1
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Burroughs A, Aravind L. New biochemistry in the Rhodanese-phosphatase superfamily: emerging roles in diverse metabolic processes, nucleic acid modifications, and biological conflicts. NAR Genom Bioinform 2023; 5:lqad029. [PMID: 36968430 PMCID: PMC10034599 DOI: 10.1093/nargab/lqad029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 02/10/2023] [Accepted: 03/09/2023] [Indexed: 03/25/2023] Open
Abstract
The protein-tyrosine/dual-specificity phosphatases and rhodanese domains constitute a sprawling superfamily of Rossmannoid domains that use a conserved active site with a cysteine to catalyze a range of phosphate-transfer, thiotransfer, selenotransfer and redox activities. While these enzymes have been extensively studied in the context of protein/lipid head group dephosphorylation and various thiotransfer reactions, their overall diversity and catalytic potential remain poorly understood. Using comparative genomics and sequence/structure analysis, we comprehensively investigate and develop a natural classification for this superfamily. As a result, we identified several novel clades, both those which retain the catalytic cysteine and those where a distinct active site has emerged in the same location (e.g. diphthine synthase-like methylases and RNA 2' OH ribosyl phosphate transferases). We also present evidence that the superfamily has a wider range of catalytic capabilities than previously known, including a set of parallel activities operating on various sugar/sugar alcohol groups in the context of NAD+-derivatives and RNA termini, and potential phosphate transfer activities involving sugars and nucleotides. We show that such activities are particularly expanded in the RapZ-C-DUF488-DUF4326 clade, defined here for the first time. Some enzymes from this clade are predicted to catalyze novel DNA-end processing activities as part of nucleic-acid-modifying systems that are likely to function in biological conflicts between viruses and their hosts.
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Affiliation(s)
- A Maxwell Burroughs
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA
| | - L Aravind
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA
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2
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Hecher L, Harms FL, Lisfeld J, Alawi M, Denecke J, Kutsche K. INPP4A-related genetic and phenotypic spectrum and functional relevance of subcellular targeting of INPP4A isoforms. Neurogenetics 2023; 24:79-93. [PMID: 36653678 DOI: 10.1007/s10048-023-00709-9] [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: 11/15/2022] [Accepted: 01/07/2023] [Indexed: 01/20/2023]
Abstract
Type I inositol polyphosphate-4-phosphatase (INPP4A) belongs to the group of phosphoinositide phosphatases controlling proliferation, apoptosis, and endosome function by hydrolyzing phosphatidylinositol 3,4-bisphosphate. INPP4A produces multiple transcripts encoding shorter and longer INPP4A isoforms with hydrophilic or hydrophobic C-terminus. Biallelic INPP4A truncating variants cause a spectrum of neurodevelopmental disorders ranging from moderate intellectual disability to postnatal microcephaly with developmental and epileptic encephalopathy and (ponto)cerebellar hypoplasia. We report a girl with the novel homozygous INPP4A variant NM_001134224.2:c.2840del/p.(Gly947Glufs*12) (isoform d). She presented with postnatal microcephaly, global developmental delay, visual impairment, myoclonic seizures, and pontocerebellar hypoplasia and died at the age of 27 months. The level of mutant INPP4A mRNAs in proband-derived leukocytes was comparable to controls suggesting production of C-terminally altered INPP4A isoforms. We transiently expressed eGFP-tagged INPP4A isoform a (NM_004027.3) wildtype and p.(Gly908Glufs*12) mutant [p.(Gly947Glufs*12) according to NM_001134224.2] as well as INPP4A isoform b (NM_001566.2) wildtype and p.(Asp915Alafs*2) mutant, previously reported in family members with moderate intellectual disability, in HeLa cells and determined their subcellular distributions. While INPP4A isoform a was preferentially found in perinuclear clusters co-localizing with the GTPase Rab5, isoform b showed a net-like distribution, possibly localizing near and/or on microtubules. Quantification of intracellular localization patterns of the two INPP4A mutants revealed significant differences compared with the respective wildtype and similarity with each other. Our data suggests an important non-redundant function of INPP4A isoforms with hydrophobic or hydrophilic C-terminus in the brain.
