, 48149 Münster, Germany; Cells in Motion Interfaculty Centre (CiM), University of Münster, Münster, Germany.
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9
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Fuggetta N, Rigolli N, Magdeleine M, Hamaï A, Seminara A, Drin G. Reconstitution of ORP-mediated lipid exchange coupled to PI4P metabolism. Proc Natl Acad Sci U S A 2024; 121:e2315493121. [PMID: 38408242 PMCID: PMC10927502 DOI: 10.1073/pnas.2315493121] [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: 09/13/2023] [Accepted: 01/24/2024] [Indexed: 02/28/2024] Open
Abstract
Oxysterol-binding protein-related proteins (ORPs) play key roles in the distribution of lipids in eukaryotic cells by exchanging sterol or phosphatidylserine for PI4P between the endoplasmic reticulum (ER) and other cell regions. However, it is unclear how their exchange capacity is coupled to PI4P metabolism. To address this question quantitatively, we analyze the activity of a representative ORP, Osh4p, in an ER/Golgi interface reconstituted with ER- and Golgi-mimetic membranes functionalized with PI4P phosphatase Sac1p and phosphatidylinositol (PI) 4-kinase, respectively. Using real-time assays, we demonstrate that upon adenosine triphosphate (ATP) addition, Osh4p creates a sterol gradient between these membranes, relying on the spatially distant synthesis and hydrolysis of PI4P, and quantify how much PI4P is needed for this process. Then, we develop a quantitatively accurate kinetic model, validated by our data, and extrapolate this to estimate to what extent PI4P metabolism can drive ORP-mediated sterol transfer in cells. Finally, we show that Sec14p can support PI4P metabolism and Osh4p activity by transferring PI between membranes. This study establishes that PI4P synthesis drives ORP-mediated lipid exchange and that ATP energy is needed to generate intermembrane lipid gradients. Furthermore, it defines to what extent ORPs can distribute lipids in the cell and reassesses the role of PI-transfer proteins in PI4P metabolism.
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Affiliation(s)
- Nicolas Fuggetta
- Université Côte d’Azur, Centre National de la Recherche Scientifique, Institut de Pharmacologie Moléculaire et Cellulaire, Valbonne06560, France
| | - Nicola Rigolli
- Department of Physics, École Normale Supérieure (LPENS), Paris75005, France
| | - Maud Magdeleine
- Université Côte d’Azur, Centre National de la Recherche Scientifique, Institut de Pharmacologie Moléculaire et Cellulaire, Valbonne06560, France
| | - Amazigh Hamaï
- Université Côte d’Azur, Centre National de la Recherche Scientifique, Institut de Pharmacologie Moléculaire et Cellulaire, Valbonne06560, France
| | - Agnese Seminara
- Malga, Department of Civil, Chemical and Environmental Engineering, University of Genoa, Genoa16145, Italy
| | - Guillaume Drin
- Université Côte d’Azur, Centre National de la Recherche Scientifique, Institut de Pharmacologie Moléculaire et Cellulaire, Valbonne06560, France
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10
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Matsuse K, Hara M, Iwama R, Horiuchi H, Fukuda R. Phosphatidylserine synthase plays a critical role in the utilization of n-alkanes in the yeast Yarrowia lipolytica. FEMS Yeast Res 2024; 24:foae030. [PMID: 39293814 PMCID: PMC11462088 DOI: 10.1093/femsyr/foae030] [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: 07/26/2024] [Revised: 09/06/2024] [Accepted: 09/17/2024] [Indexed: 09/20/2024] Open
Abstract
The yeast Yarrowia lipolytica can assimilate n-alkane as a carbon and energy source. To elucidate the significance of phosphatidylserine (PS) in the utilization of n-alkane in Y. lipolytica, we investigated the role of the Y. lipolytica ortholog (PSS1) of Saccharomyces cerevisiae PSS1/CHO1, which encodes a PS synthase. The PSS1 deletion mutant (pss1Δ) of Y. lipolytica could not grow on minimal medium in the absence of ethanolamine and choline but grew when either ethanolamine or choline was supplied to synthesize phosphatidylethanolamine and phosphatidylcholine. The pss1Δ strain exhibited severe growth defects on media containing n-alkanes even in the presence of ethanolamine and choline. In the pss1Δ strain, the transcription of ALK1, which encodes a primary cytochrome P450 that catalyses the hydroxylation of n-alkanes in the endoplasmic reticulum, was upregulated by n-alkane as in the wild-type strain. However, the production of functional P450 was not detected, as indicated by the absence of reduced CO-difference spectra in the pss1Δ strain. PS was undetectable in the lipid extracts of the pss1Δ strain. These results underscore the critical role of PSS1 in the biosynthesis of PS, which is essential for the production of functional P450 enzymes involved in n-alkane hydroxylation in Y. lipolytica.
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Affiliation(s)
- Katsuro Matsuse
- Department of Biotechnology, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Mariho Hara
- Department of Biotechnology, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Ryo Iwama
- Department of Biotechnology, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo 113-8657, Japan
- Collaborative Research Institute for Innovative Microbiology, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Hiroyuki Horiuchi
- Department of Biotechnology, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo 113-8657, Japan
- Collaborative Research Institute for Innovative Microbiology, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Ryouichi Fukuda
- Department of Biotechnology, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo 113-8657, Japan
- Collaborative Research Institute for Innovative Microbiology, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo 113-8657, Japan
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11
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Chi ES, Stivison EA, Blind RD. SF-1 Induces Nuclear PIP2. Biomolecules 2023; 13:1509. [PMID: 37892191 PMCID: PMC10604688 DOI: 10.3390/biom13101509] [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: 09/01/2023] [Revised: 10/06/2023] [Accepted: 10/07/2023] [Indexed: 10/29/2023] Open
Abstract
Metazoan cell nuclei contain non-membrane pools of the phosphoinositide lipid PI(4,5)P2 (PIP2), but how this hydrophobic lipid exists within the aqueous nucleoplasm remains unclear. Steroidogenic Factor-1 (NR5A1, SF-1) is a nuclear receptor that binds PIP2 in vitro, and a co-crystal structure of the complex suggests the acyl chains of PIP2 are hidden in the hydrophobic core of the SF-1 protein while the PIP2 headgroup is solvent-exposed. This binding mode explains how SF-1 can solubilize nuclear PIP2; however, cellular evidence that SF-1 expression associates with nuclear PIP2 has been lacking. Here, we examined if tetracycline induction of SF-1 expression would associate with nuclear accumulation of PIP2, using antibodies directed against the PIP2 headgroup. Indeed, tetracycline induction of wild-type SF-1 induced a signal in the nucleus of HEK cells that cross-reacts with PIP2 antibodies, but did not cross-react with antibodies against the lower abundance phosphoinositide PI(3,4,5)P3 (PIP3). The nuclear PIP2 signal co-localized with FLAG-tagged SF-1 in the nuclear compartment. To determine if the nuclear PIP2 signal was dependent on the ability of SF-1 to bind PIP2, we examined a "pocket mutant" of SF-1 (A270W, L345F) shown to be deficient in phospholipid binding by mass spectrometry. Tetracycline induction of this pocket mutant SF-1 in HEK cells failed to induce a detectable PIP2 antibody cross-reactive signal, despite similar Tet-induced expression levels of the wild-type and pocket mutant SF-1 proteins in these cells. Together, these data are the first to suggest that expression of SF-1 induces a PIP2 antibody cross-reactive signal in the nucleus, consistent with X-ray crystallographic and biochemical evidence suggesting SF-1 binds PIP2 in human cells.
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Affiliation(s)
| | | | - Raymond D. Blind
- Department of Medicine, Division of Diabetes, Endocrinology and Metabolism, Vanderbilt University Medical Center, Nashville, TN 37232, USA
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12
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Wilson S, Panagabko C, Laleye T, Robinson M, Jagas S, Bowman D, Atkinson J. Synthesis of a photocleavable bola-phosphatidylcholine. Bioorg Med Chem 2023; 93:117465. [PMID: 37688997 DOI: 10.1016/j.bmc.2023.117465] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Revised: 09/01/2023] [Accepted: 09/02/2023] [Indexed: 09/11/2023]
Abstract
Phosphatidylinositol transfer proteins (PITPs) are ubiquitous in eukaryotes and are involved in the regulation of phospholipid metabolism, membrane trafficking, and signal transduction. Sec14 is a yeast PITP that has been shown to transfer phosphatidylinositol (PI) or phosphatidylcholine (PC) from the endoplasmic reticulum to the Golgi. It is now believed that Sec14 may play a greater role than just shuttling PI and PC throughout the cell. Genetic evidence suggests that retrieval of membrane-bound PI by Sec14 also manages to present PI to the phosphatidylinositol-4-kinase, Pik1, to generate phosphatidylinositol-4-phosphate, PI(4)P. To test this hypothetical model, we designed a photocleavable bolalipid to span the entire membrane, having one phosphatidylcholine or phosphatidylinositol headgroup on each leaflet connected by a photocleavable diacid. Sec14 should not be able to present the bola-PI to Pik1 for phosphorylation as the head group will be difficult to lift from the bilayer as it is tethered on the opposite leaflet. After photocleavage the two halves would behave as a normal phospholipid, thus phosphorylation by Pik1 would resume. We report here the synthesis of a photocleavable bola-PC, a precursor to the desired bola-PI. The mono-photocleavable bola-PC lipid was designed to contain two glycerol molecules with choline head groups connected through a phosphodiester bond at the sn3 position. Each glycerol was acylated with palmitic acid at the sn1 position. These two glycerol moieties were then connected through their respective sn2 hydroxyls via a photocleavable dicarboxylic acid containing a nitrophenyl ethyl photolabile protecting group. The bola-PC and its precursors were found to undergo efficient photocleavage when irradiated in solution or in vesicles with 365 nm light for two minutes. Treatment of the bola-PC with a mutant phospholipase D and myo-inositol produced a mono-inositol bola-PC-PI.
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Affiliation(s)
- Sean Wilson
- Department of Chemistry, Brock University, Ontario, Canada
| | | | - Tayo Laleye
- Department of Chemistry, Brock University, Ontario, Canada
| | | | - Samuel Jagas
- Department of Chemistry, Brock University, Ontario, Canada
| | - David Bowman
- Advanced Biomanufacturing Centre, Brock University, Ontario, Canada
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13
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Arabiotorre A, Bankaitis VA, Grabon A. Regulation of phosphoinositide metabolism in Apicomplexan parasites. Front Cell Dev Biol 2023; 11:1163574. [PMID: 37791074 PMCID: PMC10543664 DOI: 10.3389/fcell.2023.1163574] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Accepted: 07/11/2023] [Indexed: 10/05/2023] Open
Abstract
Phosphoinositides are a biologically essential class of phospholipids that contribute to organelle membrane identity, modulate membrane trafficking pathways, and are central components of major signal transduction pathways that operate on the cytosolic face of intracellular membranes in eukaryotes. Apicomplexans (such as Toxoplasma gondii and Plasmodium spp.) are obligate intracellular parasites that are important causative agents of disease in animals and humans. Recent advances in molecular and cell biology of Apicomplexan parasites reveal important roles for phosphoinositide signaling in key aspects of parasitosis. These include invasion of host cells, intracellular survival and replication, egress from host cells, and extracellular motility. As Apicomplexans have adapted to the organization of essential signaling pathways to accommodate their complex parasitic lifestyle, these organisms offer experimentally tractable systems for studying the evolution, conservation, and repurposing of phosphoinositide signaling. In this review, we describe the regulatory mechanisms that control the spatial and temporal regulation of phosphoinositides in the Apicomplexan parasites Plasmodium and T. gondii. We further discuss the similarities and differences presented by Apicomplexan phosphoinositide signaling relative to how these pathways are regulated in other eukaryotic organisms.
