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Fuentealba LM, Pizarro H, Marzolo MP. OCRL1 Deficiency Affects the Intracellular Traffic of ApoER2 and Impairs Reelin-Induced Responses. Biomolecules 2024; 14:799. [PMID: 39062513 PMCID: PMC11274606 DOI: 10.3390/biom14070799] [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: 05/29/2024] [Revised: 07/01/2024] [Accepted: 07/02/2024] [Indexed: 07/28/2024] Open
Abstract
Lowe Syndrome (LS) is a rare X-linked disorder characterized by renal dysfunction, cataracts, and several central nervous system (CNS) anomalies. The mechanisms underlying the neurological dysfunction in LS remain unclear, albeit they share some phenotypic characteristics similar to the deficiency or dysfunction of the Reelin signaling, a relevant pathway with roles in CNS development and neuronal functions. In this study, we investigated the role of OCRL1, an inositol polyphosphate 5-phosphatase encoded by the OCRL gene, mutated in LS, focusing on its impact on endosomal trafficking and receptor recycling in human neuronal cells. Specifically, we tested the effects of OCRL1 deficiency in the trafficking and signaling of ApoER2/LRP8, a receptor for the ligand Reelin. We found that loss of OCRL1 impairs ApoER2 intracellular trafficking, leading to reduced receptor expression and decreased levels at the plasma membrane. Additionally, human neurons deficient in OCRL1 showed impairments in ApoER2/Reelin-induced responses. Our findings highlight the critical role of OCRL1 in regulating ApoER2 endosomal recycling and its impact on the ApoER2/Reelin signaling pathway, providing insights into potential mechanisms underlying the neurological manifestations of LS.
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Affiliation(s)
| | | | - María-Paz Marzolo
- Laboratorio de Tráfico Intracelular y Señalización, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago 7810128, Chile; (L.M.F.); (H.P.)
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2
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Mukhametova LI, Zherdev DO, Kuznetsov AN, Yudina ON, Tsvetkov YE, Eremin SA, Krylov VB, Nifantiev NE. Fluorescence-Polarization-Based Assaying of Lysozyme with Chitooligosaccharide Tracers. Biomolecules 2024; 14:170. [PMID: 38397407 PMCID: PMC10886901 DOI: 10.3390/biom14020170] [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: 01/03/2024] [Revised: 01/27/2024] [Accepted: 01/29/2024] [Indexed: 02/25/2024] Open
Abstract
Lysozyme is a well-known enzyme found in many biological fluids which plays an important role in the antibacterial protection of humans and animals. Lysozyme assays are used for the diagnosis of a number of diseases and utilized in immunohistochemistry, genetic and cellular engineering studies. The assaying methods are divided into two categories measuring either the concentration of lysozyme as a protein or its activity as an enzyme. While the first category of methods traditionally uses an enzyme-linked immunosorbent assay (ELISA), the methods for the determination of the enzymatic activity of lysozyme use either live bacteria, which is rather inconvenient, or natural peptidoglycans of high heterogeneity and variability, which leads to the low reproducibility of the assay results. In this work, we propose the use of a chemically synthesized substrate of a strictly defined structure to measure in a single experiment both the concentration of lysozyme as a protein and its enzymatic activity by means of the fluorescence polarization (FP) method. Chito-oligosaccharides of different chain lengths were fluorescently labeled and tested leading to the selection of the pentasaccharide as the optimal size tracer and the further optimization of the assay conditions for the accurate (detection limit 0.3 μM) and rapid (<30 min) determination of human lysozyme. The proposed protocol was applied to assay human lysozyme in tear samples and resulted in good correlation with the reference assay. The use of synthetic fluorescently labeled tracer, in contrast to natural peptidoglycan, in FP analysis allows for the development of a reproducible method for the determination of lysozyme activity.
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Affiliation(s)
- Liliya I. Mukhametova
- Faculty of Chemistry, M.V. Lomonosov Moscow State University, Leninsky Gory 1/3, 119991 Moscow, Russia; (L.I.M.); (S.A.E.)
| | - Dmitry O. Zherdev
- Faculty of Chemistry, M.V. Lomonosov Moscow State University, Leninsky Gory 1/3, 119991 Moscow, Russia; (L.I.M.); (S.A.E.)
- Laboratory of Glycoconjugate Chemistry, N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky Prospect 47, 119991 Moscow, Russia (Y.E.T.)
| | - Anton N. Kuznetsov
- Laboratory of Synthetic Glycovaccines, N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky Prospect 47, 119991 Moscow, Russia;
| | - Olga N. Yudina
- Laboratory of Glycoconjugate Chemistry, N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky Prospect 47, 119991 Moscow, Russia (Y.E.T.)
| | - Yury E. Tsvetkov
- Laboratory of Glycoconjugate Chemistry, N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky Prospect 47, 119991 Moscow, Russia (Y.E.T.)
| | - Sergei A. Eremin
- Faculty of Chemistry, M.V. Lomonosov Moscow State University, Leninsky Gory 1/3, 119991 Moscow, Russia; (L.I.M.); (S.A.E.)
| | - Vadim B. Krylov
- Laboratory of Synthetic Glycovaccines, N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky Prospect 47, 119991 Moscow, Russia;
| | - Nikolay E. Nifantiev
- Laboratory of Glycoconjugate Chemistry, N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky Prospect 47, 119991 Moscow, Russia (Y.E.T.)
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3
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Kaur H, Modgil V, Chaudhary N, Mohan B, Taneja N. Computational Guided Drug Targets Identification against Extended-Spectrum Beta-Lactamase-Producing Multi-Drug Resistant Uropathogenic Escherichia coli. Biomedicines 2023; 11:2028. [PMID: 37509666 PMCID: PMC10377140 DOI: 10.3390/biomedicines11072028] [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: 06/28/2023] [Revised: 07/14/2023] [Accepted: 07/15/2023] [Indexed: 07/30/2023] Open
Abstract
Urinary tract infections (UTIs) are one of the most frequent bacterial infections in the world, both in the hospital and community settings. Uropathogenic Escherichia coli (UPEC) are the predominant etiological agents causing UTIs. Extended-spectrum beta-lactamase (ESBL) production is a prominent mechanism of resistance that hinders the antimicrobial treatment of UTIs caused by UPEC and poses a substantial danger to the arsenal of antibiotics now in use. As bacteria have several methods to counteract the effects of antibiotics, identifying new potential drug targets may help in the design of new antimicrobial agents, and in the control of the rising trend of antimicrobial resistance (AMR). The public availability of the entire genome sequences of humans and many disease-causing organisms has accelerated the hunt for viable therapeutic targets. Using a unique, hierarchical, in silico technique using computational tools, we discovered and described potential therapeutic drug targets against the ESBL-producing UPEC strain NA114. Three different sets of proteins (chokepoint, virulence, and resistance genes) were explored in phase 1. In phase 2, proteins shortlisted from phase 1 were analyzed for their essentiality, non-homology to the human genome, and gut flora. In phase 3, the further shortlisted putative drug targets were qualitatively characterized, including their subcellular location, broad-spectrum potential, and druggability evaluations. We found seven distinct targets for the pathogen that showed no similarity to the human proteome. Thus, possibilities for cross-reactivity between a target-specific antibacterial and human proteins were minimized. The subcellular locations of two targets, ECNA114_0085 and ECNA114_1060, were predicted as cytoplasmic and periplasmic, respectively. These proteins play an important role in bacterial peptidoglycan biosynthesis and inositol phosphate metabolism, and can be used in the design of drugs against these bacteria. Inhibition of these proteins will be helpful to combat infections caused by MDR UPEC.
