1
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Ma M, Zheng Y, Lu S, Pan X, Worley KC, Burrage LC, Blieden LS, Allworth A, Chen WL, Merla G, Mandriani B, Rosenfeld JA, Li-Kroeger D, Dutta D, Yamamoto S, Wangler MF, Glass IA, Strohbehn S, Blue E, Prontera P, Lalani SR, Bellen HJ. De novo variants in PLCG1 are associated with hearing impairment, ocular pathology, and cardiac defects. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2024:2024.01.08.23300523. [PMID: 38260438 PMCID: PMC10802640 DOI: 10.1101/2024.01.08.23300523] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
Phospholipase C isozymes (PLCs) hydrolyze phosphatidylinositol 4,5-bisphosphate into inositol 1,4,5-trisphosphate and diacylglycerol, important signaling molecules involved in many cellular processes. PLCG1 encodes the PLCγ1 isozyme that is broadly expressed. Hyperactive somatic mutations of PLCG1 are observed in multiple cancers, but only one germline variant has been reported. Here we describe three unrelated individuals with de novo heterozygous missense variants in PLCG1 (p.Asp1019Gly, p.His380Arg, and p.Asp1165Gly) who exhibit variable phenotypes including hearing loss, ocular pathology and cardiac septal defects. To model these variants in vivo, we generated the analogous variants in the Drosophila ortholog, small wing (sl). We created a null allele slT2A and assessed the expression pattern. sl is broadly expressed, including in wing discs, eye discs, and a subset of neurons and glia. Loss of sl causes wing size reductions, ectopic wing veins and supernumerary photoreceptors. We document that mutant flies exhibit a reduced lifespan and age-dependent locomotor defects. Expressing wild-type sl in slT2A mutant rescues the loss-of-function phenotypes whereas expressing the variants causes lethality. Ubiquitous overexpression of the variants also reduces viability, suggesting that the variants are toxic. Ectopic expression of an established hyperactive PLCG1 variant (p.Asp1165His) in the wing pouch causes severe wing phenotypes, resembling those observed with overexpression of the p.Asp1019Gly or p.Asp1165Gly variants, further arguing that these two are gain-of-function variants. However, the wing phenotypes associated with p.His380Arg overexpression are mild. Our data suggest that the PLCG1 de novo heterozygous missense variants are pathogenic and contribute to the features observed in the probands.
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Affiliation(s)
- Mengqi Ma
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- Jan and Dan Duncan Neurological Research Institute at Texas Children’s Hospital, Houston, TX 77030, USA
| | - Yiming Zheng
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- Jan and Dan Duncan Neurological Research Institute at Texas Children’s Hospital, Houston, TX 77030, USA
- Current affiliation: State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiamen 361102, China
| | - Shenzhao Lu
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- Jan and Dan Duncan Neurological Research Institute at Texas Children’s Hospital, Houston, TX 77030, USA
| | - Xueyang Pan
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- Jan and Dan Duncan Neurological Research Institute at Texas Children’s Hospital, Houston, TX 77030, USA
| | - Kim C. Worley
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Lindsay C. Burrage
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Lauren S. Blieden
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Aimee Allworth
- Division of Medical Genetics, Department of Medicine, University of Washington School of Medicine, Seattle, WA 98195, USA
| | - Wei-Liang Chen
- Division of Medical Genetics, Department of Medicine, University of Washington School of Medicine, Seattle, WA 98195, USA
- Current affiliation: Children’s National Medical Center and George Washington University, Washington DC 20010, USA
| | - Giuseppe Merla
- Laboratory of Regulatory & Functional Genomics, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Foggia 71013, Italy
- Department of Molecular Medicine & Medical Biotechnology, University of Naples Federico II, Naples 80131, Italy
| | - Barbara Mandriani
- Department of Interdisciplinary Medicine, University of Bari “Aldo Moro”, Bari 70121, Italy
| | - Jill A. Rosenfeld
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - David Li-Kroeger
- Department of Neurology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Debdeep Dutta
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- Jan and Dan Duncan Neurological Research Institute at Texas Children’s Hospital, Houston, TX 77030, USA
| | - Shinya Yamamoto
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- Jan and Dan Duncan Neurological Research Institute at Texas Children’s Hospital, Houston, TX 77030, USA
| | - Michael F. Wangler
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- Jan and Dan Duncan Neurological Research Institute at Texas Children’s Hospital, Houston, TX 77030, USA
| | | | - Ian A. Glass
- Division of Medical Genetics, Department of Medicine, University of Washington School of Medicine, Seattle, WA 98195, USA
- Division of Genetic Medicine, Department of Pediatrics, University of Washington School of Medicine, Seattle, WA 98195, USA
- Brotman Baty Institute, Seattle, WA 98195, USA
| | - Sam Strohbehn
- Division of Medical Genetics, Department of Medicine, University of Washington School of Medicine, Seattle, WA 98195, USA
| | - Elizabeth Blue
- Division of Medical Genetics, Department of Medicine, University of Washington School of Medicine, Seattle, WA 98195, USA
- Brotman Baty Institute, Seattle, WA 98195, USA
- Institute for Public Health Genetics, University of Washington, Seattle, WA 98195, USA
| | - Paolo Prontera
- Medical Genetics Unit, Hospital of Perugia, Perugia 06129, Italy
| | - Seema R. Lalani
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Hugo J. Bellen
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- Jan and Dan Duncan Neurological Research Institute at Texas Children’s Hospital, Houston, TX 77030, USA
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2
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Baysac K, Sun G, Nakano H, Schmitz EG, Cruz AC, Fisher C, Bailey AC, Mace E, Milner JD, Ombrello MJ. PLCG2-associated immune dysregulation (PLAID) comprises broad and distinct clinical presentations related to functional classes of genetic variants. J Allergy Clin Immunol 2024; 153:230-242. [PMID: 37769878 DOI: 10.1016/j.jaci.2023.08.036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Revised: 08/11/2023] [Accepted: 08/21/2023] [Indexed: 10/02/2023]
Abstract
BACKGROUND Pathogenic variants of phospholipase C gamma 2 (PLCG2) cause 2 related forms of autosomal-dominant immune dysregulation (ID), PLCγ2-associated antibody deficiency and immune dysregulation (PLAID) and autoinflammatory PLAID (APLAID). Since describing these conditions, many PLCG2 variants of uncertain significance have been identified by clinical sequencing of patients with diverse features of ID. OBJECTIVE We sought to functionally classify PLCG2 variants and explore known and novel genotype-function-phenotype relationships. METHODS Clinical data from patients with PLCG2 variants were obtained via standardized questionnaire. PLCG2 variants were generated by mutagenesis of enhanced green fluorescent protein (EGFP)-PLCG2 plasmid, which was overexpressed in Plcg2-deficient DT-40 B cells. B-cell receptor-induced calcium flux and extracellular signal-regulated kinase phosphorylation were assayed by flow cytometry. In some cases, stimulation-induced calcium flux was also measured in primary patient cells. RESULTS Three-fourths of PLCG2 variants produced functional alteration of B-cell activation, in vitro. Thirteen variants led to gain of function (GOF); however, most functional variants defined a new class of PLCG2 mutation, monoallelic loss of function (LOF). Susceptibility to infection and autoinflammation were common with both GOF and LOF variants, whereas a new phenotypic cluster consisting of humoral immune deficiency, autoinflammation, susceptibility to herpesvirus infection, and natural killer cell dysfunction was observed in association with multiple heterozygous LOF variants detected in both familial and sporadic cases. In some cases, PLCG2 variants produced greater effects in natural killer cells than in B cells. CONCLUSIONS This work expands the genotypic and phenotypic associations with functional variation in PLCG2, including a novel form of ID in carriers of heterozygous loss of PLCG2 function. It also demonstrates the need for more diverse assays for assessing the impact of PLCG2 variants on human disease.
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Affiliation(s)
- Kathleen Baysac
- Translational Genetics and Genomics Section, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, Md
| | - Guangping Sun
- Laboratory of Allergic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Md
| | - Hiroto Nakano
- Translational Genetics and Genomics Section, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, Md
| | - Elizabeth G Schmitz
- Translational Genetics and Genomics Section, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, Md
| | - Anthony C Cruz
- Translational Genetics and Genomics Section, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, Md
| | - Charles Fisher
- Translational Genetics and Genomics Section, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, Md
| | - Alexis C Bailey
- Translational Genetics and Genomics Section, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, Md
| | - Emily Mace
- Division of Allergy, Immunology and Rheumatology, Department of Pediatrics, Columbia University Vagelos College of Physicians and Surgeons, New York, NY
| | - Joshua D Milner
- Division of Allergy, Immunology and Rheumatology, Department of Pediatrics, Columbia University Vagelos College of Physicians and Surgeons, New York, NY
| | - Michael J Ombrello
- Translational Genetics and Genomics Section, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, Md.
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3
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Liu C, Yuan W, Yang H, Ni J, Tang L, Zhao H, Neumann D, Ding X, Zhu L. Associating bovine herpesvirus 1 envelope glycoprotein gD with activated phospho-PLC-γ1(S1248). Microbiol Spectr 2023; 11:e0196323. [PMID: 37655900 PMCID: PMC10580943 DOI: 10.1128/spectrum.01963-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Accepted: 07/23/2023] [Indexed: 09/02/2023] Open
Abstract
Phospholipase C gamma 1 (PLC-γ1) may locate at distinct subcellular locations, such as cytosol, plasma membrane, and nucleus for varied biological functions. Bovine herpesvirus 1 (BoHV-1) productive infection activates PLC-γ1 signaling, as demonstrated by increased protein levels of phosphorylated-PLC-γ1 at Ser1248 [p-PLC-γ1(S1248)], which benefits virus productive infection. Here, for the first time, we reported that Golgi apparatus also contains activated p-PLC-γ1(S1248). And BoHV-1 productive infection at later stages (24 hpi) increased the accumulation of p-PLC-γ1(S1248) in the Golgi apparatus, where p-PLC-γ1(S1248) forms highlighted puncta observed via a confocal microscope. Coimmunoprecipitation studies demonstrated that the Golgi p-PLC-γ1(S1248) is specifically associated with the viral protein gD but not gC. In addition, we found that p-PLC-γ1(S1248) is consistently associated with both the plasma membrane-associated virions and the released virions. When the virus-infected cells were treated with PLC-γ1-specific inhibitor, U73122, for a short duration of 4 hours prior to the endpoint of virus infection, we found that the viral protein gD was trapped in the Golgi apparatus, suggesting that the PLC-γ1 signaling may facilitate trafficking of progeny virions out of this organelle. These findings provide a novel insight into the interplay between PLC-γ1 signaling and BoHV-1 replication. IMPORTANCE Bovine herpesvirus 1 (BoHV-1) productive infection increases protein levels of phosphorylated-phospholipase C gamma 1 at Ser1248 [p-PLC-γ1(S1248)]. However, whether it causes any variations to p-PLC-γ1(S1248) localization is not well understood. Here, for the first time, we found that partial p-PLC-γ1(S1248) is residing in the Golgi apparatus, where the accumulation is enhanced by virus infection. p-PLC-γ1(S1248) is consistently associated with virions, partially via binding to gD, in both the Golgi apparatus and cytoplasm membranes. Surprisingly, it also associates with the released virions. Of note, this is the first evidenced BoHV-1 virion-bound host protein. It seems that p-PLC-γ1(S1248) works as an escort during trafficking of progeny virions out of Golgi apparatus to the plasma membranes as well as releasing outside of the cell membranes. Furthermore, we showed that the activated p-PLC-γ1(S1248) is potentially implicated in the transport of virions out of Golgi apparatus, which may represent a novel mechanism to regulate virus productive infection.
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Affiliation(s)
- Chang Liu
- College of Life Sciences, Hebei University, Baoding, China
| | - Weifeng Yuan
- Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Hao Yang
- College of Life Sciences, Hebei University, Baoding, China
| | - Junqing Ni
- Animal Husbandry and Improved Breeds Work Station of Hebei Province, Shijiazhuang, China
| | - Linke Tang
- College of Life Sciences, Hebei University, Baoding, China
| | - Heci Zhao
- College of Life Sciences, Hebei University, Baoding, China
| | - Donna Neumann
- Department of Ophthalmology and Visual Sciences, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Xiuyan Ding
- College of Life Sciences, Hebei University, Baoding, China
| | - Liqian Zhu
- College of Life Sciences, Hebei University, Baoding, China
- Key Laboratory of Microbial Diversity Research and Application of Hebei Province, College of Life Science, Hebei University, Baoding, China
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4
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Wang N, Shi Y, Jiang Q, Li H, Fan W, Feng Y, Li L, Liu B, Lin F, Jing W, Zhang W, Shen L. A 14-3-3 protein positively regulates rice salt tolerance by stabilizing phospholipase C1. PLANT, CELL & ENVIRONMENT 2023; 46:1232-1248. [PMID: 36539986 DOI: 10.1111/pce.14520] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Revised: 11/06/2022] [Accepted: 12/17/2022] [Indexed: 06/17/2023]
Abstract
The phosphatidylinositol-specific phospholipase Cs (PI-PLCs) catalyze the hydrolysis of phosphatidylinositols, which play crucial roles in signaling transduction during plant development and stress response. However, the regulation of PI-PLC is still poorly understood. A previous study showed that a rice PI-PLC, OsPLC1, was essential to rice salt tolerance. Here, we identified a 14-3-3 protein, OsGF14b, as an interaction partner of OsPLC1. Similar to OsPLC1, OsGF14b also positively regulates rice salt tolerance, and their interaction can be promoted by NaCl stress. OsGF14b also positively regulated the hydrolysis activity of OsPLC1, and is essential to NaCl-induced activation of rice PI-PLCs. We further discovered that OsPLC1 was degraded via ubiquitin-proteasome pathway, and OsGF14b could inhibit the ubiquitination of OsPLC1 to protect OsPLC1 from degradation. Under salt stress, the OsPLC1 protein level in osgf14b was lower than the corresponding value of WT, whereas overexpression of OsGF14b results in a significant increase of OsPLC1 stability. Taken together, we propose that OsGF14b can interact with OsPLC1 and promote its activity and stability, thereby improving rice salt tolerance. This study provides novel insights into the important roles of 14-3-3 proteins in regulating protein stability and function in response to salt stress.
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Affiliation(s)
- Ningna Wang
- Department of Plant Biology, State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Life Sciences, Nanjing Agricultural University, Nanjing, China
| | - Yiyuan Shi
- Department of Plant Biology, State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Life Sciences, Nanjing Agricultural University, Nanjing, China
| | - Qun Jiang
- Department of Plant Biology, State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Life Sciences, Nanjing Agricultural University, Nanjing, China
| | - Huan Li
- Department of Plant Biology, State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Life Sciences, Nanjing Agricultural University, Nanjing, China
| | - Wenxia Fan
- Department of Plant Biology, State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Life Sciences, Nanjing Agricultural University, Nanjing, China
| | - Yu Feng
- Department of Plant Biology, State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Life Sciences, Nanjing Agricultural University, Nanjing, China
| | - Li Li
- Department of Plant Biology, State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Life Sciences, Nanjing Agricultural University, Nanjing, China
| | - Bin Liu
- Guangdong Key Laboratory of New Technology in Rice Breeding, Rice Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou, China
| | - Feng Lin
- Department of Plant Biology, State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Life Sciences, Nanjing Agricultural University, Nanjing, China
| | - Wen Jing
- Department of Plant Biology, State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Life Sciences, Nanjing Agricultural University, Nanjing, China
| | - Wenhua Zhang
- Department of Plant Biology, State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Life Sciences, Nanjing Agricultural University, Nanjing, China
| | - Like Shen
- Department of Plant Biology, State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Life Sciences, Nanjing Agricultural University, Nanjing, China
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5
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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. SCIENCE ADVANCES 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] [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.
