1
|
Gong GQ, Bilanges B, Allsop B, Masson GR, Roberton V, Askwith T, Oxenford S, Madsen RR, Conduit SE, Bellini D, Fitzek M, Collier M, Najam O, He Z, Wahab B, McLaughlin SH, Chan AWE, Feierberg I, Madin A, Morelli D, Bhamra A, Vinciauskaite V, Anderson KE, Surinova S, Pinotsis N, Lopez-Guadamillas E, Wilcox M, Hooper A, Patel C, Whitehead MA, Bunney TD, Stephens LR, Hawkins PT, Katan M, Yellon DM, Davidson SM, Smith DM, Phillips JB, Angell R, Williams RL, Vanhaesebroeck B. A small-molecule PI3Kα activator for cardioprotection and neuroregeneration. Nature 2023; 618:159-168. [PMID: 37225977 PMCID: PMC7614683 DOI: 10.1038/s41586-023-05972-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Accepted: 03/17/2023] [Indexed: 05/26/2023]
Abstract
Harnessing the potential beneficial effects of kinase signalling through the generation of direct kinase activators remains an underexplored area of drug development1-5. This also applies to the PI3K signalling pathway, which has been extensively targeted by inhibitors for conditions with PI3K overactivation, such as cancer and immune dysregulation. Here we report the discovery of UCL-TRO-1938 (referred to as 1938 hereon), a small-molecule activator of the PI3Kα isoform, a crucial effector of growth factor signalling. 1938 allosterically activates PI3Kα through a distinct mechanism by enhancing multiple steps of the PI3Kα catalytic cycle and causes both local and global conformational changes in the PI3Kα structure. This compound is selective for PI3Kα over other PI3K isoforms and multiple protein and lipid kinases. It transiently activates PI3K signalling in all rodent and human cells tested, resulting in cellular responses such as proliferation and neurite outgrowth. In rodent models, acute treatment with 1938 provides cardioprotection from ischaemia-reperfusion injury and, after local administration, enhances nerve regeneration following nerve crush. This study identifies a chemical tool to directly probe the PI3Kα signalling pathway and a new approach to modulate PI3K activity, widening the therapeutic potential of targeting these enzymes through short-term activation for tissue protection and regeneration. Our findings illustrate the potential of activating kinases for therapeutic benefit, a currently largely untapped area of drug development.
Collapse
Affiliation(s)
- Grace Q Gong
- Cell Signalling, Cancer Institute, University College London, London, UK
| | - Benoit Bilanges
- Cell Signalling, Cancer Institute, University College London, London, UK
| | - Ben Allsop
- Drug Discovery Group, Translational Research Office, University College London, London, UK
| | - Glenn R Masson
- Medical Research Council Laboratory of Molecular Biology, Cambridge, UK
- Division of Cellular Medicine, School of Medicine, University of Dundee, Dundee, UK
| | - Victoria Roberton
- UCL Centre for Nerve Engineering, UCL School of Pharmacy, University College London, London, UK
| | - Trevor Askwith
- Drug Discovery Group, Translational Research Office, University College London, London, UK
| | - Sally Oxenford
- Drug Discovery Group, Translational Research Office, University College London, London, UK
| | - Ralitsa R Madsen
- Cell Signalling, Cancer Institute, University College London, London, UK
| | - Sarah E Conduit
- Cell Signalling, Cancer Institute, University College London, London, UK
| | - Dom Bellini
- Medical Research Council Laboratory of Molecular Biology, Cambridge, UK
| | - Martina Fitzek
- Hit Discovery, Discovery Sciences, R&D, AstraZeneca, Alderley Park, Macclesfield, UK
| | - Matt Collier
- Hit Discovery, Discovery Sciences, R&D, AstraZeneca, Alderley Park, Macclesfield, UK
| | - Osman Najam
- The Hatter Cardiovascular Institute, University College London, London, UK
| | - Zhenhe He
- The Hatter Cardiovascular Institute, University College London, London, UK
| | - Ben Wahab
- Medicines Discovery Institute, School of Biosciences, Cardiff University, Cardiff, UK
| | | | - A W Edith Chan
- Wolfson Institute for Biomedical Research, University College London, London, UK
| | | | - Andrew Madin
- Hit Discovery, Discovery Sciences, R&D, AstraZeneca, Cambridge, UK
| | - Daniele Morelli
- Cell Signalling, Cancer Institute, University College London, London, UK
| | - Amandeep Bhamra
- Proteomics Research Translational Technology Platform, Cancer Institute, University College London, London, UK
| | - Vanesa Vinciauskaite
- Division of Cellular Medicine, School of Medicine, University of Dundee, Dundee, UK
| | | | - Silvia Surinova
- Proteomics Research Translational Technology Platform, Cancer Institute, University College London, London, UK
| | - Nikos Pinotsis
- Institute of Structural and Molecular Biology, Birkbeck College, London, UK
| | | | - Matthew Wilcox
- UCL Centre for Nerve Engineering, UCL School of Pharmacy, University College London, London, UK
| | - Alice Hooper
- Drug Discovery Group, Translational Research Office, University College London, London, UK
| | - Chandni Patel
- Drug Discovery Group, Translational Research Office, University College London, London, UK
| | - Maria A Whitehead
- Cell Signalling, Cancer Institute, University College London, London, UK
| | - Tom D Bunney
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, London, UK
| | | | | | - Matilda Katan
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, London, UK
| | - Derek M Yellon
- The Hatter Cardiovascular Institute, University College London, London, UK
| | - Sean M Davidson
- The Hatter Cardiovascular Institute, University College London, London, UK
| | - David M Smith
- Emerging Innovations, Discovery Sciences, R&D, AstraZeneca, Cambridge, UK
| | - James B Phillips
- UCL Centre for Nerve Engineering, UCL School of Pharmacy, University College London, London, UK
| | - Richard Angell
- Drug Discovery Group, Translational Research Office, University College London, London, UK
- Medicines Discovery Institute, School of Biosciences, Cardiff University, Cardiff, UK
| | - Roger L Williams
- Medical Research Council Laboratory of Molecular Biology, Cambridge, UK
| | | |
Collapse
|
2
|
Bunney TD, Katan M. Targeting G-CSF to treat autoinflammation. Nat Immunol 2023; 24:736-737. [PMID: 36997672 DOI: 10.1038/s41590-023-01474-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/07/2023]
Affiliation(s)
- Tom D Bunney
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, London, UK
| | - Matilda Katan
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, London, UK.
| |
Collapse
|
3
|
Prawiro C, Bunney TD, Kampyli C, Yaguchi H, Katan M, Bangham CRM. A frequent PLCγ1 mutation in adult T-cell leukemia/lymphoma determines functional properties of the malignant cells. Biochim Biophys Acta Mol Basis Dis 2023; 1869:166601. [PMID: 36442790 DOI: 10.1016/j.bbadis.2022.166601] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 10/27/2022] [Accepted: 11/08/2022] [Indexed: 11/26/2022]
Abstract
BACKGROUND Development of adult T-cell leukemia/lymphoma (ATL) involves human T-cell leukemia virus type 1 (HTLV-1) infection and accumulation of somatic mutations. The most frequently mutated gene in ATL (36 % of cases) is phospholipase C gamma1 (PLCG1). PLCG1 is also frequently mutated in other T-cell lymphomas. However, the functional consequences of the PLCG1 mutations in cancer cells have not been characterized. METHODS We compared the activity of the wild-type PLCγ1 with that of a mutant carrying a hot-spot mutation of PLCγ1 (S345F) observed in ATL, both in cells and in cell-free assays. To analyse the impact of the mutation on cellular properties, we quantified cellular proliferation, aggregation, chemotaxis and apoptosis by live cell-imaging in an S345F+ ATL-derived cell line (KK1) and a KK1 cell line in which we reverted the mutation to the wild-type sequence using CRISPR/Cas9 and homology-directed repair. FINDINGS The PLCγ1 S345F mutation results in an increase of basal PLC activity in vitro and in different cell types. This higher basal activity is further enhanced by upstream signalling. Reversion of the S345F mutation in the KK1 cell line resulted in reduction of the PLC activity, lower rates of proliferation and aggregation, and a marked reduction in chemotaxis towards CCL22. The PLCγ1-pathway inhibitors ibrutinib and ritonavir reduced both the PLC activity and the tested functions of KK1 cells. INTERPRETATION Consistent with observations from clinical studies, our data provide direct evidence that activated variants of the PLCγ1 enzyme contribute to the properties of the malignant T-cell clone in ATL. FUNDING MRC (UK) Project Grant (P028160).
Collapse
Affiliation(s)
- Christy Prawiro
- Department of Infectious Diseases, Faculty of Medicine, Imperial College London, London, UK
| | - Tom D Bunney
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, London, UK
| | - Charis Kampyli
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, London, UK
| | - Hiroko Yaguchi
- Department of Infectious Diseases, Faculty of Medicine, Imperial College London, London, UK
| | - Matilda Katan
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, London, UK.
| | - Charles R M Bangham
- Department of Infectious Diseases, Faculty of Medicine, Imperial College London, London, UK.
| |
Collapse
|
4
|
Le Huray KIP, Bunney TD, Pinotsis N, Kalli AC, Katan M. Characterization of the membrane interactions of phospholipase Cγ reveals key features of the active enzyme. Sci Adv 2022; 8:eabp9688. [PMID: 35749497 PMCID: PMC9232102 DOI: 10.1126/sciadv.abp9688] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Accepted: 05/06/2022] [Indexed: 06/15/2023]
Abstract
PLCγ enzymes are autoinhibited in resting cells and form key components of intracellular signaling that are also linked to disease development. Insights into physiological and aberrant activation of PLCγ require understanding of an active, membrane-bound form, which can hydrolyze inositol-lipid substrates. Here, we demonstrate that PLCγ1 cannot bind membranes unless the autoinhibition is disrupted. Through extensive molecular dynamics simulations and experimental evidence, we characterize membrane binding by the catalytic core domains and reveal previously unknown sites of lipid interaction. The identified sites act in synergy, overlap with autoinhibitory interfaces, and are shown to be critical for the phospholipase activity in cells. This work provides direct evidence that PLCγ1 is inhibited through obstruction of its membrane-binding surfaces by the regulatory region and that activation must shift PLCγ1 to a conformation competent for membrane binding. Knowledge of the critical sites of membrane interaction extends the mechanistic framework for activation, dysregulation, and therapeutic intervention.
Collapse
Affiliation(s)
- Kyle I. P. Le Huray
- Astbury Centre for Structural Molecular Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
- School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT UK
- Leeds Institute of Cardiovascular and Metabolic Medicine, School of Medicine, University of Leeds, Leeds LS2 9JT, UK
| | - Tom D. Bunney
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, Gower St., London WC1E 6BT, UK
| | - Nikos Pinotsis
- Institute of Structural and Molecular Biology, Birkbeck College, London, WC1E 6BT, UK
| | - Antreas C. Kalli
- Astbury Centre for Structural Molecular Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
- Leeds Institute of Cardiovascular and Metabolic Medicine, School of Medicine, University of Leeds, Leeds LS2 9JT, UK
| | - Matilda Katan
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, Gower St., London WC1E 6BT, UK
| |
Collapse
|
5
|
Magno L, Bunney TD, Mead E, Svensson F, Bictash MN. TREM2/PLCγ2 signalling in immune cells: function, structural insight, and potential therapeutic modulation. Mol Neurodegener 2021; 16:22. [PMID: 33823896 PMCID: PMC8022522 DOI: 10.1186/s13024-021-00436-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Accepted: 02/24/2021] [Indexed: 01/21/2023] Open
Abstract
The central role of the resident innate immune cells of the brain (microglia) in neurodegeneration has become clear over the past few years largely through genome-wide association studies (GWAS), and has rapidly become an active area of research. However, a mechanistic understanding (gene to function) has lagged behind. That is now beginning to change, as exemplified by a number of recent exciting and important reports that provide insight into the function of two key gene products – TREM2 (Triggering Receptor Expressed On Myeloid Cells 2) and PLCγ2 (Phospholipase C gamma2) – in microglia, and their role in neurodegenerative disorders. In this review we explore and discuss these recent advances and the opportunities that they may provide for the development of new therapies.
Collapse
Affiliation(s)
- Lorenza Magno
- Alzheimer's Research UK UCL Drug Discovery Institute, University College London, Cruciform Building, Gower Street, London, WC1E 6BT, UK.
| | - Tom D Bunney
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, Gower Street, London, WC1E 6BT, UK
| | - Emma Mead
- Alzheimer's Research UK Oxford Drug Discovery Institute, Nuffield Department of Medicine Research Building, University of Oxford, Oxford, OX3 7FZ, UK
| | - Fredrik Svensson
- Alzheimer's Research UK UCL Drug Discovery Institute, University College London, Cruciform Building, Gower Street, London, WC1E 6BT, UK
| | - Magda N Bictash
- Alzheimer's Research UK UCL Drug Discovery Institute, University College London, Cruciform Building, Gower Street, London, WC1E 6BT, UK
| |
Collapse
|
6
|
Martín-Nalda A, Fortuny C, Rey L, Bunney TD, Alsina L, Esteve-Solé A, Bull D, Anton MC, Basagaña M, Casals F, Deyá A, García-Prat M, Gimeno R, Juan M, Martinez-Banaclocha H, Martinez-Garcia JJ, Mensa-Vilaró A, Rabionet R, Martin-Begue N, Rudilla F, Yagüe J, Estivill X, García-Patos V, Pujol RM, Soler-Palacín P, Katan M, Pelegrín P, Colobran R, Vicente A, Arostegui JI. Severe Autoinflammatory Manifestations and Antibody Deficiency Due to Novel Hypermorphic PLCG2 Mutations. J Clin Immunol 2020; 40:987-1000. [PMID: 32671674 PMCID: PMC7505877 DOI: 10.1007/s10875-020-00794-7] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Accepted: 05/20/2020] [Indexed: 01/28/2023]
Abstract
Autoinflammatory diseases (AIDs) were first described as clinical disorders characterized by recurrent episodes of seemingly unprovoked sterile inflammation. In the past few years, the identification of novel AIDs expanded their phenotypes toward more complex clinical pictures associating vasculopathy, autoimmunity, or immunodeficiency. Herein, we describe two unrelated patients suffering since the neonatal period from a complex disease mainly characterized by severe sterile inflammation, recurrent bacterial infections, and marked humoral immunodeficiency. Whole-exome sequencing detected a novel, de novo heterozygous PLCG2 variant in each patient (p.Ala708Pro and p.Leu845_Leu848del). A clear enhanced PLCγ2 activity for both variants was demonstrated by both ex vivo calcium responses of the patient's B cells to IgM stimulation and in vitro assessment of PLC activity. These data supported the autoinflammation and PLCγ2-associated antibody deficiency and immune dysregulation (APLAID) diagnosis in both patients. Immunological evaluation revealed a severe decrease of immunoglobulins and B cells, especially class-switched memory B cells, with normal T and NK cell counts. Analysis of bone marrow of one patient revealed a reduced immature B cell fraction compared with controls. Additional investigations showed that both PLCG2 variants activate the NLRP3-inflammasome through the alternative pathway instead of the canonical pathway. Collectively, the evidences here shown expand APLAID diversity toward more severe phenotypes than previously reported including dominantly inherited agammaglobulinemia, add novel data about its genetic basis, and implicate the alternative NLRP3-inflammasome activation pathway in the basis of sterile inflammation.