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Affiliation(s)
- Harpreet Kaur
- Department of Medical Microbiology, Post Graduate Institute of Medical Education and Research, Chandigarh 160012, India
| | - Vinay Modgil
- Department of Medical Microbiology, Post Graduate Institute of Medical Education and Research, Chandigarh 160012, India
| | - Naveen Chaudhary
- Department of Medical Microbiology, Post Graduate Institute of Medical Education and Research, Chandigarh 160012, India
| | - Balvinder Mohan
- Department of Medical Microbiology, Post Graduate Institute of Medical Education and Research, Chandigarh 160012, India
| | - Neelam Taneja
- Department of Medical Microbiology, Post Graduate Institute of Medical Education and Research, Chandigarh 160012, India
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4
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Lee JJ, Ramadesikan S, Black AF, Christoffer C, Pacheco AFP, Subramanian S, Hanna CB, Barth G, Stauffacher CV, Kihara D, Aguilar RC. Heterogeneity in Lowe Syndrome: Mutations Affecting the Phosphatase Domain of OCRL1 Differ in Impact on Enzymatic Activity and Severity of Cellular Phenotypes. Biomolecules 2023; 13:615. [PMID: 37189363 PMCID: PMC10135975 DOI: 10.3390/biom13040615] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 03/23/2023] [Accepted: 03/25/2023] [Indexed: 04/01/2023] Open
Abstract
Lowe Syndrome (LS) is a condition due to mutations in the OCRL1 gene, characterized by congenital cataracts, intellectual disability, and kidney malfunction. Unfortunately, patients succumb to renal failure after adolescence. This study is centered in investigating the biochemical and phenotypic impact of patient's OCRL1 variants (OCRL1VAR). Specifically, we tested the hypothesis that some OCRL1VAR are stabilized in a non-functional conformation by focusing on missense mutations affecting the phosphatase domain, but not changing residues involved in binding/catalysis. The pathogenic and conformational characteristics of the selected variants were evaluated in silico and our results revealed some OCRL1VAR to be benign, while others are pathogenic. Then we proceeded to monitor the enzymatic activity and function in kidney cells of the different OCRL1VAR. Based on their enzymatic activity and presence/absence of phenotypes, the variants segregated into two categories that also correlated with the severity of the condition they induce. Overall, these two groups mapped to opposite sides of the phosphatase domain. In summary, our findings highlight that not every mutation affecting the catalytic domain impairs OCRL1's enzymatic activity. Importantly, data support the inactive-conformation hypothesis. Finally, our results contribute to establishing the molecular and structural basis for the observed heterogeneity in severity/symptomatology displayed by patients.
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Affiliation(s)
- Jennifer J. Lee
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, USA; (J.J.L.); (A.F.B.); (A.F.P.P.); (S.S.); (C.B.H.); (G.B.); (C.V.S.); (D.K.)
- Purdue Institute for Cancer Research, Purdue University, West Lafayette, IN 47907, USA
| | - Swetha Ramadesikan
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, USA; (J.J.L.); (A.F.B.); (A.F.P.P.); (S.S.); (C.B.H.); (G.B.); (C.V.S.); (D.K.)
- Purdue Institute for Cancer Research, Purdue University, West Lafayette, IN 47907, USA
| | - Adrianna F. Black
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, USA; (J.J.L.); (A.F.B.); (A.F.P.P.); (S.S.); (C.B.H.); (G.B.); (C.V.S.); (D.K.)
- Purdue Institute for Cancer Research, Purdue University, West Lafayette, IN 47907, USA
| | - Charles Christoffer
- Department of Computer Science, Purdue University, West Lafayette, IN 47907, USA;
| | - Andres F. Pacheco Pacheco
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, USA; (J.J.L.); (A.F.B.); (A.F.P.P.); (S.S.); (C.B.H.); (G.B.); (C.V.S.); (D.K.)
- Purdue Institute for Cancer Research, Purdue University, West Lafayette, IN 47907, USA
| | - Sneha Subramanian
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, USA; (J.J.L.); (A.F.B.); (A.F.P.P.); (S.S.); (C.B.H.); (G.B.); (C.V.S.); (D.K.)
- Purdue Institute for Cancer Research, Purdue University, West Lafayette, IN 47907, USA
| | - Claudia B. Hanna
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, USA; (J.J.L.); (A.F.B.); (A.F.P.P.); (S.S.); (C.B.H.); (G.B.); (C.V.S.); (D.K.)
- Purdue Institute for Cancer Research, Purdue University, West Lafayette, IN 47907, USA
| | - Gillian Barth
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, USA; (J.J.L.); (A.F.B.); (A.F.P.P.); (S.S.); (C.B.H.); (G.B.); (C.V.S.); (D.K.)
- Purdue Institute for Cancer Research, Purdue University, West Lafayette, IN 47907, USA
| | - Cynthia V. Stauffacher
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, USA; (J.J.L.); (A.F.B.); (A.F.P.P.); (S.S.); (C.B.H.); (G.B.); (C.V.S.); (D.K.)
- Purdue Institute for Cancer Research, Purdue University, West Lafayette, IN 47907, USA
| | - Daisuke Kihara
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, USA; (J.J.L.); (A.F.B.); (A.F.P.P.); (S.S.); (C.B.H.); (G.B.); (C.V.S.); (D.K.)
- Purdue Institute for Cancer Research, Purdue University, West Lafayette, IN 47907, USA
- Department of Computer Science, Purdue University, West Lafayette, IN 47907, USA;
| | - Ruben Claudio Aguilar
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, USA; (J.J.L.); (A.F.B.); (A.F.P.P.); (S.S.); (C.B.H.); (G.B.); (C.V.S.); (D.K.)