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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
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6
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Siraliev-Perez E, Stariha JTB, Hoffmann RM, Temple BRS, Zhang Q, Hajicek N, Jenkins ML, Burke JE, Sondek J. Dynamics of allosteric regulation of the phospholipase C-γ isozymes upon recruitment to membranes. eLife 2022; 11:77809. [PMID: 35708309 PMCID: PMC9203054 DOI: 10.7554/elife.77809] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Accepted: 05/22/2022] [Indexed: 11/13/2022] Open
Abstract
Numerous receptor tyrosine kinases and immune receptors activate phospholipase C-γ (PLC-γ) isozymes at membranes to control diverse cellular processes including phagocytosis, migration, proliferation, and differentiation. The molecular details of this process are not well understood. Using hydrogen-deuterium exchange mass spectrometry, we show that PLC-γ1 is relatively inert to lipid vesicles that contain its substrate, phosphatidylinositol 4,5-bisphosphate (PIP2), unless first bound to the kinase domain of the fibroblast growth factor receptor (FGFR1). Exchange occurs throughout PLC-γ1 and is exaggerated in PLC-γ1 containing an oncogenic substitution (D1165H) that allosterically activates the lipase. These data support a model whereby initial complex formation shifts the conformational equilibrium of PLC-γ1 to favor activation. This receptor-induced priming of PLC-γ1 also explains the capacity of a kinase-inactive fragment of FGFR1 to modestly enhance the lipase activity of PLC-γ1 operating on lipid vesicles but not a soluble analog of PIP2 and highlights potential cooperativity between receptor engagement and membrane proximity. Priming is expected to be greatly enhanced for receptors embedded in membranes and nearly universal for the myriad of receptors and co-receptors that bind the PLC-γ isozymes.
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Affiliation(s)
- Edhriz Siraliev-Perez
- Department of Biochemistry and Biophysics, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, United States
| | - Jordan T B Stariha
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, Canada
| | - Reece M Hoffmann
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, Canada
| | - Brenda R S Temple
- Department of Biochemistry and Biophysics, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, United States
| | - Qisheng Zhang
- Department of Biochemistry and Biophysics, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, United States.,Division of Chemical Biology and Medicinal Chemistry, School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, United States.,Lineberger Comprehensive Cancer Center, School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, United States
| | - Nicole Hajicek
- Department of Pharmacology, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, United States
| | - Meredith L Jenkins
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, Canada
| | - John E Burke
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, Canada.,Department of Biochemistry and Molecular Biology, The University of British Columbia, Vancouver, Canada
| | - John Sondek
- Department of Biochemistry and Biophysics, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, United States.,Lineberger Comprehensive Cancer Center, School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, United States.,Department of Pharmacology, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, United States
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7
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Nosbisch JL, Bear JE, Haugh JM. A kinetic model of phospholipase C-γ1 linking structure-based insights to dynamics of enzyme autoinhibition and activation. J Biol Chem 2022; 298:101886. [PMID: 35367415 PMCID: PMC9097458 DOI: 10.1016/j.jbc.2022.101886] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Revised: 03/27/2022] [Accepted: 03/28/2022] [Indexed: 01/31/2023] Open
Abstract
Phospholipase C-γ1 (PLC-γ1) is a receptor-proximal enzyme that promotes signal transduction through PKC in mammalian cells. Because of the complexity of PLC-γ1 regulation, a two-state (inactive/active) model does not account for the intricacy of activation and inactivation steps at the plasma membrane. Here, we introduce a structure-based kinetic model of PLC-γ1, considering interactions of its regulatory Src homology 2 (SH2) domains and perturbation of those dynamics upon phosphorylation of Tyr783, a hallmark of activation. For PLC-γ1 phosphorylation to dramatically enhance enzyme activation as observed, we found that high intramolecular affinity of the C-terminal SH2 (cSH2) domain-pTyr783 interaction is critical, but this affinity need not outcompete the autoinhibitory interaction of the cSH2 domain. Under conditions for which steady-state PLC-γ1 activity is sensitive to the rate of Tyr783 phosphorylation, maintenance of the active state is surprisingly insensitive to the phosphorylation rate, since pTyr783 is well protected by the cSH2 domain while the enzyme is active. In contrast, maintenance of enzyme activity is sensitive to the rate of PLC-γ1 membrane (re)binding. Accordingly, we found that hypothetical PLC-γ1 mutations that either weaken autoinhibition or strengthen membrane binding influence the activation kinetics differently, which could inform the characterization of oncogenic variants. Finally, we used this newly informed kinetic scheme to refine a spatial model of PLC/PKC polarization during chemotaxis. The refined model showed improved stability of the polarized pattern while corroborating previous qualitative predictions. As demonstrated here for PLC-γ1, this approach may be adapted to model the dynamics of other receptor- and membrane-proximal enzymes.
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Affiliation(s)
- Jamie L Nosbisch
- Biomathematics Graduate Program, North Carolina State University, Raleigh, North Carolina, USA
| | - James E Bear
- Department of Cell Biology and Physiology, UNC Lineberger Comprehensive Cancer Center, University of North Carolina School of Medicine, Chapel Hill, North Carolina, USA
| | - Jason M Haugh
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina, USA.
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8
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Lin CC, Suen KM, Jeffrey PA, Wieteska L, Lidster JA, Bao P, Curd AP, Stainthorp A, Seiler C, Koss H, Miska E, Ahmed Z, Evans SD, Molina-París C, Ladbury JE. Receptor tyrosine kinases regulate signal transduction through a liquid-liquid phase separated state. Mol Cell 2022; 82:1089-1106.e12. [PMID: 35231400 PMCID: PMC8937303 DOI: 10.1016/j.molcel.2022.02.005] [Citation(s) in RCA: 35] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Revised: 11/02/2021] [Accepted: 02/01/2022] [Indexed: 11/20/2022]
Abstract
The recruitment of signaling proteins into activated receptor tyrosine kinases (RTKs) to produce rapid, high-fidelity downstream response is exposed to the ambiguity of random diffusion to the target site. Liquid-liquid phase separation (LLPS) overcomes this by providing elevated, localized concentrations of the required proteins while impeding competitor ligands. Here, we show a subset of phosphorylation-dependent RTK-mediated LLPS states. We then investigate the formation of phase-separated droplets comprising a ternary complex including the RTK, (FGFR2); the phosphatase, SHP2; and the phospholipase, PLCγ1, which assembles in response to receptor phosphorylation. SHP2 and activated PLCγ1 interact through their tandem SH2 domains via a previously undescribed interface. The complex of FGFR2 and SHP2 combines kinase and phosphatase activities to control the phosphorylation state of the assembly while providing a scaffold for active PLCγ1 to facilitate access to its plasma membrane substrate. Thus, LLPS modulates RTK signaling, with potential consequences for therapeutic intervention.
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Affiliation(s)
- Chi-Chuan Lin
- School of Molecular and Cellular Biology, University of Leeds, Leeds LS2 9JT, UK.
| | - Kin Man Suen
- School of Molecular and Cellular Biology, University of Leeds, Leeds LS2 9JT, UK; Wellcome Trust Cancer Research UK Gurdon Institute, University of Cambridge, Tennis Court Road, Cambridge CB2 1QN, UK
| | | | - Lukasz Wieteska
- School of Molecular and Cellular Biology, University of Leeds, Leeds LS2 9JT, UK
| | - Jessica A Lidster
- School of Molecular and Cellular Biology, University of Leeds, Leeds LS2 9JT, UK
| | - Peng Bao
- School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, UK
| | - Alistair P Curd
- School of Molecular and Cellular Biology, University of Leeds, Leeds LS2 9JT, UK
| | - Amy Stainthorp
- School of Molecular and Cellular Biology, University of Leeds, Leeds LS2 9JT, UK
| | - Caroline Seiler
- School of Molecular and Cellular Biology, University of Leeds, Leeds LS2 9JT, UK
| | - Hans Koss
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, Gower Street, London WC1E 6BT, UK; Francis Crick Institute, London NW1 1AT, UK
| | - Eric Miska
- Wellcome Trust Cancer Research UK Gurdon Institute, University of Cambridge, Tennis Court Road, Cambridge CB2 1QN, UK
| | - Zamal Ahmed
- Department of Molecular and Cellular Oncology, University of Texas M D Anderson Cancer Center, Houston, TX 77030, USA
| | - Stephen D Evans
- School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, UK
| | | | - John E Ladbury
- School of Molecular and Cellular Biology, University of Leeds, Leeds LS2 9JT, UK.
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9
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Joseph RE, Lowe J, Fulton DB, Engen JR, Wales TE, Andreotti AH. The Conformational State of the BTK Substrate PLCγ Contributes to Ibrutinib Resistance. J Mol Biol 2022; 434:167422. [PMID: 34954235 PMCID: PMC8924901 DOI: 10.1016/j.jmb.2021.167422] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Revised: 12/06/2021] [Accepted: 12/16/2021] [Indexed: 12/17/2022]
Abstract
Mutations in PLCγ, a substrate of the tyrosine kinase BTK, are often found in patients who develop resistance to the BTK inhibitor Ibrutinib. However, the mechanisms by which these PLCγ mutations cause Ibrutinib resistance are unclear. Under normal signaling conditions, BTK mediated phosphorylation of Y783 within the PLCγ cSH2-linker promotes the intramolecular association of this site with the adjacent cSH2 domain resulting in active PLCγ. Thus, the cSH2-linker region in the center of the regulatory gamma specific array (γSA) of PLCγ is a key feature controlling PLCγ activity. Even in the unphosphorylated state this linker exists in a conformational equilibrium between free and bound to the cSH2 domain. The position of this equilibrium is optimized within the properly regulated PLCγ enzyme but may be altered in the context of mutations. We therefore assessed the conformational status of four resistance associated mutations within the PLCγ γSA and find that they each alter the conformational equilibrium of the γSA leading to a shift toward active PLCγ. Interestingly, two distinct modes of mutation induced activation are revealed by this panel of Ibrutinib resistance mutations. These findings, along with the recently determined structure of fully autoinhibited PLCγ, provide new insight into the nature of the conformational change that occurs within the γSA regulatory region to affect PLCγ activation. Improving our mechanistic understanding of how B cell signaling escapes Ibrutinib treatment via mutations in PLCγ will aid in the development of strategies to counter drug resistance.
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Affiliation(s)
- Raji E Joseph
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA 50011, USA
| | - Jacques Lowe
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA 50011, USA
| | - D Bruce Fulton
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA 50011, USA. https://twitter.com/dbfulton
| | - John R Engen
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, MA 02115, USA. https://twitter.com/jrengen
| | - Thomas E Wales
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, MA 02115, USA.
| | - Amy H Andreotti
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA 50011, USA.
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10
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Wada J, Rathnayake U, Jenkins LM, Singh A, Mohammadi M, Appella E, Randazzo PA, Samelson LE. In vitro reconstitution reveals cooperative mechanisms of adapter protein-mediated activation of phospholipase C-γ1 in T cells. J Biol Chem 2022; 298:101680. [PMID: 35124007 PMCID: PMC8908268 DOI: 10.1016/j.jbc.2022.101680] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 01/31/2022] [Accepted: 02/01/2022] [Indexed: 12/16/2022] Open
Abstract
Activation of T cells upon engagement of the T cell antigen receptor rapidly leads to a number of phosphorylation and plasma membrane recruitment events. For example, translocation of phospholipase-Cγ1 (PLC−γ1) to the plasma membrane and its association with the transmembrane adapter protein LAT and two other adapter proteins, Gads and SLP-76, are critical events in the early T cell activation process. We have previously characterized the formation of a tetrameric LAT-Gads-SLP-76-PLC−γ1 complex by reconstitution in vitro and have also characterized the thermodynamics of tetramer formation. In the current study, we define how PLC−γ1 recruitment to liposomes, which serve as a plasma membrane surrogate, and PLC−γ1 activation are regulated both independently and additively by recruitment of PLC−γ1 to phosphorylated LAT, by formation of the LAT-Gads-SLP-76-PLC−γ1 tetramer, and by tyrosine phosphorylation of PLC−γ1. The recently solved structure of PLC−γ1 indicates that, in the resting state, several PLC−γ1 domains inhibit its enzymatic activity and contact with the plasma membrane. We propose the multiple cooperative steps that we observed likely lead to conformational alterations in the regulatory domains of PLC−γ1, enabling contact with its membrane substrate, disinhibition of PLC−γ1 enzymatic activity, and production of the phosphoinositide cleavage products necessary for T cell activation.
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11
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Lowe J, Joseph RE, Andreotti AH. Conformational switches that control the TEC kinase – PLCγ signaling axis. J Struct Biol X 2022; 6:100061. [PMID: 35128378 PMCID: PMC8803661 DOI: 10.1016/j.yjsbx.2022.100061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 01/15/2022] [Accepted: 01/18/2022] [Indexed: 11/27/2022] Open
Abstract
TEC kinases and PLCγ transition between autoinhibited state and active conformation. PLCγ structures reveal both autoinhibited form and active form of gamma specific array (γSA); the four regulatory domains unique to the PLCγ isozymes. Domain dynamics likely control activation mechanism. PLCγ phosphorylation triggers conformational switch.
Cell surface receptors such as the T-cell receptor (TCR) and B-cell receptor (BCR) engage with external stimuli to transmit information into the cell and initiate a cascade of signaling events that lead to gene expression that drives the immune response. At the heart of controlling T- and B-cell cell signaling, phospholipase Cγ hydrolyzes membrane associated PIP2, leading to generation of the second messengers IP3 and DAG. These small molecules trigger mobilization of intracellular Ca2+ and promote transcription factor transport into the nucleus launching the adaptive immune response. The TEC family kinases are responsible for phosphorylating and activating PLCγ, and our group aims to understand mechanisms that regulate immune cell signal transduction by focusing on this kinase/phospholipase axis in T-cells and B-cells. Here, we review the current molecular level understanding of how the TEC kinases (ITK and BTK) and PLCγ1/2 are autoinhibited prior to activation of cell surface receptors, how TEC kinases are activated to specifically recognize the PLCγ substrate, and how conformational changes induced by phosphorylation trigger PLCγ activation.