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Affiliation(s)
- Laura Hecher
- Department of Pediatrics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Frederike L Harms
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Jasmin Lisfeld
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Malik Alawi
- Bioinformatics Core, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Jonas Denecke
- Department of Pediatrics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Kerstin Kutsche
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
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3
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Cabral-Dias R, Lucarelli S, Zak K, Rahmani S, Judge G, Abousawan J, DiGiovanni LF, Vural D, Anderson KE, Sugiyama MG, Genc G, Hong W, Botelho RJ, Fairn GD, Kim PK, Antonescu CN. Fyn and TOM1L1 are recruited to clathrin-coated pits and regulate Akt signaling. J Cell Biol 2022; 221:213045. [PMID: 35238864 PMCID: PMC8899389 DOI: 10.1083/jcb.201808181] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Revised: 12/15/2021] [Accepted: 01/24/2022] [Indexed: 12/24/2022] Open
Abstract
The epidermal growth factor (EGF) receptor (EGFR) controls many aspects of cell physiology. EGF binding to EGFR elicits the membrane recruitment and activation of phosphatidylinositol-3-kinase, leading to Akt phosphorylation and activation. Concomitantly, EGFR is recruited to clathrin-coated pits (CCPs), eventually leading to receptor endocytosis. Previous work uncovered that clathrin, but not receptor endocytosis, is required for EGF-stimulated Akt activation, and that some EGFR signals are enriched in CCPs. Here, we examine how CCPs control EGFR signaling. The signaling adaptor TOM1L1 and the Src-family kinase Fyn are enriched within a subset of CCPs with unique lifetimes and protein composition. Perturbation of TOM1L1 or Fyn impairs EGF-stimulated phosphorylation of Akt2 but not Akt1. EGF stimulation also triggered the TOM1L1- and Fyn-dependent recruitment of the phosphoinositide 5-phosphatase SHIP2 to CCPs. Thus, the recruitment of TOM1L1 and Fyn to a subset of CCPs underlies a role for these structures in the support of EGFR signaling leading to Akt activation.
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Affiliation(s)
- Rebecca Cabral-Dias
- Department of Chemistry and Biology, Ryerson University, Toronto, Ontario, Canada.,Graduate Program in Molecular Science, Ryerson University, Toronto, Ontario, Canada
| | - Stefanie Lucarelli
- Department of Chemistry and Biology, Ryerson University, Toronto, Ontario, Canada.,Graduate Program in Molecular Science, Ryerson University, Toronto, Ontario, Canada
| | - Karolina Zak
- Department of Chemistry and Biology, Ryerson University, Toronto, Ontario, Canada.,Graduate Program in Molecular Science, Ryerson University, Toronto, Ontario, Canada
| | - Sadia Rahmani
- Department of Chemistry and Biology, Ryerson University, Toronto, Ontario, Canada.,Graduate Program in Molecular Science, Ryerson University, Toronto, Ontario, Canada
| | - Gurjeet Judge
- Department of Chemistry and Biology, Ryerson University, Toronto, Ontario, Canada.,Graduate Program in Molecular Science, Ryerson University, Toronto, Ontario, Canada
| | - John Abousawan
- Department of Chemistry and Biology, Ryerson University, Toronto, Ontario, Canada.,Graduate Program in Molecular Science, Ryerson University, Toronto, Ontario, Canada
| | - Laura F DiGiovanni
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada.,Program in Cell Biology, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Dafne Vural
- Department of Chemistry and Biology, Ryerson University, Toronto, Ontario, Canada.,Graduate Program in Molecular Science, Ryerson University, Toronto, Ontario, Canada
| | - Karen E Anderson
- Signalling Programme, Babraham Institute, Babraham Research Campus, Cambridge, UK
| | - Michael G Sugiyama
- Department of Chemistry and Biology, Ryerson University, Toronto, Ontario, Canada
| | - Gizem Genc