Collapse
Affiliation(s)
- Andrea Martín-Nalda
- Pediatric Infectious Diseases and Immunodeficiencies Unit, Vall d'Hebron Institut de Recerca, Hospital Universitari Vall d'Hebron, Barcelona, Spain
- Jeffrey Modell Diagnostic and Research Center for Primary Immunodeficiencies, Barcelona, Spain
| | - Claudia Fortuny
- Pediatric Infectious Diseases and Immunodeficiencies Unit, Vall d'Hebron Institut de Recerca, Hospital Universitari Vall d'Hebron, Barcelona, Spain
- Department of Pediatrics, Hospital Sant Joan de Deu, Esplugues, Spain
- Institut de Recerca Hospital Sant Joan de Déu, Universitat de Barcelona, Esplugues, Spain
| | - Lourdes Rey
- Department of Pediatrics, Hospital Alvaro Cunqueiro, Vigo, Spain
| | - Tom D Bunney
- Institute of Structural and Molecular Biology, University College London, London, UK
| | - Laia Alsina
- Institut de Recerca Hospital Sant Joan de Déu, Universitat de Barcelona, Esplugues, Spain
- Department of Allergy and Clinical Immunology Clinical Immunology and Primary, Immunodeficiencies Unit, Hospital Sant Joan de Déu, Esplugues, Spain
- Clinical Immunology Unit, Hospital Sant Joan de Déu-Hospital Clínic, Barcelona, Spain
| | - Ana Esteve-Solé
- Institut de Recerca Hospital Sant Joan de Déu, Universitat de Barcelona, Esplugues, Spain
- Department of Allergy and Clinical Immunology Clinical Immunology and Primary, Immunodeficiencies Unit, Hospital Sant Joan de Déu, Esplugues, Spain
- Clinical Immunology Unit, Hospital Sant Joan de Déu-Hospital Clínic, Barcelona, Spain
| | - Daniel Bull
- ARUK Drug Discovery Institute, University College London, London, UK
| | - Maria Carmen Anton
- Department of Immunology-CDB (esc 4-pl 0), Hospital Clínic, Villarroel, 170, 08036, Barcelona, Spain
| | - María Basagaña
- Allergy Section, Hospital Universitari Germans Trias i Pujol, Autonomous University of Barcelona, Badalona, Spain
| | - Ferran Casals
- Genomics Core Facility, Experimental and Health Sciences Department, Universitat Pompeu Fabra, Barcelona, Spain
| | - Angela Deyá
- Institut de Recerca Hospital Sant Joan de Déu, Universitat de Barcelona, Esplugues, Spain
- Department of Allergy and Clinical Immunology Clinical Immunology and Primary, Immunodeficiencies Unit, Hospital Sant Joan de Déu, Esplugues, Spain
- Clinical Immunology Unit, Hospital Sant Joan de Déu-Hospital Clínic, Barcelona, Spain
| | - Marina García-Prat
- Pediatric Infectious Diseases and Immunodeficiencies Unit, Vall d'Hebron Institut de Recerca, Hospital Universitari Vall d'Hebron, Barcelona, Spain
- Jeffrey Modell Diagnostic and Research Center for Primary Immunodeficiencies, Barcelona, Spain
| | - Ramon Gimeno
- Department of Immunology, Hospital del Mar, Institut Mar d'Investigacions Mèdiques, Barcelona, Spain
| | - Manel Juan
- Department of Immunology-CDB (esc 4-pl 0), Hospital Clínic, Villarroel, 170, 08036, Barcelona, Spain
- Institut d'Investigacions Biomèdiques August Pi i Sunyer, Barcelona, Spain
- School of Medicine, Universitat de Barcelona, Barcelona, Spain
| | - Helios Martinez-Banaclocha
- Instituto Murciano de Investigación Biosanitaria IMIB-Arrixaca, Hospital Clínico Universitario Virgen de la Arrixaca, Murcia, Spain
| | - Juan J Martinez-Garcia
- Instituto Murciano de Investigación Biosanitaria IMIB-Arrixaca, Hospital Clínico Universitario Virgen de la Arrixaca, Murcia, Spain
| | - Anna Mensa-Vilaró
- Department of Immunology-CDB (esc 4-pl 0), Hospital Clínic, Villarroel, 170, 08036, Barcelona, Spain
| | - Raquel Rabionet
- Institut de Recerca Hospital Sant Joan de Déu, Universitat de Barcelona, Esplugues, Spain
- Department of Genetics, Microbiology and Statistics, Faculty of Biology, University of Barcelona, IBUB, IRJSD, CIBERER, Barcelona, Spain
| | - Nieves Martin-Begue
- Department of Pediatric Ophthalmology, Hospital Universitari Vall d'Hebron, Vall d'Hebron Institut de Recerca, Barcelona, Spain
| | - Francesc Rudilla
- Histocompatibility and Immunogenetics Laboratory, Blood and Tissue Bank, Barcelona, Spain
- Transfusional Medicine Group, Vall d'Hebron Research Institute, Autonomous University of Barcelona, Barcelona, Spain
| | - Jordi Yagüe
- Department of Immunology-CDB (esc 4-pl 0), Hospital Clínic, Villarroel, 170, 08036, Barcelona, Spain
- Institut d'Investigacions Biomèdiques August Pi i Sunyer, Barcelona, Spain
- School of Medicine, Universitat de Barcelona, Barcelona, Spain
| | - Xavier Estivill
- Quantitative Genomic Medicine Laboratories (qGenomics), Esplugues del Llobregat, Barcelona, Catalonia, Spain
| | - Vicente García-Patos
- Department of Pediatric Dermatology, Hospital Universitari Vall d'Hebron, Vall d'Hebron Institut de Recerca, Barcelona, Spain
| | - Ramon M Pujol
- Department of Dermatology, Hospital del Mar, Institut Mar d'Investigacions Mèdiques, Universitat Autonoma de Barcelona, Barcelona, Spain
| | - Pere Soler-Palacín
- Pediatric Infectious Diseases and Immunodeficiencies Unit, Vall d'Hebron Institut de Recerca, Hospital Universitari Vall d'Hebron, Barcelona, Spain
- Jeffrey Modell Diagnostic and Research Center for Primary Immunodeficiencies, Barcelona, Spain
- Universitat Autonoma de Barcelona, Barcelona, Spain
| | - Matilda Katan
- Institute of Structural and Molecular Biology, University College London, London, UK
| | - Pablo Pelegrín
- Instituto Murciano de Investigación Biosanitaria IMIB-Arrixaca, Hospital Clínico Universitario Virgen de la Arrixaca, Murcia, Spain
| | - Roger Colobran
- Jeffrey Modell Diagnostic and Research Center for Primary Immunodeficiencies, Barcelona, Spain
- Immunology Division, Department of Clinical and Molecular Genetics, Hospital Universitari Vall d'Hebron, Vall d'Hebron Research Institute, Barcelona, Spain
- Department of Cell Biology, Physiology and Immunology, Autonomous University of Barcelona, Barcelona, Spain
| | - Asun Vicente
- Department of Pediatric Dermatology, Hospital Sant Joan de Deu, Esplugues, Spain
| | - Juan I Arostegui
- Department of Immunology-CDB (esc 4-pl 0), Hospital Clínic, Villarroel, 170, 08036, Barcelona, Spain.
- Institut d'Investigacions Biomèdiques August Pi i Sunyer, Barcelona, Spain.
- School of Medicine, Universitat de Barcelona, Barcelona, Spain.
| |
Collapse
|
7
|
Lima NC, Atkinson E, Bunney TD, Katan M, Huang PH. Targeting the Src Pathway Enhances the Efficacy of Selective FGFR Inhibitors in Urothelial Cancers with FGFR3 Alterations. Int J Mol Sci 2020; 21:E3214. [PMID: 32370101 PMCID: PMC7246793 DOI: 10.3390/ijms21093214] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2020] [Revised: 04/24/2020] [Accepted: 04/27/2020] [Indexed: 01/08/2023] Open
Abstract
Selective FGFR inhibitors such as infigratinib (BGJ398) and erdafitinib (JNJ-42756493) have been evaluated in clinical trials for cancers with FGFR3 molecular alterations, particularly in urothelial carcinoma patients. However, a substantial proportion of these patients (up to 50%) display intrinsic resistance to these drugs and receive minimal clinical benefit. There is thus an unmet need for alternative therapeutic strategies to overcome primary resistance to selective FGFR inhibitors. In this study, we demonstrate that cells expressing cancer-associated activating FGFR3 mutants and the FGFR3-TACC3 fusion showed primary resistance to infigratinib in long-term colony formation assays in both NIH-3T3 and urothelial carcinoma models. We find that expression of these FGFR3 molecular alterations resulted in elevated constitutive Src activation compared to wildtype FGFR3 and that cells co-opted this pathway as a means to achieve intrinsic resistance to infigratinib. Targeting the Src pathway with low doses of the kinase inhibitor dasatinib synergistically sensitized multiple urothelial carcinoma lines harbouring endogenous FGFR3 alterations to infigratinib. Our data provide preclinical rationale that supports the use of dasatinib in combination with selective FGFR inhibitors as a means to overcome intrinsic drug resistance in the salvage therapy setting in urothelial cancer patients with FGFR3 molecular alterations.
Collapse
Affiliation(s)
- Nadia Carvalho Lima
- Division of Molecular Pathology, The Institute of Cancer Research, London SM2 5NG, UK; (N.C.L.); (E.A.)
| | - Eliza Atkinson
- Division of Molecular Pathology, The Institute of Cancer Research, London SM2 5NG, UK; (N.C.L.); (E.A.)
| | - Tom D. Bunney
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, London WC1E 6BT, UK; (T.D.B.); (M.K.)
| | - Matilda Katan
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, London WC1E 6BT, UK; (T.D.B.); (M.K.)
| | - Paul H. Huang
- Division of Molecular Pathology, The Institute of Cancer Research, London SM2 5NG, UK; (N.C.L.); (E.A.)
| |
Collapse
|
8
|
Liu Y, Bunney TD, Khosa S, Macé K, Beckenbauer K, Askwith T, Maslen S, Stubbs C, de Oliveira TM, Sader K, Skehel M, Gavin AC, Phillips C, Katan M. Structural insights and activating mutations in diverse pathologies define mechanisms of deregulation for phospholipase C gamma enzymes. EBioMedicine 2020; 51:102607. [PMID: 31918402 PMCID: PMC7000336 DOI: 10.1016/j.ebiom.2019.102607] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Revised: 12/10/2019] [Accepted: 12/13/2019] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND PLCγ enzymes are key nodes in cellular signal transduction and their mutated and rare variants have been recently implicated in development of a range of diseases with unmet need including cancer, complex immune disorders, inflammation and neurodegenerative diseases. However, molecular nature of activation and the impact and dysregulation mechanisms by mutations, remain unclear; both are critically dependent on comprehensive characterization of the intact PLCγ enzymes. METHODS For structural studies we applied cryo-EM, cross-linking mass spectrometry and hydrogen-deuterium exchange mass spectrometry. In parallel, we compiled mutations linked to main pathologies, established their distribution and assessed their impact in cells and in vitro. FINDINGS We define structure of a complex containing an intact, autoinhibited PLCγ1 and the intracellular part of FGFR1 and show that the interaction is centred on the nSH2 domain of PLCγ1. We define the architecture of PLCγ1 where an autoinhibitory interface involves the cSH2, spPH, TIM-barrel and C2 domains; this relative orientation occludes PLCγ1 access to its substrate. Based on this framework and functional characterization, the mechanism leading to an increase in PLCγ1 activity for the largest group of mutations is consistent with the major, direct impact on the autoinhibitory interface. INTERPRETATION We reveal features of PLCγ enzymes that are important for determining their activation status. Targeting such features, as an alternative to targeting the PLC active site that has so far not been achieved for any PLC, could provide new routes for clinical interventions related to various pathologies driven by PLCγ deregulation. FUND: CR UK, MRC and AstaZeneca.