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12
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Sathee L, Krishna GK, Adavi SB, Jha SK, Jain V. Role of protein phosphatases in the regulation of nitrogen nutrition in plants. PHYSIOLOGY AND MOLECULAR BIOLOGY OF PLANTS : AN INTERNATIONAL JOURNAL OF FUNCTIONAL PLANT BIOLOGY 2021; 27:2911-2922. [PMID: 35035144 PMCID: PMC8720119 DOI: 10.1007/s12298-021-01115-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Revised: 11/18/2021] [Accepted: 12/07/2021] [Indexed: 05/20/2023]
Abstract
The reversible protein phosphorylation and dephosphorylation mediated by protein kinases and phosphatases regulate different biological processes and their response to environmental cues, including nitrogen (N) availability. Nitrate assimilation is under the strict control of phosphorylation-dephosphorylation mediated post-translational regulation. The protein phosphatase family with approximately 150 members in Arabidopsis and around 130 members in rice is a promising player in N uptake and assimilation pathways. Protein phosphatase 2A (PP2A) enhances the activation of nitrate reductase (NR) by deactivating SnRK1 and reduces the binding of inhibitory 14-3-3 proteins on NR. The functioning of nitrate transporter NPF6.3 is regulated by phosphorylation of CBL9 (Calcineurin B like protein 9) and CIPK23 (CBL interacting protein kinase 23) module. Phosphorylation by CIPK23 inhibits the activity of NPF6.3, whereas protein phosphatases (PP2C) enhance the NPF6.3-dependent nitrate sensing. PP2Cs and CIPK23 also regulate ammonium transporters (AMTs). Under either moderate ammonium supply or high N demand, CIPK23 is bound and inactivated by PP2Cs. Ammonium uptake is mediated by nonphosphorylated and active AMT1s. Whereas, under high ammonium availability, CIPK23 gets activated and phosphorylate AMT1;1 and AMT1;2 rendering them inactive. Recent reports suggest the critical role of protein phosphatases in regulating N use efficiency (NUE). In rice, PP2C9 regulates NUE by improving N uptake and assimilation. Comparative leaf proteome of wild type and PP2C9 over-expressing transgenic rice lines showed 30 differentially expressed proteins under low N level. These proteins are involved in photosynthesis, N metabolism, signalling, and defence.
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Affiliation(s)
- Lekshmy Sathee
- Division of Plant Physiology, ICAR-Indian Agricultural Research Institute, New Delhi, 110 012 India
| | - G. K. Krishna
- Division of Plant Physiology, ICAR-Indian Agricultural Research Institute, New Delhi, 110 012 India
- Department of Plant Physiology, College of Agriculture, Kerala Agricultural University, Thrissur, 680 656 India
| | - Sandeep B. Adavi
- Division of Plant Physiology, ICAR-Indian Agricultural Research Institute, New Delhi, 110 012 India
| | - Shailendra K. Jha
- Division of Genetics, ICAR-Indian Agricultural Research Institute, New Delhi, 110 012 India
| | - Vanita Jain
- Agricultural Education Division, ICAR, KAB-II, New Delhi, 110 012 India
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13
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Park HS, Oh A, Keum CW, Lee J, Lee JK, Son BR, Shin KS, Hahn YS. A novel likely pathogenic PLCG2 variant in a patient with a recurrent skin blistering disease and B-cell lymphopenia. Eur J Med Genet 2021; 65:104387. [PMID: 34768012 DOI: 10.1016/j.ejmg.2021.104387] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Revised: 09/15/2021] [Accepted: 11/07/2021] [Indexed: 11/03/2022]
Abstract
Pathogenic variants of PLCG2 encoding phospholipase C gamma 2 (PLCγ2) were first reported in 2012 and their clinical manifestations vary widely. PLCG2-associated antibody deficiency and immune dysregulation (PLAID) and autoinflammation and PLCγ2-associated antibody deficiency and immune dysregulation (APLAID) are representative examples of PLCG2 pathogenic variants. In this report, we describe a 17-year-old male with recurrent blistering skin lesions, B-cell lymphopenia, and asthma. Distinct from the patients in previous reports, this patient had the heterozygous de novo c.2119T > C missense variant (NM_002661.4) resulting in a serine to proline amino acid substitution (p.Ser707Pro). The variant located to the PLCγ2 C-terminal Src homology 2 (cSH2) domain, which is a critical site for the restriction of intrinsic enzyme activity. This variant could be classified as "likely pathogenic" according to American College of Medical Genetics and Genomics guidelines. Laboratory results showed a reduction in circulating B cells without a decrease of serum IgG and IgA. Our findings expand the variety of clinical phenotypes for PLCG2 missense variants.
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Affiliation(s)
- Hee Sue Park
- Department of Laboratory Medicine, Chungbuk National University Hospital, Cheongju, Republic of Korea; Department of Laboratory Medicine, Chungbuk National University, College of Medicine, Cheongju, Republic of Korea
| | - Arum Oh
- Department of Pediatrics, Chungbuk National University Hospital, Cheongju, Republic of Korea; Department of Pediatrics, Chungbuk National University, College of Medicine, Cheongju, Republic of Korea
| | - Chang Won Keum
- Rare Genetic Disease Research Center, 3billion Inc, Seoul, Republic of Korea
| | - Jisu Lee
- Department of Pediatrics, Chungbuk National University Hospital, Cheongju, Republic of Korea
| | - Joon Kee Lee
- Department of Pediatrics, Chungbuk National University Hospital, Cheongju, Republic of Korea; Department of Pediatrics, Chungbuk National University, College of Medicine, Cheongju, Republic of Korea
| | - Bo Ra Son
- Department of Laboratory Medicine, Chungbuk National University Hospital, Cheongju, Republic of Korea; Department of Laboratory Medicine, Chungbuk National University, College of Medicine, Cheongju, Republic of Korea
| | - Kyeong Seob Shin
- Department of Laboratory Medicine, Chungbuk National University Hospital, Cheongju, Republic of Korea; Department of Laboratory Medicine, Chungbuk National University, College of Medicine, Cheongju, Republic of Korea
| | - Youn-Soo Hahn
- Department of Pediatrics, Chungbuk National University Hospital, Cheongju, Republic of Korea; Department of Pediatrics, Chungbuk National University, College of Medicine, Cheongju, Republic of Korea.
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14
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Ridone P, Pandzic E, Vassalli M, Cox CD, Macmillan A, Gottlieb PA, Martinac B. Disruption of membrane cholesterol organization impairs the activity of PIEZO1 channel clusters. J Gen Physiol 2021; 152:151885. [PMID: 32582958 PMCID: PMC7398139 DOI: 10.1085/jgp.201912515] [Citation(s) in RCA: 80] [Impact Index Per Article: 26.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Accepted: 05/12/2020] [Indexed: 11/20/2022] Open
Abstract
The human mechanosensitive ion channel PIEZO1 is gated by membrane tension and regulates essential biological processes such as vascular development and erythrocyte volume homeostasis. Currently, little is known about PIEZO1 plasma membrane localization and organization. Using a PIEZO1-GFP fusion protein, we investigated whether cholesterol enrichment or depletion by methyl-β-cyclodextrin (MBCD) and disruption of membrane cholesterol organization by dynasore affects PIEZO1-GFP's response to mechanical force. Electrophysiological recordings in the cell-attached configuration revealed that MBCD caused a rightward shift in the PIEZO1-GFP pressure-response curve, increased channel latency in response to mechanical stimuli, and markedly slowed channel inactivation. The same effects were seen in native PIEZO1 in N2A cells. STORM superresolution imaging revealed that, at the nanoscale, PIEZO1-GFP channels in the membrane associate as clusters sensitive to membrane manipulation. Both cluster distribution and diffusion rates were affected by treatment with MBCD (5 mM). Supplementation of polyunsaturated fatty acids appeared to sensitize the PIEZO1-GFP response to applied pressure. Together, our results indicate that PIEZO1 function is directly dependent on the membrane composition and lateral organization of membrane cholesterol domains, which coordinate the activity of clustered PIEZO1 channels.
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Affiliation(s)
- Pietro Ridone
- The Victor Chang Cardiac Research Institute, Darlinghurst, NSW, Australia
| | - Elvis Pandzic
- Biomedical Imaging Facility, Mark Wainwright Analytical Centre, Lowy Cancer Research Centre, The University of New South Wales, Sydney, NSW, Australia
| | - Massimo Vassalli
- Institute of Biophysics, National Research Council, Genova, Italy
| | - Charles D Cox
- The Victor Chang Cardiac Research Institute, Darlinghurst, NSW, Australia.,St. Vincent's Clinical School, University of New South Wales, Darlinghurst, NSW, Australia
| | - Alexander Macmillan
- Biomedical Imaging Facility, Mark Wainwright Analytical Centre, Lowy Cancer Research Centre, The University of New South Wales, Sydney, NSW, Australia
| | - Philip A Gottlieb
- Physiology and Biophysics, State University of New York at Buffalo, Buffalo, NY
| | - Boris Martinac
- The Victor Chang Cardiac Research Institute, Darlinghurst, NSW, Australia.,St. Vincent's Clinical School, University of New South Wales, Darlinghurst, NSW, Australia
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15
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Mandal S, Bandyopadhyay S, Tyagi K, Roy A. Recent advances in understanding the molecular role of phosphoinositide-specific phospholipase C gamma 1 as an emerging onco-driver and novel therapeutic target in human carcinogenesis. Biochim Biophys Acta Rev Cancer 2021; 1876:188619. [PMID: 34454048 DOI: 10.1016/j.bbcan.2021.188619] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Revised: 08/04/2021] [Accepted: 08/21/2021] [Indexed: 02/07/2023]
Abstract
Phosphoinositide metabolism is crucial intracellular signaling system that regulates a plethora of biological functions including mitogenesis, cell proliferation and division. Phospholipase C gamma 1 (PLCγ1) which belongs to phosphoinositide-specific phospholipase C (PLC) family, is activated by many extracellular stimuli including hormones, neurotransmitters, growth factors and modulates several cellular and physiological functions necessary for tumorigenesis such as cell survival, migration, invasion and angiogenesis by generating inositol 1,4,5-triphosphate (IP3) and diacylglycerol (DAG) via hydrolysis of phosphatidylinositol 4,5-biphosphate (PIP2). Cancer remains as a leading cause of global mortality and aberrant expression and regulation of PLCγ1 is linked to a plethora of deadly human cancers including carcinomas of the breast, lung, pancreas, stomach, prostate and ovary. Although PLCγ1 cross-talks with many onco-drivers and signaling circuits including PI3K, AKT, HIF1-α and RAF/MEK/ERK cascade, its precise role in carcinogenesis is not completely understood. This review comprehensively discussed the status quo of this ubiquitously expressed phospholipase as a tumor driver and highlighted its significance as a novel therapeutic target in cancer. Furthermore, we have highlighted the significance of somatic driver mutations in PLCG1 gene and molecular roles of PLCγ1 in several major human cancers, a knowledgebase that can be utilized to develop novel, isoform-specific small molecule inhibitors of PLCγ1.
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Affiliation(s)
- Supratim Mandal
- Department of Microbiology, University of Kalyani, Kalyani, Nadia, West Bengal 741235, India.
| | - Shrabasti Bandyopadhyay
- Department of Microbiology, University of Kalyani, Kalyani, Nadia, West Bengal 741235, India
| | - Komal Tyagi
- Amity Institute of Molecular Medicine & Stem Cell Research, Amity University, Sector 125, Noida, Uttar Pradesh 201303, India
| | - Adhiraj Roy
- Amity Institute of Molecular Medicine & Stem Cell Research, Amity University, Sector 125, Noida, Uttar Pradesh 201303, India.
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16
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Samarina N, Ssebyatika G, Tikla T, Waldmann JY, Abere B, Nanna V, Marasco M, Carlomagno T, Krey T, Schulz TF. Recruitment of phospholipase Cγ1 to the non-structural membrane protein pK15 of Kaposi Sarcoma-associated herpesvirus promotes its Src-dependent phosphorylation. PLoS Pathog 2021; 17:e1009635. [PMID: 34143834 PMCID: PMC8244865 DOI: 10.1371/journal.ppat.1009635] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Revised: 06/30/2021] [Accepted: 05/11/2021] [Indexed: 11/19/2022] Open
Abstract
Kaposi Sarcoma-associated herpesvirus (KSHV) causes three human malignancies, Kaposi Sarcoma (KS), Primary Effusion Lymphoma (PEL) and the plasma cell variant of multicentric Castleman’s Disease (MCD), as well as an inflammatory cytokine syndrome (KICS). Its non-structural membrane protein, pK15, is among a limited set of viral proteins expressed in KSHV-infected KS tumor cells. Following its phosphorylation by Src family tyrosine kinases, pK15 recruits phospholipase C gamma 1 (PLCγ1) to activate downstream signaling cascades such as the MEK/ERK, NFkB and PI3K pathway, and thereby contributes to the increased proliferation and migration as well as the spindle cell morphology of KSHV-infected endothelial cells. Here, we show that a phosphorylated Y481EEVL motif in pK15 preferentially binds into the PLCγ1 C-terminal SH2 domain (cSH2), which is involved in conformational changes occurring during the activation of PLCγ1 by receptor tyrosine kinases. We determined the crystal structure of a pK15 12mer peptide containing the phosphorylated pK15 Y481EEVL motif in complex with a shortened PLCγ1 tandem SH2 (tSH2) domain. This structure demonstrates that the pK15 peptide binds to the PLCγ1 cSH2 domain in a position that is normally occupied by the linker region connecting the PLCγ1 cSH2 and SH3 domains. We also show that longer pK15 peptides containing the phosphorylated pK15 Y481EEVL motif can increase the Src-mediated phosphorylation of the PLCγ1 tSH2 region in vitro. This pK15-induced increase in Src-mediated phosphorylation of PLCγ1 can be inhibited with the small pK15-derived peptide which occupies the PLCγ1 cSH2 domain. Our findings thus suggest that pK15 may act as a scaffold protein to promote PLCγ1 activation in a manner similar to the cellular scaffold protein SLP-76, which has been shown to promote PLCγ1 activation in the context of T-cell receptor signaling. Reminiscent of its positional homologue in Epstein-Barr Virus, LMP2A, pK15 may therefore mimic aspects of antigen-receptor signaling. Our findings also suggest that it may be possible to inhibit the recruitment and activation of PLCγ1 pharmacologically. Kaposi’s Sarcoma-Associated Herpesvirus (KSHV) causes three human malignancies (Kaposi Sarcoma, Primary Effusion Lymphoma, Multicentric Castleman’s Disease) and an inflammatory condition, KICS. One of its non-structural membrane proteins, pK15, is expressed in tumor cells and has previously been shown to contribute to its ability to reactivate from latency and to its pathogenetic properties in endothelial cells by recruiting the cellular signaling enzyme phospholipase Cγ1 (PLCγ1). Here we investigate the interaction of pK15 with PLCγ1, report the structure of a PLCγ1 domain in complex with a pK15 peptide and show that pK15 primes PLCγ1 for phosphorylation by the cellular kinase Src. We also show that the pK15-dependent activation of PLCγ1 can be inhibited with a small peptide. Our findings therefore identify the pK15-PLCγ1 interaction as a putative druggable target and provide the basis for the development of small molecule inhibitors that could perhaps serve to inhibit KSHV replication and pathogenesis.