- Purdue Institute for Cancer Research, Purdue University, West Lafayette, IN 47907, USA
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5
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Bura A, de Matteis MA, Bender M, Swinkels M, Versluis J, Jansen AJG, Jurak Begonja A. Oculocerebrorenal syndrome of Lowe protein controls cytoskeletal reorganisation during human platelet spreading. Br J Haematol 2023; 200:87-99. [PMID: 36176266 DOI: 10.1111/bjh.18478] [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: 05/10/2022] [Revised: 09/05/2022] [Accepted: 09/14/2022] [Indexed: 11/28/2022]
Abstract
Lowe syndrome (LS) is a rare, X-linked disorder characterised by numerous symptoms affecting the brain, the eyes, and the kidneys. It is caused by mutations in the oculocerebrorenal syndrome of Lowe (OCRL) protein, a 5-phosphatase localised in different cellular compartments that dephosphorylates phosphatidylinositol-4,5-bisphosphate into phosphatidylinositol-4-monophosphate. Some patients with LS also have bleeding disorders, with normal to low platelet (PLT) count and impaired PLT function. However, the mechanism of PLT dysfunction in patients with LS is not completely understood. The main function of PLTs is to activate upon vessel wall injury and stop the bleeding by clot formation. PLT activation is accompanied by a shape change that is a result of massive cytoskeletal rearrangements. Here, we show that OCRL-inhibited human PLTs do not fully spread, form mostly filopodia, and accumulate actin nodules. These nodules co-localise with ARP2/3 subunit p34, vinculin, and sorting nexin 9. Furthermore, OCRL-inhibited PLTs have a retained microtubular coil with high levels of acetylated tubulin. Also, myosin light chain phosphorylation is decreased upon OCRL inhibition, without impaired degranulation or integrin activation. Taken together, these results suggest that OCRL contributes to cytoskeletal rearrangements during PLT activation that could explain mild bleeding problems in patients with LS.
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Affiliation(s)
- Ana Bura
- Department of Biotechnology, University of Rijeka, Rijeka, Croatia
| | - Maria Antonietta de Matteis
- Telethon Institute of Genetics and Medicine, TIGEM, Pozzuoli, Naples, Italy.,Department of Molecular Medicine and Medical Biotechnology, University of Naples Federico II, Naples, Italy
| | - Markus Bender
- Institute of Experimental Biomedicine, University Hospital Wuerzburg, Rudolf Virchow Center, Wuerzburg, Germany
| | - Maurice Swinkels
- Erasmus MC University Medical Center, Rotterdam, the Netherlands
| | - Jurjen Versluis
- Erasmus MC University Medical Center, Rotterdam, the Netherlands
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6
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Sandoval L, Fuentealba LM, Marzolo MP. Participation of OCRL1, and APPL1, in the expression, proteolysis, phosphorylation and endosomal trafficking of megalin: Implications for Lowe Syndrome. Front Cell Dev Biol 2022; 10:911664. [PMID: 36340038 PMCID: PMC9630597 DOI: 10.3389/fcell.2022.911664] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2022] [Accepted: 10/10/2022] [Indexed: 11/13/2022] Open
Abstract
Megalin/LRP2 is the primary multiligand receptor for the re-absorption of low molecular weight proteins in the proximal renal tubule. Its function is significantly dependent on its endosomal trafficking. Megalin recycling from endosomal compartments is altered in an X-linked disease called Lowe Syndrome (LS), caused by mutations in the gene encoding for the phosphatidylinositol 5-phosphatase OCRL1. LS patients show increased low-molecular-weight proteins with reduced levels of megalin ectodomain in the urine and accumulation of the receptor in endosomal compartments of the proximal tubule cells. To gain insight into the deregulation of megalin in the LS condition, we silenced OCRL1 in different cell lines to evaluate megalin expression finding that it is post-transcriptionally regulated. As an indication of megalin proteolysis, we detect the ectodomain of the receptor in the culture media. Remarkably, in OCRL1 silenced cells, megalin ectodomain secretion appeared significantly reduced, according to the observation in the urine of LS patients. Besides, the silencing of APPL1, a Rab5 effector associated with OCRL1 in endocytic vesicles, also reduced the presence of megalin’s ectodomain in the culture media. In both silencing conditions, megalin cell surface levels were significantly decreased. Considering that GSK3ß-mediated megalin phosphorylation reduces receptor recycling, we determined that the endosomal distribution of megalin depends on its phosphorylation status and OCRL1 function. As a physiologic regulator of GSK3ß, we focused on insulin signaling that reduces kinase activity. Accordingly, megalin phosphorylation was significantly reduced by insulin in wild-type cells. Moreover, even though in cells with low activity of OCRL1 the insulin response was reduced, the phosphorylation of megalin was significantly decreased and the receptor at the cell surface increased, suggesting a protective role of insulin in a LS cellular model.
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Affiliation(s)
- Lisette Sandoval
- Laboratorio de Tráfico Intracelular y Señalización, Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
- Instituto de Ciencias Biomédicas, Facultad de Ciencias de la Salud, Universidad Autónoma de Chile, Santiago, Chile
| | - Luz M. Fuentealba
- Laboratorio de Tráfico Intracelular y Señalización, Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - María-Paz Marzolo
- Laboratorio de Tráfico Intracelular y Señalización, Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
- *Correspondence: María-Paz Marzolo,
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7
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Droubi A, Wallis C, Anderson KE, Rahman S, de Sa A, Rahman T, Stephens LR, Hawkins PT, Lowe M. The inositol 5-phosphatase INPP5B regulates B cell receptor clustering and signaling. J Cell Biol 2022; 221:e202112018. [PMID: 35878408 PMCID: PMC9351708 DOI: 10.1083/jcb.202112018] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 05/27/2022] [Accepted: 07/05/2022] [Indexed: 11/22/2022] Open
Abstract
Upon antigen binding, the B cell receptor (BCR) undergoes clustering to form a signalosome that propagates downstream signaling required for normal B cell development and physiology. BCR clustering is dependent on remodeling of the cortical actin network, but the mechanisms that regulate actin remodeling in this context remain poorly defined. In this study, we identify the inositol 5-phosphatase INPP5B as a key regulator of actin remodeling, BCR clustering, and downstream signaling in antigen-stimulated B cells. INPP5B acts via dephosphorylation of the inositol lipid PI(4,5)P2 that in turn is necessary for actin disassembly, BCR mobilization, and cell spreading on immobilized surface antigen. These effects can be explained by increased actin severing by cofilin and loss of actin linking to the plasma membrane by ezrin, both of which are sensitive to INPP5B-dependent PI(4,5)P2 hydrolysis. INPP5B is therefore a new player in BCR signaling and may represent an attractive target for treatment of B cell malignancies caused by aberrant BCR signaling.
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Affiliation(s)
- Alaa Droubi
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Connor Wallis
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | | | - Saifur Rahman
- Department of Pharmacology, University of Cambridge, Cambridge, UK
| | - Aloka de Sa
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Taufiq Rahman
- Department of Pharmacology, University of Cambridge, Cambridge, UK
| | | | | | - Martin Lowe
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
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8
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Lebecq A, Doumane M, Fangain A, Bayle V, Leong JX, Rozier F, Marques-Bueno MD, Armengot L, Boisseau R, Simon ML, Franz-Wachtel M, Macek B, Üstün S, Jaillais Y, Caillaud MC. The Arabidopsis SAC9 enzyme is enriched in a cortical population of early endosomes and restricts PI(4,5)P 2 at the plasma membrane. eLife 2022; 11:73837. [PMID: 36044021 PMCID: PMC9436410 DOI: 10.7554/elife.73837] [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: 09/16/2021] [Accepted: 07/09/2022] [Indexed: 01/10/2023] Open
Abstract
Membrane lipids, and especially phosphoinositides, are differentially enriched within the eukaryotic endomembrane system. This generates a landmark code by modulating the properties of each membrane. Phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2] specifically accumulates at the plasma membrane in yeast, animal, and plant cells, where it regulates a wide range of cellular processes including endocytic trafficking. However, the functional consequences of mispatterning PI(4,5)P2 in plants are unknown. Here, we functionally characterized the putative phosphoinositide phosphatase SUPPRESSOR OF ACTIN9 (SAC9) in Arabidopsis thaliana (Arabidopsis). We found that SAC9 depletion led to the ectopic localization of PI(4,5)P2 on cortical intracellular compartments, which depends on PI4P and PI(4,5)P2 production at the plasma membrane. SAC9 localizes to a subpopulation of trans-Golgi Network/early endosomes that are enriched in a region close to the cell cortex and that are coated with clathrin. Furthermore, it interacts and colocalizes with Src Homology 3 Domain Protein 2 (SH3P2), a protein involved in endocytic trafficking. In the absence of SAC9, SH3P2 localization is altered and the clathrin-mediated endocytosis rate is reduced. Together, our results highlight the importance of restricting PI(4,5)P2 at the plasma membrane and illustrate that one of the consequences of PI(4,5)P2 misspatterning in plants is to impact the endocytic trafficking.