Collapse
Affiliation(s)
- Yang Liu
- Discovery Sciences, R&D, AstraZeneca, Cambridge, CB4 0WG, UK
| | - Tom D. Bunney
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, Gower Street, London WC1E 6BT, UK
| | - Sakshi Khosa
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, Gower Street, London WC1E 6BT, UK
| | - Kévin Macé
- Institute of Structural and Molecular Biology, Birkbeck College, Malet Street, London WC1E 7HX, UK
| | - Katharina Beckenbauer
- European Molecular Biology Laboratory, Structural and Computational Biology Unit, Meyerhofstrasse 1, 69117 Heidelberg, Germany
| | - Trevor Askwith
- Drug Discovery Group, Translational Research Office, School of Pharmacy, University College London, 29-39 Brunswick Square, London, WC1N 1AX, UK
| | - Sarah Maslen
- MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, UK
| | | | | | - Kasim Sader
- Cambridge Cryo-EM Pharmaceutical Consortium, Thermo Fisher Scientific, 11 JJ Thomson Avenue, Madingley Road, Cambridge, CB3 0FF, UK
| | - Mark Skehel
- Drug Discovery Group, Translational Research Office, School of Pharmacy, University College London, 29-39 Brunswick Square, London, WC1N 1AX, UK
| | - Anne-Claude Gavin
- Institute of Structural and Molecular Biology, Birkbeck College, Malet Street, London WC1E 7HX, UK
- Department for Cell Physiology and Metabolism, University of Geneva, Centre Medical Universitaire, Rue Michel-Servet 1, CH-1211 Geneva 4, Switzerland
| | | | - Matilda Katan
- Discovery Sciences, R&D, AstraZeneca, Cambridge, CB4 0WG, UK
| |
Collapse
|
9
|
Sanfelice D, Koss H, Bunney TD, Thompson GS, Farrell B, Katan M, Breeze AL. NMR backbone assignments of the tyrosine kinase domain of human fibroblast growth factor receptor 3 in apo state and in complex with inhibitor PD173074. Biomol NMR Assign 2018; 12:231-235. [PMID: 29582384 PMCID: PMC6132846 DOI: 10.1007/s12104-018-9814-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Accepted: 03/20/2018] [Indexed: 05/03/2023]
Abstract
Fibroblast growth factors receptors (FGFR) are transmembrane protein tyrosine kinases involved in many cellular process, including growth, differentiation and angiogenesis. Dysregulation of FGFR enzymatic activity is associated with developmental disorders and cancers; therefore FGFRs have become attractive targets for drug discovery, with a number of agents in late-stage clinical trials. Here, we present the backbone resonance assignments of FGFR3 tyrosine kinase domain in the ligand-free form and in complex with the canonical FGFR kinase inhibitor PD173074. Analysis of chemical shift changes upon inhibitor binding highlights a characteristic pattern of allosteric network perturbations that is of relevance for future drug discovery activities aimed at development of conformationally-selective FGFR inhibitors.
Collapse
Affiliation(s)
- Domenico Sanfelice
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, Gower St, London, WC1E 6BT, UK.
| | - Hans Koss
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, Gower St, London, WC1E 6BT, UK
| | - Tom D Bunney
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, Gower St, London, WC1E 6BT, UK
| | - Gary S Thompson
- Astbury Centre for Structural Molecular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, UK
- Wellcome Trust Biomolecular NMR Facility, School of Biosciences, University of Kent, Canterbury, CT2 7NZ, UK
| | - Brendan Farrell
- Astbury Centre for Structural Molecular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, UK
| | - Matilda Katan
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, Gower St, London, WC1E 6BT, UK
| | - Alexander L Breeze
- Astbury Centre for Structural Molecular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, UK.
| |
Collapse
|
10
|
Koss H, Bunney TD, Esposito D, Martins M, Katan M, Driscoll PC. Dynamic Allostery in PLCγ1 and Its Modulation by a Cancer Mutation Revealed by MD Simulation and NMR. Biophys J 2018; 115:31-45. [PMID: 29972810 PMCID: PMC6035297 DOI: 10.1016/j.bpj.2018.05.031] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Revised: 04/27/2018] [Accepted: 05/21/2018] [Indexed: 12/11/2022] Open
Abstract
Phosphatidylinositol phospholipase Cγ (PLCγ) is an intracellular membrane-associated second-messenger signaling protein activated by tyrosine kinases such as fibroblast growth factor receptor 1. PLCγ contains the regulatory γ-specific array (γSA) comprising a tandem Src homology 2 (SH2) pair, an SH3 domain, and a split pleckstrin homology domain. Binding of an activated growth factor receptor to γSA leads to Tyr783 phosphorylation and consequent PLCγ activation. Several disease-relevant mutations in γSA have been identified; all lead to elevated phospholipase activity. In this work, we describe an allosteric mechanism that connects the Tyr783 phosphorylation site to the nSH2-cSH2 junction and involves dynamic interactions between the cSH2-SH3 linker and cSH2. Molecular dynamics simulations of the tandem SH2 protein suggest that Tyr783 phosphorylation is communicated to the nSH2-cSH2 junction by modulating cSH2 binding to sections of the cSH2-SH3 linker. NMR chemical shift perturbation analyses for designed tandem SH2 constructs reveal combined fast and slow dynamic processes that can be attributed to allosteric communication involving these regions of the protein, establishing an example in which complex N-site exchange can be directly inferred from 1H,15N-HSQC spectra. Furthermore, in tandem SH2 and γSA constructs, molecular dynamics and NMR results show that the Arg687Trp mutant in PLCγ1 (equivalent to the cancer mutation Arg665Trp in PLCγ2) perturbs the dynamic allosteric pathway. This combined experimental and computational study reveals a rare example of multistate kinetics involved in a dynamic allosteric process that is modulated in the context of a disease-relevant mutation. The allosteric influences and the weakened binding of the cSH2-SH3 linker to cSH2 should be taken into account in any more holistic investigation of PLCγ regulation.
Collapse
Affiliation(s)
- Hans Koss
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, London, United Kingdom; The Francis Crick Institute, London, United Kingdom
| | - Tom D Bunney
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, London, United Kingdom
| | | | - Marta Martins
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, London, United Kingdom
| | - Matilda Katan
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, London, United Kingdom
| | | |
Collapse
|
11
|
Bunney TD, Inglis AJ, Sanfelice D, Farrell B, Kerr CJ, Thompson GS, Masson GR, Thiyagarajan N, Svergun DI, Williams RL, Breeze AL, Katan M. Disease Variants of FGFR3 Reveal Molecular Basis for the Recognition and Additional Roles for Cdc37 in Hsp90 Chaperone System. Structure 2018; 26:446-458.e8. [PMID: 29478821 PMCID: PMC5846801 DOI: 10.1016/j.str.2018.01.016] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2017] [Revised: 12/06/2017] [Accepted: 01/26/2018] [Indexed: 11/21/2022]
Abstract
Receptor tyrosine kinase FGFR3 is involved in many signaling networks and is frequently mutated in developmental disorders and cancer. The Hsp90/Cdc37 chaperone system is essential for function of normal and neoplastic cells. Here we uncover the mechanistic inter-relationships between these proteins by combining approaches including NMR, HDX-MS, and SAXS. We show that several disease-linked mutations convert FGFR3 to a stronger client, where the determinant underpinning client strength involves an allosteric network through the N-lobe and at the lobe interface. We determine the architecture of the client kinase/Cdc37 complex and demonstrate, together with site-specific information, that binding of Cdc37 to unrelated kinases induces a common, extensive conformational remodeling of the kinase N-lobe, beyond localized changes and interactions within the binary complex. As further shown for FGFR3, this processing by Cdc37 deactivates the kinase and presents it, in a specific orientation established in the complex, for direct recognition by Hsp90.
Collapse
Affiliation(s)
- Tom D Bunney
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, Gower St, London WC1E 6BT, UK.
| | - Alison J Inglis
- Medical Research Council (MRC) Laboratory of Molecular Biology, Cambridge CB2 0QH, UK
| | - Domenico Sanfelice
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, Gower St, London WC1E 6BT, UK
| | - Brendan Farrell
- Astbury Centre for Structural Molecular Biology, Faculty of Biological Sciences, Leeds LS2 9JT, UK
| | - Christopher J Kerr
- European Molecular Biology Laboratory (EMBL) Hamburg Outstation, DESY, Hamburg, Germany
| | - Gary S Thompson
- Astbury Centre for Structural Molecular Biology, Faculty of Biological Sciences, Leeds LS2 9JT, UK
| | - Glenn R Masson
- Medical Research Council (MRC) Laboratory of Molecular Biology, Cambridge CB2 0QH, UK
| | - Nethaji Thiyagarajan
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, Gower St, London WC1E 6BT, UK
| | - Dmitri I Svergun
- European Molecular Biology Laboratory (EMBL) Hamburg Outstation, DESY, Hamburg, Germany
| | - Roger L Williams
- Medical Research Council (MRC) Laboratory of Molecular Biology, Cambridge CB2 0QH, UK
| | - Alexander L Breeze
- Astbury Centre for Structural Molecular Biology, Faculty of Biological Sciences, Leeds LS2 9JT, UK.
| | - Matilda Katan
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, Gower St, London WC1E 6BT, UK.
| |
Collapse
|
12
|
Perdios L, Lowe AR, Saladino G, Bunney TD, Thiyagarajan N, Alexandrov Y, Dunsby C, French PMW, Chin JW, Gervasio FL, Tate EW, Katan M. Conformational transition of FGFR kinase activation revealed by site-specific unnatural amino acid reporter and single molecule FRET. Sci Rep 2017; 7:39841. [PMID: 28045057 PMCID: PMC5206623 DOI: 10.1038/srep39841] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Accepted: 11/29/2016] [Indexed: 02/06/2023] Open
Abstract
Protein kinases share significant structural similarity; however, structural features alone are insufficient to explain their diverse functions. Thus, bridging the gap between static structure and function requires a more detailed understanding of their dynamic properties. For example, kinase activation may occur via a switch-like mechanism or by shifting a dynamic equilibrium between inactive and active states. Here, we utilize a combination of FRET and molecular dynamics (MD) simulations to probe the activation mechanism of the kinase domain of Fibroblast Growth Factor Receptor (FGFR). Using genetically-encoded, site-specific incorporation of unnatural amino acids in regions essential for activation, followed by specific labeling with fluorescent moieties, we generated a novel class of FRET-based reporter to monitor conformational differences corresponding to states sampled by non phosphorylated/inactive and phosphorylated/active forms of the kinase. Single molecule FRET analysis in vitro, combined with MD simulations, shows that for FGFR kinase, there are populations of inactive and active states separated by a high free energy barrier resulting in switch-like activation. Compared to recent studies, these findings support diversity in features of kinases that impact on their activation mechanisms. The properties of these FRET-based constructs will also allow further studies of kinase dynamics as well as applications in vivo.
Collapse
Affiliation(s)
- Louis Perdios
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, Gower St, London WC1E 6BT, UK
- Department of Chemistry, Imperial College London, South Kensington Campus, Exhibition Road, London SW7 2AZ, UK
| | - Alan R. Lowe
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, Gower St, London WC1E 6BT, UK
- London Centre for Nanotechnology, 17-19 Gower St, London, WC1H 0AH, UK
- Division of Biosciences, Birkbeck College, Malet St, London, WC1E 7HX, UK
| | - Giorgio Saladino
- Institute of Structural and Molecular Biology, Department of Chemistry, University College London, Gower St, London WC1E 6BT, UK
| | - Tom D. Bunney
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, Gower St, London WC1E 6BT, UK
| | - Nethaji Thiyagarajan
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, Gower St, London WC1E 6BT, UK
| | - Yuriy Alexandrov
- Department of Physics, Imperial College London, South Kensington Campus, Exhibition Road, London SW7 2AZ, UK
| | - Christopher Dunsby
- Department of Physics, Imperial College London, South Kensington Campus, Exhibition Road, London SW7 2AZ, UK
| | - Paul M. W. French
- Department of Physics, Imperial College London, South Kensington Campus, Exhibition Road, London SW7 2AZ, UK
| | - Jason W. Chin
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Francesco Luigi Gervasio
- Institute of Structural and Molecular Biology, Department of Chemistry, University College London, Gower St, London WC1E 6BT, UK
| | - Edward W. Tate
- Department of Chemistry, Imperial College London, South Kensington Campus, Exhibition Road, London SW7 2AZ, UK
| | - Matilda Katan
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, Gower St, London WC1E 6BT, UK
| |
Collapse
|
13
|
Patani H, Bunney TD, Thiyagarajan N, Norman RA, Ogg D, Breed J, Ashford P, Potterton A, Edwards M, Williams SV, Thomson GS, Pang CS, Knowles MA, Breeze AL, Orengo C, Phillips C, Katan M. Landscape of activating cancer mutations in FGFR kinases and their differential responses to inhibitors in clinical use. Oncotarget 2016; 7:24252-68. [PMID: 26992226 PMCID: PMC5029699 DOI: 10.18632/oncotarget.8132] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Accepted: 02/28/2016] [Indexed: 01/09/2023] Open
Abstract
Frequent genetic alterations discovered in FGFRs and evidence implicating some as drivers in diverse tumors has been accompanied by rapid progress in targeting FGFRs for anticancer treatments. Wider assessment of the impact of genetic changes on the activation state and drug responses is needed to better link the genomic data and treatment options. We here apply a direct comparative and comprehensive analysis of FGFR3 kinase domain variants representing the diversity of point-mutations reported in this domain. We reinforce the importance of N540K and K650E and establish that not all highly activating mutations (for example R669G) occur at high-frequency and conversely, that some "hotspots" may not be linked to activation. Further structural characterization consolidates a mechanistic view of FGFR kinase activation and extends insights into drug binding. Importantly, using several inhibitors of particular clinical interest (AZD4547, BGJ-398, TKI258, JNJ42756493 and AP24534), we find that some activating mutations (including different replacements of the same residue) result in distinct changes in their efficacy. Considering that there is no approved inhibitor for anticancer treatments based on FGFR-targeting, this information will be immediately translatable to ongoing clinical trials.