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Affiliation(s)
- Naira Samarina
- Institute of Virology, Hannover Medical School, Hannover, Germany
- German Center for Infection Research, Hannover Braunschweig Site, Hannover, Germany
| | | | - Tanvi Tikla
- Institute of Virology, Hannover Medical School, Hannover, Germany
- German Center for Infection Research, Hannover Braunschweig Site, Hannover, Germany
| | - Ja-Yun Waldmann
- Institute of Virology, Hannover Medical School, Hannover, Germany
- German Center for Infection Research, Hannover Braunschweig Site, Hannover, Germany
| | - Bizunesh Abere
- Institute of Virology, Hannover Medical School, Hannover, Germany
- German Center for Infection Research, Hannover Braunschweig Site, Hannover, Germany
| | - Vittoria Nanna
- Institute of Organic Chemistry, Leibniz University Hannover, Hannover, Germany
| | | | - Teresa Carlomagno
- Institute of Organic Chemistry, Leibniz University Hannover, Hannover, Germany
| | - Thomas Krey
- Institute of Virology, Hannover Medical School, Hannover, Germany
- German Center for Infection Research, Hannover Braunschweig Site, Hannover, Germany
- Excellence Cluster 2155 RESIST, Hannover Medical School, Hannover, Germany
- Centre for Structural Systems Biology (CSSB), Hamburg, Germany
| | - Thomas F. Schulz
- Institute of Virology, Hannover Medical School, Hannover, Germany
- German Center for Infection Research, Hannover Braunschweig Site, Hannover, Germany
- Excellence Cluster 2155 RESIST, Hannover Medical School, Hannover, Germany
- * E-mail:
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17
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Schwob MR, Zhan J, Dempsey A. Modeling Cell Communication with Time-Dependent Signaling Hypergraphs. IEEE/ACM TRANSACTIONS ON COMPUTATIONAL BIOLOGY AND BIOINFORMATICS 2021; 18:1151-1163. [PMID: 31449029 DOI: 10.1109/tcbb.2019.2937033] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Signaling pathways describe a group of molecules in a cell that collaborate to control one or more cell functions, such as cell division or cell death. The pathways communicate by sending signals between molecules, and this process is repeated until the terminal molecule is activated and the cell function is executed. Signaling pathways are often represented as directed graphs, which does not provide enough information when modeling cell functions and reactions. Recently, directed hypergraphs have been proposed to more accurately represent reactions such as protein activation and interaction. To further improve the representation of signaling pathways, time dependency must be considered to improve the representation of cell signaling at any given time. In this paper, the importance of time dependency in modeling signaling pathways is presented. An algorithm that finds the shortest a priori path using time-dependent hypergraphs to more robustly model signaling pathways is adopted. The shortest time-dependent hyperpaths representing signaling pathways are an improvement to the recent adoption of hypergraphs representing these pathways. The results display the improved representation of signaling pathways and motivate the adoption of time-dependent signaling hypergraphs.
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18
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Zeng L, Palaia I, Šarić A, Su X. PLCγ1 promotes phase separation of T cell signaling components. J Cell Biol 2021; 220:212040. [PMID: 33929486 PMCID: PMC8094118 DOI: 10.1083/jcb.202009154] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Revised: 01/21/2021] [Accepted: 03/05/2021] [Indexed: 02/07/2023] Open
Abstract
The T cell receptor (TCR) pathway receives, processes, and amplifies the signal from pathogenic antigens to the activation of T cells. Although major components in this pathway have been identified, the knowledge on how individual components cooperate to effectively transduce signals remains limited. Phase separation emerges as a biophysical principle in organizing signaling molecules into liquid-like condensates. Here, we report that phospholipase Cγ1 (PLCγ1) promotes phase separation of LAT, a key adaptor protein in the TCR pathway. PLCγ1 directly cross-links LAT through its two SH2 domains. PLCγ1 also protects LAT from dephosphorylation by the phosphatase CD45 and promotes LAT-dependent ERK activation and SLP76 phosphorylation. Intriguingly, a nonmonotonic effect of PLCγ1 on LAT clustering was discovered. Computer simulations, based on patchy particles, revealed how the cluster size is regulated by protein compositions. Together, these results define a critical function of PLCγ1 in promoting phase separation of the LAT complex and TCR signal transduction.
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Affiliation(s)
- Longhui Zeng
- Department of Cell Biology, Yale School of Medicine, New Haven, CT
| | - Ivan Palaia
- Department of Physics and Astronomy, Institute for the Physics of Living Systems, University College London, London, UK.,Medical Research Council Laboratory for Molecular Cell Biology, University College London, London, UK
| | - Anđela Šarić
- Department of Physics and Astronomy, Institute for the Physics of Living Systems, University College London, London, UK.,Medical Research Council Laboratory for Molecular Cell Biology, University College London, London, UK
| | - Xiaolei Su
- Department of Cell Biology, Yale School of Medicine, New Haven, CT.,Yale Cancer Center, Yale University, New Haven, CT
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19
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Pfeil EM, Brands J, Merten N, Vögtle T, Vescovo M, Rick U, Albrecht IM, Heycke N, Kawakami K, Ono Y, Ngako Kadji FM, Hiratsuka S, Aoki J, Häberlein F, Matthey M, Garg J, Hennen S, Jobin ML, Seier K, Calebiro D, Pfeifer A, Heinemann A, Wenzel D, König GM, Nieswandt B, Fleischmann BK, Inoue A, Simon K, Kostenis E. Heterotrimeric G Protein Subunit Gαq Is a Master Switch for Gβγ-Mediated Calcium Mobilization by Gi-Coupled GPCRs. Mol Cell 2020; 80:940-954.e6. [PMID: 33202251 DOI: 10.1016/j.molcel.2020.10.027] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Revised: 09/21/2020] [Accepted: 10/16/2020] [Indexed: 12/18/2022]
Abstract
Mechanisms that control mobilization of cytosolic calcium [Ca2+]i are key for regulation of numerous eukaryotic cell functions. One such paradigmatic mechanism involves activation of phospholipase Cβ (PLCβ) enzymes by G protein βγ subunits from activated Gαi-Gβγ heterotrimers. Here, we report identification of a master switch to enable this control for PLCβ enzymes in living cells. We find that the Gαi-Gβγ-PLCβ-Ca2+ signaling module is entirely dependent on the presence of active Gαq. If Gαq is pharmacologically inhibited or genetically ablated, Gβγ can bind to PLCβ but does not elicit Ca2+ signals. Removal of an auto-inhibitory linker that occludes the active site of the enzyme is required and sufficient to empower "stand-alone control" of PLCβ by Gβγ. This dependence of Gi-Gβγ-Ca2+ on Gαq places an entire signaling branch of G-protein-coupled receptors (GPCRs) under hierarchical control of Gq and changes our understanding of how Gi-GPCRs trigger [Ca2+]i via PLCβ enzymes.
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Affiliation(s)
- Eva Marie Pfeil
- Molecular, Cellular and Pharmacobiology Section, Institute for Pharmaceutical Biology, University of Bonn, Nussallee 6, 53115 Bonn, Germany; Research Training Group 1873, University of Bonn, Bonn, Germany
| | - Julian Brands
- Molecular, Cellular and Pharmacobiology Section, Institute for Pharmaceutical Biology, University of Bonn, Nussallee 6, 53115 Bonn, Germany; Research Training Group 1873, University of Bonn, Bonn, Germany
| | - Nicole Merten
- Molecular, Cellular and Pharmacobiology Section, Institute for Pharmaceutical Biology, University of Bonn, Nussallee 6, 53115 Bonn, Germany
| | - Timo Vögtle
- Institute of Experimental Biomedicine I, University Hospital Würzburg and Rudolf Virchow Center, University of Würzburg, 97080 Würzburg, Germany
| | - Maddalena Vescovo
- Molecular, Cellular and Pharmacobiology Section, Institute for Pharmaceutical Biology, University of Bonn, Nussallee 6, 53115 Bonn, Germany
| | - Ulrike Rick
- Molecular, Cellular and Pharmacobiology Section, Institute for Pharmaceutical Biology, University of Bonn, Nussallee 6, 53115 Bonn, Germany
| | - Ina-Maria Albrecht
- Molecular, Cellular and Pharmacobiology Section, Institute for Pharmaceutical Biology, University of Bonn, Nussallee 6, 53115 Bonn, Germany
| | - Nina Heycke
- Molecular, Cellular and Pharmacobiology Section, Institute for Pharmaceutical Biology, University of Bonn, Nussallee 6, 53115 Bonn, Germany
| | - Kouki Kawakami
- Graduate School of Pharmaceutical Science, Tohoku University, Sendai 980-8578, Japan
| | - Yuki Ono
- Graduate School of Pharmaceutical Science, Tohoku University, Sendai 980-8578, Japan
| | | | - Suzune Hiratsuka
- Graduate School of Pharmaceutical Science, Tohoku University, Sendai 980-8578, Japan
| | - Junken Aoki
- Graduate School of Pharmaceutical Science, Tohoku University, Sendai 980-8578, Japan
| | - Felix Häberlein
- Molecular, Cellular and Pharmacobiology Section, Institute for Pharmaceutical Biology, University of Bonn, Nussallee 6, 53115 Bonn, Germany; Research Training Group 1873, University of Bonn, Bonn, Germany
| | - Michaela Matthey
- Department of Systems Physiology, Medical Faculty, Ruhr University Bochum, 44801 Bochum, Germany; Institute of Physiology I, Life and Brain Center, Medical Faculty, University of Bonn, Venusberg-Campus 1, 53127 Bonn, Germany
| | - Jaspal Garg
- Institute of Pharmacology and Toxicology, University Hospital Bonn, University of Bonn, 53127 Bonn, Germany
| | - Stephanie Hennen
- Molecular, Cellular and Pharmacobiology Section, Institute for Pharmaceutical Biology, University of Bonn, Nussallee 6, 53115 Bonn, Germany
| | - Marie-Lise Jobin
- Institute of Pharmacology and Toxicology and Bio-Imaging Center, University of Würzburg, 97078 Würzburg, Germany
| | - Kerstin Seier
- Institute of Pharmacology and Toxicology and Bio-Imaging Center, University of Würzburg, 97078 Würzburg, Germany
| | - Davide Calebiro
- Institute of Pharmacology and Toxicology and Bio-Imaging Center, University of Würzburg, 97078 Würzburg, Germany; Institute of Metabolism and Systems Research and Centre of Membrane Proteins and Receptors, University of Birmingham, B15 2TT Birmingham, UK
| | - Alexander Pfeifer
- Institute of Physiology I, Life and Brain Center, Medical Faculty, University of Bonn, Venusberg-Campus 1, 53127 Bonn, Germany
| | - Akos Heinemann
- Division of Pharmacology, Otto-Loewi Research Center for Vascular Biology, Immunology and Inflammation, Medical University of Graz, 8010 Graz, Austria
| | - Daniela Wenzel
- Department of Systems Physiology, Medical Faculty, Ruhr University Bochum, 44801 Bochum, Germany; Institute of Physiology I, Life and Brain Center, Medical Faculty, University of Bonn, Venusberg-Campus 1, 53127 Bonn, Germany
| | - Gabriele M König
- Institute for Pharmaceutical Biology, University of Bonn, Nussallee 6, 53115 Bonn, Germany
| | - Bernhard Nieswandt
- Institute of Experimental Biomedicine I, University Hospital Würzburg and Rudolf Virchow Center, University of Würzburg, 97080 Würzburg, Germany
| | - Bernd K Fleischmann
- Institute of Physiology I, Life and Brain Center, Medical Faculty, University of Bonn, Venusberg-Campus 1, 53127 Bonn, Germany
| | - Asuka Inoue
- Graduate School of Pharmaceutical Science, Tohoku University, Sendai 980-8578, Japan
| | - Katharina Simon
- Molecular, Cellular and Pharmacobiology Section, Institute for Pharmaceutical Biology, University of Bonn, Nussallee 6, 53115 Bonn, Germany.
| | - Evi Kostenis
- Molecular, Cellular and Pharmacobiology Section, Institute for Pharmaceutical Biology, University of Bonn, Nussallee 6, 53115 Bonn, Germany.
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20
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Huang W, Carr AJ, Hajicek N, Sokolovski M, Siraliev-Perez E, Hardy PB, Pearce KH, Sondek J, Zhang Q. A High-Throughput Assay to Identify Allosteric Inhibitors of the PLC-γ Isozymes Operating at Membranes. Biochemistry 2020; 59:4029-4038. [PMID: 33028071 DOI: 10.1021/acs.biochem.0c00511] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The two phospholipase C-γ (PLC-γ) isozymes are major signaling hubs and emerging therapeutic targets for various diseases, yet there are no selective inhibitors for these enzymes. We have developed a high-throughput, liposome-based assay that features XY-69, a fluorogenic, membrane-associated reporter for mammalian PLC isozymes. The assay was validated using a pilot screen of the Library of Pharmacologically Active Compounds 1280 (LOPAC1280) in 384-well format; it is highly reproducible and has the potential to capture both orthosteric and allosteric inhibitors. Selected hit compounds were confirmed with secondary assays, and further profiling led to the interesting discovery that adenosine triphosphate potently inhibits the PLC-γ isozymes through noncompetitive inhibition, raising the intriguing possibility of endogenous, nucleotide-dependent regulation of these phospholipases. These results highlight the merit of the assay platform for large scale screening of chemical libraries to identify allosteric modulators of the PLC-γ isozymes as chemical probes and for drug discovery.
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21
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Saliakoura M, Rossi Sebastiano M, Pozzato C, Heidel FH, Schnöder TM, Savic Prince S, Bubendorf L, Pinton P, A Schmid R, Baumgartner J, Freigang S, Berezowska SA, Rimessi A, Konstantinidou G. PLCγ1 suppression promotes the adaptation of KRAS-mutant lung adenocarcinomas to hypoxia. Nat Cell Biol 2020; 22:1382-1395. [PMID: 33077911 PMCID: PMC7610419 DOI: 10.1038/s41556-020-00592-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Accepted: 09/15/2020] [Indexed: 12/25/2022]
Abstract
Mutant KRAS modulates the metabolic plasticity of cancer cells conferring growth advantage during hypoxia, but the molecular underpinnings are largely unknown. Using a lipidomic screen, we found that PLCγ1 is suppressed during hypoxia in KRAS-mutant human lung adenocarcinoma cancer cell lines. Suppression of PLCγ1 in hypoxia promotes a less oxidative cancer cell metabolism, reduces the formation of mitochondrial reactive oxygen species and switches tumor bioenergetics towards glycolysis by impairing Ca2+ entry into the mitochondria. This event prevents lipid peroxidation, antagonizes apoptosis and increases cancer cell proliferation. Accordingly, loss-of-function of Plcγ1 in a mouse model of KrasG12D-driven lung adenocarcinoma increased the expression of glycolytic genes, boosted tumor growth and reduced survival. In patients with mutant KRAS lung adenocarcinomas, low PLCγ1 expression correlates with increased expression of hypoxia markers and predicts poor patient survival. Thus, our work reveals a mechanism of cancer cell adaptation to hypoxia with potential therapeutic value.