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Affiliation(s)
- Angela Arabiotorre
- Department of Cell Biology and Genetics, College of Medicine Texas A&M Health Sciences Center College Station, Bryan, TX, United States
| | - Vytas A. Bankaitis
- Department of Cell Biology and Genetics, College of Medicine Texas A&M Health Sciences Center College Station, Bryan, TX, United States
- Department of Biochemistry and Biophysics Texas A&M University College Station, College Station, TX, United States
- Department of Chemistry Texas A&M University College Station, College Station, TX, United States
| | - Aby Grabon
- Department of Cell Biology and Genetics, College of Medicine Texas A&M Health Sciences Center College Station, Bryan, TX, United States
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14
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Qin Y, Zhang B, Wang Y, Su R. Characterization of SEC14 family in wheat and the function of TaSEC14-7B in salt stress tolerance. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2023; 202:107926. [PMID: 37566993 DOI: 10.1016/j.plaphy.2023.107926] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 07/08/2023] [Accepted: 08/01/2023] [Indexed: 08/13/2023]
Abstract
Phospholipids are important components of plant biofilms and signal transduction. They are divided into glycerophospholipids and sphingolipids. Phosphatidylinositol (PI) is an intracellular glycerophospholipid. SEC14s are PI transporter proteins that are widely presented in eukaryotic. They take part in membrane transportation, inositol phosphate metabolism and adversity stress response. To date, systematic analysis of the SEC14 gene family in wheat, especially the function of SEC14 in salt stress tolerance has not been reported. In this study, 106 SEC14 family members have been identified in wheat. Then, a salt inducible Sec14 family member TaSEC14-7B was selected for further functional study in response to salt stress. Expression analysis demonstrated TaSEC14-7B was induced by NaCl, PEG treatment and localized both in the cell membrane and nucleus. TaSEC14-7B over-expressing Arabidopsis increased salt stress tolerance. Under salt stress, the transgenic plants displayed higher germination rate, longer primary root length, more soluble sugar accumulation, higher antioxidant enzyme activity and lower oxidative damage than the wild type plants. Also, at the presence of NaCl stress, the expression level of ABF4, P5CS, PLC4 and AtPLC7 genes was higher in TaSEC14 transgenic Arabidopsis than in the wild type ones. All these results lay a foundation for further study of Sec14 in wheat.
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Affiliation(s)
- Yuxiang Qin
- School of Biological Science and Technology, University of Jinan, Jinan, 250022, Shandong, China.
| | - Bao Zhang
- School of Biological Science and Technology, University of Jinan, Jinan, 250022, Shandong, China
| | - Yuning Wang
- School of Biological Science and Technology, University of Jinan, Jinan, 250022, Shandong, China
| | - Ruiping Su
- School of Biological Science and Technology, University of Jinan, Jinan, 250022, Shandong, China
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15
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Liu C, Mentzelopoulou A, Papagavriil F, Ramachandran P, Perraki A, Claus L, Barg S, Dörmann P, Jaillais Y, Johnen P, Russinova E, Gizeli E, Schaaf G, Moschou PN. SEC14-like condensate phase transitions at plasma membranes regulate root growth in Arabidopsis. PLoS Biol 2023; 21:e3002305. [PMID: 37721949 PMCID: PMC10538751 DOI: 10.1371/journal.pbio.3002305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Revised: 09/28/2023] [Accepted: 08/20/2023] [Indexed: 09/20/2023] Open
Abstract
Protein function can be modulated by phase transitions in their material properties, which can range from liquid- to solid-like; yet, the mechanisms that drive these transitions and whether they are important for physiology are still unknown. In the model plant Arabidopsis, we show that developmental robustness is reinforced by phase transitions of the plasma membrane-bound lipid-binding protein SEC14-like. Using imaging, genetics, and in vitro reconstitution experiments, we show that SEC14-like undergoes liquid-like phase separation in the root stem cells. Outside the stem cell niche, SEC14-like associates with the caspase-like protease separase and conserved microtubule motors at unique polar plasma membrane interfaces. In these interfaces, SEC14-like undergoes processing by separase, which promotes its liquid-to-solid transition. This transition is important for root development, as lines expressing an uncleavable SEC14-like variant or mutants of separase and associated microtubule motors show similar developmental phenotypes. Furthermore, the processed and solidified but not the liquid form of SEC14-like interacts with and regulates the polarity of the auxin efflux carrier PINFORMED2. This work demonstrates that robust development can involve liquid-to-solid transitions mediated by proteolysis at unique plasma membrane interfaces.
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Affiliation(s)
- Chen Liu
- Department of Biology, University of Crete, Heraklion, Greece
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, Heraklion, Greece
- Department of Plant Biology, Uppsala BioCenter, Swedish University of Agricultural Sciences and Linnean Center for Plant Biology, Uppsala, Sweden
| | - Andriani Mentzelopoulou
- Department of Biology, University of Crete, Heraklion, Greece
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, Heraklion, Greece
| | - Fotini Papagavriil
- Department of Biology, University of Crete, Heraklion, Greece
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, Heraklion, Greece
| | - Prashanth Ramachandran
- Department of Organismal Biology, Physiological Botany, Linnean Centre for Plant Biology, Uppsala University, Uppsala, Sweden
| | - Artemis Perraki
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, Heraklion, Greece
| | - Lucas Claus
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- Center for Plant Systems Biology, Ghent, Belgium
| | - Sebastian Barg
- Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden
| | - Peter Dörmann
- Institute of Molecular Physiology and Biotechnology of Plants, University of Bonn, Bonn, Germany
| | - Yvon Jaillais
- Laboratoire Reproduction et Développement des Plantes, ENS de Lyon, Université Claude Bernard Lyon 1, CNRS, INRAE, Lyon, France
| | - Philipp Johnen
- Department of Plant Nutrition, Institute of Crop Science and Resource Conservation, University of Bonn, Bonn, Germany
| | - Eugenia Russinova
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- Center for Plant Systems Biology, Ghent, Belgium
| | - Electra Gizeli
- Department of Biology, University of Crete, Heraklion, Greece
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, Heraklion, Greece
| | - Gabriel Schaaf
- Department of Plant Nutrition, Institute of Crop Science and Resource Conservation, University of Bonn, Bonn, Germany
| | - Panagiotis Nikolaou Moschou
- Department of Biology, University of Crete, Heraklion, Greece
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, Heraklion, Greece
- Department of Plant Biology, Uppsala BioCenter, Swedish University of Agricultural Sciences and Linnean Center for Plant Biology, Uppsala, Sweden
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16
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Fuggetta N, Rigolli N, Magdeleine M, Seminara A, Drin G. Reconstitution of ORP-mediated lipid exchange process coupled to PI(4)P metabolism. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.04.551917. [PMID: 37577629 PMCID: PMC10418177 DOI: 10.1101/2023.08.04.551917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/15/2023]
Abstract
Lipid distribution in the eukaryotic cells depends on tight couplings between lipid transfer and lipid metabolism. Yet these couplings remain poorly described. Notably, it is unclear to what extent lipid exchangers of the OSBP-related proteins (ORPs) family, coupled to PI(4)P metabolism, contribute to the formation of sterol and phosphatidylserine gradient between the endoplasmic reticulum (ER) and other cell regions. To address this question, we have examined in vitro the activity of Osh4p, a representative ORP, between Golgi mimetic membranes in which PI(4)P is produced by a PI 4-kinase and ER mimetic membranes in which PI(4)P is hydrolyzed by the phosphatase Sac1p. Using quantitative, real-time assays, we demonstrate that Osh4p creates a sterol gradient between the two membranes by sterol/PI(4)P exchange as soon as a PI(4)P gradient is generated at this interface following ATP addition, and define how much PI(4)P must be synthesized for this process. Then, using a kinetic model supported by our in vitro data, we estimate to what extent PI(4)P metabolism can drive lipid transfer in cells. Finally, we show that Sec14p, by transferring phosphatidylinositol between membranes, can support the synthesis of PI(4)P and the creation of a sterol gradient by Osh4p. These results indicate to what extent ORPs, under the control of PI(4)P metabolism, can distribute lipids in the cell.
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Affiliation(s)
- Nicolas Fuggetta
- Université Côte d'Azur, Centre National de la Recherche Scientifique, Institut de Pharmacologie Moléculaire et Cellulaire, 660 route des lucioles, 06560 Valbonne, France
| | - Nicola Rigolli
- Laboratoire de Physique, École Normale Supérieure (LPENS), 75005 Paris, France
| | - Maud Magdeleine
- Université Côte d'Azur, Centre National de la Recherche Scientifique, Institut de Pharmacologie Moléculaire et Cellulaire, 660 route des lucioles, 06560 Valbonne, France
| | - Agnese Seminara
- Malga, Department of Civil, Chemical and Environmental Engineering, University of Genoa, Villa Cambiaso 1, 16145 Genoa, Italy
| | - Guillaume Drin
- Université Côte d'Azur, Centre National de la Recherche Scientifique, Institut de Pharmacologie Moléculaire et Cellulaire, 660 route des lucioles, 06560 Valbonne, France
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17
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Yeh YT, Sona C, Yan X, Li Y, Pathak A, McDermott MI, Xie Z, Liu L, Arunagiri A, Wang Y, Cazenave-Gassiot A, Ghosh A, von Meyenn F, Kumarasamy S, Najjar SM, Jia S, Wenk MR, Traynor-Kaplan A, Arvan P, Barg S, Bankaitis VA, Poy MN. Restoration of PITPNA in Type 2 diabetic human islets reverses pancreatic beta-cell dysfunction. Nat Commun 2023; 14:4250. [PMID: 37460527 PMCID: PMC10352338 DOI: 10.1038/s41467-023-39978-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Accepted: 07/06/2023] [Indexed: 07/20/2023] Open
Abstract
Defects in insulin processing and granule maturation are linked to pancreatic beta-cell failure during type 2 diabetes (T2D). Phosphatidylinositol transfer protein alpha (PITPNA) stimulates activity of phosphatidylinositol (PtdIns) 4-OH kinase to produce sufficient PtdIns-4-phosphate (PtdIns-4-P) in the trans-Golgi network to promote insulin granule maturation. PITPNA in beta-cells of T2D human subjects is markedly reduced suggesting its depletion accompanies beta-cell dysfunction. Conditional deletion of Pitpna in the beta-cells of Ins-Cre, Pitpnaflox/flox mice leads to hyperglycemia resulting from decreasing glucose-stimulated insulin secretion (GSIS) and reducing pancreatic beta-cell mass. Furthermore, PITPNA silencing in human islets confirms its role in PtdIns-4-P synthesis and leads to impaired insulin granule maturation and docking, GSIS, and proinsulin processing with evidence of ER stress. Restoration of PITPNA in islets of T2D human subjects reverses these beta-cell defects and identify PITPNA as a critical target linked to beta-cell failure in T2D.
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Affiliation(s)
- Yu-Te Yeh
- Johns Hopkins University, All Children's Hospital, St. Petersburg, FL, 33701, USA
- Johns Hopkins University, Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, Baltimore, MD, 21287, USA
| | - Chandan Sona
- Johns Hopkins University, All Children's Hospital, St. Petersburg, FL, 33701, USA
- Johns Hopkins University, Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, Baltimore, MD, 21287, USA
| | - Xin Yan
- Translational Neurodegeneration Section "Albrecht-Kossel", Department of Neurology, University Medical Center Rostock, Rostock, 18147, Germany
- Max Delbrück Center for Molecular Medicine, Robert Rössle Strasse 10, Berlin, 13125, Germany
| | - Yunxiao Li
- Translational Neurodegeneration Section "Albrecht-Kossel", Department of Neurology, University Medical Center Rostock, Rostock, 18147, Germany
| | - Adrija Pathak
- Department of Biochemistry & Biophysics, Texas A&M University, College Station, TX, 77843, USA
| | - Mark I McDermott
- Department of Cell Biology & Genetics, Texas A&M Health Science Center, College Station, TX, 77843, USA
| | - Zhigang Xie
- Department of Cell Biology & Genetics, Texas A&M Health Science Center, College Station, TX, 77843, USA
| | - Liangwen Liu
- Medical Cell Biology, Uppsala University, 75123, Uppsala, Sweden
| | - Anoop Arunagiri
- Division of Metabolism, Endocrinology & Diabetes, University of Michigan Medical School, Ann Arbor, MI, 48105, USA
| | - Yuting Wang
- Max Delbrück Center for Molecular Medicine, Robert Rössle Strasse 10, Berlin, 13125, Germany
| | - Amaury Cazenave-Gassiot
- Singapore Lipidomics Incubator, Life Sciences Institute, National University of Singapore, 117456, Singapore, Singapore
- Department of Biochemistry and Precision Medicine TRP, Yong Loo Lin School of Medicine, National University of Singapore, 117597, Singapore, Singapore
| | - Adhideb Ghosh
- Laboratory of Nutrition and Metabolic Epigenetics, Department of Health Sciences and Technology, ETH Zurich, Schwerzenbach, 8603, Switzerland
| | - Ferdinand von Meyenn
- Laboratory of Nutrition and Metabolic Epigenetics, Department of Health Sciences and Technology, ETH Zurich, Schwerzenbach, 8603, Switzerland
| | - Sivarajan Kumarasamy
- Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Athens, OH, 45701, USA
- Diabetes Institute, Heritage College of Osteopathic Medicine, Ohio University, Athens, OH, 45701, USA
| | - Sonia M Najjar
- Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Athens, OH, 45701, USA
- Diabetes Institute, Heritage College of Osteopathic Medicine, Ohio University, Athens, OH, 45701, USA
| | - Shiqi Jia
- The First Affiliated Hospital of Jinan University, Guangzhou, China
| | - Markus R Wenk
- Singapore Lipidomics Incubator, Life Sciences Institute, National University of Singapore, 117456, Singapore, Singapore
- Department of Biochemistry and Precision Medicine TRP, Yong Loo Lin School of Medicine, National University of Singapore, 117597, Singapore, Singapore
| | - Alexis Traynor-Kaplan
- Department of Medicine, University of Washington School of Medicine, Seattle, WA, 98195, USA
- ATK Analytics, Innovation and Discovery, LLC, North Bend, WA, 98045, USA
| | - Peter Arvan
- Division of Metabolism, Endocrinology & Diabetes, University of Michigan Medical School, Ann Arbor, MI, 48105, USA
| | - Sebastian Barg
- Medical Cell Biology, Uppsala University, 75123, Uppsala, Sweden
| | - Vytas A Bankaitis
- Department of Biochemistry & Biophysics, Texas A&M University, College Station, TX, 77843, USA
- Department of Cell Biology & Genetics, Texas A&M Health Science Center, College Station, TX, 77843, USA
- Department of Chemistry, Texas A&M University, College Station, TX, 77843, USA
| | - Matthew N Poy
- Johns Hopkins University, All Children's Hospital, St. Petersburg, FL, 33701, USA.