- Department of Chemistry and Biology, Ryerson University, Toronto, Ontario, Canada
| | - Wanjin Hong
- Institute of Molecular and Cell Biology, A*STAR, Singapore
| | - Roberto J Botelho
- Department of Chemistry and Biology, Ryerson University, Toronto, Ontario, Canada.,Graduate Program in Molecular Science, Ryerson University, Toronto, Ontario, Canada
| | - Gregory D Fairn
- Department of Pathology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Peter K Kim
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada.,Program in Cell Biology, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Costin N Antonescu
- Department of Chemistry and Biology, Ryerson University, Toronto, Ontario, Canada.,Graduate Program in Molecular Science, Ryerson University, Toronto, Ontario, Canada.,Keenan Research Centre for Biomedical Science of St. Michael's Hospital, Toronto, Ontario, Canada
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4
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Lo WT, Zhang Y, Vadas O, Roske Y, Gulluni F, De Santis MC, Zagar AV, Stephanowitz H, Hirsch E, Liu F, Daumke O, Kudryashev M, Haucke V. Structural basis of phosphatidylinositol 3-kinase C2α function. Nat Struct Mol Biol 2022; 29:218-228. [PMID: 35256802 PMCID: PMC8930771 DOI: 10.1038/s41594-022-00730-w] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Accepted: 01/21/2022] [Indexed: 12/16/2022]
Abstract
Phosphatidylinositol 3-kinase type 2α (PI3KC2α) is an essential member of the structurally unresolved class II PI3K family with crucial functions in lipid signaling, endocytosis, angiogenesis, viral replication, platelet formation and a role in mitosis. The molecular basis of these activities of PI3KC2α is poorly understood. Here, we report high-resolution crystal structures as well as a 4.4-Å cryogenic-electron microscopic (cryo-EM) structure of PI3KC2α in active and inactive conformations. We unravel a coincident mechanism of lipid-induced activation of PI3KC2α at membranes that involves large-scale repositioning of its Ras-binding and lipid-binding distal Phox-homology and C-C2 domains, and can serve as a model for the entire class II PI3K family. Moreover, we describe a PI3KC2α-specific helical bundle domain that underlies its scaffolding function at the mitotic spindle. Our results advance our understanding of PI3K biology and pave the way for the development of specific inhibitors of class II PI3K function with wide applications in biomedicine.
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Affiliation(s)
- Wen-Ting Lo
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Berlin, Germany.
| | - Yingyi Zhang
- Max Planck Institute for Biophysics, Frankfurt am Main, Germany.,Buchmann Institute for Molecular Life Sciences, Goethe University, Frankfurt am Main, Germany.,Biological Cryo-EM Center, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Oscar Vadas
- University of Geneva, Faculty of Medicine, Geneva, Switzerland
| | - Yvette Roske
- Max Delbrück Centre for Molecular Medicine (MDC), Crystallography, Berlin, Germany
| | - Federico Gulluni
- Department of Molecular Biotechnology and Health Sciences, University of Torino, Torino, Italy
| | - Maria Chiara De Santis
- Department of Molecular Biotechnology and Health Sciences, University of Torino, Torino, Italy
| | | | - Heike Stephanowitz
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Berlin, Germany
| | - Emilio Hirsch
- Department of Molecular Biotechnology and Health Sciences, University of Torino, Torino, Italy
| | - Fan Liu
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Berlin, Germany
| | - Oliver Daumke
- Max Delbrück Centre for Molecular Medicine (MDC), Crystallography, Berlin, Germany
| | - Misha Kudryashev
- Max Planck Institute for Biophysics, Frankfurt am Main, Germany.,Buchmann Institute for Molecular Life Sciences, Goethe University, Frankfurt am Main, Germany
| | - Volker Haucke
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Berlin, Germany. .,Department of Biology, Chemistry, Pharmacy, Freie Universität Berlin, Berlin, Germany.