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Affiliation(s)
- Alexis Lebecq
- Laboratoire Reproduction et Développement des Plantes, Université de Lyon, Lyon, France
| | - Mehdi Doumane
- Laboratoire Reproduction et Développement des Plantes, Université de Lyon, Lyon, France
| | - Aurelie Fangain
- Laboratoire Reproduction et Développement des Plantes, Université de Lyon, Lyon, France
| | - Vincent Bayle
- Laboratoire Reproduction et Développement des Plantes, Université de Lyon, Lyon, France
| | - Jia Xuan Leong
- University of Tübingen, Center for Plant Molecular Biology (ZMBP), Tübingen, Germany
| | - Frédérique Rozier
- Laboratoire Reproduction et Développement des Plantes, Université de Lyon, Lyon, France
| | | | - Laia Armengot
- Laboratoire Reproduction et Développement des Plantes, Université de Lyon, Lyon, France
| | - Romain Boisseau
- Division of Biological Science, University of Montana, Missoula, United States
| | | | - Mirita Franz-Wachtel
- Interfaculty Institute for Cell Biology, Department of Quantitative Proteomics, University of Tübingen, Tübingen, Germany
| | - Boris Macek
- Interfaculty Institute for Cell Biology, Department of Quantitative Proteomics, University of Tübingen, Tübingen, Germany
| | - Suayib Üstün
- University of Tübingen, Center for Plant Molecular Biology (ZMBP), Tübingen, Germany.,Faculty of Biology & Biotechnology, Ruhr-University Bochum, Bochum, Germany
| | - Yvon Jaillais
- Laboratoire Reproduction et Développement des Plantes, Université de Lyon, Lyon, France
| | - Marie-Cécile Caillaud
- Laboratoire Reproduction et Développement des Plantes, Université de Lyon, Lyon, France
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9
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Deng J, Lin X, Li Q, Cai XY, Wu LW, Wang W, Zhang B, Li YL, Hu J, Lin NM. Decreased INPP5B expression predicts poor prognosis in lung adenocarcinoma. Cancer Cell Int 2022; 22:189. [PMID: 35568951 PMCID: PMC9107680 DOI: 10.1186/s12935-022-02609-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Accepted: 05/06/2022] [Indexed: 12/03/2022] Open
Abstract
Background Inositol Polyphosphate-5-Phosphatase B (INPP5B), a inositol 5-phosphatase, plays an important role in many biological processes through phosphorylating PI(4,5)P2 and/or PI(3,4,5)P3 at the 5-position. Nevertheless, little is known about its function and cellular pathways in tumors. This study aims to investigate the potential role of INPP5B as a diagnostic and prognostic biomarker for lung adenocarcinoma (LUAD), as well as its biological functions and molecular mechanisms in LUAD. Methods TCGA, GEO, CTPAC, and HPA datasets were used for differential expression analysis and pathological stratification comparison. The prognostic and diagnostic role of INPP5B was determined by Kaplan–Meier curves, univariate and multivariate Cox regression analysis, and receiver operating characteristics (ROC) curve analyses. The potential mechanism of INPP5B was explored through GO, KEGG, and GSEA enrichment analysis, as well as GeneMANIA and STRING protein–protein interaction (PPI) network. PicTar, PITA, and miRmap databases were used for exploring miRNA targeting INPP5B. In molecular biology experiments, immunohistochemical analyses and Western blot analyses were used to determine protein expression. Co-immunoprecipitation assay was used to detect protein–protein interactions. CCK8 assays and colony formation assays were used for the measurement of cell proliferation. Cell cycle was assessed by PI staining with flow cytometry. Cell migration was performed by Transwell assays and wound healing assays. Result INPP5B was decreased in LUAD tissues compared with normal adjacent tissues. And the low expression of INPP5B was associated with late-stage pathological features. In addition, INPP5B was found to be a significant independent prognostic and diagnostic factor for LUAD patients. Hsa-miR-582-5p was predicted as a negative regulator of INPP5B mRNA expression. INPP5B was significantly correlated with the expression of PTEN and the activity of PI3K/AKT signaling pathways, as determined by enrichment analysis and PPI network. In vitro experiments partially confirmed the aforementioned findings. INPP5B could interact directly with PTEN. INPP5B overexpression inhibited LUAD cell proliferation and migration while downregulating the AKT pathway. Conclusion Our results demonstrated that INPP5B could inhibit the proliferation and metastasis of LUAD cells. It could serve as a novel diagnostic and prognostic biomarker for LUAD patients. Trial registration LUAD tissues and corresponding para-cancerous tissues were collected from 10 different LUAD patients at Hangzhou First People’s Hospital. The Ethics Committee of Hangzhou First People’s Hospital has approved this study. (registration number: IIT-20210907-0031-01; registration date: 2021.09.13) Supplementary Information The online version contains supplementary material available at 10.1186/s12935-022-02609-8.
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Affiliation(s)
- Jun Deng
- Key Laboratory of Clinical Cancer Pharmacology and Toxicology Research of Zhejiang Province, Affiliated Hangzhou First People's Hospital, Zhejiang University School of Medicine, Hangzhou, 310006, China
| | - Xu Lin
- Department of Thoracic Surgery, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310003, China
| | - Qi Li
- Key Laboratory of Clinical Cancer Pharmacology and Toxicology Research of Zhejiang Province, Affiliated Hangzhou First People's Hospital, Zhejiang University School of Medicine, Hangzhou, 310006, China
| | - Xiao-Yu Cai
- Key Laboratory of Clinical Cancer Pharmacology and Toxicology Research of Zhejiang Province, Affiliated Hangzhou First People's Hospital, Zhejiang University School of Medicine, Hangzhou, 310006, China.,Department of Clinical Pharmacy, Affiliated Hangzhou First People's Hospital, Zhejiang University School of Medicine, Hangzhou, 310006, China
| | - Lin-Wen Wu
- Key Laboratory of Clinical Cancer Pharmacology and Toxicology Research of Zhejiang Province, Affiliated Hangzhou First People's Hospital, Zhejiang University School of Medicine, Hangzhou, 310006, China.,Department of Clinical Pharmacy, Affiliated Hangzhou First People's Hospital, Zhejiang University School of Medicine, Hangzhou, 310006, China
| | - Wei Wang
- Department of Pathology, Affiliated Hangzhou First People's Hospital, Zhejiang University School of Medicine, Hangzhou, 310006, China
| | - Bo Zhang
- Key Laboratory of Clinical Cancer Pharmacology and Toxicology Research of Zhejiang Province, Affiliated Hangzhou First People's Hospital, Zhejiang University School of Medicine, Hangzhou, 310006, China.,Department of Clinical Pharmacy, Affiliated Hangzhou First People's Hospital, Zhejiang University School of Medicine, Hangzhou, 310006, China
| | - Yang-Ling Li
- Key Laboratory of Clinical Cancer Pharmacology and Toxicology Research of Zhejiang Province, Affiliated Hangzhou First People's Hospital, Zhejiang University School of Medicine, Hangzhou, 310006, China.,Department of Clinical Pharmacy, Affiliated Hangzhou First People's Hospital, Zhejiang University School of Medicine, Hangzhou, 310006, China
| | - Jian Hu
- Department of Thoracic Surgery, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310003, China.