- Johns Hopkins University, Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, Baltimore, MD, 21287, USA.
- Max Delbrück Center for Molecular Medicine, Robert Rössle Strasse 10, Berlin, 13125, Germany.
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18
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Das K, Nozaki T. Non-Vesicular Lipid Transport Machinery in Leishmania donovani: Functional Implications in Host-Parasite Interaction. Int J Mol Sci 2023; 24:10637. [PMID: 37445815 DOI: 10.3390/ijms241310637] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2023] [Revised: 05/21/2023] [Accepted: 05/22/2023] [Indexed: 07/15/2023] Open
Abstract
Eukaryotic cells have distinct membrane-enclosed organelles, each with a unique biochemical signature and specialized function. The unique identity of each organelle is greatly governed by the asymmetric distribution and regulated intracellular movement of two important biomolecules, lipids, and proteins. Non-vesicular lipid transport mediated by lipid-transfer proteins (LTPs) plays essential roles in intra-cellular lipid trafficking and cellular lipid homeostasis, while vesicular transport regulates protein trafficking. A comparative analysis of non-vesicular lipid transport machinery in protists could enhance our understanding of parasitism and basis of eukaryotic evolution. Leishmania donovani, the trypanosomatid parasite, greatly depends on receptor-ligand mediated signalling pathways for cellular differentiation, nutrient uptake, secretion of virulence factors, and pathogenesis. Lipids, despite being important signalling molecules, have intracellular transport mechanisms that are largely unexplored in L. donovani. We have identified a repertoire of sixteen (16) potential lipid transfer protein (LTP) homologs based on a domain-based search on TriTrypDB coupled with bioinformatics analyses, which signifies the presence of well-organized lipid transport machinery in this parasite. We emphasized here their evolutionary uniqueness and conservation and discussed their potential implications for parasite biology with regards to future therapeutic targets against visceral leishmaniasis.
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Affiliation(s)
- Koushik Das
- Department of Allied Health Sciences, School of Health Sciences and Technology, University of Petroleum and Energy Studies, Dehradun 248007, India
| | - Tomoyoshi Nozaki
- Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan
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19
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Montag K, Ivanov R, Bauer P. Role of SEC14-like phosphatidylinositol transfer proteins in membrane identity and dynamics. FRONTIERS IN PLANT SCIENCE 2023; 14:1181031. [PMID: 37255567 PMCID: PMC10225987 DOI: 10.3389/fpls.2023.1181031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Accepted: 04/05/2023] [Indexed: 06/01/2023]
Abstract
Membrane identity and dynamic processes, that act at membrane sites, provide important cues for regulating transport, signal transduction and communication across membranes. There are still numerous open questions as to how membrane identity changes and the dynamic processes acting at the surface of membranes are regulated in diverse eukaryotes in particular plants and which roles are being played by protein interaction complexes composed of peripheral and integral membrane proteins. One class of peripheral membrane proteins conserved across eukaryotes comprises the SEC14-like phosphatidylinositol transfer proteins (SEC14L-PITPs). These proteins share a SEC14 domain that contributes to membrane identity and fulfills regulatory functions in membrane trafficking by its ability to sense, bind, transport and exchange lipophilic substances between membranes, such as phosphoinositides and diverse other lipophilic substances. SEC14L-PITPs can occur as single-domain SEC14-only proteins in all investigated organisms or with a modular domain structure as multi-domain proteins in animals and streptophytes (comprising charales and land plants). Here, we present an overview on the functional roles of SEC14L-PITPs, with a special focus on the multi-domain SEC14L-PITPs of the SEC14-nodulin and SEC14-GOLD group (PATELLINs, PATLs in plants). This indicates that SEC14L-PITPs play diverse roles from membrane trafficking to organism fitness in plants. We concentrate on the structure of SEC14L-PITPs, their ability to not only bind phospholipids but also other lipophilic ligands, and their ability to regulate complex cellular responses through interacting with proteins at membrane sites.
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Affiliation(s)
- Karolin Montag
- Institute of Botany, Heinrich Heine University, Düsseldorf, Germany
| | - Rumen Ivanov
- Institute of Botany, Heinrich Heine University, Düsseldorf, Germany
| | - Petra Bauer
- Institute of Botany, Heinrich Heine University, Düsseldorf, Germany
- Center of Excellence on Plant Sciences (CEPLAS), Germany
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20
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Hornbergs J, Montag K, Loschwitz J, Mohr I, Poschmann G, Schnake A, Gratz R, Brumbarova T, Eutebach M, Angrand K, Fink-Straube C, Stühler K, Zeier J, Hartmann L, Strodel B, Ivanov R, Bauer P. SEC14-GOLD protein PATELLIN2 binds IRON-REGULATED TRANSPORTER1 linking root iron uptake to vitamin E. PLANT PHYSIOLOGY 2023; 192:504-526. [PMID: 36493393 PMCID: PMC10152663 DOI: 10.1093/plphys/kiac563] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Revised: 09/23/2022] [Accepted: 12/07/2022] [Indexed: 05/03/2023]
Abstract
Organisms require micronutrients, and Arabidopsis (Arabidopsis thaliana) IRON-REGULATED TRANSPORTER1 (IRT1) is essential for iron (Fe2+) acquisition into root cells. Uptake of reactive Fe2+ exposes cells to the risk of membrane lipid peroxidation. Surprisingly little is known about how this is avoided. IRT1 activity is controlled by an intracellular variable region (IRT1vr) that acts as a regulatory protein interaction platform. Here, we describe that IRT1vr interacted with peripheral plasma membrane SEC14-Golgi dynamics (SEC14-GOLD) protein PATELLIN2 (PATL2). SEC14 proteins bind lipophilic substrates and transport or present them at the membrane. To date, no direct roles have been attributed to SEC14 proteins in Fe import. PATL2 affected root Fe acquisition responses, interacted with ROS response proteins in roots, and alleviated root lipid peroxidation. PATL2 had high affinity in vitro for the major lipophilic antioxidant vitamin E compound α-tocopherol. Molecular dynamics simulations provided insight into energetic constraints and the orientation and stability of the PATL2-ligand interaction in atomic detail. Hence, this work highlights a compelling mechanism connecting vitamin E with root metal ion transport at the plasma membrane with the participation of an IRT1-interacting and α-tocopherol-binding SEC14 protein.
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Affiliation(s)
- Jannik Hornbergs
- Institute of Botany, Heinrich Heine University, Düsseldorf 40225, Germany
| | - Karolin Montag
- Institute of Botany, Heinrich Heine University, Düsseldorf 40225, Germany
| | - Jennifer Loschwitz
- Institute of Theoretical Chemistry and Computer Chemistry, Heinrich Heine University, Düsseldorf 40225, Germany
- Institute of Biological Information Processing (IBI-7: Structural Biochemistry), Forschungszentrum Jülich, 52425 Jülich, Germany
| | - Inga Mohr
- Institute of Botany, Heinrich Heine University, Düsseldorf 40225, Germany
| | - Gereon Poschmann
- Institute of Molecular Medicine, Proteome Research, Medical Faculty and University Hospital, Heinrich-Heine-University Düsseldorf, Düsseldorf 40225, Germany
| | - Anika Schnake
- Institute for Molecular Ecophysiology of Plants, Heinrich Heine University, Düsseldorf 40225, Germany
| | - Regina Gratz
- Institute of Botany, Heinrich Heine University, Düsseldorf 40225, Germany
| | | | - Monique Eutebach
- Institute of Botany, Heinrich Heine University, Düsseldorf 40225, Germany
| | - Kalina Angrand
- Department of Biosciences-Plant Biology, Saarland University, Campus A2.4, D-66123 Saarbrücken, Germany
| | | | - Kai Stühler
- Institute of Molecular Medicine, Proteome Research, Medical Faculty and University Hospital, Heinrich-Heine-University Düsseldorf, Düsseldorf 40225, Germany
- Molecular Proteomics Laboratory, Heinrich Heine University, Düsseldorf 40225, Germany
| | - Jürgen Zeier
- Institute for Molecular Ecophysiology of Plants, Heinrich Heine University, Düsseldorf 40225, Germany
- Cluster of Excellence on Plant Science (CEPLAS), Heinrich Heine University, Düsseldorf 40225, Germany
| | - Laura Hartmann
- Institute of Macromolecular Chemistry, Heinrich Heine University, Düsseldorf 40225, Germany
| | - Birgit Strodel
- Institute of Theoretical Chemistry and Computer Chemistry, Heinrich Heine University, Düsseldorf 40225, Germany
- Institute of Biological Information Processing (IBI-7: Structural Biochemistry), Forschungszentrum Jülich, 52425 Jülich, Germany
| | - Rumen Ivanov
- Institute of Botany, Heinrich Heine University, Düsseldorf 40225, Germany
| | - Petra Bauer
- Institute of Botany, Heinrich Heine University, Düsseldorf 40225, Germany
- Cluster of Excellence on Plant Science (CEPLAS), Heinrich Heine University, Düsseldorf 40225, Germany
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21
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Arabidopsis Sec14 proteins (SFH5 and SFH7) mediate interorganelle transport of phosphatidic acid and regulate chloroplast development. Proc Natl Acad Sci U S A 2023; 120:e2221637120. [PMID: 36716376 PMCID: PMC9963013 DOI: 10.1073/pnas.2221637120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Lipids establish the specialized thylakoid membrane of chloroplast in eukaryotic photosynthetic organisms, while the molecular basis of lipid transfer from other organelles to chloroplast remains further elucidation. Here we revealed the structural basis of Arabidopsis Sec14 homology proteins AtSFH5 and AtSFH7 in transferring phosphatidic acid (PA) from endoplasmic reticulum (ER) to chloroplast, and whose function in regulating the lipid composition of chloroplast and thylakoid development. AtSFH5 and AtSFH7 localize at both ER and chloroplast, whose deficiency resulted in an abnormal chloroplast structure and a decreased thickness of stacked thylakoid membranes. We demonstrated that AtSFH5, but not yeast and human Sec14 proteins, could specifically recognize and transfer PA in vitro. Crystal structures of the AtSFH5-Sec14 domain in complex with L-α-phosphatidic acid (L-α-PA) and 1,2-dipalmitoyl-sn-glycero-3-phosphate (DPPA) revealed that two PA ligands nestled in the central cavity with different configurations, elucidating the specific binding mode of PA to AtSFH5, different from the reported phosphatidylethanolamine (PE)/phosphatidylcholine (PC)/phosphatidylinositol (PI) binding modes. Quantitative lipidomic analysis of chloroplast lipids showed that PA and monogalactosyldiacylglycerol (MGDG), particularly the C18 fatty acids at sn-2 position in MGDG were significantly decreased, indicating a disrupted ER-to-plastid (chloroplast) lipid transfer, under deficiency of AtSFH5 and AtSFH7. Our studies identified the role and elucidated the structural basis of plant SFH proteins in transferring PA between organelles, and suggested a model for ER-chloroplast interorganelle phospholipid transport from inherent ER to chloroplast derived from endosymbiosis of a cyanobacteriumproviding a mechanism involved in the adaptive evolution of cellular plastids.