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Abstract
Phosphoinositides are signalling lipids derived from phosphatidylinositol, a ubiquitous phospholipid in the cytoplasmic leaflet of eukaryotic membranes. Initially discovered for their roles in cell signalling, phosphoinositides are now widely recognized as key integrators of membrane dynamics that broadly impact on all aspects of cell physiology and on disease. The past decade has witnessed a vast expansion of our knowledge of phosphoinositide biology. On the endocytic and exocytic routes, phosphoinositides direct the inward and outward flow of membrane as vesicular traffic is coupled to the conversion of phosphoinositides. Moreover, recent findings on the roles of phosphoinositides in autophagy and the endolysosomal system challenge our view of lysosome biology. The non-vesicular exchange of lipids, ions and metabolites at membrane contact sites in between organelles has also been found to depend on phosphoinositides. Here we review our current understanding of how phosphoinositides shape and direct membrane dynamics to impact on cell physiology, and provide an overview of emerging concepts in phosphoinositide regulation.
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6
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Müller R, Kojic A, Citir M, Schultz C. Synthesis and Cellular Labeling of Multifunctional Phosphatidylinositol Bis- and Trisphosphate Derivatives. Angew Chem Int Ed Engl 2021; 60:19759-19765. [PMID: 34075669 PMCID: PMC8390440 DOI: 10.1002/anie.202103599] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Revised: 05/07/2021] [Indexed: 12/15/2022]
Abstract
We synthesized the first multifunctionalized phosphoinositide polyphosphate derivatives featuring a photo-removable protecting group ("cage"), a photo-crosslinkable diazirine group, and a terminal alkyne group useful for click chemistry. We demonstrate that the lipid derivatives readily enter cells. After photo-crosslinking, cell fixation and fluorescent tagging via click chemistry, we determined the intracellular location of the lipid derivatives before and after uncaging of the lipids. We find that there is rapid trafficking of PI(3,4)P2 and PI(3,4,5)P3 derivatives to the plasma membrane, opening the intriguing possibility that there is active transport of these lipids involved. We employed the photo-crosslinking and click chemistry functions to analyze the proteome of PI(3,4,5)P3 -binding proteins. From the latter, we validated by RNAi that the putative lipid binding proteins ATP11A and MPP6 are involved in the transport of PI(3,4,5)P3 to the plasma membrane.
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Affiliation(s)
- Rainer Müller
- European Molecular Biology Laboratory (EMBL)Cell Biology & Biophysics UnitMeyerhofstr. 169117HeidelbergGermany
| | - Ana Kojic
- European Molecular Biology Laboratory (EMBL)Cell Biology & Biophysics UnitMeyerhofstr. 169117HeidelbergGermany
- Faculty of BiosciencesCollaboration for Joint Ph.D. Degree between EMBL and Heidelberg University69117HeidelbergGermany
- Oregon Health & Science UniversityDepartment of Chemical Physiology and Biochemistry3181 SW Sam Jackson Park RdPortlandOR97239-3098USA
| | - Mevlut Citir
- European Molecular Biology Laboratory (EMBL)Cell Biology & Biophysics UnitMeyerhofstr. 169117HeidelbergGermany
- Faculty of BiosciencesCollaboration for Joint Ph.D. Degree between EMBL and Heidelberg University69117HeidelbergGermany
| | - Carsten Schultz
- European Molecular Biology Laboratory (EMBL)Cell Biology & Biophysics UnitMeyerhofstr. 169117HeidelbergGermany
- Oregon Health & Science UniversityDepartment of Chemical Physiology and Biochemistry3181 SW Sam Jackson Park RdPortlandOR97239-3098USA
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7