| | - Neng-Ming Lin
- Key Laboratory of Clinical Cancer Pharmacology and Toxicology Research of Zhejiang Province, Affiliated Hangzhou First People's Hospital, Zhejiang University School of Medicine, Hangzhou, 310006, China. .,Department of Clinical Pharmacy, Affiliated Hangzhou First People's Hospital, Zhejiang University School of Medicine, Hangzhou, 310006, China. .,Westlake Laboratory of Life Sciences and Biomedicine of Zhejiang Province, Hangzhou, 310024, China. .,Cancer Center, Zhejiang University, Hangzhou, 310058, China.
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10
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Moy RH, Nguyen A, Loo JM, Yamaguchi N, Kajba CM, Santhanam B, Ostendorf BN, Wu YG, Tavazoie S, Tavazoie SF. Functional genetic screen identifies ITPR3/calcium/RELB axis as a driver of colorectal cancer metastatic liver colonization. Dev Cell 2022; 57:1146-1159.e7. [PMID: 35487218 PMCID: PMC9446818 DOI: 10.1016/j.devcel.2022.04.010] [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: 09/12/2021] [Revised: 03/02/2022] [Accepted: 04/06/2022] [Indexed: 11/29/2022]
Abstract
Metastatic colonization is the primary cause of death from colorectal cancer (CRC). We employed genome-scale in vivo short hairpin RNA (shRNA) screening and validation to identify 26 promoters of CRC liver colonization. Among these genes, we identified a cluster that contains multiple targetable genes, including ITPR3, which promoted liver-metastatic colonization and elicited similar downstream gene expression programs. ITPR3 is a caffeine-sensitive inositol 1,4,5-triphosphate (IP3) receptor that releases calcium from the endoplasmic reticulum and enhanced metastatic colonization by inducing expression of RELB, a transcription factor that is associated with non-canonical NF-κB signaling. Genetic, cell biological, pharmacologic, and clinical association studies revealed that ITPR3 and RELB drive CRC colony formation by promoting cell survival upon substratum detachment or hypoxic exposure. RELB was sufficient to drive colonization downstream of ITPR3. Our findings implicate the ITPR3/calcium/RELB axis in CRC metastatic colony formation and uncover multiple clinico-pathologically associated targetable proteins as drivers of CRC metastatic colonization.
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Affiliation(s)
- Ryan H Moy
- Laboratory of Systems Cancer Biology, The Rockefeller University, New York, NY 10065, USA
| | - Alexander Nguyen
- Laboratory of Systems Cancer Biology, The Rockefeller University, New York, NY 10065, USA
| | - Jia Min Loo
- Laboratory of Systems Cancer Biology, The Rockefeller University, New York, NY 10065, USA
| | - Norihiro Yamaguchi
- Laboratory of Systems Cancer Biology, The Rockefeller University, New York, NY 10065, USA
| | - Christina M Kajba
- Laboratory of Systems Cancer Biology, The Rockefeller University, New York, NY 10065, USA
| | - Balaji Santhanam
- Department of Biochemistry and Molecular Biophysics and Department of Systems Biology, Columbia University, New York, NY 10032, USA; Department of Biological Sciences, Columbia University, New York, NY 10027, USA
| | - Benjamin N Ostendorf
- Laboratory of Systems Cancer Biology, The Rockefeller University, New York, NY 10065, USA
| | - Y Gloria Wu
- Laboratory of Systems Cancer Biology, The Rockefeller University, New York, NY 10065, USA
| | - Saeed Tavazoie
- Department of Biochemistry and Molecular Biophysics and Department of Systems Biology, Columbia University, New York, NY 10032, USA; Department of Biological Sciences, Columbia University, New York, NY 10027, USA
| | - Sohail F Tavazoie
- Laboratory of Systems Cancer Biology, The Rockefeller University, New York, NY 10065, USA.
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11
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Schechter M, Sharon R. An Emerging Role for Phosphoinositides in the Pathophysiology of Parkinson’s Disease. JOURNAL OF PARKINSON'S DISEASE 2021; 11:1725-1750. [PMID: 34151859 PMCID: PMC8609718 DOI: 10.3233/jpd-212684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Recent data support an involvement of defects in homeostasis of phosphoinositides (PIPs) in the pathophysiology of Parkinson’s disease (PD). Genetic mutations have been identified in genes encoding for PIP-regulating and PIP-interacting proteins, that are associated with familial and sporadic PD. Many of these proteins are implicated in vesicular membrane trafficking, mechanisms that were recently highlighted for their close associations with PD. PIPs are phosphorylated forms of the membrane phospholipid, phosphatidylinositol. Their composition in the vesicle’s membrane of origin, as well as membrane of destination, controls vesicular membrane trafficking. We review the converging evidence that points to the involvement of PIPs in PD. The review describes PD- and PIP-associated proteins implicated in clathrin-mediated endocytosis and autophagy, and highlights the involvement of α-synuclein in these mechanisms.
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Affiliation(s)
- Meir Schechter
- Department of Biochemistry and Molecular Biology, IMRIC, The Hebrew University-Hadassah Medical School, Ein Kerem, Jerusalem, Israel
| | - Ronit Sharon
- Department of Biochemistry and Molecular Biology, IMRIC, The Hebrew University-Hadassah Medical School, Ein Kerem, Jerusalem, Israel
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12
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Whitfield H, Hemmings AM, Mills SJ, Baker K, White G, Rushworth S, Riley AM, Potter BVL, Brearley CA. Allosteric Site on SHIP2 Identified Through Fluorescent Ligand Screening and Crystallography: A Potential New Target for Intervention. J Med Chem 2021; 64:3813-3826. [PMID: 33724834 PMCID: PMC7610569 DOI: 10.1021/acs.jmedchem.0c01944] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Src homology 2 domain-containing inositol phosphate phosphatase 2 (SHIP2) is one of the 10 human inositol phosphate 5-phosphatases. One of its physiological functions is dephosphorylation of phosphatidylinositol 3,4,5-trisphosphate, PtdIns(3,4,5)P3. It is therefore a therapeutic target for pathophysiologies dependent on PtdIns(3,4,5)P3 and PtdIns(3,4)P2. Therapeutic interventions are limited by the dearth of crystallographic data describing ligand/inhibitor binding. An active site-directed fluorescent probe facilitated screening of compound libraries for SHIP2 ligands. With two additional orthogonal assays, several ligands including galloflavin were identified as low micromolar Ki inhibitors. One ligand, an oxo-linked ethylene-bridged dimer of benzene 1,2,4-trisphosphate, was shown to be an uncompetitive inhibitor that binds to a regulatory site on the catalytic domain. We posit that binding of ligands to this site restrains L4 loop motions that are key to interdomain communications that accompany high catalytic activity with phosphoinositide substrate. This site may, therefore, be a future druggable target for medicinal chemistry.