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22
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Chen XR, Poudel L, Hong Z, Johnen P, Katti S, Tripathi A, Nile AH, Green SM, Khan D, Schaaf G, Bono F, Bankaitis VA, Igumenova TI. Mechanisms by which small molecules of diverse chemotypes arrest Sec14 lipid transfer activity. J Biol Chem 2023; 299:102861. [PMID: 36603766 PMCID: PMC9898755 DOI: 10.1016/j.jbc.2022.102861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2022] [Revised: 12/27/2022] [Accepted: 12/28/2022] [Indexed: 01/04/2023] Open
Abstract
Phosphatidylinositol (PtdIns) transfer proteins (PITPs) enhance the activities of PtdIns 4-OH kinases that generate signaling pools of PtdIns-4-phosphate. In that capacity, PITPs serve as key regulators of lipid signaling in eukaryotic cells. Although the PITP phospholipid exchange cycle is the engine that stimulates PtdIns 4-OH kinase activities, the underlying mechanism is not understood. Herein, we apply an integrative structural biology approach to investigate interactions of the yeast PITP Sec14 with small-molecule inhibitors (SMIs) of its phospholipid exchange cycle. Using a combination of X-ray crystallography, solution NMR spectroscopy, and atomistic MD simulations, we dissect how SMIs compete with native Sec14 phospholipid ligands and arrest phospholipid exchange. Moreover, as Sec14 PITPs represent new targets for the development of next-generation antifungal drugs, the structures of Sec14 bound to SMIs of diverse chemotypes reported in this study will provide critical information required for future structure-based design of next-generation lead compounds directed against Sec14 PITPs of virulent fungi.
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Affiliation(s)
- Xiao-Ru Chen
- Department of Biochemistry & Biophysics, Texas A&M University, College Station, Texas USA
| | - Lokendra Poudel
- Department of Biochemistry & Biophysics, Texas A&M University, College Station, Texas USA
| | - Zebin Hong
- Max Planck Institute for Developmental Biology, Tübingen, Germany
| | - Philipp Johnen
- Institute for Crop Science and Resource Conservation, Universität Bonn, Bonn, Germany
| | - Sachin Katti
- Department of Biochemistry & Biophysics, Texas A&M University, College Station, Texas USA
| | - Ashutosh Tripathi
- Department of Cell Biology & Genetics, Texas A&M University, College Station, Texas, USA
| | - Aaron H Nile
- Department of Cell Biology & Genetics, Texas A&M University, College Station, Texas, USA
| | - Savana M Green
- Department of Biochemistry & Biophysics, Texas A&M University, College Station, Texas USA; Department of Cell Biology & Genetics, Texas A&M University, College Station, Texas, USA
| | - Danish Khan
- Department of Biochemistry & Biophysics, Texas A&M University, College Station, Texas USA
| | - Gabriel Schaaf
- Institute for Crop Science and Resource Conservation, Universität Bonn, Bonn, Germany
| | - Fulvia Bono
- Max Planck Institute for Developmental Biology, Tübingen, Germany
| | - Vytas A Bankaitis
- Department of Biochemistry & Biophysics, Texas A&M University, College Station, Texas USA; Department of Cell Biology & Genetics, Texas A&M University, College Station, Texas, USA.
| | - Tatyana I Igumenova
- Department of Biochemistry & Biophysics, Texas A&M University, College Station, Texas USA.
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23
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Arabiotorre A, Formanowicz M, Bankaitis VA, Grabon A. Phosphatidylinositol-4-phosphate signaling regulates dense granule biogenesis and exocytosis in Toxoplasma gondii. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.09.523261. [PMID: 36712082 PMCID: PMC9882004 DOI: 10.1101/2023.01.09.523261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Phosphoinositide metabolism defines the foundation of a major signaling pathway that is conserved throughout the eukaryotic kingdom. The 4-OH phosphorylated phosphoinositides such as phosphatidylinositol-4-phosphate (PtdIns4P) and phosphatidylinositol-4,5-bisphosphate are particularly important molecules as these execute intrinsically essential activities required for the viability of all eukaryotic cells studied thus far. Using intracellular tachyzoites of the apicomplexan parasite Toxoplasma gondii as model for assessing primordial roles for PtdIns4P signaling, we demonstrate the presence of PtdIns4P pools in Golgi/trans-Golgi (TGN) system and in post-TGN compartments of the parasite. Moreover, we show that deficits in PtdIns4P signaling result in structural perturbation of compartments that house dense granule cargo with accompanying deficits in dense granule exocytosis. Taken together, the data report a direct role for PtdIns4P in dense granule biogenesis and exocytosis. The data further indicate that the biogenic pathway for secretion-competent dense granule formation in T. gondii is more complex than simple budding of fully matured dense granules from the TGN.
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Affiliation(s)
- Angela Arabiotorre
- Department of Cell Biology & Genetics, College of Medicine, Texas A&M Health Sciences Center, College Station, Texas 77843-1114, USA
| | - Megan Formanowicz
- Department of Biochemistry & Biophysics, Texas A&M University, College Station, Texas 77843-2128
| | - Vytas A. Bankaitis
- Department of Cell Biology & Genetics, College of Medicine, Texas A&M Health Sciences Center, College Station, Texas 77843-1114, USA
- Department of Biochemistry & Biophysics, Texas A&M University, College Station, Texas 77843-2128
- Department of Chemistry, Texas A&M University, College Station, Texas 77843-2128
| | - Aby Grabon
- Department of Cell Biology & Genetics, College of Medicine, Texas A&M Health Sciences Center, College Station, Texas 77843-1114, USA
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24
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Balla T, Gulyas G, Mandal A, Alvarez-Prats A, Niu Y, Kim YJ, Pemberton J. Roles of Phosphatidylinositol 4-Phosphorylation in Non-vesicular Cholesterol Trafficking. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2023; 1422:327-352. [PMID: 36988887 PMCID: PMC11135459 DOI: 10.1007/978-3-031-21547-6_12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/30/2023]
Abstract
Cholesterol (Chol) is an essential component of all eukaryotic cell membranes that affects the function of numerous peripheral as well as integral membrane proteins. Chol is synthesized in the ER, but it is selectively enriched within the plasma membrane (PM) and other endomembranes, which requires Chol to cross the aqueous phase of the cytoplasm. In addition to the classical vesicular trafficking pathways that are known to facilitate the bulk transport of membrane intermediates, Chol is also transported via non-vesicular lipid transfer proteins that work primarily within specialized membrane contact sites. Some of these transport pathways work against established concentration gradients and hence require energy. Recent studies highlight the unique role of phosphoinositides (PPIns), and phosphatidylinositol 4-phosphate (PI4P) in particular, for the control of non-vesicular Chol transport. In this chapter, we will review the emerging connection between Chol, PPIns, and lipid transfer proteins that include the important family of oxysterol-binding protein related proteins, or ORPs.
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Affiliation(s)
- Tamas Balla
- Section on Molecular Signal Transduction, Program for Developmental Neuroscience, Eunice Kennedy Shriver NICHD, National Institutes of Health, Bethesda, MD, USA.
| | | | - Amrita Mandal
- Section on Molecular Signal Transduction, Program for Developmental Neuroscience, Eunice Kennedy Shriver NICHD, National Institutes of Health, Bethesda, MD, USA
| | - Alejandro Alvarez-Prats
- Section on Molecular Signal Transduction, Program for Developmental Neuroscience, Eunice Kennedy Shriver NICHD, National Institutes of Health, Bethesda, MD, USA
| | | | - Yeun Ju Kim
- Section on Molecular Signal Transduction, Program for Developmental Neuroscience, Eunice Kennedy Shriver NICHD, National Institutes of Health, Bethesda, MD, USA
| | - Joshua Pemberton
- Section on Molecular Signal Transduction, Program for Developmental Neuroscience, Eunice Kennedy Shriver NICHD, National Institutes of Health, Bethesda, MD, USA
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25
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Hippo pathway regulation by phosphatidylinositol transfer protein and phosphoinositides. Nat Chem Biol 2022; 18:1076-1086. [PMID: 35788180 DOI: 10.1038/s41589-022-01061-z] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Accepted: 05/12/2022] [Indexed: 12/30/2022]
Abstract
The Hippo pathway plays a key role in development, organ size control and tissue homeostasis, and its dysregulation contributes to cancer. The LATS tumor suppressor kinases phosphorylate and inhibit the YAP/TAZ transcriptional co-activators to suppress gene expression and cell growth. Through a screen of marine natural products, we identified microcolin B (MCB) as a Hippo activator that preferentially kills YAP-dependent cancer cells. Structure-activity optimization yielded more potent MCB analogs, which led to the identification of phosphatidylinositol transfer proteins α and β (PITPα/β) as the direct molecular targets. We established a critical role of PITPα/β in regulating LATS and YAP. Moreover, we showed that PITPα/β influence the Hippo pathway via plasma membrane phosphatidylinositol-4-phosphate. This study uncovers a previously unrecognized role of PITPα/β in Hippo pathway regulation and as potential cancer therapeutic targets.
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26
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Huang X, Yao J, Liu L, Luo Y, Yang A. Atg8-PE protein-based in vitro biochemical approaches to autophagy studies. Autophagy 2022; 18:2020-2035. [PMID: 35072587 PMCID: PMC9397461 DOI: 10.1080/15548627.2022.2025572] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Macroautophagy/autophagy is an evolutionarily conserved intracellular degradation pathway that maintains cellular homeostasis. Over the past two decades, a series of scientific breakthroughs have helped explain autophagy-related molecular mechanisms and physiological functions. This tremendous progress continues to depend largely on powerful research methods, specifically, various autophagy marker Atg8-PE protein-based methods for studying membrane dynamics and monitoring autophagic activity. Recently, several biochemical approaches have been successfully developed to produce the lipidated protein Atg8-PE or its mimics in vitro, including enzyme-mediated reconstitution systems, chemically defined reconstitution systems, cell-free lipidation systems and protein chemical synthesis. These approaches have contributed important insights into the mechanisms underlying Atg8-mediated membrane dynamics and protein-protein interactions, creating a new perspective in autophagy studies. In this review, we comprehensively summarize Atg8-PE protein-based in vitro biochemical approaches and recent advances to facilitate a better understanding of autophagy mechanisms. In addition, we highlight the advantages and disadvantages of various Atg8-PE protein-based approaches to provide general guidance for their use in studying autophagy.Abbreviations: ATG: autophagy related; ATP: adenosine triphosphate; COPII: coat protein complex II; DGS-NTA: 1,2-dioleoyl-sn-glycero-3-[(N-(5-amino-1-carboxypentyl)iminodiacetic acid)succinyl] (nickel salt); DPPE: 1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine; DSPE: 1,2-distearoyl-sn-glycero-3-phosphoethanolamine; E. coli: Escherichia coli; EPL: expressed protein ligation; ERGIC: ER-Golgi intermediate compartment; GABARAP: GABA type A receptor-associated protein; GABARAPL1: GABA type A receptor associated protein like 1; GABARAPL2: GABA type A receptor associated protein like 2; GFP: green fluorescent protein; GUVs: giant unilamellar vesicles; LIR: LC3-interacting region; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; MBP: maltose binding protein; MEFs: mouse embryonic fibroblasts; MESNa: 2-mercaptoethanesulfonic acid sodium salt; NCL: native chemical ligation; NTA: nitrilotriacetic acid; PE: phosphatidylethanolamine; PS: phosphatidylserine; PtdIns3K: class III phosphatidylinositol 3-kinase; PtdIns3P: phosphatidylinositol-3-phosphate; SPPS: solid-phase peptide synthesis; TEV: tobacco etch virus; WT: wild-type.