Collapse
Affiliation(s)
- Harshnira Patani
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, Gower St, London WC1E 6BT, UK
| | - Tom D. Bunney
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, Gower St, London WC1E 6BT, UK
| | - Nethaji Thiyagarajan
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, Gower St, London WC1E 6BT, UK
| | - Richard A. Norman
- Discovery Sciences, AstraZeneca, Mereside, Alderley Park, Macclesfield, Cheshire SK10 4TG, UK
| | - Derek Ogg
- Discovery Sciences, AstraZeneca, Mereside, Alderley Park, Macclesfield, Cheshire SK10 4TG, UK
| | - Jason Breed
- Discovery Sciences, AstraZeneca, Mereside, Alderley Park, Macclesfield, Cheshire SK10 4TG, UK
| | - Paul Ashford
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, Gower St, London WC1E 6BT, UK
| | - Andrew Potterton
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, Gower St, London WC1E 6BT, UK
| | - Mina Edwards
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, Gower St, London WC1E 6BT, UK
| | - Sarah V. Williams
- Section of Experimental Oncology, Leeds Institute of Molecular Medicine, St James's University Hospital, Leeds LS9 7TF, UK
| | - Gary S. Thomson
- Astbury Centre for Structural Molecular Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
| | - Camilla S.M. Pang
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, Gower St, London WC1E 6BT, UK
| | - Margaret A. Knowles
- Section of Experimental Oncology, Leeds Institute of Molecular Medicine, St James's University Hospital, Leeds LS9 7TF, UK
| | - Alexander L. Breeze
- Astbury Centre for Structural Molecular Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
| | - Christine Orengo
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, Gower St, London WC1E 6BT, UK
| | - Chris Phillips
- Discovery Sciences, AstraZeneca, Mereside, Alderley Park, Macclesfield, Cheshire SK10 4TG, UK
| | - Matilda Katan
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, Gower St, London WC1E 6BT, UK
| |
Collapse
|
14
|
Perdios L, Bunney TD, Warren SC, Dunsby C, French PMW, Tate EW, Katan M. Time-resolved FRET reports FGFR1 dimerization and formation of a complex with its effector PLCγ1. Adv Biol Regul 2016; 60:6-13. [PMID: 26482290 PMCID: PMC4739061 DOI: 10.1016/j.jbior.2015.09.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Accepted: 09/22/2015] [Indexed: 11/05/2022]
Abstract
In vitro and in vivo imaging of protein tyrosine kinase activity requires minimally invasive, molecularly precise optical probes to provide spatiotemporal mechanistic information of dimerization and complex formation with downstream effectors. We present here a construct with genetically encoded, site-specifically incorporated, bioorthogonal reporter that can be selectively labelled with exogenous fluorogenic probes to monitor the structure and function of fibroblast growth factor receptor (FGFR). GyrB.FGFR1KD.TC contains a coumermycin-induced artificial dimerizer (GyrB), FGFR1 kinase domain (KD) and a tetracysteine (TC) motif that enables fluorescent labelling with biarsenical dyes FlAsH-EDT2 and ReAsH-EDT2. We generated bimolecular system for time-resolved FRET (TR-FRET) studies, which pairs FlAsH-tagged GyrB.FGFR1KD.TC and N-terminal Src homology 2 (nSH2) domain of phospholipase Cγ (PLCγ), a downstream effector of FGFR1, fused to mTurquoise fluorescent protein (mTFP). We demonstrated phosphorylation-dependent TR-FRET readout of complex formation between mTFP.nSH2 and GyrB.FGFR1KD.TC. By further application of TR-FRET, we also demonstrated formation of the GyrB.FGFR1KD.TC homodimer by coumermycin-induced dimerization. Herein, we present a spectroscopic FRET approach to facilitate and propagate studies that would provide structural and functional insights for FGFR and other tyrosine kinases.
Collapse
Affiliation(s)
- Louis Perdios
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, Gower St, London WC1E 6BT, UK; Department of Chemistry, Imperial College London, South Kensington Campus, Exhibition Road, London SW7 2AZ, UK
| | - Tom D Bunney
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, Gower St, London WC1E 6BT, UK
| | - Sean C Warren
- Department of Physics, Imperial College London, South Kensington Campus, Exhibition Road, London SW7 2AZ, UK
| | - Christopher Dunsby
- Department of Physics, Imperial College London, South Kensington Campus, Exhibition Road, London SW7 2AZ, UK
| | - Paul M W French
- Department of Physics, Imperial College London, South Kensington Campus, Exhibition Road, London SW7 2AZ, UK
| | - Edward W Tate
- Department of Chemistry, Imperial College London, South Kensington Campus, Exhibition Road, London SW7 2AZ, UK
| | - Matilda Katan
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, Gower St, London WC1E 6BT, UK.
| |
Collapse
|
15
|
Broncel M, Serwa RA, Bunney TD, Katan M, Tate EW. Global Profiling of Huntingtin-associated protein E (HYPE)-Mediated AMPylation through a Chemical Proteomic Approach. Mol Cell Proteomics 2015; 15:715-25. [PMID: 26604261 DOI: 10.1074/mcp.o115.054429] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2015] [Indexed: 01/31/2023] Open
Abstract
AMPylation of mammalian small GTPases by bacterial virulence factors can be a key step in bacterial infection of host cells, and constitutes a potential drug target. This posttranslational modification also exists in eukaryotes, and AMP transferase activity was recently assigned to HYPE Filamentation induced by cyclic AMP domain containing protein (FICD) protein, which is conserved from Caenorhabditis elegans to humans. In contrast to bacterial AMP transferases, only a small number of HYPE substrates have been identified by immunoprecipitation and mass spectrometry approaches, and the full range of targets is yet to be determined in mammalian cells. We describe here the first example of global chemoproteomic screening and substrate validation for HYPE-mediated AMPylation in mammalian cell lysate. Through quantitative mass-spectrometry-based proteomics coupled with novel chemoproteomic tools providing MS/MS evidence of AMP modification, we identified a total of 25 AMPylated proteins, including the previously validated substrate endoplasmic reticulum (ER) chaperone BiP (HSPA5), and also novel substrates involved in pathways of gene expression, ATP biosynthesis, and maintenance of the cytoskeleton. This dataset represents the largest library of AMPylated human proteins reported to date and a foundation for substrate-specific investigations that can ultimately decipher the complex biological networks involved in eukaryotic AMPylation.
Collapse
Affiliation(s)
- Malgorzata Broncel
- From the ‡Department of Chemistry, Imperial College London, Exhibition Road, London SW7 2AZ, UK; ¶Current address: The Institute of Cancer Research, Division of Cancer Biology, 237 Fulham Road, London SW3 6JB, UK
| | - Remigiusz A Serwa
- From the ‡Department of Chemistry, Imperial College London, Exhibition Road, London SW7 2AZ, UK
| | - Tom D Bunney
- §Division of Biosciences, Institute of Structural and Molecular Biology, University College London, Gower Street, London WC1E 6BT, UK
| | - Matilda Katan
- §Division of Biosciences, Institute of Structural and Molecular Biology, University College London, Gower Street, London WC1E 6BT, UK
| | - Edward W Tate
- From the ‡Department of Chemistry, Imperial College London, Exhibition Road, London SW7 2AZ, UK;
| |
Collapse
|
16
|
Bunney TD, Cole AR, Broncel M, Esposito D, Tate EW, Katan M. Crystal structure of the human, FIC-domain containing protein HYPE and implications for its functions. Structure 2015; 22:1831-1843. [PMID: 25435325 PMCID: PMC4342408 DOI: 10.1016/j.str.2014.10.007] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2014] [Revised: 09/22/2014] [Accepted: 10/06/2014] [Indexed: 01/06/2023]
Abstract
Protein AMPylation, the transfer of AMP from ATP to protein targets, has been recognized as a new mechanism of host-cell disruption by some bacterial effectors that typically contain a FIC-domain. Eukaryotic genomes also encode one FIC-domain protein, HYPE, which has remained poorly characterized. Here we describe the structure of human HYPE, solved by X-ray crystallography, representing the first structure of a eukaryotic FIC-domain protein. We demonstrate that HYPE forms stable dimers with structurally and functionally integrated FIC-domains and with TPR-motifs exposed for protein-protein interactions. As HYPE also uniquely possesses a transmembrane helix, dimerization is likely to affect its positioning and function in the membrane vicinity. The low rate of autoAMPylation of the wild-type HYPE could be due to autoinhibition, consistent with the mechanism proposed for a number of putative FIC AMPylators. Our findings also provide a basis to further consider possible alternative cofactors of HYPE and distinct modes of target-recognition. The first crystal structure of a eukaryotic FIC-domain protein is solved Interdomain interactions and dimerization of HYPE result in a rigid structure TPR-motifs and the active site of the autoinhibited FIC domain are exposed In contrast to bacterial FICs, HYPE does not preferentially AMPylate small GTPases
Collapse
Affiliation(s)
- Tom D Bunney
- Division of Biosciences, Institute of Structural and Molecular Biology, University College London, Gower Street, London WC1E 6BT, UK.
| | - Ambrose R Cole
- Institute of Structural and Molecular Biology, Birkbeck College, London WC1 7HX, UK
| | - Malgorzata Broncel
- Department of Chemistry, Imperial College London, South Kensington Campus, Exhibition Road, London SW7 2AZ, UK
| | - Diego Esposito
- Division of Molecular Structure, MRC-National Institute for Medical Research, Mill Hill, London NW7 1AA, UK
| | - Edward W Tate
- Department of Chemistry, Imperial College London, South Kensington Campus, Exhibition Road, London SW7 2AZ, UK
| | - Matilda Katan
- Division of Biosciences, Institute of Structural and Molecular Biology, University College London, Gower Street, London WC1E 6BT, UK.
| |
Collapse
|
17
|
Bunney TD, Wan S, Thiyagarajan N, Sutto L, Williams SV, Ashford P, Koss H, Knowles MA, Gervasio FL, Coveney PV, Katan M. The Effect of Mutations on Drug Sensitivity and Kinase Activity of Fibroblast Growth Factor Receptors: A Combined Experimental and Theoretical Study. EBioMedicine 2015; 2:194-204. [PMID: 26097890 PMCID: PMC4471147 DOI: 10.1016/j.ebiom.2015.02.009] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Revised: 02/11/2015] [Accepted: 02/13/2015] [Indexed: 12/13/2022] Open
Abstract
Fibroblast growth factor receptors (FGFRs) are recognized therapeutic targets in cancer. We here describe insights underpinning the impact of mutations on FGFR1 and FGFR3 kinase activity and drug efficacy, using a combination of computational calculations and experimental approaches including cellular studies, X-ray crystallography and biophysical and biochemical measurements. Our findings reveal that some of the tested compounds, in particular TKI258, could provide therapeutic opportunity not only for patients with primary alterations in FGFR but also for acquired resistance due to the gatekeeper mutation. The accuracy of the computational methodologies applied here shows a potential for their wider application in studies of drug binding and in assessments of functional and mechanistic impacts of mutations, thus assisting efforts in precision medicine.
Collapse
Affiliation(s)
- Tom D. Bunney
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, Gower St., London WC1E 6BT, UK
| | - Shunzhou Wan
- Centre for Computational Science, Department of Chemistry, University College London, 20 Gordon St., London WC1H 0AJ, UK
| | - Nethaji Thiyagarajan
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, Gower St., London WC1E 6BT, UK
| | - Ludovico Sutto
- Institute of Structural and Molecular Biology, Department of Chemistry, University College London, Gower St., London WC1E 6BT, UK
| | - Sarah V. Williams
- Section of Experimental Oncology, Leeds Institute of Molecular Medicine, St James's University Hospital, Beckett Street, Leeds LS9 7TF, UK
| | - Paul Ashford
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, Gower St., London WC1E 6BT, UK
| | - Hans Koss
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, Gower St., London WC1E 6BT, UK
- Division of Molecular Structure, MRC-National Institute for Medical Research, Mill Hill, London NW7 1AA, UK
| | - Margaret A. Knowles
- Section of Experimental Oncology, Leeds Institute of Molecular Medicine, St James's University Hospital, Beckett Street, Leeds LS9 7TF, UK
| | - Francesco L. Gervasio
- Institute of Structural and Molecular Biology, Department of Chemistry, University College London, Gower St., London WC1E 6BT, UK
| | - Peter V. Coveney
- Centre for Computational Science, Department of Chemistry, University College London, 20 Gordon St., London WC1H 0AJ, UK
| | - Matilda Katan
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, Gower St., London WC1E 6BT, UK
| |
Collapse
|
18
|
Koss H, Bunney TD, Behjati S, Katan M. Dysfunction of phospholipase Cγ in immune disorders and cancer. Trends Biochem Sci 2014; 39:603-11. [PMID: 25456276 DOI: 10.1016/j.tibs.2014.09.004] [Citation(s) in RCA: 82] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Revised: 09/19/2014] [Accepted: 09/24/2014] [Indexed: 12/15/2022]
Abstract
The surge in genetic and genomic investigations over the past 5 years has resulted in many discoveries of causative variants relevant to disease pathophysiology. Although phospholipase C (PLC) enzymes have long been recognized as important components in intracellular signal transmission, it is only recently that this approach highlighted their role in disease development through gain-of-function mutations. In this review we describe the new findings that link the PLCγ family to immune disorders and cancer, and illustrate further efforts to elucidate the molecular mechanisms that underpin their dysfunction.