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Affiliation(s)
- Hayley Whitfield
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, U.K
| | - Andrew M Hemmings
- School of Chemistry, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, U.K
| | - Stephen J Mills
- Medicinal Chemistry & Drug Discovery, Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, U.K
| | - Kendall Baker
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, U.K
| | - Gaye White
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, U.K
| | - Stuart Rushworth
- Department of Molecular Haematology; Norwich Medical School, University of East Anglia, Norwich NR4 7TJ, U.K
| | - Andrew M Riley
- Medicinal Chemistry & Drug Discovery, Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, U.K
| | - Barry V L Potter
- Medicinal Chemistry & Drug Discovery, Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, U.K
| | - Charles A Brearley
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, U.K
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13
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Targeting SHIP1 and SHIP2 in Cancer. Cancers (Basel) 2021; 13:cancers13040890. [PMID: 33672717 PMCID: PMC7924360 DOI: 10.3390/cancers13040890] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2021] [Revised: 02/12/2021] [Accepted: 02/13/2021] [Indexed: 12/31/2022] Open
Abstract
Simple Summary Phosphoinositol signaling pathways and their dysregulation have been shown to have a fundamental role in health and disease, respectively. The SH2-containing 5′ inositol phosphatases, SHIP1 and SHIP2, are regulators of the PI3K/AKT pathway that have crucial roles in cancer progression. This review aims to summarize the role of SHIP1 and SHIP2 in cancer signaling and the immune response to cancer, the discovery and use of SHIP inhibitors and agonists as possible cancer therapeutics. Abstract Membrane-anchored and soluble inositol phospholipid species are critical mediators of intracellular cell signaling cascades. Alterations in their normal production or degradation are implicated in the pathology of a number of disorders including cancer and pro-inflammatory conditions. The SH2-containing 5′ inositol phosphatases, SHIP1 and SHIP2, play a fundamental role in these processes by depleting PI(3,4,5)P3, but also by producing PI(3,4)P2 at the inner leaflet of the plasma membrane. With the intent of targeting SHIP1 or SHIP2 selectively, or both paralogs simultaneously, small molecule inhibitors and agonists have been developed and tested in vitro and in vivo over the last decade in various disease models. These studies have shown promising results in various pre-clinical models of disease including cancer and tumor immunotherapy. In this review the potential use of SHIP inhibitors in cancer is discussed with particular attention to the molecular structure, binding site and efficacy of these SHIP inhibitors.
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14
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Montaño-Rendón F, Grinstein S, Walpole GFW. Monitoring Phosphoinositide Fluxes and Effectors During Leukocyte Chemotaxis and Phagocytosis. Front Cell Dev Biol 2021; 9:626136. [PMID: 33614656 PMCID: PMC7890364 DOI: 10.3389/fcell.2021.626136] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Accepted: 01/06/2021] [Indexed: 01/22/2023] Open
Abstract
The dynamic re-organization of cellular membranes in response to extracellular stimuli is fundamental to the cell physiology of myeloid and lymphoid cells of the immune system. In addition to maintaining cellular homeostatic functions, remodeling of the plasmalemma and endomembranes endow leukocytes with the potential to relay extracellular signals across their biological membranes to promote rolling adhesion and diapedesis, migration into the tissue parenchyma, and to ingest foreign particles and effete cells. Phosphoinositides, signaling lipids that control the interface of biological membranes with the external environment, are pivotal to this wealth of functions. Here, we highlight the complex metabolic transitions that occur to phosphoinositides during several stages of the leukocyte lifecycle, namely diapedesis, migration, and phagocytosis. We describe classical and recently developed tools that have aided our understanding of these complex lipids. Finally, major downstream effectors of inositides are highlighted including the cytoskeleton, emphasizing the importance of these rare lipids in immunity and disease.
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Affiliation(s)
- Fernando Montaño-Rendón
- Program in Cell Biology, Hospital for Sick Children, Toronto, ON, Canada.,Institute of Medical Sciences, University of Toronto, Toronto, ON, Canada
| | - Sergio Grinstein
- Program in Cell Biology, Hospital for Sick Children, Toronto, ON, Canada.,Institute of Medical Sciences, University of Toronto, Toronto, ON, Canada.,Department of Biochemistry, University of Toronto, Toronto, ON, Canada.,Keenan Research Centre for Biomedical Science, St. Michael's Hospital, Toronto, ON, Canada
| | - Glenn F W Walpole
- Program in Cell Biology, Hospital for Sick Children, Toronto, ON, Canada.,Department of Biochemistry, University of Toronto, Toronto, ON, Canada
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15
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Palamiuc L, Ravi A, Emerling BM. Phosphoinositides in autophagy: current roles and future insights. FEBS J 2019; 287:222-238. [DOI: 10.1111/febs.15127] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Revised: 08/27/2019] [Accepted: 11/05/2019] [Indexed: 12/22/2022]
Affiliation(s)
- Lavinia Palamiuc
- Sanford Burnham Prebys Medical Discovery Institute Cancer Metabolism and Signaling Networks Program La JollaCA USA
| | - Archna Ravi
- Sanford Burnham Prebys Medical Discovery Institute Cancer Metabolism and Signaling Networks Program La JollaCA USA
| | - Brooke M. Emerling
- Sanford Burnham Prebys Medical Discovery Institute Cancer Metabolism and Signaling Networks Program La JollaCA USA
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16
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Ramos AR, Ghosh S, Erneux C. The impact of phosphoinositide 5-phosphatases on phosphoinositides in cell function and human disease. J Lipid Res 2018; 60:276-286. [PMID: 30194087 DOI: 10.1194/jlr.r087908] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Revised: 09/01/2018] [Indexed: 02/06/2023] Open
Abstract
Phosphoinositides (PIs) are recognized as major signaling molecules in many different functions of eukaryotic cells. PIs can be dephosphorylated by multiple phosphatase activities at the 5-, 4-, and 3- positions. Human PI 5-phosphatases belong to a family of 10 members. Except for inositol polyphosphate 5-phosphatase A, they all catalyze the dephosphorylation of PI(4,5)P2 and/or PI(3,4,5)P3 at the 5- position. PI 5-phosphatases thus directly control the levels of PI(3,4,5)P3 and participate in the fine-tuning regulatory mechanisms of PI(3,4)P2 and PI(4,5)P2 Second messenger functions have been demonstrated for PI(3,4)P2 in invadopodium maturation and lamellipodia formation. PI 5-phosphatases can use several substrates on isolated enzymes, and it has been challenging to establish their real substrate in vivo. PI(4,5)P2 has multiple functions in signaling, including interacting with scaffold proteins, ion channels, and cytoskeleton proteins. PI 5-phosphatase isoenzymes have been individually implicated in human diseases, such as the oculocerebrorenal syndrome of Lowe, through mechanisms that include lipid control. Oncogenic and tumor-suppressive functions of PI 5-phosphatases have also been reported in different cell contexts. The mechanisms responsible for genetic diseases and for oncogenic or tumor-suppressive functions are not fully understood. The regulation of PI 5-phosphatases is thus crucial in understanding cell functions.