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Malek M, Wawrzyniak AM, Koch P, Lüchtenborg C, Hessenberger M, Sachsenheimer T, Jang W, Brügger B, Haucke V. Inositol triphosphate-triggered calcium release blocks lipid exchange at endoplasmic reticulum-Golgi contact sites. Nat Commun 2021; 12:2673. [PMID: 33976123 PMCID: PMC8113574 DOI: 10.1038/s41467-021-22882-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Accepted: 04/02/2021] [Indexed: 02/03/2023] Open
Abstract
Vesicular traffic and membrane contact sites between organelles enable the exchange of proteins, lipids, and metabolites. Recruitment of tethers to contact sites between the endoplasmic reticulum (ER) and the plasma membrane is often triggered by calcium. Here we reveal a function for calcium in the repression of cholesterol export at membrane contact sites between the ER and the Golgi complex. We show that calcium efflux from ER stores induced by inositol-triphosphate [IP3] accumulation upon loss of the inositol 5-phosphatase INPP5A or receptor signaling triggers depletion of cholesterol and associated Gb3 from the cell surface, resulting in a blockade of clathrin-independent endocytosis (CIE) of Shiga toxin. This phenotype is caused by the calcium-induced dissociation of oxysterol binding protein (OSBP) from the Golgi complex and from VAP-containing membrane contact sites. Our findings reveal a crucial function for INPP5A-mediated IP3 hydrolysis in the control of lipid exchange at membrane contact sites.
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Affiliation(s)
- Mouhannad Malek
- grid.418832.40000 0001 0610 524XLeibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Berlin, Germany
| | - Anna M. Wawrzyniak
- grid.418832.40000 0001 0610 524XLeibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Berlin, Germany
| | - Peter Koch
- grid.418832.40000 0001 0610 524XLeibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Berlin, Germany
| | - Christian Lüchtenborg
- grid.7700.00000 0001 2190 4373Heidelberg University Biochemistry Center (BZH), Heidelberg University, Heidelberg, Germany
| | - Manuel Hessenberger
- grid.418832.40000 0001 0610 524XLeibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Berlin, Germany
| | - Timo Sachsenheimer
- grid.7700.00000 0001 2190 4373Heidelberg University Biochemistry Center (BZH), Heidelberg University, Heidelberg, Germany
| | - Wonyul Jang
- grid.418832.40000 0001 0610 524XLeibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Berlin, Germany
| | - Britta Brügger
- grid.7700.00000 0001 2190 4373Heidelberg University Biochemistry Center (BZH), Heidelberg University, Heidelberg, Germany
| | - Volker Haucke
- grid.418832.40000 0001 0610 524XLeibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Berlin, Germany ,grid.14095.390000 0000 9116 4836Faculty of Biology, Chemistry and Pharmacy, Freie Universität Berlin, Berlin, Germany
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8
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Koch PA, Dornan GL, Hessenberger M, Haucke V. The molecular mechanisms mediating class II PI 3-kinase function in cell physiology. FEBS J 2021; 288:7025-7042. [PMID: 33387369 DOI: 10.1111/febs.15692] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Revised: 12/14/2020] [Accepted: 12/30/2020] [Indexed: 12/13/2022]
Abstract
The phosphoinositide 3-kinase (PI3K) family of lipid-modifying enzymes plays vital roles in cell signaling and membrane trafficking through the production of 3-phosphorylated phosphoinositides. Numerous studies have analyzed the structure and function of class I and class III PI3Ks. In contrast, we know comparably little about the structure and physiological functions of the class II enzymes. Only recent studies have begun to unravel their roles in development, endocytic and endolysosomal membrane dynamics, signal transduction, and cell migration, while the mechanisms that control their localization and enzymatic activity remain largely unknown. Here, we summarize our current knowledge of the class II PI3Ks and outline open questions related to their structure, enzymatic activity, and their physiological and pathophysiological functions.