Collapse
Affiliation(s)
- Hans Koss
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, London, UK; Division of Molecular Structure, Medical Research Council (MRC) National Institute for Medical Research, London, UK
| | - Tom D Bunney
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, London, UK.
| | - Sam Behjati
- Cancer Genome Project, Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, UK
| | - Matilda Katan
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, London, UK.
| |
Collapse
|
19
|
Behjati S, Tarpey PS, Sheldon H, Martincorena I, Van Loo P, Gundem G, Wedge DC, Ramakrishna M, Cooke SL, Pillay N, Vollan HKM, Papaemmanuil E, Koss H, Bunney TD, Hardy C, Joseph OR, Martin S, Mudie L, Butler A, Teague JW, Patil M, Steers G, Cao Y, Gumbs C, Ingram D, Lazar AJ, Little L, Mahadeshwar H, Protopopov A, Al Sannaa GA, Seth S, Song X, Tang J, Zhang J, Ravi V, Torres KE, Khatri B, Halai D, Roxanis I, Baumhoer D, Tirabosco R, Amary MF, Boshoff C, McDermott U, Katan M, Stratton MR, Futreal PA, Flanagan AM, Harris A, Campbell PJ. Recurrent PTPRB and PLCG1 mutations in angiosarcoma. Nat Genet 2014; 46:376-379. [PMID: 24633157 PMCID: PMC4032873 DOI: 10.1038/ng.2921] [Citation(s) in RCA: 224] [Impact Index Per Article: 22.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2013] [Accepted: 02/18/2014] [Indexed: 12/14/2022]
Abstract
Angiosarcoma is an aggressive malignancy that arises spontaneously or secondarily to ionizing radiation or chronic lymphoedema. Previous work has identified aberrant angiogenesis, including occasional somatic mutations in angiogenesis signaling genes, as a key driver of angiosarcoma. Here we employed whole-genome, whole-exome and targeted sequencing to study the somatic changes underpinning primary and secondary angiosarcoma. We identified recurrent mutations in two genes, PTPRB and PLCG1, which are intimately linked to angiogenesis. The endothelial phosphatase PTPRB, a negative regulator of vascular growth factor tyrosine kinases, harbored predominantly truncating mutations in 10 of 39 tumors (26%). PLCG1, a signal transducer of tyrosine kinases, encoded a recurrent, likely activating p.Arg707Gln missense variant in 3 of 34 cases (9%). Overall, 15 of 39 tumors (38%) harbored at least one driver mutation in angiogenesis signaling genes. Our findings inform and reinforce current therapeutic efforts to target angiogenesis signaling in angiosarcoma.
Collapse
Affiliation(s)
- Sam Behjati
- Cancer Genome Project, Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridgeshire, CB10 1SA, UK
- Department of Paediatrics, University of Cambridge, Hills Road, Cambridge, CB2 2XY, UK
| | - Patrick S Tarpey
- Cancer Genome Project, Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridgeshire, CB10 1SA, UK
| | - Helen Sheldon
- The Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, OX3 9DS, UK
| | - Inigo Martincorena
- Cancer Genome Project, Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridgeshire, CB10 1SA, UK
| | - Peter Van Loo
- Cancer Genome Project, Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridgeshire, CB10 1SA, UK
- Human Genome Laboratory, Department of Human Genetics, VIB and KU Leuven, B-3000 Leuven, Belgium
| | - Gunes Gundem
- Cancer Genome Project, Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridgeshire, CB10 1SA, UK
| | - David C Wedge
- Cancer Genome Project, Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridgeshire, CB10 1SA, UK
| | - Manasa Ramakrishna
- Cancer Genome Project, Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridgeshire, CB10 1SA, UK
| | - Susanna L Cooke
- Cancer Genome Project, Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridgeshire, CB10 1SA, UK
| | - Nischalan Pillay
- Histopathology, Royal National Orthopaedic Hospital NHS Trust, Stanmore, Middlesex, HA7 4LP, UK
- University College London Cancer Institute, Huntley Street, London, WC1E 6BT, UK
| | - Hans Kristian M Vollan
- Cancer Genome Project, Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridgeshire, CB10 1SA, UK
- Department of Oncology, Oslo University Hospital, N-0310 Oslo, Norway
- The K.G. Jebsen Center for Breast Cancer Research, University of Oslo, N-0424 Oslo, Norway
| | - Elli Papaemmanuil
- Cancer Genome Project, Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridgeshire, CB10 1SA, UK
| | - Hans Koss
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, London WC1E 6BT, UK
- Division of Molecular Structure, MRC-National Institute for Medical Research, Mill Hill, London NW7 1AA, UK
| | - Tom D Bunney
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, London WC1E 6BT, UK
| | - Claire Hardy
- Cancer Genome Project, Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridgeshire, CB10 1SA, UK
| | - Olivia R Joseph
- Cancer Genome Project, Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridgeshire, CB10 1SA, UK
| | - Sancha Martin
- Cancer Genome Project, Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridgeshire, CB10 1SA, UK
| | - Laura Mudie
- Cancer Genome Project, Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridgeshire, CB10 1SA, UK
| | - Adam Butler
- Cancer Genome Project, Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridgeshire, CB10 1SA, UK
| | - Jon W Teague
- Cancer Genome Project, Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridgeshire, CB10 1SA, UK
| | - Meena Patil
- Department of Pathology, John Radcliffe Hospital, Oxford, OX3 9DS, UK
| | - Graham Steers
- Department of Pathology, John Radcliffe Hospital, Oxford, OX3 9DS, UK
| | - Yu Cao
- M. D. Anderson Cancer Center, The University of Texas, 1901 East Road, Houston, Texas 77054, USA
| | - Curtis Gumbs
- M. D. Anderson Cancer Center, The University of Texas, 1901 East Road, Houston, Texas 77054, USA
| | - Davis Ingram
- M. D. Anderson Cancer Center, The University of Texas, 1901 East Road, Houston, Texas 77054, USA
| | - Alexander J Lazar
- M. D. Anderson Cancer Center, The University of Texas, 1901 East Road, Houston, Texas 77054, USA
| | - Latasha Little
- M. D. Anderson Cancer Center, The University of Texas, 1901 East Road, Houston, Texas 77054, USA
| | - Harshad Mahadeshwar
- M. D. Anderson Cancer Center, The University of Texas, 1901 East Road, Houston, Texas 77054, USA
| | - Alexei Protopopov
- M. D. Anderson Cancer Center, The University of Texas, 1901 East Road, Houston, Texas 77054, USA
| | - Ghadah A Al Sannaa
- M. D. Anderson Cancer Center, The University of Texas, 1901 East Road, Houston, Texas 77054, USA
| | - Sahil Seth
- M. D. Anderson Cancer Center, The University of Texas, 1901 East Road, Houston, Texas 77054, USA
| | - Xingzhi Song
- M. D. Anderson Cancer Center, The University of Texas, 1901 East Road, Houston, Texas 77054, USA
| | - Jiabin Tang
- M. D. Anderson Cancer Center, The University of Texas, 1901 East Road, Houston, Texas 77054, USA
| | - Jianhua Zhang
- M. D. Anderson Cancer Center, The University of Texas, 1901 East Road, Houston, Texas 77054, USA
| | - Vinod Ravi
- M. D. Anderson Cancer Center, The University of Texas, 1901 East Road, Houston, Texas 77054, USA
| | - Keila E Torres
- M. D. Anderson Cancer Center, The University of Texas, 1901 East Road, Houston, Texas 77054, USA
| | - Bhavisha Khatri
- Histopathology, Royal National Orthopaedic Hospital NHS Trust, Stanmore, Middlesex, HA7 4LP, UK
| | - Dina Halai
- Histopathology, Royal National Orthopaedic Hospital NHS Trust, Stanmore, Middlesex, HA7 4LP, UK
| | - Ioannis Roxanis
- Department of Pathology, John Radcliffe Hospital, Oxford, OX3 9DS, UK
| | - Daniel Baumhoer
- Bone Tumour Reference Centre, Institute of Pathology, University Hospital Basel, Basel, Institute for Applied Cancer Science, Switzerland
| | - Roberto Tirabosco
- Histopathology, Royal National Orthopaedic Hospital NHS Trust, Stanmore, Middlesex, HA7 4LP, UK
| | - M Fernanda Amary
- Histopathology, Royal National Orthopaedic Hospital NHS Trust, Stanmore, Middlesex, HA7 4LP, UK
| | - Chris Boshoff
- University College London Cancer Institute, Huntley Street, London, WC1E 6BT, UK
- Pfizer Oncology, 10555 Science Center Dr, La Jolla, CA, 92121
| | - Ultan McDermott
- Cancer Genome Project, Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridgeshire, CB10 1SA, UK
| | - Matilda Katan
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, London WC1E 6BT, UK
| | - Michael R Stratton
- Cancer Genome Project, Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridgeshire, CB10 1SA, UK
| | - P Andrew Futreal
- Cancer Genome Project, Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridgeshire, CB10 1SA, UK
- M. D. Anderson Cancer Center, The University of Texas, 1901 East Road, Houston, Texas 77054, USA
| | - Adrienne M Flanagan
- Histopathology, Royal National Orthopaedic Hospital NHS Trust, Stanmore, Middlesex, HA7 4LP, UK
- University College London Cancer Institute, Huntley Street, London, WC1E 6BT, UK
| | - Adrian Harris
- The Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, OX3 9DS, UK
- Department of Pathology, John Radcliffe Hospital, Oxford, OX3 9DS, UK
| | - Peter J Campbell
- Cancer Genome Project, Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridgeshire, CB10 1SA, UK
- Department of Haematology, Addenbrooke's Hospital, Cambridge, UK
- Department of Haematology, University of Cambridge, Hills Road, Cambridge, CB2 2XY, UK
| |
Collapse
|
20
|
Zhou Q, Lee GS, Brady J, Datta S, Katan M, Sheikh A, Martins MS, Bunney TD, Santich BH, Moir S, Kuhns DB, Long Priel DA, Ombrello A, Stone D, Ombrello MJ, Khan J, Milner JD, Kastner DL, Aksentijevich I. A hypermorphic missense mutation in PLCG2, encoding phospholipase Cγ2, causes a dominantly inherited autoinflammatory disease with immunodeficiency. Am J Hum Genet 2012; 91:713-20. [PMID: 23000145 DOI: 10.1016/j.ajhg.2012.08.006] [Citation(s) in RCA: 239] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2012] [Revised: 06/11/2012] [Accepted: 08/08/2012] [Indexed: 12/13/2022] Open
Abstract
Whole-exome sequencing was performed in a family affected by dominantly inherited inflammatory disease characterized by recurrent blistering skin lesions, bronchiolitis, arthralgia, ocular inflammation, enterocolitis, absence of autoantibodies, and mild immunodeficiency. Exome data from three samples, including the affected father and daughter and unaffected mother, were filtered for the exclusion of reported variants, along with benign variants, as determined by PolyPhen-2. A total of eight transcripts were identified as possible candidate genes. We confirmed a variant, c.2120C>A (p.Ser707Tyr), within PLCG2 as the only de novo variant that was present in two affected family members and not present in four unaffected members. PLCG2 encodes phospholipase Cγ2 (PLCγ2), an enzyme with a critical regulatory role in various immune and inflammatory pathways. The p.Ser707Tyr substitution is located in an autoinhibitory SH2 domain that is crucial for PLCγ2 activation. Overexpression of the altered p.Ser707Tyr protein and ex vivo experiments using affected individuals' leukocytes showed clearly enhanced PLCγ2 activity, suggesting increased intracellular signaling in the PLCγ2-mediated pathway. Recently, our laboratory identified in individuals with cold-induced urticaria and immune dysregulation PLCG2 exon-skipping mutations resulting in protein products with constitutive phospholipase activity but with reduced intracellular signaling at physiological temperatures. In contrast, the p.Ser707Tyr substitution in PLCγ2 causes a distinct inflammatory phenotype that is not provoked by cold temperatures and that has different end-organ involvement and increased intracellular signaling at physiological temperatures. Our results highlight the utility of exome-sequencing technology in finding causal mutations in nuclear families with dominantly inherited traits otherwise intractable by linkage analysis.
Collapse
Affiliation(s)
- Qing Zhou
- Inflammatory Disease Section, National Human Genome Research Institute, Bethesda, MD 20892, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
21
|
Ombrello MJ, Remmers EF, Sun G, Freeman AF, Datta S, Torabi-Parizi P, Subramanian N, Bunney TD, Baxendale RW, Martins MS, Romberg N, Komarow H, Aksentijevich I, Kim HS, Ho J, Cruse G, Jung MY, Gilfillan AM, Metcalfe DD, Nelson C, O'Brien M, Wisch L, Stone K, Douek DC, Gandhi C, Wanderer AA, Lee H, Nelson SF, Shianna KV, Cirulli ET, Goldstein DB, Long EO, Moir S, Meffre E, Holland SM, Kastner DL, Katan M, Hoffman HM, Milner JD. Cold urticaria, immunodeficiency, and autoimmunity related to PLCG2 deletions. N Engl J Med 2012; 366:330-8. [PMID: 22236196 PMCID: PMC3298368 DOI: 10.1056/nejmoa1102140] [Citation(s) in RCA: 279] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
BACKGROUND Mendelian analysis of disorders of immune regulation can provide insight into molecular pathways associated with host defense and immune tolerance. METHODS We identified three families with a dominantly inherited complex of cold-induced urticaria, antibody deficiency, and susceptibility to infection and autoimmunity. Immunophenotyping methods included flow cytometry, analysis of serum immunoglobulins and autoantibodies, lymphocyte stimulation, and enzymatic assays. Genetic studies included linkage analysis, targeted Sanger sequencing, and next-generation whole-genome sequencing. RESULTS Cold urticaria occurred in all affected subjects. Other, variable manifestations included atopy, granulomatous rash, autoimmune thyroiditis, the presence of antinuclear antibodies, sinopulmonary infections, and common variable immunodeficiency. Levels of serum IgM and IgA and circulating natural killer cells and class-switched memory B cells were reduced. Linkage analysis showed a 7-Mb candidate interval on chromosome 16q in one family, overlapping by 3.5 Mb a disease-associated haplotype in a smaller family. This interval includes PLCG2, encoding phospholipase Cγ(2) (PLCγ(2)), a signaling molecule expressed in B cells, natural killer cells, and mast cells. Sequencing of complementary DNA revealed heterozygous transcripts lacking exon 19 in two families and lacking exons 20 through 22 in a third family. Genomic sequencing identified three distinct in-frame deletions that cosegregated with disease. These deletions, located within a region encoding an autoinhibitory domain, result in protein products with constitutive phospholipase activity. PLCG2-expressing cells had diminished cellular signaling at 37°C but enhanced signaling at subphysiologic temperatures. CONCLUSIONS Genomic deletions in PLCG2 cause gain of PLCγ(2) function, leading to signaling abnormalities in multiple leukocyte subsets and a phenotype encompassing both excessive and deficient immune function. (Funded by the National Institutes of Health Intramural Research Programs and others.).