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Affiliation(s)
- Ana Raquel Ramos
- Interdisciplinary Research Institute (IRIBHM), Université Libre de Bruxelles, 1070 Brussels, Belgium
| | - Somadri Ghosh
- Interdisciplinary Research Institute (IRIBHM), Université Libre de Bruxelles, 1070 Brussels, Belgium
| | - Christophe Erneux
- Interdisciplinary Research Institute (IRIBHM), Université Libre de Bruxelles, 1070 Brussels, Belgium
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17
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Abstract
Phosphatases play key roles in normal physiology and diseases. Studying phosphatases has been both essential and challenging, and the application of conventional genetic and biochemical methods has led to crucial but still limited understanding of their mechanisms, substrates, and exclusive functions within highly intricate networks. With the advances in technologies such as cellular imaging and molecular and chemical biology in terms of sensitive tools and methods, the phosphatase field has thrived in the past years and has set new insights for cell signaling studies and for therapeutic development. In this review, we give an overview of the existing interdisciplinary tools for phosphatases, give examples on how they have been applied to increase our understanding of these enzymes, and suggest how they-and other tools yet barely used in the phosphatase field-might be adapted to address future questions and challenges.
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Affiliation(s)
- Sara Fahs
- European Molecular Biology Laboratory, Genome Biology
Unit, Meyerhofstrasse
1, 69117 Heidelberg, Germany
| | - Pablo Lujan
- European Molecular Biology Laboratory, Genome Biology
Unit, Meyerhofstrasse
1, 69117 Heidelberg, Germany
| | - Maja Köhn
- European Molecular Biology Laboratory, Genome Biology
Unit, Meyerhofstrasse
1, 69117 Heidelberg, Germany
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18
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Autophagosome-lysosome fusion triggers a lysosomal response mediated by TLR9 and controlled by OCRL. Nat Cell Biol 2016; 18:839-850. [PMID: 27398910 PMCID: PMC5040511 DOI: 10.1038/ncb3386] [Citation(s) in RCA: 129] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2015] [Accepted: 06/09/2016] [Indexed: 12/14/2022]
Abstract
Phosphoinositides (PtdIns) control fundamental cell processes, and inherited defects of PtdIns kinases or phosphatases cause severe human diseases, including Lowe syndrome due to mutations in OCRL, which encodes a PtdIns(4,5)P2 5-phosphatase. Here we unveil a lysosomal response to the arrival of autophagosomal cargo in which OCRL plays a key part. We identify mitochondrial DNA and TLR9 as the cargo and the receptor that triggers and mediates, respectively, this response. This lysosome-cargo response is required to sustain the autophagic flux and involves a local increase in PtdIns(4,5)P2 that is confined in space and time by OCRL. Depleting or inhibiting OCRL leads to an accumulation of lysosomal PtdIns(4,5)P2, an inhibitor of the calcium channel mucolipin-1 that controls autophagosome-lysosome fusion. Hence, autophagosomes accumulate in OCRL-depleted cells and in the kidneys of Lowe syndrome patients. Importantly, boosting the activity of mucolipin-1 with selective agonists restores the autophagic flux in cells from Lowe syndrome patients.
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19
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Hall MD, Yasgar A, Peryea T, Braisted JC, Jadhav A, Simeonov A, Coussens NP. Fluorescence polarization assays in high-throughput screening and drug discovery: a review. Methods Appl Fluoresc 2016; 4:022001. [PMID: 28809163 DOI: 10.1088/2050-6120/4/2/022001] [Citation(s) in RCA: 119] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The sensitivity of fluorescence polarization (FP) and fluorescence anisotropy (FA) to molecular weight changes has enabled the interrogation of diverse biological mechanisms, ranging from molecular interactions to enzymatic activity. Assays based on FP/FA technology have been widely utilized in high-throughput screening (HTS) and drug discovery due to the homogenous format, robust performance and relative insensitivity to some types of interferences, such as inner filter effects. Advancements in assay design, fluorescent probes, and technology have enabled the application of FP assays to increasingly complex biological processes. Herein we discuss different types of FP/FA assays developed for HTS, with examples to emphasize the diversity of applicable targets. Furthermore, trends in target and fluorophore selection, as well as assay type and format, are examined using annotated HTS assays within the PubChem database. Finally, practical considerations for the successful development and implementation of FP/FA assays for HTS are provided based on experience at our center and examples from the literature, including strategies for flagging interference compounds among a list of hits.
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Affiliation(s)
- Matthew D Hall
- National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, MD, USA
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20
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Deciphering the roles of phosphoinositide lipids in phagolysosome biogenesis. Commun Integr Biol 2016; 9:e1174798. [PMID: 27489580 PMCID: PMC4951175 DOI: 10.1080/19420889.2016.1174798] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Revised: 03/29/2016] [Accepted: 03/31/2016] [Indexed: 01/01/2023] Open
Abstract
Professional phagocytes engulf microbial invaders into plasma membrane-derived phagosomes. These mature into microbicidal phagolysosomes, leading to killing of the ingested microbe. Phagosome maturation involves sequential fusion of the phagosome with early endosomes, late endosomes, and the main degradative compartments in cells, lysosomes. Some bacterial pathogens manipulate the phosphoinositide (PIP) composition of phagosome membranes and are not delivered to phagolysosomes, pointing at a role of PIPs in phagosome maturation. This hypothesis is supported by comprehensive microscopic studies. Recently, cell-free reconstitution of fusion between phagosomes and endo(lyso)somes identified phosphatidylinositol 4-phosphate [PI(4)P] and phosphatidylinositol 3-phosphate [PI(3)P] as key regulators of phagolysosome biogenesis. Here, we describe the emerging roles of PIPs in phagosome maturation and we present tools to study PIP involvement in phagosome trafficking using intact cells or purified compartments.
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21
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Mills SJ, Silvander C, Cozier G, Trésaugues L, Nordlund P, Potter BVL. Crystal Structures of Type-II Inositol Polyphosphate 5-Phosphatase INPP5B with Synthetic Inositol Polyphosphate Surrogates Reveal New Mechanistic Insights for the Inositol 5-Phosphatase Family. Biochemistry 2016; 55:1384-97. [PMID: 26854536 PMCID: PMC4785718 DOI: 10.1021/acs.biochem.5b00838] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
![]()
The inositol polyphosphate 5-phosphatase
INPP5B hydrolyzes the
5-phosphate group from water- and lipid-soluble signaling messengers.