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Affiliation(s)
- Maria Saliakoura
- Institute of Pharmacology, University of Bern, Bern, Switzerland
| | | | - Chiara Pozzato
- Institute of Pharmacology, University of Bern, Bern, Switzerland
| | - Florian H Heidel
- Internal Medicine II, Hematology and Oncology, University Hospital Jena, Jena, Germany.,Leibniz-Institute on Aging, Fritz-Lipmann-Institute, Jena, Jena, Germany
| | - Tina M Schnöder
- Internal Medicine II, Hematology and Oncology, University Hospital Jena, Jena, Germany.,Leibniz-Institute on Aging, Fritz-Lipmann-Institute, Jena, Jena, Germany
| | | | - Lukas Bubendorf
- Institute of Pathology, University Hospital Basel, Basel, Switzerland
| | - Paolo Pinton
- Department of Medical Sciences, Laboratory for Technologies of Advanced Therapies (LTTA), University of Ferrara, Ferrara, Italy
| | - Ralph A Schmid
- Department of General Thoracic Surgery, Inselspital, Bern, Switzerland
| | | | - Stefan Freigang
- Institute of Pathology, University of Bern, Bern, Switzerland
| | | | - Alessandro Rimessi
- Department of Medical Sciences, Laboratory for Technologies of Advanced Therapies (LTTA), University of Ferrara, Ferrara, Italy
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22
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Patel VM, Flanagan CE, Martins M, Jones CL, Butler RM, Woollard WJ, Bakr FS, Yoxall A, Begum N, Katan M, Whittaker SJ, Mitchell TJ. Frequent and Persistent PLCG1 Mutations in Sézary Cells Directly Enhance PLCγ1 Activity and Stimulate NFκB, AP-1, and NFAT Signaling. J Invest Dermatol 2020; 140:380-389.e4. [PMID: 31376383 DOI: 10.1016/j.jid.2019.07.693] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2018] [Revised: 06/17/2019] [Accepted: 07/01/2019] [Indexed: 12/16/2022]
Abstract
Phospholipase C Gamma 1 (PLCG1) is frequently mutated in primary cutaneous T-cell lymphoma (CTCL). This study functionally interrogated nine PLCG1 mutations (p.R48W, p.S312L, p.D342N, p.S345F, p.S520F, p.R1158H, p.E1163K, p.D1165H, and the in-frame indel p.VYEEDM1161V) identified in Sézary Syndrome, the leukemic variant of CTCL. The mutations were demonstrated in diagnostic samples and persisted in multiple tumor compartments over time, except in patients who achieved a complete clinical remission. In basal conditions, the majority of the mutations confer PLCγ1 gain-of-function activity through increased inositol phosphate production and the downstream activation of NFκB, AP-1, and NFAT transcriptional activity. Phosphorylation of the p.Y783 residue is essential for the proximal activity of wild-type PLCγ1, but we provide evidence that activating mutations do not require p.Y783 phosphorylation to stimulate downstream NFκB, NFAT, and AP-1 transcriptional activity. Finally, the gain-of-function effects associated with the p.VYEEDM1161V indel suggest that the C2 domain may have a role in regulating PLCγ1 activity. These data provide compelling evidence to support the development of therapeutic strategies targeting mutant PLCγ1.
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Affiliation(s)
- Varsha M Patel
- St. John's Institute of Dermatology, School of Basic & Medical Biosciences, King's College London, Guy's Hospital, London, United Kingdom
| | - Charlotte E Flanagan
- St. John's Institute of Dermatology, School of Basic & Medical Biosciences, King's College London, Guy's Hospital, London, United Kingdom
| | - Marta Martins
- Insituto de Medicina Molecular- João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| | - Christine L Jones
- St. John's Institute of Dermatology, School of Basic & Medical Biosciences, King's College London, Guy's Hospital, London, United Kingdom
| | - Rosie M Butler
- St. John's Institute of Dermatology, School of Basic & Medical Biosciences, King's College London, Guy's Hospital, London, United Kingdom
| | - Wesley J Woollard
- St. John's Institute of Dermatology, School of Basic & Medical Biosciences, King's College London, Guy's Hospital, London, United Kingdom
| | - Farrah S Bakr
- St. John's Institute of Dermatology, School of Basic & Medical Biosciences, King's College London, Guy's Hospital, London, United Kingdom
| | - Antoinette Yoxall
- St. John's Institute of Dermatology, School of Basic & Medical Biosciences, King's College London, Guy's Hospital, London, United Kingdom
| | - Nelema Begum
- St. John's Institute of Dermatology, School of Basic & Medical Biosciences, King's College London, Guy's Hospital, London, United Kingdom
| | - Matilda Katan
- Structural and Molecular Biology, Division of Biosciences, University College London, United Kingdom
| | - Sean J Whittaker
- St. John's Institute of Dermatology, School of Basic & Medical Biosciences, King's College London, Guy's Hospital, London, United Kingdom
| | - Tracey J Mitchell
- St. John's Institute of Dermatology, School of Basic & Medical Biosciences, King's College London, Guy's Hospital, London, United Kingdom.
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23
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Khabbazi A, Rahbar Kafshboran H, Nasiri Aghdam M, Nouri Nojadeh J, Daghagh H, Daneshmandpour Y, Kazemzadeh M, Hamzeiy H, Sakhinia E. A new report of autoinflammation and PLCG2-associated antibody deficiency and immune dysregulation (APLAID) with a homozygous pattern from Iran. Immunol Lett 2020; 221:27-32. [PMID: 32014489 DOI: 10.1016/j.imlet.2020.01.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Revised: 01/24/2020] [Accepted: 01/31/2020] [Indexed: 11/26/2022]
Abstract
Autoinflammation and PLCG2-associated antibody deficiency and immune dysregulation (APLAID) is an autosomal dominant autoinflammatory disease characterized by episodic skin, musculoskeletal, ophthalmic and gastrointestinal tract symptoms. Here we report an 11-year-old girl with a history of repeated episodes of fever, myalgia, arthralgia, abdominal pain, and urticarial rash in the trunk and limbs. Chest and pelvic X-Ray, sacroiliac joints MRI, brain MRI and abdominal CT scan were normal. Anti-nuclear antibody, Rheumatoid factor, cryoglobulin, ANCA/PR3, p-ANCA/MPO, anti-smooth muscle antibody and anti-mitochondrial antibody were negative. Serology for cytomegalovirus, Epstein-Barr, hepatitis B, hepatitis C, and HIV viruses was negative. Serum immunoglobulins were in the normal range. Genetic analysis for familial Mediterranean fever syndrome was negative. Whole exome sequencing was carried out to identify the genetic cause of our patient. We identified a homozygous missense variant (c.579C > G, p. His193Gln) in exon 7 of the PLCG2 gene. Bioinformatic analysis and clinical symptoms suggests this variant to be pathogenic in the homozygous state for APLAID and thus probably acting in an autosomal recessive manner. Our bioinformatic analysis also showed this novel mutation to have detrimental effects on the 3D structure of the PLCG2 protein, which is well conserved among many other similar species.
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Affiliation(s)
- Alireza Khabbazi
- Connective Tissue Diseases Research Centre, Tabriz University of Medical Sciences, Tabriz, Iran
| | | | - Maryam Nasiri Aghdam
- Tabriz Genetic Analysis Centre (TGAC), Tabriz University of Medical Sciences, Tabriz, Iran
| | - Jafar Nouri Nojadeh
- Department of Medical Genetics, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Hossein Daghagh
- Tabriz Genetic Analysis Centre (TGAC), Tabriz University of Medical Sciences, Tabriz, Iran; Department of Medical Genetics, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Yousef Daneshmandpour
- Tabriz Genetic Analysis Centre (TGAC), Tabriz University of Medical Sciences, Tabriz, Iran; Department of Medical Genetics, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran; Student Research Committee, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Mina Kazemzadeh
- Tabriz Genetic Analysis Centre (TGAC), Tabriz University of Medical Sciences, Tabriz, Iran
| | - Hamid Hamzeiy
- Tabriz Genetic Analysis Centre (TGAC), Tabriz University of Medical Sciences, Tabriz, Iran; Genomize Inc., Istanbul, Turkey
| | - Ebrahim Sakhinia
- Connective Tissue Diseases Research Centre, Tabriz University of Medical Sciences, Tabriz, Iran; Tabriz Genetic Analysis Centre (TGAC), Tabriz University of Medical Sciences, Tabriz, Iran; Department of Medical Genetics, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran.
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24
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Nongpiur RC, Singla-Pareek SL, Pareek A. The quest for osmosensors in plants. JOURNAL OF EXPERIMENTAL BOTANY 2020; 71:595-607. [PMID: 31145792 DOI: 10.1093/jxb/erz263] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Accepted: 05/22/2019] [Indexed: 05/20/2023]
Abstract
Osmotic stress has severe effects on crop productivity. Since climate change is predicted to exacerbate this problem, the development of new crops that are tolerant to osmotic stresses, especially drought and salinity stress, is required. However, only limited success has been achieved to date, primarily because of the lack of a clear understanding of the mechanisms that facilitate osmosensing. Here, we discuss the potential mechanisms of osmosensing in plants. We highlight the roles of proteins such as receptor-like kinases, which sense stress-induced cell wall damage, mechanosensitive calcium channels, which initiate a calcium-induced stress response, and phospholipase C, a membrane-bound enzyme that is integral to osmotic stress perception. We also discuss the roles of aquaporins and membrane-bound histidine kinases, which could potentially detect changes in extracellular osmolarity in plants, as they do in prokaryotes and lower eukaryotes. These putative osmosensors have the potential to serve as master regulators of the osmotic stress response in plants and could prove to be useful targets for the selection of osmotic stress-tolerant crops.
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Affiliation(s)
- Ramsong Chantre Nongpiur
- Stress Physiology and Molecular Biology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, India
| | - Sneh Lata Singla-Pareek
- International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, India
| | - Ashwani Pareek
- Stress Physiology and Molecular Biology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, India
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25
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Hajicek N, Keith NC, Siraliev-Perez E, Temple BRS, Huang W, Zhang Q, Harden TK, Sondek J. Structural basis for the activation of PLC-γ isozymes by phosphorylation and cancer-associated mutations. eLife 2019; 8:e51700. [PMID: 31889510 PMCID: PMC7004563 DOI: 10.7554/elife.51700] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Accepted: 12/30/2019] [Indexed: 12/14/2022] Open
Abstract
Direct activation of the human phospholipase C-γ isozymes (PLC-γ1, -γ2) by tyrosine phosphorylation is fundamental to the control of diverse biological processes, including chemotaxis, platelet aggregation, and adaptive immunity. In turn, aberrant activation of PLC-γ1 and PLC-γ2 is implicated in inflammation, autoimmunity, and cancer. Although structures of isolated domains from PLC-γ isozymes are available, these structures are insufficient to define how release of basal autoinhibition is coupled to phosphorylation-dependent enzyme activation. Here, we describe the first high-resolution structure of a full-length PLC-γ isozyme and use it to underpin a detailed model of their membrane-dependent regulation. Notably, an interlinked set of regulatory domains integrates basal autoinhibition, tyrosine kinase engagement, and additional scaffolding functions with the phosphorylation-dependent, allosteric control of phospholipase activation. The model also explains why mutant forms of the PLC-γ isozymes found in several cancers have a wide spectrum of activities, and highlights how these activities are tuned during disease.
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Affiliation(s)
- Nicole Hajicek
- Department of PharmacologyThe University of North Carolina at Chapel HillChapel HillUnited States
| | - Nicholas C Keith
- Department of PharmacologyThe University of North Carolina at Chapel HillChapel HillUnited States
| | - Edhriz Siraliev-Perez
- Department of Biochemistry and BiophysicsThe University of North Carolina at Chapel HillChapel HillUnited States
| | - Brenda RS Temple
- Department of Biochemistry and BiophysicsThe University of North Carolina at Chapel HillChapel HillUnited States
- R L Juliano Structural Bioinformatics Core FacilityThe University of North Carolina at Chapel HillChapel HillUnited States
| | - Weigang Huang
- Division of Chemical Biology and Medicinal ChemistryThe University of North Carolina at Chapel HillChapel HillUnited States
| | - Qisheng Zhang
- Department of PharmacologyThe University of North Carolina at Chapel HillChapel HillUnited States
- Division of Chemical Biology and Medicinal ChemistryThe University of North Carolina at Chapel HillChapel HillUnited States
- Lineberger Comprehensive Cancer CenterThe University of North Carolina at Chapel HillChapel HillUnited States
| | - T Kendall Harden
- Department of PharmacologyThe University of North Carolina at Chapel HillChapel HillUnited States
| | - John Sondek
- Department of PharmacologyThe University of North Carolina at Chapel HillChapel HillUnited States
- Department of Biochemistry and BiophysicsThe University of North Carolina at Chapel HillChapel HillUnited States
- Lineberger Comprehensive Cancer CenterThe University of North Carolina at Chapel HillChapel HillUnited States
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26
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Lauenstein JU, Udgata A, Bartram A, De Sutter D, Fisher DI, Halabi S, Eyckerman S, Gay NJ. Phosphorylation of the multifunctional signal transducer B-cell adaptor protein (BCAP) promotes recruitment of multiple SH2/SH3 proteins including GRB2. J Biol Chem 2019; 294:19852-19861. [PMID: 31527084 PMCID: PMC6937578 DOI: 10.1074/jbc.ra119.009931] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 09/10/2019] [Indexed: 12/21/2022] Open
Abstract
B-cell adaptor protein (BCAP) is a multimodular, multifunctional signal transducer that regulates signal transduction pathways in leukocytes, including macrophages, B-cells, and T-cells. In particular, BCAP suppresses inflammatory signaling by Toll-like receptors (TLRs). However, how BCAP itself is regulated and what its interaction partners are is unclear. Here, using human immune cell lines, including THP-1 cells, we characterized the complex phosphorylation patterns of BCAP and used a novel protein complex trapping strategy, called virotrap, to identify its interaction partners. This analysis identified known interactions of BCAP with phosphoinositide 3-kinase (PI3K) p85 subunit and NCK adaptor protein (NCK), together with previously unknown interactions of BCAP with Src homology 2 (SH2) and SH3 domain-containing adaptor proteins, notably growth factor receptor-bound protein 2 (GRB2) and CRK-like proto-oncogene, adaptor protein (CRKL). We show that the SH3 domain of GRB2 can bind to BCAP independently of BCAP phosphorylation status, suggesting that the SH2 domains mediate interactions with activated receptor tyrosine kinase complexes including the CD19 subunit of the B-cell receptor. Our results also suggested that the PI3K p85 subunit binds to BCAP via SH3 domains forming an inactive complex that is then activated by sequential binding with the SH2 domains. Taken together, our results indicate that BCAP is a complex hub that processes signals from multiple pathways in diverse cell types of the immune system.