Collapse
Affiliation(s)
- Michael J Ombrello
- Inflammatory Disease Section, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
22
|
Bunney TD, Katan M. PLC regulation: emerging pictures for molecular mechanisms. Trends Biochem Sci 2010; 36:88-96. [PMID: 20870410 DOI: 10.1016/j.tibs.2010.08.003] [Citation(s) in RCA: 142] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2010] [Revised: 08/20/2010] [Accepted: 08/23/2010] [Indexed: 11/28/2022]
Abstract
Phosphoinositide-specific phospholipase C (PLC) enzymes are common signalling components linked to the activation of most cellular receptors. All PLC families are complex, modular, multi-domain proteins and together cover a broad spectrum of regulatory interactions, including direct binding to G protein subunits, small GTPases from Rho and Ras families, receptor and non-receptor tyrosine kinases and lipid components of cellular membranes. Recent structural determinations of PLC components and their complexes with regulatory proteins and direct mechanistic studies, together with earlier work, have provided the foundation to propose molecular mechanisms that stringently regulate PLC activity.
Collapse
Affiliation(s)
- Tom D Bunney
- The Institute of Cancer Research, Section for Cell and Molecular Biology, Chester Beatty Laboratories, Fulham Road, London SW3 6JB, UK
| | | |
Collapse
|
23
|
Abstract
There are numerous studies that suggest multiple links between the cellular phosphoinositide system and cancer. As key roles in cancer have been established for PI3K and PTEN - enzymes that regulate the levels of phosphatidylinositol-3,4,5-trisphosphate - compounds targeting this pathway are entering the clinic at a rapid pace. Several other phosphoinositide-modifying enzymes, including phosphoinositide kinases, phosphatases and phospholipase C enzymes, have been implicated in the generation and progression of tumours. Studies of these enzymes are providing new insights into the mechanisms and the extent of their involvement in cancer, highlighting new potential targets for therapeutic intervention.
Collapse
Affiliation(s)
- Tom D Bunney
- The Institute of Cancer Research, Section for Cell and Molecular Biology, Chester Beatty Laboratories, Fulham Road, London SW3 6JB, UK
| | | |
Collapse
|
24
|
Affiliation(s)
- Tom D Bunney
- Cancer Research UK Centre for Cell and Molecular Biology Chester Beatty Laboratories, The Institute of Cancer Research, Fulham Road, London SW36JB, UK
| | | | | |
Collapse
|
25
|
Everett KL, Bunney TD, Yoon Y, Rodrigues-Lima F, Harris R, Driscoll PC, Abe K, Fuchs H, de Angelis MH, Yu P, Cho W, Katan M. Characterization of phospholipase C gamma enzymes with gain-of-function mutations. J Biol Chem 2009; 284:23083-93. [PMID: 19531496 DOI: 10.1074/jbc.m109.019265] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Phospholipase C gamma isozymes (PLC gamma 1 and PLC gamma 2) have a crucial role in the regulation of a variety of cellular functions. Both enzymes have also been implicated in signaling events underlying aberrant cellular responses. Using N-ethyl-N-nitrosourea (ENU) mutagenesis, we have recently identified single point mutations in murine PLC gamma 2 that lead to spontaneous inflammation and autoimmunity. Here we describe further, mechanistic characterization of two gain-of-function mutations, D993G and Y495C, designated as ALI5 and ALI14. The residue Asp-993, mutated in ALI5, is a conserved residue in the catalytic domain of PLC enzymes. Analysis of PLC gamma 1 and PLC gamma 2 with point mutations of this residue showed that removal of the negative charge enhanced PLC activity in response to EGF stimulation or activation by Rac. Measurements of PLC activity in vitro and analysis of membrane binding have suggested that ALI5-type mutations facilitate membrane interactions without compromising substrate binding and hydrolysis. The residue mutated in ALI14 (Tyr-495) is within the spPH domain. Replacement of this residue had no effect on folding of the domain and enhanced Rac activation of PLC gamma 2 without increasing Rac binding. Importantly, the activation of the ALI14-PLC gamma 2 and corresponding PLC gamma 1 variants was enhanced in response to EGF stimulation and bypassed the requirement for phosphorylation of critical tyrosine residues. ALI5- and ALI14-type mutations affected basal activity only slightly; however, their combination resulted in a constitutively active PLC. Based on these data, we suggest that each mutation could compromise auto-inhibition in the inactive PLC, facilitating the activation process; in addition, ALI5-type mutations could enhance membrane interaction in the activated state.
Collapse
Affiliation(s)
- Katy L Everett
- Section of Cell and Molecular Biology, Chester Beatty Laboratories, The Institute of Cancer Research, London SW3 6JB, United Kingdom
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
26
|
Bunney TD, Opaleye O, Roe SM, Vatter P, Baxendale RW, Walliser C, Everett KL, Josephs MB, Christow C, Rodrigues-Lima F, Gierschik P, Pearl LH, Katan M. Structural insights into formation of an active signaling complex between Rac and phospholipase C gamma 2. Mol Cell 2009; 34:223-33. [PMID: 19394299 DOI: 10.1016/j.molcel.2009.02.023] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2008] [Revised: 01/28/2009] [Accepted: 02/20/2009] [Indexed: 10/20/2022]
Abstract
Rho family GTPases are important cellular switches and control a number of physiological functions. Understanding the molecular basis of interaction of these GTPases with their effectors is crucial in understanding their functions in the cell. Here we present the crystal structure of the complex of Rac2 bound to the split pleckstrin homology (spPH) domain of phospholipase C-gamma(2) (PLCgamma(2)). Based on this structure, we illustrate distinct requirements for PLCgamma(2) activation by Rac and EGF and generate Rac effector mutants that specifically block activation of PLCgamma(2), but not the related PLCbeta(2) isoform. Furthermore, in addition to the complex, we report the crystal structures of free spPH and Rac2 bound to GDP and GTPgammaS. These structures illustrate a mechanism of conformational switches that accompany formation of signaling active complexes and highlight the role of effector binding as a common feature of Rac and Cdc42 interactions with a variety of effectors.
Collapse
Affiliation(s)
- Tom D Bunney
- Section of Cell and Molecular Biology , The Institute of Cancer Research, London, UK.
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
27
|
Walliser C, Retlich M, Harris R, Everett KL, Josephs MB, Vatter P, Esposito D, Driscoll PC, Katan M, Gierschik P, Bunney TD. Rac regulates its effector phospholipase Cγ2 through interaction with a split pleckstrin homology domain. VOLUME 283 (2008) PAGES 30351-30362. J Biol Chem 2009. [DOI: 10.1016/s0021-9258(20)32447-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
|
28
|
Gandarillas NL, Bunney TD, Josephs MB, Gierschik P, Katan M. In vitro reconstitution of activation of PLCepsilon by Ras and Rho GTPases. Methods Mol Biol 2009; 462:379-89. [PMID: 19160682 DOI: 10.1007/978-1-60327-115-8_24] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
Phosphatidylinositol-specific phospholipase C (PLC) enzymes catalyze the hydrolysis of phophatidylinositol 4,5-bisphosphate [PtdIns(4,5)P2] to diacylglycerol (DAG) and inositol 1,4,5-triphosphate [Ins(1,4,5)P3]. PLCepsilon is a recently discovered isoform that has been shown to be activated by members of the Ras and Rho families of guanosine trisphosphatases (GTPases) as well as subunits of heterotrimeric G-proteins. We describe a method for expressing a truncated PLCepsilon variant as an MBP fusion protein in E. coli. Subsequently, we describe the methodology necessary to reconstitute this protein with K-Ras-4B and RhoA GTPases and measure its activation.
Collapse
Affiliation(s)
- Natalia Lamuño Gandarillas
- Cancer Research UK Centre for Cell and Molecular Biology, Chester Beatty Laboratories, The Institute of Cancer Research, London, UK
| | | | | | | | | |
Collapse
|
29
|
Talbot CB, McGinty J, Grant DM, McGhee EJ, Owen DM, Zhang W, Bunney TD, Munro I, Isherwood B, Eagle R, Hargreaves A, Dunsby C, Neil MAA, French PMW. High speed unsupervised fluorescence lifetime imaging confocal multiwell plate reader for high content analysis. J Biophotonics 2008. [PMID: 19343673 DOI: 10.1002/jbio.v1:6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
We report an automated optically sectioning fluorescence lifetime imaging (FLIM) multiwell plate reader for high content analysis (HCA) in drug discovery and accelerated research in cell biology. The system utilizes a Nipkow disc confocal microscope and performs unsupervised FLIM with autofocus, automatic setting of acquisition parameters and automated localisation of cells in the field of view. We demonstrate its applications to test dye solutions, fixed and live cells and FLIM-FRET.
Collapse
|
30
|
Talbot CB, McGinty J, Grant DM, McGhee EJ, Owen DM, Zhang W, Bunney TD, Munro I, Isherwood B, Eagle R, Hargreaves A, Dunsby C, Neil MAA, French PMW. High speed unsupervised fluorescence lifetime imaging confocal multiwell plate reader for high content analysis. J Biophotonics 2008; 1:514-521. [PMID: 19343677 DOI: 10.1002/jbio.200810054] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
We report an automated optically sectioning fluorescence lifetime imaging (FLIM) multiwell plate reader for high content analysis (HCA) in drug discovery and accelerated research in cell biology. The system utilizes a Nipkow disc confocal microscope and performs unsupervised FLIM with autofocus, automatic setting of acquisition parameters and automated localisation of cells in the field of view. We demonstrate its applications to test dye solutions, fixed and live cells and FLIM-FRET.
Collapse
|
31
|
Walliser C, Retlich M, Harris R, Everett KL, Josephs MB, Vatter P, Esposito D, Driscoll PC, Katan M, Gierschik P, Bunney TD. rac regulates its effector phospholipase Cgamma2 through interaction with a split pleckstrin homology domain. J Biol Chem 2008; 283:30351-62. [PMID: 18728011 PMCID: PMC2573054 DOI: 10.1074/jbc.m803316200] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2008] [Revised: 07/31/2008] [Indexed: 11/16/2022] Open
Abstract
Several isoforms of phospholipase C (PLC) are regulated through interactions with Ras superfamily GTPases, including Rac proteins. Interestingly, of two closely related PLCgamma isoforms, only PLCgamma(2) has previously been shown to be activated by Rac. Here, we explore the molecular basis of this interaction as well as the structural properties of PLCgamma(2) required for activation. Based on reconstitution experiments with isolated PLCgamma variants and Rac2, we show that an unusual pleckstrin homology (PH) domain, designated as the split PH domain (spPH), is both necessary and sufficient to effect activation of PLCgamma(2) by Rac2. We also demonstrate that Rac2 directly binds to PLCgamma(2) as well as to the isolated spPH of this isoform. Furthermore, through the use of NMR spectroscopy and mutational analysis, we determine the structure of spPH, define the structural features of spPH required for Rac interaction, and identify critical amino acid residues at the interaction interface. We further discuss parallels and differences between PLCgamma(1) and PLCgamma(2) and the implications of our findings for their respective signaling roles.
Collapse
Affiliation(s)
- Claudia Walliser
- Institute of Pharmacology and Toxicology, University of Ulm Medical Center, 89070 Ulm, Germany
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
32
|
Grant DM, McGinty J, McGhee EJ, Bunney TD, Owen DM, Talbot CB, Zhang W, Kumar S, Munro I, Lanigan PM, Kennedy GT, Dunsby C, Magee AI, Courtney P, Katan M, Neil MAA, French PMW. High speed optically sectioned fluorescence lifetime imaging permits study of live cell signaling events. Opt Express 2007; 15:15656-73. [PMID: 19550853 DOI: 10.1364/oe.15.015656] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
We present a time domain optically sectioned fluorescence lifetime imaging (FLIM) microscope developed for high-speed live cell imaging. This single photon excited system combines wide field parallel pixel detection with confocal sectioning utilizing spinning Nipkow disc microscopy. It can acquire fluorescence lifetime images of live cells at up to 10 frames per second (fps), permitting high-speed FLIM of cell dynamics and protein interactions with potential for high throughput cell imaging and screening applications. We demonstrate the application of this FLIM microscope to real-time monitoring of changes in lipid order in cell membranes following cholesterol depletion using cyclodextrin and to the activation of the small GTP-ase Ras in live cells using FRET.
Collapse
|
33
|
Miertzschke M, Stanley P, Bunney TD, Rodrigues-Lima F, Hogg N, Katan M. Characterization of Interactions of Adapter Protein RAPL/Nore1B with RAP GTPases and Their Role in T Cell Migration. J Biol Chem 2007; 282:30629-42. [PMID: 17716979 DOI: 10.1074/jbc.m704361200] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Using a model of integrin-triggered random migration of T cells, we show that stimulation of LFA-1 integrins leads to the activation of Rap1 and Rap2 small GTPases. We further show that Rap1 and Rap2 have distinct roles in adhesion and random migration of these cells and that an adapter protein from the Ras association domain family (Rassf), RAPL, has a role downstream of Rap2 in addition to its link to Rap1. Further characterization of the RAPL protein and its interactions with small GTPases from the Ras family shows that RAPL forms more stable complexes with Rap2 and classical Ras proteins compared with Rap1. The different interaction pattern of RAPL with Rap1 and Rap2 is not affected by the disruption of the C-terminal SARAH domain that we identified as the alpha-helical region responsible for RAPL dimerization in vitro and in cells. Based on mutagenesis and three-dimensional modeling, we propose that interaction surfaces in RAPL-Rap1 and RAPL-Rap2 complexes are different and that a single residue in the switch I region of Rap proteins (residue 39) contributes considerably to the different kinetics of these protein-protein interactions. Furthermore, the distinct role of Rap2 in migration of T cells is lost when this critical residue is converted to the residue present in Rap1. Together, these observations suggest a wider role for Rassf adapter protein RAPL and Rap GTPases in cell motility and show that subtle differences between highly similar Rap proteins could be reflected in distinct interactions with common effectors and their cellular function.