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Affiliation(s)
- Xue Huang
- School of Life Sciences, Chongqing University, Chongqing, China
| | - Jia Yao
- School of Life Sciences, Chongqing University, Chongqing, China
| | - Lu Liu
- School of Life Sciences, Chongqing University, Chongqing, China
| | - Yu Luo
- School of Life Sciences, Chongqing University, Chongqing, China
| | - Aimin Yang
- School of Life Sciences, Chongqing University, Chongqing, China,CONTACT Aimin Yang School of Life Sciences, Chongqing University, Chongqing, China
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27
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Chen L, Tan L, Im YJ. Structural basis of ligand recognition and transport by Sfh2, a yeast phosphatidylinositol transfer protein of the Sec14 superfamily. Acta Crystallogr D Struct Biol 2022; 78:853-864. [DOI: 10.1107/s2059798322005666] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Accepted: 05/25/2022] [Indexed: 11/10/2022] Open
Abstract
Sec14-like phosphatidylinositol transfer proteins (PITPs) are involved in lipid metabolism and phosphatidylinositol 4-phosphate signaling by transporting phosphatidylinositol (PI) and a secondary ligand between the organellar membranes in eukaryotes. Yeast Sfh2 is a PITP that transfers PI and squalene without phosphatidylcholine transfer activity. To investigate the structural determinants for ligand specificity and transport in Sfh2, crystal structures of Sfh2 in complex with PI and squalene were determined at 1.5 and 2.4 Å resolution, respectively. The inositol head group of PI is recognized by highly conserved residues around the pocket entrance. The acyl chains of PI bind into a large hydrophobic cavity. Squalene is accommodated in the bottom of the cavity entirely by hydrophobic interactions. The binding of PI and squalene are mutually exclusive due to their overlapping binding sites, correlating with the role in lipid exchange. The binding mode of PI is well conserved in Sfh family proteins. However, squalene binding is unique to the Sfh2 homolog due to the specific hydrophobic residues forming a shape-complementary binding pocket. Recombinant apo Sfh2 forms a homodimer in vitro by the hydrophobic interaction of the gating α10–α11 helices in an open conformation. Ligand binding closes the lid and dissociates the dimer into monomers. This study reveals the structural determinants for the recognition of the conserved PI and a secondary ligand, squalene, and provides implications for the lipid-transfer function of Sfh2.
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28
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Jain A, Zoncu R. Organelle transporters and inter-organelle communication as drivers of metabolic regulation and cellular homeostasis. Mol Metab 2022; 60:101481. [PMID: 35342037 PMCID: PMC9043965 DOI: 10.1016/j.molmet.2022.101481] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 03/14/2022] [Accepted: 03/21/2022] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Spatial compartmentalization of metabolic pathways within membrane-separated organelles is key to the ability of eukaryotic cells to precisely regulate their biochemical functions. Membrane-bound organelles such as mitochondria, endoplasmic reticulum (ER) and lysosomes enable the concentration of metabolic precursors within optimized chemical environments, greatly accelerating the efficiency of both anabolic and catabolic reactions, enabling division of labor and optimal utilization of resources. However, metabolic compartmentalization also poses a challenge to cells because it creates spatial discontinuities that must be bridged for reaction cascades to be connected and completed. To do so, cells employ different methods to coordinate metabolic fluxes occurring in different organelles, such as membrane-localized transporters to facilitate regulated metabolite exchange between mitochondria and lysosomes, non-vesicular transport pathways via physical contact sites connecting the ER with both mitochondria and lysosomes, as well as localized regulatory signaling processes that coordinately regulate the activity of all these organelles. SCOPE OF REVIEW This review covers how cells use membrane transporters, membrane contact sites, and localized signaling pathways to mediate inter-organelle communication and coordinate metabolism. We also describe how disruption of inter-organelle communication is an emerging driver in a multitude of diseases, from cancer to neurodegeneration. MAJOR CONCLUSIONS Effective communication among organelles is essential to cellular health and function. Identifying the major molecular players involved in mediating metabolic coordination between organelles will further our understanding of cellular metabolism in health and lead us to design better therapeutics against dysregulated metabolism in disease.
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Affiliation(s)
- Aakriti Jain
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Roberto Zoncu
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA.
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29
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Xie Z, Bankaitis VA. Phosphatidylinositol transfer protein/planar cell polarity axis regulates neocortical morphogenesis by supporting interkinetic nuclear migration. Cell Rep 2022; 39:110869. [PMID: 35649377 PMCID: PMC9230501 DOI: 10.1016/j.celrep.2022.110869] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 03/08/2022] [Accepted: 05/05/2022] [Indexed: 11/29/2022] Open
Abstract
The neocortex expands explosively during embryonic development. The earliest populations of neural stem cells (NSCs) form a thin pseudostratified epithelium whose contour determines that of the adult neocortex. Neocortical complexity is accompanied by disproportional expansion of the NSC layer in its tangential dimension to increase tissue surface area. How such disproportional expansion is controlled remains unknown. We demonstrate that a phosphatidylinositol transfer protein (PITP)/non-canonical Wnt planar cell polarity (ncPCP) signaling axis promotes tangential expansion of developing neocortex. PITP signaling supports trafficking of specific ncPCP receptors from the NSC Golgi system to potentiate actomyosin activity important for cell-cycle-dependent interkinetic nuclear migration (IKNM). In turn, IKNM promotes lateral dispersion of newborn NSCs and tangential growth of the cerebral wall. These findings clarify functional roles for IKNM in NSC biology and identify tissue dysmorphogenesis resulting from impaired IKNM as a factor in autism risk, developmental brain disabilities, and neural tube birth defects. Xie and Bankaitis report that a phosphatidylinositol transfer protein/non-canonical planar cell polarity signaling axis supports interkinetic nuclear migration by promoting trafficking of specific non-canonical planar cell polarity receptors from the Golgi system to the plasma membrane, activating actomyosin, and supporting lateral expansion of the neocortex via a convergent extension mechanism.
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Affiliation(s)
- Zhigang Xie
- Department of Molecular & Cellular Medicine, Texas A&M Health Science Center, College Station, TX 77843, USA.
| | - Vytas A Bankaitis
- Department of Molecular & Cellular Medicine, Texas A&M Health Science Center, College Station, TX 77843, USA; Department of Biochemistry & Biophysics, Texas A&M University, College Station, TX 77843, USA; Department of Chemistry, Texas A&M University, College Station, TX 77843, USA.
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30
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Bankaitis VA, Tripathi A, Chen XR, Igumenova TI. New strategies for combating fungal infections: Inhibiting inositol lipid signaling by targeting Sec14 phosphatidylinositol transfer proteins. Adv Biol Regul 2022; 84:100891. [PMID: 35240534 PMCID: PMC9149032 DOI: 10.1016/j.jbior.2022.100891] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Accepted: 02/22/2022] [Indexed: 12/13/2022]
Abstract
Virulent fungi represent a particularly difficult problem in the infectious disease arena as these organisms are eukaryotes that share many orthologous activities with their human hosts. The fact that these activities are often catalyzed by conserved proteins places additional demands on development of pharmacological strategies for specifically inhibiting target fungal activities without imposing undesirable secondary effects on the host. While deployment of a limited set of anti-mycotics has to date satisfied the clinical needs for treatment of fungal infections, the recent emergence of multi-drug resistant fungal 'superbugs' now poses a serious global health threat with rapidly diminishing options for treatment. This escalating infectious disease problem emphasizes the urgent need for development of new classes of anti-mycotics. In that regard, Sec14 phosphatidylinositol transfer proteins offer interesting possibilities for interfering with fungal phosphoinositide signaling with exquisite specificity and without targeting the highly conserved lipid kinases responsible for phosphoinositide production. Herein, we review the establishment of proof-of-principle that demonstrates the feasibility of such an approach. We also describe the lead compounds of four chemotypes that directly target fungal Sec14 proteins. The rules that pertain to the mechanism(s) of Sec14 inhibition by validated small molecule inhibitors, and the open questions that remain, are discussed - as are the challenges that face development of next generation Sec14-directed inhibitors.
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Affiliation(s)
- Vytas A Bankaitis
- Department of Molecular & Cellular Medicine, Texas A&M University, College Station, TX, 77843-0014, USA; Department of Biochemistry & Biophysics, Texas A&M University, College Station, TX, 77843-0014, USA.
| | - Ashutosh Tripathi
- Department of Molecular & Cellular Medicine, Texas A&M University, College Station, TX, 77843-0014, USA
| | - Xiao-Ru Chen
- Department of Biochemistry & Biophysics, Texas A&M University, College Station, TX, 77843-0014, USA
| | - Tatyana I Igumenova
- Department of Biochemistry & Biophysics, Texas A&M University, College Station, TX, 77843-0014, USA
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31
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Zingg JM, Stamatiou C, Montalto G, Daunert S. Modulation of CD36-mediated lipid accumulation and senescence by vitamin E analogs in monocytes and macrophages. Biofactors 2022; 48:665-682. [PMID: 35084073 DOI: 10.1002/biof.1821] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2021] [Accepted: 12/14/2021] [Indexed: 01/10/2023]
Abstract
The CD36/FAT scavenger receptor/fatty acids transporter regulates cellular lipid accumulation important for inflammation, atherosclerosis, lipotoxicity, and initiation of cellular senescence. Here we compared the regulatory effects of the vitamin E analogs alpha-tocopherol (αT), alpha-tocopheryl phosphate (αTP), and αTP/βCD (a nanocarrier complex between αTP and β-cyclodextrin [βCD]) and investigated their regulatory effects on lipid accumulation, phagocytosis, and senescence in THP-1 monocytes and macrophages. Both, αTP and αTP/βCD inhibited CD36 surface exposition stronger than αT leading to more pronounced CD36-mediated events such as inhibition of DiI-labeled oxLDL uptake, phagocytosis of fluorescent Staphylococcus aureus bioparticles, and cell proliferation. When compared to βCD, the complex of αTP/βCD extracted cholesterol from cellular membranes with higher efficiency and was associated with the delivery of αTP to the cells. Interestingly, both, αTP and more so αTP/βCD inhibited lysosomal senescence-associated beta-galactosidase (SA-β-gal) activity and increased lysosomal pH, suggesting CD36-mediated uptake into the endo-lysosomal phagocytic compartment. Accordingly, the observed pH increase was more pronounced with αTP/βCD in macrophages whereas no significant increase occurred with αT, alpha-tocopheryl acetate (αTA) or βCD. In contrast to αT and αTA, the αTP molecule is di-anionic at neutral pH, but upon moving into the acidic endo-lysosomal compartment becomes protonated and thus is acting as a base. Moreover, it is expected to be retained in lysosomes since it still carries one negative charge, similar to lysosomotropic drugs. Thus, treatment with αTP or αTP/βCD and/or inhibition of conversion of αTP to αT as it occurs in aged cells may counteract CD36-mediated overlapping inflammatory, senescent, and atherosclerotic events.
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Affiliation(s)
- Jean-Marc Zingg
- Department of Biochemistry and Molecular Biology, Miller School of Medicine, University of Miami, Miami, Florida, USA
- Dr. JT Macdonald Foundation Biomedical Nanotechnology Institute, University of Miami, Miami, Florida, USA
| | - Christina Stamatiou
- Department of Biochemistry and Molecular Biology, Miller School of Medicine, University of Miami, Miami, Florida, USA
- Dr. JT Macdonald Foundation Biomedical Nanotechnology Institute, University of Miami, Miami, Florida, USA
| | - Giulia Montalto
- Department of Biochemistry and Molecular Biology, Miller School of Medicine, University of Miami, Miami, Florida, USA
- Section of General Pathology, Department of Experimental Medicine, University of Genoa, Genoa, Italy
| | - Sylvia Daunert
- Department of Biochemistry and Molecular Biology, Miller School of Medicine, University of Miami, Miami, Florida, USA
- Dr. JT Macdonald Foundation Biomedical Nanotechnology Institute, University of Miami, Miami, Florida, USA
- University of Miami Clinical and Translational Science Institute, University of Miami, Miami, Florida, USA
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Mendes LFS, Costa-Filho AJ. A gold revision of the Golgi Dynamics (GOLD) domain structure and associated cell functionalities. FEBS Lett 2022; 596:973-990. [PMID: 35099811 DOI: 10.1002/1873-3468.14300] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 01/04/2022] [Accepted: 01/20/2022] [Indexed: 11/06/2022]
Abstract
The classical secretory pathway is the key membrane-based delivery system in eukaryotic cells. Several families of proteins involved in the secretory pathway, with functionalities going from cargo sorting receptors to the maintenance and dynamics of secretory organelles, share soluble globular domains predicted to mediate protein-protein interactions. One of them is "Golgi Dynamics" (GOLD) domain, named after its strong association with the Golgi apparatus. There are many GOLD-containing protein families, such as the Transmembrane emp24 domain-containing proteins (TMED/p24 family), animal SEC14-like proteins, Human Golgi resident protein ACBD3, a splice variant of TICAM2 called TRAM with GOLD domain and FYCO1. Here, we critically review the state-of-the-art knowledge of the structures and functions of the main representatives of GOLD-containing proteins in vertebrates. We provide the first unified description of the GOLD domain structure across different families since the first high-resolution structure was determined. With a brand-new update on the definition of the GOLD domain, we also discuss how its tertiary structure fits the β-sandwich-like fold map and give exciting new directions for forthcoming studies.