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Affiliation(s)
- Philipp Alexander Koch
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Berlin, Germany.,Faculty of Biology, Chemistry and Pharmacy, Freie Universität Berlin, Germany
| | | | - Manuel Hessenberger
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Berlin, Germany
| | - Volker Haucke
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Berlin, Germany.,Faculty of Biology, Chemistry and Pharmacy, Freie Universität Berlin, Germany
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9
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Walpole GFW, Grinstein S. Endocytosis and the internalization of pathogenic organisms: focus on phosphoinositides. F1000Res 2020; 9. [PMID: 32494357 PMCID: PMC7233180 DOI: 10.12688/f1000research.22393.1] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 05/07/2020] [Indexed: 12/18/2022] Open
Abstract
Despite their comparatively low abundance in biological membranes, phosphoinositides are key to the regulation of a diverse array of signaling pathways and direct membrane traffic. The role of phosphoinositides in the initiation and progression of endocytic pathways has been studied in considerable depth. Recent advances have revealed that distinct phosphoinositide species feature prominently in clathrin-dependent and -independent endocytosis as well as in phagocytosis and macropinocytosis. Moreover, a variety of intracellular and cell-associated pathogens have developed strategies to commandeer host cell phosphoinositide metabolism to gain entry and/or metabolic advantage, thereby promoting their survival and proliferation. Here, we briefly survey the current knowledge on the involvement of phosphoinositides in endocytosis, phagocytosis, and macropinocytosis and highlight several examples of molecular mimicry employed by pathogens to either “hitch a ride” on endocytic pathways endogenous to the host or create an entry path of their own.
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Affiliation(s)
- Glenn F W Walpole
- Program in Cell Biology, Hospital for Sick Children, Toronto, ON, Canada.,Department of Biochemistry, University of Toronto, Toronto, ON, Canada
| | - Sergio Grinstein
- Program in Cell Biology, Hospital for Sick Children, Toronto, ON, Canada.,Department of Biochemistry, University of Toronto, Toronto, ON, Canada.,Keenan Research Centre of the Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, ON, Canada
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10
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Xu L, Shao Y, Ren L, Liu X, Li Y, Xu J, Ye Y. IQGAP2 Inhibits Migration and Invasion of Gastric Cancer Cells via Elevating SHIP2 Phosphatase Activity. Int J Mol Sci 2020; 21:ijms21061968. [PMID: 32183047 PMCID: PMC7139352 DOI: 10.3390/ijms21061968] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2020] [Revised: 03/09/2020] [Accepted: 03/12/2020] [Indexed: 12/30/2022] Open
Abstract
Previous studies have shown reduced expression of Src homology 2-containing inositol 5-phosphatase 2 (SHIP2) and its tumor-suppressive role in gastric cancer (GC). However, the precise role of SHIP2 in the migration and invasion of GC cells remains unclear. Here, an IQ motif containing the GTPase-activating protein 2 (IQGAP2) as a SHIP2 binding partner, was screened and identified by co-immunoprecipitation and mass spectrometry studies. While IQGAP2 ubiquitously expressed in GC cells, IQGAP2 and SHIP2 co-localized in the cytoplasm of GC cells, and this physical association was confirmed by the binding of IQGAP2 to PRD and SAM domains of SHIP2. The knockdown of either SHIP2 or IQGAP2 promoted cell migration and invasion by inhibiting SHIP2 phosphatase activity, activating Akt and subsequently increasing epithelial–mesenchymal transition (EMT). Furthermore, knockdown of IQGAP2 in SHIP2-overexpressing GC cells reversed the inhibition of cell migration and invasion by SHIP2 induction, which was associated with the suppression of elevated SHIP2 phosphatase activity. Moreover, the deletion of PRD and SAM domains of SHIP2 abrogated the interaction and restored cell migration and invasion. Collectively, these results indicate that IQGAP2 interacts with SHIP2, leading to the increment of SHIP2 phosphatase activity, and thereby inhibiting the migration and invasion of GC cells via the inactivation of Akt and reduction in EMT.
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Affiliation(s)
| | | | | | | | | | | | - Yan Ye
- Correspondence: ; Tel.: +86-551-65161139
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