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Affiliation(s)
- Johannes U Lauenstein
- Department of Biochemistry, University of Cambridge, Cambridge CB2 1GA, United Kingdom
| | - Atul Udgata
- Department of Biochemistry, University of Cambridge, Cambridge CB2 1GA, United Kingdom
| | - Alex Bartram
- Department of Biochemistry, University of Cambridge, Cambridge CB2 1GA, United Kingdom
| | - Delphine De Sutter
- Department of Biomolecular Medicine, Ghent University, VIB Center for Medical Biotechnology, VIB, A. Baertsoenkaai 3, Ghent B-9000, Belgium
| | - David I Fisher
- Discovery Sciences, Discovery Biology, IMED Biotech Unit, AstraZeneca, Cambridge CB4 0WG, United Kingdom
| | - Samer Halabi
- Department of Biochemistry, University of Cambridge, Cambridge CB2 1GA, United Kingdom
| | - Sven Eyckerman
- Department of Biomolecular Medicine, Ghent University, VIB Center for Medical Biotechnology, VIB, A. Baertsoenkaai 3, Ghent B-9000, Belgium
| | - Nicholas J Gay
- Department of Biochemistry, University of Cambridge, Cambridge CB2 1GA, United Kingdom
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27
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Abstract
![]()
Life is an emergent property of transient
interactions between
biomolecules and other organic and inorganic molecules that somehow
leads to harmony and order. Measurement and quantitation of these
biological interactions are of value to scientists and are major goals
of biochemistry, as affinities provide insight into biological processes.
In an organism, these interactions occur in the context of forces
and the need for a consideration of binding affinities in the context
of a changing mechanical landscape necessitates a new way to consider
the biochemistry of protein–protein interactions. In the past
few decades, the field of mechanobiology has exploded, as both the
appreciation of, and the technical advances required to facilitate
the study of, how forces impact biological processes have become evident.
The aim of this review is to introduce the concept of force dependence
of biomolecular interactions and the requirement to be able to measure
force-dependent binding constants. The focus of this discussion will
be on the mechanotransduction that occurs at the integrin-mediated
adhesions with the extracellular matrix and the major mechanosensors
talin and vinculin. However, the approaches that the cell uses to
sense and respond to forces can be applied to other systems, and this
therefore provides a general discussion of the force dependence of
biomolecule interactions.
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Affiliation(s)
- Yinan Wang
- Department of Physics , National University of Singapore , 117542 Singapore
| | - Jie Yan
- Department of Physics , National University of Singapore , 117542 Singapore.,Mechanobiology Institute , National University of Singapore , 117411 Singapore
| | - Benjamin T Goult
- School of Biosciences , University of Kent , Canterbury , Kent CT2 7NJ , U.K
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28
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Szymanski AM, Ombrello MJ. Using genes to triangulate the pathophysiology of granulomatous autoinflammatory disease: NOD2, PLCG2 and LACC1. Int Immunol 2019. [PMID: 29538758 DOI: 10.1093/intimm/dxy021] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The intersection of granulomatosis and autoinflammatory disease is a rare occurrence that can be generally subdivided into purely granulomatous phenotypes and disease spectra that are inclusive of granulomatous features. NOD2 (nucleotide-binding oligomerization domain-containing protein 2)-related disease, which includes Blau syndrome and early-onset sarcoidosis, is the prototypic example of granulomatous inflammation in the context of monogenic autoinflammation. Granulomatous inflammation has also been observed in two related autoinflammatory diseases caused by mutations in PLCG2 (phospholipase Cγ2). More recently, mutations in LACC1 (laccase domain-containing protein 1) have been identified as the cause of a monogenic form of systemic juvenile idiopathic arthritis, which does not itself manifest granulomatous inflammation, but the same LACC1 mutations have also been shown to cause an early-onset, familial form of a well-known granulomatous condition, Crohn's disease (CD). Rare genetic variants of PLCG2 have also been shown to cause a monogenic form of CD, and moreover common variants of all three of these genes have been implicated in polygenic forms of CD. Additionally, common variants of NOD2 and LACC1 have been implicated in susceptibility to leprosy, a granulomatous infection. Although no specific mechanistic link exists between these three genes, they form an intriguing web of susceptibility to both monogenic and polygenic autoinflammatory and granulomatous phenotypes.
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Affiliation(s)
- Ann Marie Szymanski
- Translational Genetics and Genomics Unit, Intramural Research Program, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, US Department of Health & Human Services, Bethesda, MD, USA
| | - Michael J Ombrello
- Translational Genetics and Genomics Unit, Intramural Research Program, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, US Department of Health & Human Services, Bethesda, MD, USA
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29
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Cooperative assembly of a four-molecule signaling complex formed upon T cell antigen receptor activation. Proc Natl Acad Sci U S A 2018; 115:E11914-E11923. [PMID: 30510001 DOI: 10.1073/pnas.1817142115] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The T cell antigen receptor encounters foreign antigen during the immune response. Receptor engagement leads to activation of specific protein tyrosine kinases, which then phosphorylate multiple enzymes and adapter proteins. One such enzyme, phospholipase-Cγ1, is responsible for cleavage of a plasma membrane lipid substrate, a phosphoinositide, into two second messengers, diacylglycerol, which activates several enzymes including protein kinase C, and an inositol phosphate, which induces intracellular calcium elevation. In T cells, phospholipase-Cγ1 is recruited to the plasma membrane as part of a four-protein complex containing three adapter molecules. We have used recombinant proteins and synthetic phosphopeptides to reconstitute this quaternary complex in vitro. Extending biophysical tools to study concurrent interactions of the four protein components, we demonstrated the formation and determined the composition of the quaternary complex using multisignal analytical ultracentrifugation, and we characterized the thermodynamic driving forces of assembly by isothermal calorimetry. We demonstrate that the four proteins reversibly associate in a circular arrangement of binding interfaces, each protein interacting with two others. Three interactions are of high affinity, and the fourth is of low affinity, with the assembly of the quaternary complex exhibiting significant enthalpy-entropy compensation as in an entropic switch. Formation of this protein complex enables subsequent recruitment of additional molecules needed to activate phospholipase-Cγ1. Understanding the formation of this complex is fundamental to full characterization of a central pathway in T cell activation. Such knowledge is critical to developing ways in which this pathway can be selectively inhibited.
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De Keersmaecker H, Camacho R, Rantasa DM, Fron E, Uji-I H, Mizuno H, Rocha S. Mapping Transient Protein Interactions at the Nanoscale in Living Mammalian Cells. ACS NANO 2018; 12:9842-9854. [PMID: 30192513 DOI: 10.1021/acsnano.8b01227] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Protein-protein interactions (PPIs) form the basis of cellular processes, regulating cell behavior and fate. PPIs can be extremely transient in nature, which hinders their detection. In addition, traditional biochemical methods provided limited information on the spatial distribution and temporal dynamics of PPIs that is crucial for their regulation in the crowded cellular environment. Given the pivotal role of membrane micro- and nanodomains in the regulation of PPIs at the plasma membrane, the development of methods to visualize PPIs with a high spatial resolution is imperative. Here, we present a super-resolution fluorescence microscopy technique that can detect and map short-lived transient protein-protein interactions on a nanometer scale in the cellular environment. This imaging method is based on single-molecule fluorescence microscopy and exploits the effect of the difference in the mobility between cytosolic and membrane-bound proteins in the recorded fluorescence signals. After the development of the proof of concept using a model system based on membrane-bound modular protein domains and fluorescently labeled peptides, we applied this imaging approach to investigate the interactions of cytosolic proteins involved in the epidermal growth factor signaling pathway (namely, Grb2, c-Raf, and PLCγ1). The detected clusters of Grb2 and c-Raf were correlated with the distribution of the receptor at the plasma membrane. Additionally, the interactions of wild type PLCγ1 were compared with those detected with truncated mutants, which provided important information regarding the role played by specific domains in the interaction with the membrane. The results presented here demonstrate the potential of this technique to unravel the role of membrane heterogeneity in the spatiotemporal regulation of cell signaling.
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Affiliation(s)
| | | | | | | | - Hiroshi Uji-I
- Research Institute for Electronic Science , Hokkaido University , N20W10 Kita Ward, Sapporo 001-0020 , Japan
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Walliser C, Wist M, Hermkes E, Zhou Y, Schade A, Haas J, Deinzer J, Désiré L, Li SSC, Stilgenbauer S, Milner JD, Gierschik P. Functional characterization of phospholipase C-γ 2 mutant protein causing both somatic ibrutinib resistance and a germline monogenic autoinflammatory disorder. Oncotarget 2018; 9:34357-34378. [PMID: 30344948 PMCID: PMC6188132 DOI: 10.18632/oncotarget.26173] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Accepted: 09/08/2018] [Indexed: 12/17/2022] Open
Abstract
Depending on its occurrence in the germline or somatic context, a single point mutation, S707Y, of phospholipase C-γ2 (PLCγ2) gives rise to two distinct human disease states: acquired resistance of chronic lymphocytic leukemia cells (CLL) to inhibitors of Brutons´s tyrosine kinase (Btk) and dominantly inherited autoinflammation and PLCγ2-associated antibody deficiency and immune dysregulation, APLAID, respectively. The functional relationships of the PLCγ2S707Y mutation to other PLCG2 mutations causing (i) Btk inhibitor resistance of CLL cells and (ii) the APLAID-related human disease PLCγ2-associated antibody deficiency and immune dysregulation, PLAID, revealing different clinical characteristics including cold-induced urticaria, respectively, are currently incompletely understood. Here, we show that PLCγ2S707 point mutants displayed much higher activities at 37° C than the CLL Btk inhibitor resistance mutants R665W and L845F and the two PLAID mutants, PLCγ2Δ19 and PLCγ2Δ20-22. Combinations of CLL Btk inhibitor resistance mutations synergized to enhance PLCγ2 activity, with distinct functional consequences for different temporal orders of the individual mutations. Enhanced activity of PLCγ2S707Y was not observed in a cell-free system, suggesting that PLCγ2 activation in intact cells is dependent on regulatory rather than mutant-enzyme-inherent influences. Unlike the two PLAID mutants, PLCγ2S707Y was insensitive to activation by cooling and retained marked hyperresponsiveness to activated Rac upon cooling. In contrast to the PLAID mutants, which are insensitive to activation by endogenously expressed EGF receptors, the S707Y mutation markedly enhanced the stimulatory effect of EGF, explaining some of the pathophysiological discrepancies between immune cells of PLAID and APLAID patients in response to receptor-tyrosine-kinase activation.
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Affiliation(s)
- Claudia Walliser
- Institute of Pharmacology and Toxicology, Ulm University Medical Center, Ulm 89070, Germany
| | - Martin Wist
- Institute of Pharmacology and Toxicology, Ulm University Medical Center, Ulm 89070, Germany
| | - Elisabeth Hermkes
- Institute of Pharmacology and Toxicology, Ulm University Medical Center, Ulm 89070, Germany
| | - Yuan Zhou
- Institute of Pharmacology and Toxicology, Ulm University Medical Center, Ulm 89070, Germany
| | - Anja Schade
- Institute of Pharmacology and Toxicology, Ulm University Medical Center, Ulm 89070, Germany
| | - Jennifer Haas
- Institute of Pharmacology and Toxicology, Ulm University Medical Center, Ulm 89070, Germany
| | - Julia Deinzer
- Institute of Pharmacology and Toxicology, Ulm University Medical Center, Ulm 89070, Germany
| | | | - Shawn S C Li
- Department of Biochemistry and The Siebens-Drake Medical Research Institute, Schulich School of Medicine, University of Western Ontario, London, Ontario N6A 5C1, Canada
| | - Stephan Stilgenbauer
- Department of Internal Medicine III, Ulm University Medical Center, Ulm 89070, Germany
| | - Joshua D Milner
- Laboratory of Allergic Diseases, NIAID, NIH, Bethesda, MD 20892, USA
| | - Peter Gierschik
- Institute of Pharmacology and Toxicology, Ulm University Medical Center, Ulm 89070, Germany
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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] [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.
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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
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Segerer G, Engelmann D, Kaestner A, Trötzmüller M, Köfeler H, Stigloher C, Thiele C, Jeanclos E, Gohla A. A phosphoglycolate phosphatase/AUM-dependent link between triacylglycerol turnover and epidermal growth factor signaling. Biochim Biophys Acta Mol Cell Biol Lipids 2018. [DOI: 10.1016/j.bbalip.2018.03.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Huang W, Wang X, Endo-Streeter S, Barrett M, Waybright J, Wohlfeld C, Hajicek N, Harden TK, Sondek J, Zhang Q. A membrane-associated, fluorogenic reporter for mammalian phospholipase C isozymes. J Biol Chem 2017; 293:1728-1735. [PMID: 29263090 DOI: 10.1074/jbc.ra117.000926] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2017] [Revised: 12/05/2017] [Indexed: 11/06/2022] Open
Abstract
A diverse group of cell-surface receptors, including many G protein-coupled receptors and receptor tyrosine kinases, activate phospholipase C (PLC) isozymes to hydrolyze phosphatidylinositol 4,5-bisphosphate into the second messengers diacylglycerol and 1,4,5-inositol trisphosphate. Consequently, PLCs control various cellular processes, and their aberrant regulation contributes to many diseases, including cancer, atherosclerosis, and rheumatoid arthritis. Despite the widespread importance of PLCs in human biology and disease, it has been impossible to directly monitor the real-time activation of these enzymes at membranes. To overcome this limitation, here we describe XY-69, a fluorogenic reporter that preferentially partitions into membranes and provides a selective tool for measuring the real-time activity of PLCs as either purified enzymes or in cellular lysates. Indeed, XY-69 faithfully reported the membrane-dependent activation of PLC-β3 by Gαq Therefore, XY-69 can replace radioactive phosphatidylinositol 4,5-bisphosphate used in conventional PLC assays and will enable high-throughput screens to identify both orthosteric and allosteric PLC inhibitors. In the future, cell-permeable variants of XY-69 represent promising candidates for reporting the activation of PLCs in live cells with high spatiotemporal resolution.
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Affiliation(s)
- Weigang Huang
- From the Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy
| | - Xiaoyang Wang
- From the Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy
| | | | | | - Jarod Waybright
- From the Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy
| | - Christian Wohlfeld
- From the Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy
| | | | | | - John Sondek
- Departments of Pharmacology and.,Biochemistry and Biophysics, School of Medicine, and.,the Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599
| | - Qisheng Zhang
- From the Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, .,Departments of Pharmacology and.,the Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599
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Belmont J, Gu T, Mudd A, Salomon AR. A PLC-γ1 Feedback Pathway Regulates Lck Substrate Phosphorylation at the T-Cell Receptor and SLP-76 Complex. J Proteome Res 2017. [PMID: 28644030 DOI: 10.1021/acs.jproteome.6b01026] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Phospholipase C gamma 1 (PLC-γ1) occupies a critically important position in the T-cell signaling pathway. While its functions as a regulator of both Ca2+ signaling and PKC-family kinases are well characterized, PLC-γ1's role in the regulation of early T-cell receptor signaling events is incompletely understood. Activation of the T-cell receptor leads to the formation of a signalosome complex between SLP-76, LAT, PLC-γ1, Itk, and Vav1. Recent studies have revealed the existence of both positive and negative feedback pathways from SLP-76 to the apical kinase in the pathway, Lck. To determine if PLC-γ1 contributes to the regulation of these feedback networks, we performed a quantitative phosphoproteomic analysis of PLC-γ1-deficient T cells. These data revealed a previously unappreciated role for PLC-γ1 in the positive regulation of Zap-70 and T-cell receptor tyrosine phosphorylation. Conversely, PLC-γ1 negatively regulated the phosphorylation of SLP-76-associated proteins, including previously established Lck substrate phosphorylation sites within this complex. While the positive and negative regulatory phosphorylation sites on Lck were largely unchanged, Tyr192 phosphorylation was elevated in Jgamma1. The data supports a model wherein Lck's targeting, but not its kinase activity, is altered by PLC-γ1, possibly through Lck Tyr192 phosphorylation and increased association of the kinase with protein scaffolds SLP-76 and TSAd.