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Affiliation(s)
- Luis Felipe S Mendes
- Laboratório de Biofísica Molecular, Departamento de Física, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brasil
| | - Antonio J Costa-Filho
- Laboratório de Biofísica Molecular, Departamento de Física, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brasil
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Maitra N, Hammer S, Kjerfve C, Bankaitis VA, Polymenis M. Translational control of lipogenesis links protein synthesis and phosphoinositide signaling with nuclear division in Saccharomyces cerevisiae. Genetics 2022; 220:iyab171. [PMID: 34849864 PMCID: PMC8733439 DOI: 10.1093/genetics/iyab171] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Accepted: 09/23/2021] [Indexed: 12/21/2022] Open
Abstract
Continuously dividing cells coordinate their growth and division. How fast cells grow in mass determines how fast they will multiply. Yet, there are few, if any, examples of a metabolic pathway that actively drives a cell cycle event instead of just being required for it. Here, we show that translational upregulation of lipogenic enzymes in Saccharomyces cerevisiae increased the abundance of lipids and promoted nuclear elongation and division. Derepressing translation of acetyl-CoA carboxylase and fatty acid synthase also suppressed cell cycle-related phenotypes, including delayed nuclear division, associated with Sec14p phosphatidylinositol transfer protein deficiencies, and the irregular nuclear morphologies of mutants defective in phosphatidylinositol 4-OH kinase activities. Our results show that increased lipogenesis drives a critical cell cycle landmark and report a phosphoinositide signaling axis in control of nuclear division. The broad conservation of these lipid metabolic and signaling pathways raises the possibility these activities similarly govern nuclear division in other eukaryotes.
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Affiliation(s)
- Nairita Maitra
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843, USA
| | - Staci Hammer
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843, USA
| | - Clara Kjerfve
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843, USA
| | - Vytas A Bankaitis
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843, USA
- Department of Molecular & Cellular Medicine, Texas A&M Health Sciences Center, College Station, TX 77843, USA
- Department of Chemistry, Texas A&M University, College Station, TX 77843, USA
| | - Michael Polymenis
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843, USA
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OUP accepted manuscript. FEMS Yeast Res 2022; 22:6522173. [DOI: 10.1093/femsyr/foac006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Revised: 01/20/2022] [Accepted: 02/02/2022] [Indexed: 11/12/2022] Open
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Arai H, Kono N. α-Tocopherol transfer protein (α-TTP). Free Radic Biol Med 2021; 176:162-175. [PMID: 34563650 DOI: 10.1016/j.freeradbiomed.2021.09.021] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 09/01/2021] [Accepted: 09/03/2021] [Indexed: 10/20/2022]
Abstract
α-Tocopherol transfer protein (α-TTP) is so far the only known protein that specifically recognizes α-tocopherol (α-Toc), the most abundant and most biologically active form of vitamin E, in higher animals. α-TTP is highly expressed in the liver where α-TTP selects α-Toc among vitamin E forms taken up via plasma lipoproteins and promotes its secretion to circulating lipoproteins. Thus, α-TTP is a major determinant of plasma α-Toc concentrations. Familial vitamin E deficiency, also called Ataxia with vitamin E deficiency, is caused by mutations in the α-TTP gene. More than 20 different mutations have been found in the α-TTP gene worldwide, among which some missense mutations provided valuable clues to elucidate the molecular mechanisms underlying intracellular α-Toc transport. In hepatocytes, α-TTP catalyzes the vectorial transport of α-Toc from the endocytotic compartment to the plasma membrane (PM) by targeting phosphatidylinositol phosphates (PIPs) such as PI(4,5)P2. By binding PIPs at the PM, α-TTP opens the lid covering the hydrophobic pocket, thus facilitating the release of bound α-Toc to the PM.
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Affiliation(s)
- Hiroyuki Arai
- Laboratory of Microenvironmental and Metabolic Health Science, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan.
| | - Nozomu Kono
- Department of Health Chemistry, Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
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Bacle A, Buslaev P, Garcia-Fandino R, Favela-Rosales F, Mendes Ferreira T, Fuchs PFJ, Gushchin I, Javanainen M, Kiirikki AM, Madsen JJ, Melcr J, Milán Rodríguez P, Miettinen MS, Ollila OHS, Papadopoulos CG, Peón A, Piggot TJ, Piñeiro Á, Virtanen SI. Inverse Conformational Selection in Lipid-Protein Binding. J Am Chem Soc 2021; 143:13701-13709. [PMID: 34465095 DOI: 10.1021/jacs.1c05549] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Interest in lipid interactions with proteins and other biomolecules is emerging not only in fundamental biochemistry but also in the field of nanobiotechnology where lipids are commonly used, for example, in carriers of mRNA vaccines. The outward-facing components of cellular membranes and lipid nanoparticles, the lipid headgroups, regulate membrane interactions with approaching substances, such as proteins, drugs, RNA, or viruses. Because lipid headgroup conformational ensembles have not been experimentally determined in physiologically relevant conditions, an essential question about their interactions with other biomolecules remains unanswered: Do headgroups exchange between a few rigid structures, or fluctuate freely across a practically continuous spectrum of conformations? Here, we combine solid-state NMR experiments and molecular dynamics simulations from the NMRlipids Project to resolve the conformational ensembles of headgroups of four key lipid types in various biologically relevant conditions. We find that lipid headgroups sample a wide range of overlapping conformations in both neutral and charged cellular membranes, and that differences in the headgroup chemistry manifest only in probability distributions of conformations. Furthermore, the analysis of 894 protein-bound lipid structures from the Protein Data Bank suggests that lipids can bind to proteins in a wide range of conformations, which are not limited by the headgroup chemistry. We propose that lipids can select a suitable headgroup conformation from the wide range available to them to fit the various binding sites in proteins. The proposed inverse conformational selection model will extend also to lipid binding to targets other than proteins, such as drugs, RNA, and viruses.
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Affiliation(s)
- Amélie Bacle
- Laboratoire Coopératif "Lipotoxicity and Channelopathies - ConicMeds", Université de Poitiers, 1 rue Georges Bonnet, Poitiers 86000, France
| | - Pavel Buslaev
- Nanoscience Center and Department of Chemistry, University of Jyväskylä, P.O. Box 35, Jyväskylä 40014, Finland.,Research Center for Molecular Mechanisms of Aging and Age-related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny 141701, Russia
| | - Rebeca Garcia-Fandino
- Center for Research in Biological Chemistry and Molecular Materials (CiQUS), Universidade de Santiago de Compostela, Santiago de Compostela E-15782, Spain.,CIQUP, Centro de Investigao em Química, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, Porto 4169-007, Portugal
| | - Fernando Favela-Rosales
- Departamento de Ciencias Básicas, Tecnológico Nacional de México - ITS Zacatecas Occidente, Sombrerete, Zacatecas 99102, México
| | - Tiago Mendes Ferreira
- NMR group - Institute for Physics, Martin Luther University Halle-Wittenberg, Halle (Saale), 06120, Germany
| | - Patrick F J Fuchs
- Ecole Normale Supérieure, PSL University, CNRS, Laboratoire des Biomolécules (LBM), Sorbonne Université, Paris 75005, France.,UFR Sciences du Vivant, Université de Paris, Paris 75013, France
| | - Ivan Gushchin
- Research Center for Molecular Mechanisms of Aging and Age-related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny 141701, Russia
| | - Matti Javanainen
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo nám. 542/2, Prague CZ-16610, Czech Republic
| | - Anne M Kiirikki
- Institute of Biotechnology, University of Helsinki, Helsinki 00014, Finland
| | - Jesper J Madsen
- Department of Chemistry, The University of Chicago, Chicago, Illinois 60637, United States.,Global and Planetary Health, College of Public Health, University of South Florida, Tampa, Florida 33612, United States
| | - Josef Melcr
- Groningen Biomolecular Sciences and Biotechnology Institute and The Zernike Institute for Advanced Materials, University of Groningen, Groningen9747 AG, The Netherlands
| | - Paula Milán Rodríguez
- Ecole Normale Supérieure, PSL University, CNRS, Laboratoire des Biomolécules (LBM), Sorbonne Université, Paris 75005, France
| | - Markus S Miettinen
- Department of Theory and Bio-Systems, Max Planck Institute of Colloids and Interfaces, Potsdam 14424, Germany
| | - O H Samuli Ollila
- Institute of Biotechnology, University of Helsinki, Helsinki 00014, Finland
| | - Chris G Papadopoulos
- CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, Gif-sur-Yvette 91198, France
| | - Antonio Peón
- CIQUP, Centro de Investigao em Química, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, Porto 4169-007, Portugal
| | - Thomas J Piggot
- Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, United Kingdom
| | - Ángel Piñeiro
- Departamento de Física Aplicada, Facultade de Física, Universidade de Santiago de Compostela, Santiago de Compostela E-15782, Spain
| | - Salla I Virtanen
- Institute of Biotechnology, University of Helsinki, Helsinki 00014, Finland
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Overduin M, Kervin TA. The phosphoinositide code is read by a plethora of protein domains. Expert Rev Proteomics 2021; 18:483-502. [PMID: 34351250 DOI: 10.1080/14789450.2021.1962302] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
INTRODUCTION The proteins that decipher nucleic acid- and protein-based information are well known, however, those that read membrane-encoded information remain understudied. Here we report 70 different human, microbial and viral protein folds that recognize phosphoinositides (PIs), comprising the readers of a vast membrane code. AREAS COVERED Membrane recognition is best understood for FYVE, PH and PX domains, which exemplify hundreds of PI code readers. Comparable lipid interaction mechanisms may be mediated by kinases, adjacent C1 and C2 domains, trafficking arrestin, GAT and VHS modules, membrane-perturbing annexin, BAR, CHMP, ENTH, HEAT, syntaxin and Tubby helical bundles, multipurpose FERM, EH, MATH, PHD, PDZ, PROPPIN, PTB and SH2 domains, as well as systems that regulate receptors, GTPases and actin filaments, transfer lipids and assembled bacterial and viral particles. EXPERT OPINION The elucidation of how membranes are recognized has extended the genetic code to the PI code. Novel discoveries include PIP-stop and MET-stop residues to which phosphates and metabolites are attached to block phosphatidylinositol phosphate (PIP) recognition, memteins as functional membrane protein apparatuses, and lipidons as lipid "codons" recognized by membrane readers. At least 5% of the human proteome senses such membrane signals and allows eukaryotic organelles and pathogens to operate and replicate.
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Affiliation(s)
- Michael Overduin
- Department of Biochemistry, University of Alberta, Edmonton, Alberta, Canada
| | - Troy A Kervin
- Department of Biochemistry, University of Alberta, Edmonton, Alberta, Canada
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38
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Levine TP. TMEM106B in humans and Vac7 and Tag1 in yeast are predicted to be lipid transfer proteins. Proteins 2021; 90:164-175. [PMID: 34347309 DOI: 10.1002/prot.26201] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2021] [Revised: 07/11/2021] [Accepted: 07/23/2021] [Indexed: 11/05/2022]
Abstract
TMEM106B is an integral membrane protein of late endosomes and lysosomes involved in neuronal function, its overexpression being associated with familial frontotemporal lobar degeneration, and point mutation linked to hypomyelination. It has also been identified in multiple screens for host proteins required for productive SARS-CoV-2 infection. Because standard approaches to understand TMEM106B at the sequence level find no homology to other proteins, it has remained a protein of unknown function. Here, the standard tool PSI-BLAST was used in a nonstandard way to show that the lumenal portion of TMEM106B is a member of the late embryogenesis abundant-2 (LEA-2) domain superfamily. More sensitive tools (HMMER, HHpred, and trRosetta) extended this to predict LEA-2 domains in two yeast proteins. One is Vac7, a regulator of PI(3,5)P2 production in the degradative vacuole, equivalent to the lysosome, which has a LEA-2 domain in its lumenal domain. The other is Tag1, another vacuolar protein, which signals to terminate autophagy and has three LEA-2 domains in its lumenal domain. Further analysis of LEA-2 structures indicated that LEA-2 domains have a long, conserved lipid-binding groove. This implies that TMEM106B, Vac7, and Tag1 may all be lipid transfer proteins in the lumen of late endocytic organelles.