Two synthetic benzene and biphenyl polyphosphates (BzP/BiPhPs), simplified
surrogates of inositol phosphates and phospholipid headgroups, were
identified by thermodynamic studies as potent INPP5B ligands. The
X-ray structure of the complex between INPP5B and biphenyl 3,3′,4,4′,5,5′-hexakisphosphate
[BiPh(3,3′,4,4′,5,5′)P6, IC50 5.5 μM] was determined at 2.89 Å resolution. One inhibitor
pole locates in the phospholipid headgroup binding site and the second
solvent-exposed ring binds to the His-Tag of another INPP5B molecule,
while a molecule of inorganic phosphate is also present in the active
site. Benzene 1,2,3-trisphosphate [Bz(1,2,3)P3] [one ring
of BiPh(3,3′,4,4′,5,5′)P6] inhibits
INPP5B ca. 6-fold less potently. Co-crystallization with benzene 1,2,4,5-tetrakisphosphate
[Bz(1,2,4,5)P4, IC50 = 6.3 μM] yielded
a structure refined at 2.9 Å resolution. Conserved residues among
the 5-phosphatase family mediate interactions with Bz(1,2,4,5)P4 and BiPh(3,3′,4,4′,5,5′)P6 similar to those with the polar groups present in positions 1, 4,
5, and 6 on the inositol ring of the substrate. 5-Phosphatase specificity
most likely resides in the variable zone located close to the 2- and
3-positions of the inositol ring, offering insights to inhibitor design.
We propose that the inorganic phosphate present in the INPP5B–BiPh(3,3′,4,4′,5,5′)P6 complex mimics the postcleavage substrate 5-phosphate released
by INPP5B in the catalytic site, allowing elucidation of two new key
features in the catalytic mechanism proposed for the family of phosphoinositide
5-phosphatases: first, the involvement of the conserved Arg-451 in
the interaction with the 5-phosphate and second, identification of
the water molecule that initiates 5-phosphate hydrolysis. Our model
also has implications for the proposed “moving metal”
mechanism.
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Affiliation(s)
- Stephen J Mills
- Wolfson Laboratory of Medicinal Chemistry, Department of Pharmacy and Pharmacology, University of Bath , Bath BA2 7AY, U.K
| | - Camilla Silvander
- Structural Genomics Consortium, Karolinska Institutet , 17177 Stockholm, Sweden
| | - Gyles Cozier
- Wolfson Laboratory of Medicinal Chemistry, Department of Pharmacy and Pharmacology, University of Bath , Bath BA2 7AY, U.K
| | - Lionel Trésaugues
- Structural Genomics Consortium, Karolinska Institutet , 17177 Stockholm, Sweden.,Division of Biophysics, Department of Medical Biochemistry and Biophysics, Karolinska Institutet , 17177 Stockholm, Sweden
| | - Pär Nordlund
- Structural Genomics Consortium, Karolinska Institutet , 17177 Stockholm, Sweden.,Division of Biophysics, Department of Medical Biochemistry and Biophysics, Karolinska Institutet , 17177 Stockholm, Sweden.,School of Biological Sciences, Nanyang Technological University , 637551 Singapore
| | - Barry V L Potter
- Department of Pharmacology, University of Oxford , Mansfield Road, Oxford OX1 3QT, U.K.,Wolfson Laboratory of Medicinal Chemistry, Department of Pharmacy and Pharmacology, University of Bath , Bath BA2 7AY, U.K
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22
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Membrane Charge Directs the Outcome of F-BAR Domain Lipid Binding and Autoregulation. Cell Rep 2015; 13:2597-2609. [PMID: 26686642 DOI: 10.1016/j.celrep.2015.11.044] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2015] [Revised: 10/20/2015] [Accepted: 11/12/2015] [Indexed: 12/23/2022] Open
Abstract
F-BAR domain proteins regulate and sense membrane curvature by interacting with negatively charged phospholipids and assembling into higher-order scaffolds. However, regulatory mechanisms controlling these interactions are poorly understood. Here, we show that Drosophila Nervous Wreck (Nwk) is autoregulated by a C-terminal SH3 domain module that interacts directly with its F-BAR domain. Surprisingly, this autoregulation does not mediate a simple "on-off" switch for membrane remodeling. Instead, the isolated Nwk F-BAR domain efficiently assembles into higher-order structures and deforms membranes only within a limited range of negative membrane charge, and autoregulation elevates this range. Thus, autoregulation could either reduce membrane binding or promote higher-order assembly, depending on local cellular membrane composition. Our findings uncover an unexpected mechanism by which lipid composition directs membrane remodeling.
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23
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Idevall-Hagren O, De Camilli P. Detection and manipulation of phosphoinositides. Biochim Biophys Acta Mol Cell Biol Lipids 2014; 1851:736-45. [PMID: 25514766 DOI: 10.1016/j.bbalip.2014.12.008] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2014] [Revised: 11/27/2014] [Accepted: 12/09/2014] [Indexed: 12/23/2022]
Abstract
Phosphoinositides (PIs) are minor components of cell membranes, but play key roles in cell function. Recent refinements in techniques for their detection, together with imaging methods to study their distribution and changes, have greatly facilitated the study of these lipids. Such methods have been complemented by the parallel development of techniques for the acute manipulation of their levels, which in turn allow bypassing the long-term adaptive changes implicit in genetic perturbations. Collectively, these advancements have helped elucidate the role of PIs in physiology and the impact of the dysfunction of their metabolism in disease. Combining methods for detection and manipulation enables the identification of specific roles played by each of the PIs and may eventually lead to the complete deconstruction of the PI signaling network. Here, we review current techniques used for the study and manipulation of cellular PIs and also discuss advantages and disadvantages associated with the various methods. This article is part of a Special Issue entitled Phosphoinositides.
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Affiliation(s)
- Olof Idevall-Hagren
- Department of Medical Cell Biology, Uppsala University, BMC Box 571, 75123 Uppsala, Sweden.
| | - Pietro De Camilli
- Department of Cell Biology, Howard Hughes Medical Institute and Program in Cellular Neuroscience, Neurodegeneration and Repair, Yale University School of Medicine, New Haven, CT 06510, USA.
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24
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Abstract
The specific interaction of phosphoinositides with proteins is critical for a plethora of cellular processes, including cytoskeleton remodelling, mitogenic signalling, ion channel regulation and membrane traffic. The spatiotemporal restriction of different phosphoinositide species helps to define compartments within the cell, and this is particularly important for membrane trafficking within both the secretory and endocytic pathways. Phosphoinositide homoeostasis is tightly regulated by a large number of inositol kinases and phosphatases, which respectively phosphorylate and dephosphorylate distinct phosphoinositide species. Many of these enzymes have been implicated in regulating membrane trafficking and, accordingly, their dysregulation has been linked to a number of human diseases. In the present review, we focus on the inositol phosphatases, concentrating on their roles in membrane trafficking and the human diseases with which they have been associated.
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