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Affiliation(s)
- Judson Belmont
- Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University , Providence, Rhode Island 02912, United States
| | - Tao Gu
- Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University , Providence, Rhode Island 02912, United States
| | - Ashley Mudd
- Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University , Providence, Rhode Island 02912, United States
| | - Arthur R Salomon
- Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University , Providence, Rhode Island 02912, United States.,Department of Chemistry, Brown University , Providence, Rhode Island 02912, United States
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78495111110.3390/cancers9050052" />
Abstract
The epidermal growth factor receptor (EGFR) is a receptor tyrosine kinase that is commonly upregulated in cancers such as in non-small-cell lung cancer, metastatic colorectal cancer, glioblastoma, head and neck cancer, pancreatic cancer, and breast cancer. Various mechanisms mediate the upregulation of EGFR activity, including common mutations and truncations to its extracellular domain, such as in the EGFRvIII truncations, as well as to its kinase domain, such as the L858R and T790M mutations, or the exon 19 truncation. These EGFR aberrations over-activate downstream pro-oncogenic signaling pathways, including the RAS-RAF-MEK-ERK MAPK and AKT-PI3K-mTOR pathways. These pathways then activate many biological outputs that are beneficial to cancer cell proliferation, including their chronic initiation and progression through the cell cycle. Here, we review the molecular mechanisms that regulate EGFR signal transduction, including the EGFR structure and its mutations, ligand binding and EGFR dimerization, as well as the signaling pathways that lead to G1 cell cycle progression. We focus on the induction of CYCLIN D expression, CDK4/6 activation, and the repression of cyclin-dependent kinase inhibitor proteins (CDKi) by EGFR signaling pathways. We also discuss the successes and challenges of EGFR-targeted therapies, and the potential for their use in combination with CDK4/6 inhibitors.
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Wee P, Wang Z. Epidermal Growth Factor Receptor Cell Proliferation Signaling Pathways. Cancers (Basel) 2017; 9:cancers9050052. [PMID: 28513565 PMCID: PMC5447962 DOI: 10.3390/cancers9050052] [Citation(s) in RCA: 999] [Impact Index Per Article: 142.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Revised: 05/10/2017] [Accepted: 05/10/2017] [Indexed: 12/12/2022] Open
Abstract
The epidermal growth factor receptor (EGFR) is a receptor tyrosine kinase that is commonly upregulated in cancers such as in non-small-cell lung cancer, metastatic colorectal cancer, glioblastoma, head and neck cancer, pancreatic cancer, and breast cancer. Various mechanisms mediate the upregulation of EGFR activity, including common mutations and truncations to its extracellular domain, such as in the EGFRvIII truncations, as well as to its kinase domain, such as the L858R and T790M mutations, or the exon 19 truncation. These EGFR aberrations over-activate downstream pro-oncogenic signaling pathways, including the RAS-RAF-MEK-ERK MAPK and AKT-PI3K-mTOR pathways. These pathways then activate many biological outputs that are beneficial to cancer cell proliferation, including their chronic initiation and progression through the cell cycle. Here, we review the molecular mechanisms that regulate EGFR signal transduction, including the EGFR structure and its mutations, ligand binding and EGFR dimerization, as well as the signaling pathways that lead to G1 cell cycle progression. We focus on the induction of CYCLIN D expression, CDK4/6 activation, and the repression of cyclin-dependent kinase inhibitor proteins (CDKi) by EGFR signaling pathways. We also discuss the successes and challenges of EGFR-targeted therapies, and the potential for their use in combination with CDK4/6 inhibitors.
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Affiliation(s)
- Ping Wee
- Department of Medical Genetics and Signal Transduction Research Group, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G 2H7, Canada.
| | - Zhixiang Wang
- Department of Medical Genetics and Signal Transduction Research Group, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G 2H7, Canada.
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Undurraga SF, Ibarra-Henríquez C, Fredes I, Álvarez JM, Gutiérrez RA. Nitrate signaling and early responses in Arabidopsis roots. JOURNAL OF EXPERIMENTAL BOTANY 2017; 68:2541-2551. [PMID: 28369507 PMCID: PMC5854014 DOI: 10.1093/jxb/erx041] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Accepted: 01/25/2017] [Indexed: 05/18/2023]
Abstract
Nitrogen (N) is an essential macronutrient that impacts many aspects of plant physiology, growth, and development. Besides its nutritional role, N nutrient and metabolites act as signaling molecules that regulate the expression of a wide range of genes and biological processes. In this review, we describe recent advances in the understanding of components of the nitrate signaling pathway. Recent evidence posits that in one nitrate signaling pathway, nitrate sensed by NRT1.1 activates a phospholipase C activity that is necessary for increased cytosolic calcium levels. The nitrate-elicited calcium increase presumably activates calcium sensors, kinases, or phosphatases, resulting in changes in expression of primary nitrate response genes. Consistent with this model, nitrate treatments elicit proteome-wide changes in phosphorylation patterns in a wide range of proteins, including transporters, metabolic enzymes, kinases, phosphatases, and other regulatory proteins. Identifying and characterizing the function of the different players involved in this and other nitrate signaling pathways and their functional relationships is the next step to understand N responses in plants.
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Affiliation(s)
- Soledad F Undurraga
- FONDAP Center for Genome Regulation. Millennium Nucleus Center for Plant Systems and Synthetic Biology. Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Avenida Libertador Bernardo O’Higgins, Santiago, Chile
| | - Catalina Ibarra-Henríquez
- FONDAP Center for Genome Regulation. Millennium Nucleus Center for Plant Systems and Synthetic Biology. Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Avenida Libertador Bernardo O’Higgins, Santiago, Chile
| | - Isabel Fredes
- FONDAP Center for Genome Regulation. Millennium Nucleus Center for Plant Systems and Synthetic Biology. Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Avenida Libertador Bernardo O’Higgins, Santiago, Chile
| | - José Miguel Álvarez
- FONDAP Center for Genome Regulation. Millennium Nucleus Center for Plant Systems and Synthetic Biology. Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Avenida Libertador Bernardo O’Higgins, Santiago, Chile
| | - Rodrigo A Gutiérrez
- FONDAP Center for Genome Regulation. Millennium Nucleus Center for Plant Systems and Synthetic Biology. Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Avenida Libertador Bernardo O’Higgins, Santiago, Chile
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Di Blasio L, Gagliardi PA, Puliafito A, Primo L. Serine/Threonine Kinase 3-Phosphoinositide-Dependent Protein Kinase-1 (PDK1) as a Key Regulator of Cell Migration and Cancer Dissemination. Cancers (Basel) 2017; 9:cancers9030025. [PMID: 28287465 PMCID: PMC5366820 DOI: 10.3390/cancers9030025] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Revised: 03/07/2017] [Accepted: 03/08/2017] [Indexed: 02/03/2023] Open
Abstract
Dissecting the cellular signaling that governs the motility of eukaryotic cells is one of the fundamental tasks of modern cell biology, not only because of the large number of physiological processes in which cell migration is crucial, but even more so because of the pathological ones, in particular tumor invasion and metastasis. Cell migration requires the coordination of at least four major processes: polarization of intracellular signaling, regulation of the actin cytoskeleton and membrane extension, focal adhesion and integrin signaling and contractile forces generation and rear retraction. Among the molecular components involved in the regulation of locomotion, the phosphatidylinositol-3-kinase (PI3K) pathway has been shown to exert fundamental role. A pivotal node of such pathway is represented by the serine/threonine kinase 3-phosphoinositide-dependent protein kinase-1 (PDPK1 or PDK1). PDK1, and the majority of its substrates, belong to the AGC family of kinases (related to cAMP-dependent protein kinase 1, cyclic Guanosine monophosphate-dependent protein kinase and protein kinase C), and control a plethora of cellular processes, downstream either to PI3K or to other pathways, such as RAS GTPase-MAPK (mitogen-activated protein kinase). Interestingly, PDK1 has been demonstrated to be crucial for the regulation of each step of cell migration, by activating several proteins such as protein kinase B/Akt (PKB/Akt), myotonic dystrophy-related CDC42-binding kinases alpha (MRCKα), Rho associated coiled-coil containing protein kinase 1 (ROCK1), phospholipase C gamma 1 (PLCγ1) and β3 integrin. Moreover, PDK1 regulates cancer cell invasion as well, thus representing a possible target to prevent cancer metastasis in human patients. The aim of this review is to summarize the various mechanisms by which PDK1 controls the cell migration process, from cell polarization to actin cytoskeleton and focal adhesion regulation, and finally, to discuss the evidence supporting a role for PDK1 in cancer cell invasion and dissemination.
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Affiliation(s)
- Laura Di Blasio
- Candiolo Cancer Institute FPO-IRCCS, 10060 Candiolo, Torino, Italy.
| | | | | | - Luca Primo
- Candiolo Cancer Institute FPO-IRCCS, 10060 Candiolo, Torino, Italy.
- Department of Oncology, University of Torino, 10043 Orbassano, Torino, Italy.
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Egholm C, Khammy MM, Dalsgaard T, Mazur A, Tritsaris K, Hansen AJ, Aalkjaer C, Dissing S. GLP-1 inhibits VEGFA-mediated signaling in isolated human endothelial cells and VEGFA-induced dilation of rat mesenteric arteries. Am J Physiol Heart Circ Physiol 2016; 311:H1214-H1224. [DOI: 10.1152/ajpheart.00316.2016] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Accepted: 08/15/2016] [Indexed: 01/14/2023]
Abstract
We investigated the acute effects of glucagon-like peptide-1 (GLP-1), GLP-1(1–36), and GLP-1(7–36) on vascular endothelial growth factor-A (VEGFA)-induced endothelium-dependent signaling and vasodilation. Our hypothesis was that GLP-1 released from intestinal l-cells modulates processes related to PLCγ activation, Src, and endothelial NOS (eNOS) signaling, thereby controlling endothelial vessel tone. By using RT-PCR analysis, we found mRNA for the GLP-1 receptor (GLP-1R) in human dermal microvascular endothelial cells (HDMEC), human retinal microvascular endothelial cells, and rat arteries. In isolated rat mesenteric resistance arteries precontracted with the thromboxane analog U46619 to 80–90% of maximum contraction, VEGFA (25 ng/ml) caused a small and gradual relaxation (28.9 ± 3.9%). Pretreatment of arteries with either GLP-1(1–36) (500 nM) or GLP-1(7–36) (1 nM) abolished the VEGFA-induced relaxation. VEGFA-induced relaxations were also inhibited in endothelial-denuded arteries and in arteries pretreated with the nitric oxide synthase (NOS) inhibitor, Nω-nitro-l-arginine methyl ester (100 μM). In vivo studies on male Wistar rats also revealed that GLP-1(7–36) inhibited VEGFA-induced vasodilation of the same arteries. In isolated endothelial cells, GLP-1(1–36) and GLP-1(7–36) caused a reduction in VEGFA-induced phosphorylation of PLCγ. Ca2+ imaging of endothelial cells and rat mesenteric resistance arteries using fura-2, revealed that both GLP-1 analogs caused a reduction in VEGFA-induced Ca2+ signaling. GLP-1(1–36) also reduced VEGFA-induced eNOS phosphorylation in HDMEC. In conclusion, GLP-1 reduced relaxation induced by VEGFA in resistance arteries by inhibiting VEGFR2-mediated Ca2+ signaling and endothelial NO synthesis. GLP-1, on its own, also induced phosphorylation of Src and ERK1/2 that can lead to proliferation and is implicated in vessel permeability.
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Affiliation(s)
- Cecilie Egholm
- Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Makhala Michell Khammy
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Thomas Dalsgaard
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Aleksandra Mazur
- Department of Biomedicine, Aarhus University, Aarhus, Denmark; and
| | - Katerina Tritsaris
- Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Anker J. Hansen
- Department of Neuroscience and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - Christian Aalkjaer
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Department of Biomedicine, Aarhus University, Aarhus, Denmark; and
| | - Steen Dissing
- Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen, Denmark
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Cool-temperature-mediated activation of phospholipase C-γ2 in the human hereditary disease PLAID. Cell Signal 2016; 28:1237-1251. [PMID: 27196803 DOI: 10.1016/j.cellsig.2016.05.010] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2016] [Revised: 05/10/2016] [Accepted: 05/12/2016] [Indexed: 12/24/2022]
Abstract
Deletions in the gene encoding signal-transducing inositol phospholipid-specific phospholipase C-γ2 (PLCγ2) are associated with the novel human hereditary disease PLAID (PLCγ2-associated antibody deficiency and immune dysregulation). PLAID is characterized by a rather puzzling concurrence of augmented and diminished functions of the immune system, such as cold urticaria triggered by only minimal decreases in temperature, autoimmunity, and immunodeficiency. Understanding of the functional effects of the genomic alterations at the level of the affected enzyme, PLCγ2, is currently lacking. PLCγ2 is critically involved in coupling various cell surface receptors to regulation of important functions of immune cells such as mast cells, B cells, monocytes/macrophages, and neutrophils. PLCγ2 is unique by carrying three Src (SH) and one split pleckstrin homology domain (spPH) between the two catalytic subdomains (spPHn-SH2n-SH2c-SH3-spPHc). Prevailing evidence suggests that activation of PLCγ2 is primarily due to loss of SH-region-mediated autoinhibition and/or enhanced plasma membrane translocation. Here, we show that the two PLAID PLCγ2 mutants lacking portions of the SH region are strongly (>100-fold), rapidly, and reversibly activated by cooling by only a few degrees. We found that the mechanism(s) underlying PLCγ2 PLAID mutant activation by cool temperatures is distinct from a mere loss of SH-region-mediated autoinhibition and dependent on both the integrity and the pliability of the spPH domain. The results suggest a new mechanism of PLCγ activation with unique thermodynamic features and assign a novel regulatory role to its spPH domain. Involvement of this mechanism in other human disease states associated with cooling such as exertional asthma and certain acute coronary events appears an intriguing possibility.