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Gong B, Guo Y, Ding S, Liu X, Meng A, Li D, Jia S. A Golgi-derived vesicle potentiates PtdIns4P to PtdIns3P conversion for endosome fission. Nat Cell Biol 2021; 23:782-795. [PMID: 34183801 DOI: 10.1038/s41556-021-00704-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Accepted: 05/26/2021] [Indexed: 02/06/2023]
Abstract
Endosome fission is essential for cargo sorting and targeting in the endosomal system. However, whether organelles other than the endoplasmic reticulum (ER) participate in endosome fission through membrane contacts is unknown. Here, we characterize a Golgi-derived vesicle, the SEC14L2 compartment, that plays a unique role in facilitating endosome fission through ternary contacts with endosomes and the ER. Localized to the ER-mediated endosome fission site, the phosphatidylinositol transfer protein SEC14L2 promotes phosphatidylinositol 4-phosphate (PtdIns4P) to phosphatidylinositol 3-phosphate (PtdIns3P) conversion before endosome fission. In the absence of SEC14L2, endosome fission is attenuated and more enlarged endosomes arise due to endosomal accumulation of PtdIns4P and reduction in PtdIns3P. Collectively, our data suggest roles of the Golgi network in ER-associated endosome fission and a mechanism involving ER-endosome contacts in the regulation of endosomal phosphoinositide conversion.
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Affiliation(s)
- Bo Gong
- State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, China
| | - Yuting Guo
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Shihui Ding
- State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, China
| | - Xiaohui Liu
- School of Life Sciences, National Protein Science Facility, Tsinghua University, Beijing, China
| | - Anming Meng
- State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, China
| | - Dong Li
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China.
| | - Shunji Jia
- State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, China.
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Emerging Prospects for Combating Fungal Infections by Targeting Phosphatidylinositol Transfer Proteins. Int J Mol Sci 2021; 22:ijms22136754. [PMID: 34201733 PMCID: PMC8269425 DOI: 10.3390/ijms22136754] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 06/11/2021] [Accepted: 06/11/2021] [Indexed: 12/27/2022] Open
Abstract
The emergence of fungal “superbugs” resistant to the limited cohort of anti-fungal agents available to clinicians is eroding our ability to effectively treat infections by these virulent pathogens. As the threat of fungal infection is escalating worldwide, this dwindling response capacity is fueling concerns of impending global health emergencies. These developments underscore the urgent need for new classes of anti-fungal drugs and, therefore, the identification of new targets. Phosphoinositide signaling does not immediately appear to offer attractive targets due to its evolutionary conservation across the Eukaryota. However, recent evidence argues otherwise. Herein, we discuss the evidence identifying Sec14-like phosphatidylinositol transfer proteins (PITPs) as unexplored portals through which phosphoinositide signaling in virulent fungi can be chemically disrupted with exquisite selectivity. Recent identification of lead compounds that target fungal Sec14 proteins, derived from several distinct chemical scaffolds, reveals exciting inroads into the rational design of next generation Sec14 inhibitors. Development of appropriately refined next generation Sec14-directed inhibitors promises to expand the chemical weaponry available for deployment in the shifting field of engagement between fungal pathogens and their human hosts.
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Holič R, Šťastný D, Griač P. Sec14 family of lipid transfer proteins in yeasts. Biochim Biophys Acta Mol Cell Biol Lipids 2021; 1866:158990. [PMID: 34118432 DOI: 10.1016/j.bbalip.2021.158990] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 05/31/2021] [Accepted: 06/02/2021] [Indexed: 11/25/2022]
Abstract
The hydrophobicity of lipids prevents their free movement across the cytoplasm. To achieve highly heterogeneous and precisely regulated lipid distribution in different cellular membranes, lipids are transported by lipid transfer proteins (LTPs) in addition to their transport by vesicles. Sec14 family is one of the most extensively studied groups of LTPs. Here we provide an overview of Sec14 family of LTPs in the most studied yeast Saccharomyces cerevisiae as well as in other selected non-Saccharomyces yeasts-Schizosaccharomyces pombe, Kluyveromyces lactis, Candida albicans, Candida glabrata, Cryptococcus neoformans, and Yarrowia lipolytica. Discussed are specificities of Sec14-domain LTPs in various yeasts, their mode of action, subcellular localization, and physiological function. In addition, quite few Sec14 family LTPs are target of antifungal drugs, serve as modifiers of drug resistance or influence virulence of pathologic yeasts. Thus, they represent an important object of study from the perspective of human health.
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Affiliation(s)
- Roman Holič
- Institute of Animal Biochemistry and Genetics, Centre of Biosciences, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Dominik Šťastný
- Institute of Animal Biochemistry and Genetics, Centre of Biosciences, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Peter Griač
- Institute of Animal Biochemistry and Genetics, Centre of Biosciences, Slovak Academy of Sciences, Bratislava, Slovakia.
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Li W, Li Y, Guan Y, Du Y, Zhao M, Chen X, Zhu F, Guo C, Jia Y, Li Y, Wang X, Wang X, Shi Y, Wang Q, Li Y, Zhang L. TNFAIP8L2/TIPE2 impairs autolysosome reformation via modulating the RAC1-MTORC1 axis. Autophagy 2021; 17:1410-1425. [PMID: 32460619 PMCID: PMC8205099 DOI: 10.1080/15548627.2020.1761748] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Revised: 04/21/2020] [Accepted: 04/23/2020] [Indexed: 12/11/2022] Open
Abstract
Macroautophagy/autophagy is an evolutionarily conserved process that involves the selective degradation of cytoplasmic components within lysosomes in response to starvation. Autophagy is an ancient defense mechanism that has been closely integrated with the immune system and has multiple effects on innate and adaptive immunity. The pro-inflammatory and anti-inflammatory cytokines can activate and inhibit autophagy, respectively. TNFAIP8L2/TIPE2 (tumor necrosis factor, alpha-induced protein 8-like 2) is a newly identified immune negative regulator of innate and adaptive immunity that plays an important role in immune homeostasis. However, whether and how TNFAIP8L2 controls autophagy is still unknown. Murine TNFAIP8L2 can directly bind to and block the RAC1 GTPase activity to regulate innate immunity. RAC1 can also bind to MTOR and regulate MTORC1 cellular localization and activity. Here, we find that TNFAIP8L2 can compete with MTOR for binding to the GTP-bound state of RAC1 and negatively regulate MTORC1 activity. Interestingly, TNFAIP8L2 overexpression fails to induce autophagy flux by the suppression of the MTOR activity under glutamine and serum starvation. Instead, TNFAIP8L2 appears to impair autophagic lysosome reformation (ALR) during prolonged starvation. Finally, we demonstrate that TNFAIP8L2 overexpression leads to a defect in MTOR reactivation and disrupts autophagy flux, thereby leading to cell death. Furthermore, TNFAIP8L2 deficiency can exacerbate the inflammatory response and lung injury by controlling the MTOR activity in an LPS-induced mouse endotoxemia model. Our study reveals a novel role of TNFAIP8L2 in autophagy by regulating the RAC1-MTORC1 axis that supports its potential as a target for therapeutic treatment.Abbreviations: ALR: autophagic lysosome reformation; BafA1: bafilomycin A1; BMDMs: bone marrow-derived macrophages; Co-IP: Co-Immunoprecipitation; LAMP1: lysosomal associated membrane protein 1; MAP1LC3B/LC3B: microtubule associated protein 1 light chain 3 beta; MTORC1: mechanistic target of rapamycin kinase complex 1; RAPA: rapamycin; RPS6: ribosomal protein S6; SQSTM1/p62: sequestosome 1; Starv: Starvation; TNFAIP8L2/TIPE2: tumor necrosis factor-alpha-induced protein-8 like-2.
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Affiliation(s)
- Wen Li
- Department of Immunology, School of Basic Medical Science, Shandong University, Jinan, China
| | - Yulan Li
- Department of Immunology, School of Basic Medical Science, Shandong University, Jinan, China
| | - Yetong Guan
- Department of Immunology, School of Basic Medical Science, Shandong University, Jinan, China
| | - Yingxin Du
- Department of Immunology, School of Basic Medical Science, Shandong University, Jinan, China
| | - Mingsheng Zhao
- Department of Immunology, School of Basic Medical Science, Shandong University, Jinan, China
| | - Xiaotong Chen
- Department of Immunology, School of Basic Medical Science, Shandong University, Jinan, China
| | - Faliang Zhu
- Department of Immunology, School of Basic Medical Science, Shandong University, Jinan, China
| | - Chun Guo
- Department of Immunology, School of Basic Medical Science, Shandong University, Jinan, China
| | - Yufeng Jia
- Department of Immunology, School of Basic Medical Science, Shandong University, Jinan, China
| | - Yuan Li
- Department of Immunology, School of Basic Medical Science, Shandong University, Jinan, China
| | - Xiaoyu Wang
- Department of Immunology, School of Basic Medical Science, Shandong University, Jinan, China
| | - Xiaoyan Wang
- Department of Immunology, School of Basic Medical Science, Shandong University, Jinan, China
| | - Yongyu Shi
- Department of Immunology, School of Basic Medical Science, Shandong University, Jinan, China
| | - Qun Wang
- Department of Immunology, School of Basic Medical Science, Shandong University, Jinan, China
| | - Yan Li
- Department of Pathogen Biology, School of Basic Medical Science, Shandong University, Jinan, China
| | - Lining Zhang
- Department of Immunology, School of Basic Medical Science, Shandong University, Jinan, China
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Neefjes J, Cabukusta B. What the VAP: The Expanded VAP Family of Proteins Interacting With FFAT and FFAT-Related Motifs for Interorganellar Contact. CONTACT (THOUSAND OAKS (VENTURA COUNTY, CALIF.)) 2021; 4:25152564211012246. [PMID: 34036242 PMCID: PMC7610837 DOI: 10.1177/25152564211012246] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Membrane contact sites are formed by tether proteins that have the ability to bring two organellar membranes together. VAP proteins are a family of endoplasmic reticulum (ER)-resident tether proteins specialized in interacting with FFAT (two phenylalanines in an acidic tract) peptide motifs in other proteins. If the FFAT-motif-containing proteins reside on other organelles, VAP proteins form contact sites between these organelles and the ER. The role of VAPA and VAPB, the two founding members of the VAP family in recruiting proteins to the ER and forming membrane contact sites is well appreciated as numerous interaction partners of VAPA and VAPB at different intracellular contact sites have been characterized. Recently, three new proteins -MOSPD1, MOSPD2 and MOSPD3-have been added to the VAP family. While MOSPD2 has a motif preference similar to VAPA and VAPB, MOSPD1 and MOSPD3 prefer to interact with proteins containing FFNT (two phenylalanines in a neutral tract) motifs. In this review, we discuss the recent advances in motif binding by VAP proteins along with the other biological processes VAP proteins are involved in.
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Affiliation(s)
- Jacques Neefjes
- Cell and Chemical Biology, Oncode Institute, Leiden University Medical Center, Leiden, the Netherlands
| | - Birol Cabukusta
- Cell and Chemical Biology, Oncode Institute, Leiden University Medical Center, Leiden, the Netherlands
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Dubois GA, Jaillais Y. Anionic phospholipid gradients: an uncharacterized frontier of the plant endomembrane network. PLANT PHYSIOLOGY 2021; 185:577-592. [PMID: 33793905 PMCID: PMC8133617 DOI: 10.1093/plphys/kiaa056] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Accepted: 09/16/2020] [Indexed: 05/19/2023]
Abstract
Anionic phospholipids include phosphatidic acid (PA), phosphatidylserine (PS), phosphatidylinositol (PI), and its phosphorylated derivatives the phosphoinositides (e.g. phosphatidylinositol-4-phosphate [PI4P] and phosphatidylinositol-4,5-bisphosphate [PI(4,5)P2]). Although anionic phospholipids are low-abundant lipids, they are particularly important for membrane functions. In particular, anionic lipids act as biochemical and biophysical landmarks that contribute to the establishment of membrane identity, signaling activities, and compartment morphodynamics. Each anionic lipid accumulates in different endomembranes according to a unique subcellular pattern, where they locally provide docking platforms for proteins. As such, they are mostly believed to act in the compartments in which they accumulate. However, mounting evidence throughout eukaryotes suggests that anionic lipids are not as compartment-specific as initially thought and that they are instead organized as concentration gradients across different organelles. In this update, we review the evidence for the existence of anionic lipid gradients in plants. We then discuss the possible implication of these gradients in lipid dynamics and homeostasis, and also in coordinating subcellular activities. Finally, we introduce the notion that anionic lipid gradients at the cellular scale may translate into gradients at the tissue level, which could have implications for plant development.