Collapse
Affiliation(s)
- Mandy Miertzschke
- Cancer Research UK Centre for Cell and Molecular Biology, Chester Beatty Laboratories, The Institute of Cancer Research, Fulham Road, London SW3 6JB, United Kingdom
| | | | | | | | | | | |
Collapse
|
34
|
Schoonheim PJ, Sinnige MP, Casaretto JA, Veiga H, Bunney TD, Quatrano RS, de Boer AH. 14-3-3 adaptor proteins are intermediates in ABA signal transduction during barley seed germination. Plant J 2007; 49:289-301. [PMID: 17241451 DOI: 10.1111/j.1365-313x.2006.02955.x] [Citation(s) in RCA: 96] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Proteins of the 14-3-3 family have well-defined functions as regulators of plant primary metabolism and ion homeostasis. However, neither their function nor action mechanism in plant hormonal signaling have been fully addressed. Here we show that abscisic acid (ABA) affects both expression and protein levels of five 14-3-3 isoforms in embryonic barley roots. As ABA prolongs the presence of 14-3-3 proteins in the elongating radicle, we tested whether 14-3-3s are instrumental in ABA action using RNA interference. Transient co-expression of 14-3-3 RNAi constructs along with an ABA-responsive promoter showed that each 14-3-3 is functional in generating an ABA response. In a yeast two-hybrid screen, we identified three new 14-3-3 interactors that belong to the ABF protein family. Moreover, using a yeast two-hybrid assay, we show that the transcription factor HvABI5, which binds to cis-acting elements of the ABA-inducible HVA1 promoter, interacts with three of the five 14-3-3s. Our analyses identify two 14-3-3 binding motifs in HvABI5 that are essential for 14-3-3 binding and proper in vivo trans-activation activity of HvABI5. In line with these results, 14-3-3 silencing effectively blocks trans-activation. Our results indicate that 14-3-3 genes/proteins are not only under the control of ABA, but that they control ABA action as well.
Collapse
Affiliation(s)
- Peter J Schoonheim
- Department of Structural Biology, Faculty of Earth and Life Sciences, Vrije Universiteit, De Boelelaan 1085, 1081 HV Amsterdam, The Netherlands
| | | | | | | | | | | | | |
Collapse
|
35
|
Bunney TD, Katan M. Phospholipase C epsilon: linking second messengers and small GTPases. Trends Cell Biol 2006; 16:640-8. [PMID: 17085049 DOI: 10.1016/j.tcb.2006.10.007] [Citation(s) in RCA: 121] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2006] [Revised: 09/28/2006] [Accepted: 10/23/2006] [Indexed: 11/26/2022]
Abstract
Although several observations over the years suggested a link between the Ras superfamily of GTPases and second messengers generated by the isoforms of phospholipase C, such links had not been substantiated at the molecular level until recently. In particular, identification of a novel phospholipase C isoform, PLC epsilon, which also incorporates domains for guanine nucleotide exchange and Ras binding, have prompted an interest in the interplay between small GTPases and phospholipase C and possible significance of these interconnectivities. Research that followed suggests that activation of each of the major classes of phospholipase C by small GTPases could have a different mechanism and different function, and also that phospholipase C enzymes in turn control Ras GTPases through regulatory proteins that respond directly to second messengers.
Collapse
Affiliation(s)
- Tom D Bunney
- Cancer Research UK Centre for Cell and Molecular Biology, Chester Beatty Laboratories, The Institute of Cancer Research, Fulham Road, London SW3 6JB, UK
| | | |
Collapse
|
36
|
Hinkes B, Wiggins RC, Gbadegesin R, Vlangos CN, Seelow D, Nürnberg G, Garg P, Verma R, Chaib H, Hoskins BE, Ashraf S, Becker C, Hennies HC, Goyal M, Wharram BL, Schachter AD, Mudumana S, Drummond I, Kerjaschki D, Waldherr R, Dietrich A, Ozaltin F, Bakkaloglu A, Cleper R, Basel-Vanagaite L, Pohl M, Griebel M, Tsygin AN, Soylu A, Müller D, Sorli CS, Bunney TD, Katan M, Liu J, Attanasio M, O'toole JF, Hasselbacher K, Mucha B, Otto EA, Airik R, Kispert A, Kelley GG, Smrcka AV, Gudermann T, Holzman LB, Nürnberg P, Hildebrandt F. Positional cloning uncovers mutations in PLCE1 responsible for a nephrotic syndrome variant that may be reversible. Nat Genet 2006; 38:1397-405. [PMID: 17086182 DOI: 10.1038/ng1918] [Citation(s) in RCA: 375] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2006] [Accepted: 10/06/2006] [Indexed: 01/15/2023]
Abstract
Nephrotic syndrome, a malfunction of the kidney glomerular filter, leads to proteinuria, edema and, in steroid-resistant nephrotic syndrome, end-stage kidney disease. Using positional cloning, we identified mutations in the phospholipase C epsilon gene (PLCE1) as causing early-onset nephrotic syndrome with end-stage kidney disease. Kidney histology of affected individuals showed diffuse mesangial sclerosis (DMS). Using immunofluorescence, we found PLCepsilon1 expression in developing and mature glomerular podocytes and showed that DMS represents an arrest of normal glomerular development. We identified IQ motif-containing GTPase-activating protein 1 as a new interaction partner of PLCepsilon1. Two siblings with a missense mutation in an exon encoding the PLCepsilon1 catalytic domain showed histology characteristic of focal segmental glomerulosclerosis. Notably, two other affected individuals responded to therapy, making this the first report of a molecular cause of nephrotic syndrome that may resolve after therapy. These findings, together with the zebrafish model of human nephrotic syndrome generated by plce1 knockdown, open new inroads into pathophysiology and treatment mechanisms of nephrotic syndrome.
Collapse
Affiliation(s)
- Bernward Hinkes
- Department of Pediatrics, University of Michigan, Ann Arbor, Michigan 48109, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
37
|
Bunney TD, Harris R, Gandarillas NL, Josephs MB, Roe SM, Sorli SC, Paterson HF, Rodrigues-Lima F, Esposito D, Ponting CP, Gierschik P, Pearl LH, Driscoll PC, Katan M. Structural and mechanistic insights into ras association domains of phospholipase C epsilon. Mol Cell 2006; 21:495-507. [PMID: 16483931 DOI: 10.1016/j.molcel.2006.01.008] [Citation(s) in RCA: 113] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2005] [Revised: 11/24/2005] [Accepted: 01/03/2006] [Indexed: 11/30/2022]
Abstract
Ras proteins signal to a number of distinct pathways by interacting with diverse effectors. Studies of ras/effector interactions have focused on three classes, Raf kinases, ral guanylnucleotide-exchange factors, and phosphatidylinositol-3-kinases. Here we describe ras interactions with another effector, the recently identified phospholipase C epsilon (PLCepsilon). We solved structures of PLCepsilon RA domains (RA1 and RA2) by NMR and the structure of the RA2/ras complex by X-ray crystallography. Although the similarity between ubiquitin-like folds of RA1 and RA2 proves that they are homologs, only RA2 can bind ras. Some of the features of the RA2/ras interface are unique to PLCepsilon, while the ability to make contacts with both switch I and II regions of ras is shared only with phosphatidylinositol-3-kinase. Studies of PLCepsilon regulation suggest that, in a cellular context, the RA2 domain, in a mode specific to PLCepsilon, has a role in membrane targeting with further regulatory impact on PLC activity.
Collapse
Affiliation(s)
- Tom D Bunney
- Cancer Research UK Centre for Cell and Molecular Biology, Chester Beatty Laboratories, The Institute of Cancer Research, Fulham Road, London SW3 6JB, United Kingdom
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
38
|
Sinnige MP, Roobeek I, Bunney TD, Visser AJWG, Mol JNM, de Boer AH. Single amino acid variation in barley 14-3-3 proteins leads to functional isoform specificity in the regulation of nitrate reductase. Plant J 2005; 44:1001-9. [PMID: 16359392 DOI: 10.1111/j.1365-313x.2005.02599.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
The highly conserved family of 14-3-3 proteins function in the regulation of a wide variety of cellular processes. The presence of multiple 14-3-3 isoforms and the diversity of cellular processes regulated by 14-3-3 suggest functional isoform specificity of 14-3-3 isoforms in the regulation of target proteins. Indeed, several studies observed differences in affinity and functionality of 14-3-3 isoforms. However, the structural variation by which isoform specificity is accomplished remains unclear. Because other reports suggest that specificity is found in differential expression and availability of 14-3-3 isoforms, we used the nitrate reductase (NR) model system to analyse the availability and functionality of the three barley 14-3-3 isoforms. We found that 14-3-3C is unavailable in dark harvested barley leaf extract and 14-3-3A is functionally not capable to efficiently inhibit NR activity, leaving 14-3-3B as the only characterized isoform able to regulate NR in barley. Further, using site directed mutagenesis, we identified a single amino acid variation (Gly versus Ser) in loop 8 of the 14-3-3 proteins that plays an important role in the observed isoform specificity. Mutating the Gly residue of 14-3-3A to the alternative residue, as found in 14-3-3B and 14-3-3C, turned it into a potent inhibitor of NR activity. Using surface plasmon resonance, we show that the ability of 14-3-3A and the mutated version to inhibit NR activity correlates well with their binding affinity for the 14-3-3 binding motif in the NR protein, indicating involvement of this residue in ligand discrimination. These results suggest that both the availability of 14-3-3 isoforms as well as binding affinity determine isoform-specific regulation of NR activity.
Collapse
Affiliation(s)
- Mark P Sinnige
- Department of Developmental Genetics, De Boelelaan 1085, 1081 HV Amsterdam, the Netherlands
| | | | | | | | | | | |
Collapse
|
39
|
Harris R, Bunney TD, Katan M, Driscoll PC. Backbone 1H, 13C, and 15N resonance assignments for the two 13 kD Ras associating domains (RA1 and RA2) from phospholipase C epsilon. J Biomol NMR 2005; 33:138. [PMID: 16258837 DOI: 10.1007/s10858-005-3094-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
|
40
|
Yu P, Constien R, Dear N, Katan M, Hanke P, Bunney TD, Kunder S, Quintanilla-Martinez L, Huffstadt U, Schröder A, Jones NP, Peters T, Fuchs H, de Angelis MH, Nehls M, Grosse J, Wabnitz P, Meyer TPH, Yasuda K, Schiemann M, Schneider-Fresenius C, Jagla W, Russ A, Popp A, Josephs M, Marquardt A, Laufs J, Schmittwolf C, Wagner H, Pfeffer K, Mudde GC. Autoimmunity and Inflammation Due to a Gain-of-Function Mutation in Phospholipase Cγ2 that Specifically Increases External Ca2+ Entry. Immunity 2005; 22:451-65. [PMID: 15845450 DOI: 10.1016/j.immuni.2005.01.018] [Citation(s) in RCA: 120] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2004] [Revised: 01/07/2005] [Accepted: 01/12/2005] [Indexed: 01/16/2023]
Abstract
The identification of specific genetic loci that contribute to inflammatory and autoimmune diseases has proved difficult due to the contribution of multiple interacting genes, the inherent genetic heterogeneity present in human populations, and a lack of new mouse mutants. By using N-ethyl-N-nitrosourea (ENU) mutagenesis to discover new immune regulators, we identified a point mutation in the murine phospholipase Cg2 (Plcg2) gene that leads to severe spontaneous inflammation and autoimmunity. The disease is composed of an autoimmune component mediated by autoantibody immune complexes and B and T cell independent inflammation. The underlying mechanism is a gain-of-function mutation in Plcg2, which leads to hyperreactive external calcium entry in B cells and expansion of innate inflammatory cells. This mutant identifies Plcg2 as a key regulator in an autoimmune and inflammatory disease mediated by B cells and non-B, non-T haematopoietic cells and emphasizes that by distinct genetic modulation, a single point mutation can lead to a complex immunological phenotype.
Collapse
Affiliation(s)
- Philipp Yu
- Ingenium Pharmaceuticals AG, Fraunhoferstrasse 13, 82152 Martinsried, Munich, Germany.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
41
|
Frankel P, Aronheim A, Kavanagh E, Balda MS, Matter K, Bunney TD, Marshall CJ. RalA interacts with ZONAB in a cell density-dependent manner and regulates its transcriptional activity. EMBO J 2005; 24:54-62. [PMID: 15592429 PMCID: PMC544910 DOI: 10.1038/sj.emboj.7600497] [Citation(s) in RCA: 90] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2004] [Accepted: 11/05/2004] [Indexed: 11/08/2022] Open
Abstract
Ral proteins are members of the Ras superfamily of small GTPases and are involved in signalling pathways for actin cytoskeleton remodelling, cell cycle control, cellular transformation and vesicle transport. To identify novel RalA effector proteins, we used the reverse Ras recruitment system and found that RalA interacts with a Y-box transcription factor, ZO-1-associated nucleic acid-binding protein (ZONAB), in a GTP-dependent manner. The amount of the RalA-ZONAB complex increases as epithelial cells become more dense and increase cell contacts. The RalA-ZONAB interaction results in a relief of transcriptional repression of a ZONAB-regulated promoter. Additionally, expression of oncogenic Ras alleviates transcriptional repression by ZONAB in a RalA-dependent manner. The data presented here implicate the RalA/ZONAB interaction in the regulation of ZONAB function.