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PDK1: A signaling hub for cell migration and tumor invasion. Biochim Biophys Acta Rev Cancer 2015; 1856:178-88. [DOI: 10.1016/j.bbcan.2015.07.003] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2015] [Accepted: 07/28/2015] [Indexed: 01/22/2023]
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Nomikos M, Sanders JR, Parthimos D, Buntwal L, Calver BL, Stamatiadis P, Smith A, Clue M, Sideratou Z, Swann K, Lai FA. Essential Role of the EF-hand Domain in Targeting Sperm Phospholipase Cζ to Membrane Phosphatidylinositol 4,5-Bisphosphate (PIP2). J Biol Chem 2015; 290:29519-30. [PMID: 26429913 PMCID: PMC4705952 DOI: 10.1074/jbc.m115.658443] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Indexed: 11/25/2022] Open
Abstract
Sperm-specific phospholipase C-ζ (PLCζ) is widely considered to be the physiological stimulus that triggers intracellular Ca2+ oscillations and egg activation during mammalian fertilization. Although PLCζ is structurally similar to PLCδ1, it lacks a pleckstrin homology domain, and it remains unclear how PLCζ targets its phosphatidylinositol 4,5-bisphosphate (PIP2) membrane substrate. Recently, the PLCδ1 EF-hand domain was shown to bind to anionic phospholipids through a number of cationic residues, suggesting a potential mechanism for how PLCs might interact with their target membranes. Those critical cationic EF-hand residues in PLCδ1 are notably conserved in PLCζ. We investigated the potential role of these conserved cationic residues in PLCζ by generating a series of mutants that sequentially neutralized three positively charged residues (Lys-49, Lys-53, and Arg-57) within the mouse PLCζ EF-hand domain. Microinjection of the PLCζ EF-hand mutants into mouse eggs enabled their Ca2+ oscillation inducing activities to be compared with wild-type PLCζ. Furthermore, the mutant proteins were purified, and the in vitro PIP2 hydrolysis and binding properties were monitored. Our analysis suggests that PLCζ binds significantly to PIP2, but not to phosphatidic acid or phosphatidylserine, and that sequential reduction of the net positive charge within the first EF-hand domain of PLCζ significantly alters in vivo Ca2+ oscillation inducing activity and in vitro interaction with PIP2 without affecting its Ca2+ sensitivity. Our findings are consistent with theoretical predictions provided by a mathematical model that links oocyte Ca2+ frequency and the binding ability of different PLCζ mutants to PIP2. Moreover, a PLCζ mutant with mutations in the cationic residues within the first EF-hand domain and the XY linker region dramatically reduces the binding of PLCζ to PIP2, leading to complete abolishment of its Ca2+ oscillation inducing activity.
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Affiliation(s)
- Michail Nomikos
- From the Institute of Molecular and Experimental Medicine, School of Medicine, Cardiff University, Cardiff CF14 4XN, United Kingdom and
| | - Jessica R Sanders
- From the Institute of Molecular and Experimental Medicine, School of Medicine, Cardiff University, Cardiff CF14 4XN, United Kingdom and
| | - Dimitris Parthimos
- From the Institute of Molecular and Experimental Medicine, School of Medicine, Cardiff University, Cardiff CF14 4XN, United Kingdom and
| | - Luke Buntwal
- From the Institute of Molecular and Experimental Medicine, School of Medicine, Cardiff University, Cardiff CF14 4XN, United Kingdom and
| | - Brian L Calver
- From the Institute of Molecular and Experimental Medicine, School of Medicine, Cardiff University, Cardiff CF14 4XN, United Kingdom and
| | - Panagiotis Stamatiadis
- From the Institute of Molecular and Experimental Medicine, School of Medicine, Cardiff University, Cardiff CF14 4XN, United Kingdom and
| | - Adrian Smith
- From the Institute of Molecular and Experimental Medicine, School of Medicine, Cardiff University, Cardiff CF14 4XN, United Kingdom and
| | - Matthew Clue
- From the Institute of Molecular and Experimental Medicine, School of Medicine, Cardiff University, Cardiff CF14 4XN, United Kingdom and
| | - Zili Sideratou
- the National Center for Scientific Research "Demokritos," 15310 Aghia Paraskevi, Greece
| | - Karl Swann
- From the Institute of Molecular and Experimental Medicine, School of Medicine, Cardiff University, Cardiff CF14 4XN, United Kingdom and
| | - F Anthony Lai
- From the Institute of Molecular and Experimental Medicine, School of Medicine, Cardiff University, Cardiff CF14 4XN, United Kingdom and
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Gramolelli S, Weidner-Glunde M, Abere B, Viejo-Borbolla A, Bala K, Rückert J, Kremmer E, Schulz TF. Inhibiting the Recruitment of PLCγ1 to Kaposi's Sarcoma Herpesvirus K15 Protein Reduces the Invasiveness and Angiogenesis of Infected Endothelial Cells. PLoS Pathog 2015; 11:e1005105. [PMID: 26295810 PMCID: PMC4546648 DOI: 10.1371/journal.ppat.1005105] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2015] [Accepted: 07/22/2015] [Indexed: 11/28/2022] Open
Abstract
Kaposi’s sarcoma (KS), caused by Kaposi’s sarcoma herpesvirus (KSHV), is a highly vascularised tumour of endothelial origin. KSHV infected endothelial cells show increased invasiveness and angiogenesis. Here, we report that the KSHV K15 protein, which we showed previously to contribute to KSHV-induced angiogenesis, is also involved in KSHV-mediated invasiveness in a PLCγ1-dependent manner. We identified βPIX, GIT1 and cdc42, downstream effectors of PLCγ1 in cell migration, as K15 interacting partners and as contributors to KSHV-triggered invasiveness. We mapped the interaction between PLCγ1, PLCγ2 and their individual domains with two K15 alleles, P and M. We found that the PLCγ2 cSH2 domain, by binding to K15P, can be used as dominant negative inhibitor of the K15P-PLCγ1 interaction, K15P-dependent PLCγ1 phosphorylation, NFAT-dependent promoter activation and the increased invasiveness and angiogenic properties of KSHV infected endothelial cells. We increased the binding of the PLCγ2 cSH2 domain for K15P by substituting two amino acids, thereby creating an improved dominant negative inhibitor of the K15P-dependent PLCγ1 activation. Taken together, these results demonstrate a necessary role of K15 in the increased invasiveness and angiogenesis of KSHV infected endothelial cells and suggest the K15-PLCγ1 interaction as a possible new target for inhibiting the angiogenic and invasive properties of KSHV. Kaposi’s Sarcoma (KS), etiologically linked to Kaposi’s sarcoma herpesvirus (KSHV), is a tumour of endothelial origin characterised by angiogenesis and invasiveness. In vitro, KSHV infected endothelial cells display an increased invasiveness and high angiogenicity. Here we report that the KSHV protein K15, which increases the angiogenicity of endothelial cells, contributes to KSHV-mediated invasiveness by the recruitment and activation of the cellular protein PLCγ1 and its downstream effectors βPIX, GIT1 and cdc42. We explored the functional consequences of disrupting the K15-PLCγ1 interaction by using an isolated PLCγ2 cSH2 domain as a dominant negative inhibitor. This protein fragment, by interacting with K15, reduces K15-driven recruitment and activation of PLCγ1 in a dose-dependent manner. Moreover, the PCLγ2 cSH2 domain, when overexpressed in KSHV infected endothelial cells, reduces the angiogenesis and invasiveness induced by the virus. These findings highlight the role of the K15-PLCγ1 interaction in KSHV-mediated invasiveness and identify it as a possible therapeutic target.
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Affiliation(s)
- Silvia Gramolelli
- Institute of Virology, Hannover Medical School, Hannover, Germany
- German Center for Infection Research (DZIF), Braunschweig, Germany
| | - Magdalena Weidner-Glunde
- Institute of Virology, Hannover Medical School, Hannover, Germany
- German Center for Infection Research (DZIF), Braunschweig, Germany
| | - Bizunesh Abere
- Institute of Virology, Hannover Medical School, Hannover, Germany
- German Center for Infection Research (DZIF), Braunschweig, Germany
| | | | - Kiran Bala
- Institute of Virology, Hannover Medical School, Hannover, Germany
| | - Jessica Rückert
- Institute of Virology, Hannover Medical School, Hannover, Germany
- German Center for Infection Research (DZIF), Braunschweig, Germany
| | - Elisabeth Kremmer
- Institute of Molecular Immunology, Helmholtz Center Munich, German Research Center for Environmental Health (GmbH), Munich, Germany
| | - Thomas F. Schulz
- Institute of Virology, Hannover Medical School, Hannover, Germany
- German Center for Infection Research (DZIF), Braunschweig, Germany
- * E-mail:
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Singh A, Bhatnagar N, Pandey A, Pandey GK. Plant phospholipase C family: Regulation and functional role in lipid signaling. Cell Calcium 2015; 58:139-46. [DOI: 10.1016/j.ceca.2015.04.003] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2015] [Revised: 04/04/2015] [Accepted: 04/06/2015] [Indexed: 01/03/2023]
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Abstract
Egg activation is the first step of embryonic development and in mammals is triggered by a series of cytoplasmic calcium (Ca2+) oscillations. Sperm–egg fusion initiates these Ca2+ oscillations by introducing a sperm-specific protein factor into the egg cytoplasm. Substantial evidence indicates that this protein is a sperm-specific phospholipase C (PLC), termed PLC-zeta (PLCζ). PLCζ stimulates cytoplasmic Ca2+ oscillations matching those at fertilization triggering early embryonic development in several mammalian species. Structurally, PLCζ is comprised of four EF-hands, a C2 domain, and X and Y catalytic domains. PLCζ is an unusual PLC since it lacks a pleckstrin homology (PH) domain. It is also distinctive in that its X–Y linker is not involved in auto-inhibition of catalytic activity, but instead binds to phosphatidylinositol 4,5-bisphosphate (PIP2). Moreover, relative to other PLC isoforms, PLCζ possesses unique potency in stimulating Ca2+ oscillations in eggs, although it does not appear to bind to plasma membrane PIP2. In contrast, PLCζ appears to interact with intracellular vesicles in eggs that contain PIP2. I discuss the recent advances in our knowledge of the intriguing biochemical and physiological properties of sperm PLCζ and postulate potential roles for PLCζ in terms of clinical diagnosis and therapy for certain forms of male infertility.
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Devkota S, Joseph RE, Min L, Bruce Fulton D, Andreotti AH. Scaffold Protein SLP-76 Primes PLCγ1 for Activation by ITK-Mediated Phosphorylation. J Mol Biol 2015; 427:2734-47. [PMID: 25916191 DOI: 10.1016/j.jmb.2015.04.012] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2015] [Revised: 04/04/2015] [Accepted: 04/06/2015] [Indexed: 11/25/2022]
Abstract
Activation of the phospholipase, PLCγ1, is critical for proper T cell signaling following antigen receptor engagement. In T cells, the Tec family kinase, interleukin-2-induced tyrosine kinase (ITK), phosphorylates PLCγ1 at tyrosine 783 (Y783) leading to activation of phospholipase function and subsequent production of the second messengers inositol 1,4,5-trisphosphate and diacylglycerol. In this work, we demonstrate that PLCγ1 can be primed for ITK-mediated phosphorylation on Y783 by a specific region of the adaptor protein, SLP-76. The SLP-76 phosphotyrosine-containing sequence, pY(173)IDR, does not conform to the canonical recognition motif for an SH2 domain yet binds with significant affinity to the C-terminal SH2 domain of PLCγ1 (SH2C). The SLP-76 pY(173) motif competes with the autoinhibited conformation surrounding the SH2C domain of PLCγ1 leading to exposure of the ITK recognition element on the PLCγ1 SH2 domain and release of the target tyrosine, Y783. These data contribute to the evolving model for the molecular events occurring early in the T cell activation process.
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Affiliation(s)
- Sujan Devkota
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA 50011, USA
| | - Raji E Joseph
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA 50011, USA
| | - Lie Min
- Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, DE 19711, USA
| | - D Bruce Fulton
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA 50011, USA
| | - Amy H Andreotti
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA 50011, USA.
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Slomiany BL, Slomiany A. Mechanism of Rac1-induced amplification in gastric mucosal phospholipase Cγ2 activation in response to Helicobacter pylori: modulatory effect of ghrelin. Inflammopharmacology 2015; 23:101-9. [PMID: 25796615 DOI: 10.1007/s10787-015-0231-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2015] [Accepted: 03/04/2015] [Indexed: 12/27/2022]
Abstract
Membrane recruitment followed by targeted phosphorylation of specific Tyr and Ser residues and the interaction with Rac GTPases are the crucial parts of an elaborate mechanism of PLCγ2 activation essential for its role in linking the specific receptor responses to a variety of hormones and bacterial endotoxins with the intended intracellular targets. Here, we explored the involvement of Rac in mediation of PLCγ2 activation associated with gastric mucosal inflammatory responses to H. pylori LPS and the hormone, ghrelin. We show that stimulation of gastric mucosal cells with the LPS leads to the membrane translocation of Rac1 as well as PLCγ2, while the effect of ghrelin is manifested by elevation in the membrane PLCγ2 activation and suppression in Rac1 translocation. However, blocking the LPS-induced Rac1 translocation, while detrimental to the PLCγ2 activation, has no effect on its membrane translocation. We reveal further that PLCγ2, localized in the membrane in association with Rac1 following the LPS stimulation, exhibits a marked increase in phosphorylation on Ser, while the modulatory effect of ghrelin, manifested by a drop in Rac1 translocation, is associated with a distinct decrease in PLCγ2 phosphorylation on Ser. Thus, the results suggest that H. pylori-elicited increase in gastric mucosal PLCγ2 phosphorylation on Ser serves as an essential platform for Rac1 colocalization and amplification in PLCγ2 activation.
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Affiliation(s)
- B L Slomiany
- Research Center C875, Rutgers School of Dental Medicine Rutgers, The State University of New Jersey, 110 Bergen Street, PO Box 1709, Newark, NJ, 07103-2400, USA,
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Sicart A, Katan M, Egea G, Sarri E. PLCγ1 participates in protein transport and diacylglycerol production triggered by cargo arrival at the Golgi. Traffic 2015; 16:250-66. [PMID: 25491205 DOI: 10.1111/tra.12246] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Revised: 11/26/2014] [Accepted: 11/26/2014] [Indexed: 02/02/2023]
Abstract
Diacylglycerol (DAG) is required for membrane traffic and structural organization at the Golgi. DAG is a lipid metabolite of several enzymatic reactions present at this organelle, but the mechanisms by which they are regulated are still unknown. Here, we show that cargo arrival at the Golgi increases the recruitment of the DAG-sensing constructs C1-PKCθ-GFP and the PKD-wt-GFP. The recruitment of both constructs was reduced by PLCγ1 silencing. Post-Golgi trafficking of transmembrane and soluble proteins was impaired in PLCγ1-silenced cells. Under basal conditions, PLCγ1 contributed to the maintenance of the pool of DAG associated with the Golgi and to the structural organization of the organelle. Finally, we show that cytosolic phospholipase C (PLC) can hydrolyse phosphatidylinositol 4-phosphate in isolated Golgi membranes. Our results indicate that PLCγ1 is part of the molecular mechanism that couples cargo arrival at the Golgi with DAG production to co-ordinate the formation of transport carriers for post-Golgi traffic.
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Affiliation(s)
- Adrià Sicart
- Departament de Biologia Cel·lular, Immunologia i Neurociències, Facultat de Medicina, Universitat de Barcelona, C/ Casanova, 143, 08036, Barcelona, Spain; Current address: Vlaams Instituut voor Biotechnologie (VIB), Centre for the Biology of Disease and KU Leuven, Department of Human Genetics, Campus Gasthuisberg, 3000 Leuven, Belgium
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50
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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] [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.
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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.
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