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Affiliation(s)
- Gwennogan A Dubois
- Laboratoire Reproduction et Développement des Plantes, Univ Lyon, ENS de Lyon, Université Claude Bernard Lyon 1, CNRS, INRAE, F-69342, Lyon, France
| | - Yvon Jaillais
- Laboratoire Reproduction et Développement des Plantes, Univ Lyon, ENS de Lyon, Université Claude Bernard Lyon 1, CNRS, INRAE, F-69342, Lyon, France
- Author for communication:
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Wang Y, Yuan P, Grabon A, Tripathi A, Lee D, Rodriguez M, Lönnfors M, Eisenberg-Bord M, Wang Z, Man Lam S, Schuldiner M, Bankaitis VA. Noncanonical regulation of phosphatidylserine metabolism by a Sec14-like protein and a lipid kinase. J Cell Biol 2021; 219:151686. [PMID: 32303746 PMCID: PMC7199851 DOI: 10.1083/jcb.201907128] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Revised: 12/20/2019] [Accepted: 02/10/2020] [Indexed: 01/20/2023] Open
Abstract
The yeast phosphatidylserine (PtdSer) decarboxylase Psd2 is proposed to engage in a membrane contact site (MCS) for PtdSer decarboxylation to phosphatidylethanolamine (PtdEtn). This proposed MCS harbors Psd2, the Sec14-like phosphatidylinositol transfer protein (PITP) Sfh4, the Stt4 phosphatidylinositol (PtdIns) 4-OH kinase, the Scs2 tether, and an uncharacterized protein. We report that, of these components, only Sfh4 and Stt4 regulate Psd2 activity in vivo. They do so via distinct mechanisms. Sfh4 operates via a mechanism for which its PtdIns-transfer activity is dispensable but requires an Sfh4-Psd2 physical interaction. The other requires Stt4-mediated production of PtdIns-4-phosphate (PtdIns4P), where Stt4 (along with the Sac1 PtdIns4P phosphatase and endoplasmic reticulum–plasma membrane tethers) indirectly modulate Psd2 activity via a PtdIns4P homeostatic mechanism that influences PtdSer accessibility to Psd2. These results identify an example in which the biological function of a Sec14-like PITP is cleanly uncoupled from its canonical in vitro PtdIns-transfer activity and challenge popular functional assumptions regarding lipid-transfer protein involvements in MCS function.
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Affiliation(s)
- Yaxi Wang
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX.,Department of Molecular & Cellular Medicine, Texas A&M Health Science Center, College Station, TX
| | - Peihua Yuan
- Department of Molecular & Cellular Medicine, Texas A&M Health Science Center, College Station, TX
| | - Aby Grabon
- Department of Molecular & Cellular Medicine, Texas A&M Health Science Center, College Station, TX
| | - Ashutosh Tripathi
- Department of Molecular & Cellular Medicine, Texas A&M Health Science Center, College Station, TX
| | - Dongju Lee
- Department of Molecular & Cellular Medicine, Texas A&M Health Science Center, College Station, TX
| | - Martin Rodriguez
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX
| | - Max Lönnfors
- Department of Molecular & Cellular Medicine, Texas A&M Health Science Center, College Station, TX
| | | | - Zehua Wang
- University of Chinese Academy of Sciences, Beijing, China.,State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Sin Man Lam
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Maya Schuldiner
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Vytas A Bankaitis
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX.,Department of Molecular & Cellular Medicine, Texas A&M Health Science Center, College Station, TX.,Department of Chemistry, Texas A&M University, College Station, TX
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46
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Laha D, Kamleitner M, Johnen P, Schaaf G. Analyses of Inositol Phosphates and Phosphoinositides by Strong Anion Exchange (SAX)-HPLC. Methods Mol Biol 2021; 2295:365-378. [PMID: 34047987 DOI: 10.1007/978-1-0716-1362-7_20] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
The phosphate esters of myo-inositol (Ins) occur ubiquitously in biology. These molecules exist as soluble or membrane-resident derivatives and regulate a plethora of cellular functions including phosphate homeostasis, DNA repair, vesicle trafficking, metabolism, cell polarity, tip-directed growth, and membrane morphogenesis. Phosphorylation of all inositol hydroxyl groups generates phytic acid (InsP6), the most abundant inositol phosphate present in eukaryotic cells. However, phytic acid is not the most highly phosphorylated naturally occurring inositol phosphate. Specialized small molecule kinases catalyze the formation of the so-called myo-inositol pyrophosphates (PP-InsPs), such as InsP7 and InsP8. These molecules are characterized by one or several "high-energy" diphosphate moieties and are ubiquitous in eukaryotic cells. In plants, PP-InsPs play critical roles in immune responses and nutrient sensing. The detection of inositol derivatives in plants is challenging. This is particularly the case for inositol pyrophosphates because diphospho bonds are labile in plant cell extracts due to high amounts of acid phosphatase activity. We present two steady-state inositol labeling-based techniques coupled with strong anion exchange (SAX)-HPLC analyses that allow robust detection and quantification of soluble and membrane-resident inositol polyphosphates in plant extracts. These techniques will be instrumental to uncover the cellular and physiological processes controlled by these intriguing regulatory molecules in plants.
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Affiliation(s)
- Debabrata Laha
- Department of Biochemistry, Indian Institute of Science, Bangalore, India
| | - Marília Kamleitner
- Department of Plant Nutrition, Institute of Crop Science and Resource Conservation, Rheinische Friedrich-Wilhelms-University Bonn, Bonn, Germany
| | - Philipp Johnen
- Department of Plant Nutrition, Institute of Crop Science and Resource Conservation, Rheinische Friedrich-Wilhelms-University Bonn, Bonn, Germany.,BASF SE, Limburgerhof, Germany
| | - Gabriel Schaaf
- Department of Plant Nutrition, Institute of Crop Science and Resource Conservation, Rheinische Friedrich-Wilhelms-University Bonn, Bonn, Germany.
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Lete MG, Tripathi A, Chandran V, Bankaitis VA, McDermott MI. Lipid transfer proteins and instructive regulation of lipid kinase activities: Implications for inositol lipid signaling and disease. Adv Biol Regul 2020; 78:100740. [PMID: 32992233 PMCID: PMC7986245 DOI: 10.1016/j.jbior.2020.100740] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 06/16/2020] [Accepted: 06/24/2020] [Indexed: 05/17/2023]
Abstract
Cellular membranes are critical platforms for intracellular signaling that involve complex interfaces between lipids and proteins, and a web of interactions between a multitude of lipid metabolic pathways. Membrane lipids impart structural and functional information in this regulatory circuit that encompass biophysical parameters such as membrane thickness and fluidity, as well as chaperoning the interactions of protein binding partners. Phosphatidylinositol and its phosphorylated derivatives, the phosphoinositides, play key roles in intracellular membrane signaling, and these involvements are translated into an impressively diverse set of biological outcomes. The phosphatidylinositol transfer proteins (PITPs) are key regulators of phosphoinositide signaling. Found in a diverse array of organisms from plants, yeast and apicomplexan parasites to mammals, PITPs were initially proposed to be simple transporters of lipids between intracellular membranes. It now appears increasingly unlikely that the soluble versions of these proteins perform such functions within the cell. Rather, these serve to facilitate the activity of intrinsically biologically insufficient inositol lipid kinases and, in so doing, promote diversification of the biological outcomes of phosphoinositide signaling. The central engine for execution of such functions is the lipid exchange cycle that is a fundamental property of PITPs. How PITPs execute lipid exchange remains very poorly understood. Molecular dynamics simulation approaches are now providing the first atomistic insights into how PITPs, and potentially other lipid-exchange/transfer proteins, operate.
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Affiliation(s)
- Marta G Lete
- Department of Molecular and Cellular Medicine, Texas A&M Health Sciences Center, College Station, TX, 77843-1114, USA; Institute Biofisika (UPV/EHU, CSIC) and University of the Basque Country, Leioa, Spain
| | - Ashutosh Tripathi
- Department of Molecular and Cellular Medicine, Texas A&M Health Sciences Center, College Station, TX, 77843-1114, USA
| | - Vijay Chandran
- Department of Molecular and Cellular Medicine, Texas A&M Health Sciences Center, College Station, TX, 77843-1114, USA
| | - Vytas A Bankaitis
- Department of Molecular and Cellular Medicine, Texas A&M Health Sciences Center, College Station, TX, 77843-1114, USA; Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, 77843-2128, USA; Department of Chemistry, Texas A&M University, College Station, TX, 77840, USA
| | - Mark I McDermott
- Department of Molecular and Cellular Medicine, Texas A&M Health Sciences Center, College Station, TX, 77843-1114, USA.
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48
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Montag K, Hornbergs J, Ivanov R, Bauer P. Phylogenetic analysis of plant multi-domain SEC14-like phosphatidylinositol transfer proteins and structure-function properties of PATELLIN2. PLANT MOLECULAR BIOLOGY 2020; 104:665-678. [PMID: 32915352 PMCID: PMC7674337 DOI: 10.1007/s11103-020-01067-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Accepted: 08/31/2020] [Indexed: 05/19/2023]
Abstract
SEC14L-PITPs guide membrane recognition and signaling. An increasingly complex modular structure of SEC14L-PITPs evolved in land plants compared to green algae. SEC14/CRAL-TRIO and GOLD domains govern membrane binding specificity. SEC14-like phosphatidylinositol transfer proteins (SEC14L-PITPs) provide cues for membrane identity by exchanging lipophilic substrates, ultimately governing membrane signaling. Flowering plant SEC14L-PITPs often have modular structure and are associated with cell division, development, and stress responses. Yet, structure-function relationships for biochemical-cellular interactions of SEC14L-PITPs are rather enigmatic. Here, we evaluate the phylogenetic relationships of the SEC14L-PITP superfamily in the green lineage. Compared to green algae, land plants have an extended set of SEC14L-PITPs with increasingly complex modular structure. SEC14-GOLD PITPs, present in land plants but not Chara, diverged to three functional subgroups, represented by the six PATELLIN (PATL) proteins in Arabidopsis. Based on the example of Arabidopsis PATL2, we dissect the functional domains for in vitro binding to phosphoinositides and liposomes and for plant cell membrane association. While the SEC14 domain and its CRAL-TRIO-N-terminal extension serve general membrane attachment of the protein, the C-terminal GOLD domain directs it to the plasma membrane by recognizing specific phosphoinositides. We discuss that the different domains of SEC14L-PITPs integrate developmental and environmental signals to control SEC14L-PITP-mediated membrane identity, important to initiate dynamic membrane events.
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Affiliation(s)
- Karolin Montag
- Institute of Botany, Heinrich Heine University, 40225, Düsseldorf, Germany
| | - Jannik Hornbergs
- Institute of Botany, Heinrich Heine University, 40225, Düsseldorf, Germany
| | - Rumen Ivanov
- Institute of Botany, Heinrich Heine University, 40225, Düsseldorf, Germany.
| | - Petra Bauer
- Institute of Botany, Heinrich Heine University, 40225, Düsseldorf, Germany.
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Mei L, Qiu X, Jiang C, Yang A. Host Delipidation Mediated by Bacterial Effectors. Trends Microbiol 2020; 29:238-250. [PMID: 33092951 DOI: 10.1016/j.tim.2020.09.012] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Revised: 09/28/2020] [Accepted: 09/29/2020] [Indexed: 12/19/2022]
Abstract
Protein lipidation, the covalent attachment of a lipid moiety to a target protein, plays a critical role in many cellular processes in eukaryotic cells. Bacterial pathogens secrete various effectors to subvert the host signaling pathway as a mechanism of microbial pathogenesis. An increasing number of effectors from diverse bacterial pathogens function as cysteine proteases to cause irreversible delipidation of host lipidated proteins. This in turn results in disruption of crucial lipidation-mediated host signal transduction, thereby enabling pathogen survival and replication. In this review, we discuss the role of the bacterial effectors in interactions with the host and highlight our knowledge of irreversible host delipidation, with a focus on the common concerted biochemical mechanisms of the bacterial effectors.
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Affiliation(s)
- Ligang Mei
- School of Life Sciences, Chongqing University, Chongqing 401331, China
| | - Xiaofeng Qiu
- School of Life Sciences, Chongqing University, Chongqing 401331, China
| | - Chen Jiang
- School of Life Sciences, Chongqing University, Chongqing 401331, China
| | - Aimin Yang
- School of Life Sciences, Chongqing University, Chongqing 401331, China; Ultrafast Transient Materials Science Center, Institute of Advanced Interdisciplinary Studies, Chongqing University, Chongqing 401331, China.
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50
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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: 56] [Impact Index Per Article: 14.0] [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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