Collapse
Affiliation(s)
- Paul Frankel
- Oncogene Team, Cancer Research UK Centre for Cell and Molecular Biology, Chester Beatty Laboratories, Institute of Cancer Research, London, UK
| | - Ami Aronheim
- Department of Molecular Genetics, the B Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel
| | - Emma Kavanagh
- Division of Cell Biology, Institute of Ophthalmology, University College London, London, UK
| | - Maria S Balda
- Division of Cell Biology, Institute of Ophthalmology, University College London, London, UK
| | - Karl Matter
- Division of Cell Biology, Institute of Ophthalmology, University College London, London, UK
| | - Tom D Bunney
- Lipid Signalling Team, Cancer Research UK Centre for Cell and Molecular Biology, Chester Beatty Laboratories, Institute of Cancer Research, London, UK
| | - Christopher J Marshall
- Oncogene Team, Cancer Research UK Centre for Cell and Molecular Biology, Chester Beatty Laboratories, Institute of Cancer Research, London, UK
| |
Collapse
|
42
|
Sorli SC, Bunney TD, Sugden PH, Paterson HF, Katan M. Signaling properties and expression in normal and tumor tissues of two phospholipase C epsilon splice variants. Oncogene 2004; 24:90-100. [PMID: 15558028 DOI: 10.1038/sj.onc.1208168] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Phospholipase Cepsilon (PLCepsilon) is a novel member of phosphoinositide-specific phospholipase C enzymes with a unique regulatory link to Ras GTP-ases. In the present studies, we establish existence of two splice variants (PLCepsilon1a and PLCepsilon1b) derived from human PLCepsilon1 gene. When expressed in COS or HEK293 cells, PLCepsilon1a and PLCepsilon1b have similar potential to be stimulated by diverse signaling pathways via tyrosine kinase and G-protein coupled receptors and share the ability to function as an effector of Ras. The expression pattern shows broader mRNA expression of PLCepsilon1a in normal tissues; furthermore, in most cell lines expressing PLCepsilon, PLCepsilon1a is the only splice variant present. Analysis of normal/tumor matched pairs derived from colon and rectum demonstrates greatly reduced expression levels in tumor tissues. Further studies in a colorectal tumor cell line lacking PLCepsilon show restoration of transcription of PLCepsilon1a and PLCepsilon1b by demethylating agent 5-aza-2'-deoxycytidine, suggesting epigenetic silencing through hypermethylation. In addition, expression of exogenous PLCepsilon in this cell line demonstrates inhibitory effects of PLCepsilon on cell viability and proliferation. Taken together, our findings suggest that regulatory mechanisms controlling expression of PLCepsilon, broadened by diversity introduced by splice variants, could play important role in PLCepsilon regulation in normal and tumor cells.
Collapse
Affiliation(s)
- Sonia Caroline Sorli
- Cancer Research UK Centre for Cell and Molecular Biology, Chester Beatty Laboratories, The Institute of Cancer Research, Fulham Road, London SW3 6JB, UK
| | | | | | | | | |
Collapse
|
43
|
Bunney TD, De Boer AH, Levin M. Fusicoccin signaling reveals 14-3-3 protein function as a novel step in left-right patterning during amphibian embryogenesis. Development 2003; 130:4847-58. [PMID: 12930777 DOI: 10.1242/dev.00698] [Citation(s) in RCA: 94] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
To gain insight into the molecular mechanisms underlying the control of morphogenetic signals by H+ flux during embryogenesis, we tested Fusicoccin-A (FC), a compound produced by the fungus Fusicoccum amygdali Del. In plant cells, FC complexes with 14-3-3 proteins to activate H+ pumping across the plasma membrane. It has long been thought that FC acts on higher plants only; here, we show that exposing frog embryos to FC during early development specifically results in randomization of the asymmetry of the left-right (LR) axis (heterotaxia). Biochemical and molecular-genetic evidence is presented that 14-3-3-family proteins are an obligate component of Xenopus FC receptors and that perturbation of 14-3-3 protein function results in heterotaxia. The subcellular localization of 14-3-3 mRNAs and proteins reveals novel cytoplasmic destinations, and a left-right asymmetry at the first cell division. Using gain-of-function and loss-of-function experiments, we show that 14-3-3E protein is likely to be an endogenous and extremely early aspect of LR patterning. These data highlight a striking conservation of signaling pathways across kingdoms, suggest common mechanisms of polarity establishment between C. elegans and vertebrate embryos, and uncover a novel entry point into the pathway of left-right asymmetry determination.
Collapse
Affiliation(s)
- Tom D Bunney
- Vrije Universiteit, Faculty of Earth and Life Sciences, Department of Developmental Genetics, Section Molecular Plant Physiology and Biophysics, De Boelelaan 1085, 1081 HV, Amsterdam, The Netherlands
| | | | | |
Collapse
|
44
|
Abstract
In addition to their regulation of cytoplasmic enzymes, the 14-3-3 proteins are important regulators of membrane localised proteins. In particular, many of the cells' ion pumps and channels are either directly or indirectly modulated by 14-3-3 proteins. Binding of 14-3-3 can lead to the activation of pump activity as in the case of the plasma membrane H+-ATPase or inhibition as in the case of the F-type ATP synthase complexes. 14-3-3 binding can also lead to surprising results such as the recruitment of 'sleepy' outward rectifiying K+ channels in tomato cells. Our present knowledge extends to an initial understanding of isoform-specific binding of 14-3-3 to certain membrane proteins and a perception of the protein kinases and phosphatases that maintain the regulatory process in a state of flux.
Collapse
Affiliation(s)
- Tom D Bunney
- Department of Developmental Genetics, Faculty of Earth and Life Sciences, Vrije Universiteit, De Boelelaan 1087, 1081 HV Amsterdam, Netherlands
| | | | | |
Collapse
|
45
|
Bunney TD, van Walraven HS, de Boer AH. 14-3-3 protein is a regulator of the mitochondrial and chloroplast ATP synthase. Proc Natl Acad Sci U S A 2001; 98:4249-54. [PMID: 11274449 PMCID: PMC31211 DOI: 10.1073/pnas.061437498] [Citation(s) in RCA: 154] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2000] [Indexed: 11/18/2022] Open
Abstract
Mitochondrial and chloroplast ATP synthases are key enzymes in plant metabolism, providing cells with ATP, the universal energy currency. ATP synthases use a transmembrane electrochemical proton gradient to drive synthesis of ATP. The enzyme complexes function as miniature rotary engines, ensuring energy coupling with very high efficiency. Although our understanding of the structure and functioning of the synthase has made enormous progress in recent years, our understanding of regulatory mechanisms is still rather preliminary. Here we report a role for 14-3-3 proteins in the regulation of ATP synthases. These 14-3-3 proteins are highly conserved phosphoserine/phosphothreonine-binding proteins that regulate a wide range of enzymes in plants, animals, and yeast. Recently, the presence of 14-3-3 proteins in chloroplasts was illustrated, and we show here that plant mitochondria harbor 14-3-3s within the inner mitochondrial-membrane compartment. There, the 14-3-3 proteins were found to be associated with the ATP synthases, in a phosphorylation-dependent manner, through direct interaction with the F(1) beta-subunit. The activity of the ATP synthases in both organelles is drastically reduced by recombinant 14-3-3. The rapid reduction in chloroplast ATPase activity during dark adaptation was prevented by a phosphopeptide containing the 14-3-3 interaction motif, demonstrating a role for endogenous 14-3-3 in the down-regulation of the CF(o)F(1) activity. We conclude that regulation of the ATP synthases by 14-3-3 represents a mechanism for plant adaptation to environmental changes such as light/dark transitions, anoxia in roots, and fluctuations in nutrient supply.
Collapse
Affiliation(s)
- T D Bunney
- Department of Developmental Genetics, Vrije Universiteit, Faculty of Biology, BioCentrum Amsterdam, De Boelelaan 1087, 1081 HV Amsterdam, The Netherlands
| | | | | |
Collapse
|
46
|
Abstract
The conductance of the vacuolar membrane at elevated cytosolic Ca(2+) levels is dominated by the slow activating cation selective (SV) channel. At physiological, submicromolar Ca(2+) concentrations the SV currents are very small. Only recently has the role of 14-3-3 proteins in the regulation of voltage-gated and Ca(2+)-activated plasma membrane ion channels been investigated in Drosophila, Xenopus and plants. Here we report the first evidence that plant 14-3-3 proteins are involved in the down-regulation of ion channels in the vacuolar membrane as well. Using the patch-clamp technique we have demonstrated that 14-3-3 protein drastically reduces the current carried by SV channels. The current decline amounted to 80% and half-maximal reduction was reached within 5 s after 14-3-3-addition to the bath. The voltage sensitivity of the channel was not affected by 14-3-3. A coordinating role for 14-3-3 proteins in the regulation of plasma membrane and tonoplast ion transporters is discussed.
Collapse
Affiliation(s)
- P W van den Wijngaard
- BioCentrum Amsterdam, Department of Developmental Genetics, Faculty of Biology, Vrije Universiteit, Amsterdam, The Netherlands
| | | | | | | | | |
Collapse
|
47
|
Bunney TD, Watkins PA, Beven AF, Shaw PJ, Hernandez LE, Lomonossoff GP, Shanks M, Peart J, Drobak BK. Association of phosphatidylinositol 3-kinase with nuclear transcription sites in higher plants. Plant Cell 2000; 12:1679-88. [PMID: 11006340 PMCID: PMC149078 DOI: 10.1105/tpc.12.9.1679] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
The kinases responsible for phosphorylation of inositol-containing lipids are essential for many aspects of normal eukaryotic cell function. Genetic and biochemical studies have established that the phosphatidylinositol (PtdIns) 3-kinase encoded by the yeast VPS34 gene is essential for the efficient sorting and delivery of proteins to the vacuole; the kinase encoded by the human VPS34 homolog has been equally implicated in the control of intracellular vesicle traffic. The plant VPS34 homolog also is required for normal growth and development, and although a role for PtdIns 3-kinase in vesicle trafficking is likely, it has not been established. In this study, we have shown that considerable PtdIns 3-kinase activity is associated with the internal matrix of nuclei isolated from carrot suspension cells. Immunocytochemical and confocal laser scanning microscopy studies using the monoclonal antibody JIM135 (John Innes Monoclonal 135), raised against a truncated version of the soybean PtdIns 3-kinase, SPI3K-5p, revealed that this kinase appears to have a distinct and punctate distribution within the plant nucleus and nucleolus. Dual probing of root sections with JIM135 and anti-bromo-UTP antibodies, after in vitro transcription had been allowed to proceed in the presence of bromo-UTP, showed that SPI3K-5p associates with active nuclear and nucleolar transcription sites. These findings suggest a possible link between PtdIns 3-kinase activity and nuclear transcription in plants.
Collapse
Affiliation(s)
- T D Bunney
- John Innes Centre, Norwich Research Park, Colney, NR4 7UH, United Kingdom
| | | | | | | | | | | | | | | | | |
Collapse
|
48
|
Abstract
Localised alterations in cytoplasmic Ca(2+) levels are an integral part of the response of eukaryotic cells to a plethora of external stimuli. Due to the large size of nuclear pores, it has generally been assumed that intranuclear Ca(2+) levels reflect the prevailing cytoplasmic Ca(2+) levels. Using nuclei prepared from carrot (Daucus carota L.) cells, we now show that Ca(2+) can be transported across nuclear membranes in an ATP-dependent manner and that over 95% of Ca(2+) is accumulated into a pool releasable by the Ca(2+) ionophore A.23187. ATP-dependent nuclear Ca(2+) uptake did not occur in the presence of ADP or ADPgammaS and was abolished by orthovanadate. Confocal microscopy of nuclei loaded with dextran-linked Indo-1 showed that the initial ATP-induced rise in [Ca(2+)] occurs in the nuclear periphery. The occurrence of ATP-dependent Ca(2+) uptake in plant nuclei suggests that alterations of intranuclear Ca(2+) levels may occur independently of cytoplasmic [Ca(2+)] changes.
Collapse
Affiliation(s)
- T D Bunney
- Department of Cell Biology, John Innes Centre, Norwich Research Park, Colney Lane, NR4 7UH, Norwich, UK
| | | | | | | | | | | | | | | |
Collapse
|
49
|
Affiliation(s)
- T D Bunney
- Department of Cell Biology, John Innes Centre, Norwich, England
| | | | | | | |
Collapse
|
50
|
Drøbak BK, Watkins PA, Bunney TD, Dove SK, Shaw PJ, White IR, Millner PA. Association of multiple GTP-binding proteins with the plant cytoskeleton and nuclear matrix. Biochem Biophys Res Commun 1995; 210:7-13. [PMID: 7741751 DOI: 10.1006/bbrc.1995.1620] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Several types of GTP-binding proteins exist in plant cells. These include the ras-related low-molecular-weight monomeric GTP-binding proteins and the multi-subunit group which more closely resembles members of the mammalian heterotrimeric G-protein family. Proteins belonging to both of these families are known to be involved in cell signalling events and have until recently been assumed to be associated predominantly with membranes. We have investigated the possibility that GTP-binding proteins in plants also can be associated with membrane-free carrot (Daucus carota L.) cytoskeletons and nuclear matrices. Our results demonstrate that several low-molecular-weight GTP-binding proteins, and at least one G-protein alpha-subunit homologue, are associated with these cellular compartments.
Collapse
Affiliation(s)
- B K Drøbak
- Department of Cell Biology, John Innes Centre, Norwich, England
| | | | | | | | | | | | | |
Collapse
|