1
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Xia J, Wang H, Zhong Z, Jiang J. Inhibition of PIKfyve Leads to Lysosomal Disorders via Dysregulation of mTOR Signaling. Cells 2024; 13:953. [PMID: 38891085 PMCID: PMC11171791 DOI: 10.3390/cells13110953] [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: 04/24/2024] [Revised: 05/23/2024] [Accepted: 05/29/2024] [Indexed: 06/21/2024] Open
Abstract
PIKfyve is an endosomal lipid kinase that synthesizes phosphatidylinositol 3,5-biphosphate from phosphatidylinositol 3-phsphate. Inhibition of PIKfyve activity leads to lysosomal enlargement and cytoplasmic vacuolation, attributed to impaired lysosomal fission processes and homeostasis. However, the precise molecular mechanisms underlying these effects remain a topic of debate. In this study, we present findings from PIKfyve-deficient zebrafish embryos, revealing enlarged macrophages with giant vacuoles reminiscent of lysosomal storage disorders. Treatment with mTOR inhibitors or effective knockout of mTOR partially reverses these abnormalities and extend the lifespan of mutant larvae. Further in vivo and in vitro mechanistic investigations provide evidence that PIKfyve activity is essential for mTOR shutdown during early zebrafish development and in cells cultured under serum-deprived conditions. These findings underscore the critical role of PIKfyve activity in regulating mTOR signaling and suggest potential therapeutic applications of PIKfyve inhibitors for the treatment of lysosomal storage disorders.
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Affiliation(s)
- Jianhong Xia
- CAS Key Laboratory of Regenerative Biology, Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China; (J.X.); (H.W.)
| | - Haiyun Wang
- CAS Key Laboratory of Regenerative Biology, Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China; (J.X.); (H.W.)
- Centre for Regenerative Medicine and Health, Hong Kong Institute of Science & Innovation, Chinese Academy of Sciences, Hong Kong SAR, China
| | - Zhihang Zhong
- State Key Laboratory of Swine and Poultry Breeding Industry, South China Agricultural University, Guangzhou 510642, China;
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Guangzhou 510642, China
| | - Jun Jiang
- State Key Laboratory of Swine and Poultry Breeding Industry, South China Agricultural University, Guangzhou 510642, China;
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Guangzhou 510642, China
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2
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Vines JH, Maib H, Buckley CM, Gueho A, Zhu Z, Soldati T, Murray DH, King JS. A PI(3,5)P2 reporter reveals PIKfyve activity and dynamics on macropinosomes and phagosomes. J Cell Biol 2023; 222:e202209077. [PMID: 37382666 PMCID: PMC10309190 DOI: 10.1083/jcb.202209077] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Revised: 05/12/2023] [Accepted: 06/13/2023] [Indexed: 06/30/2023] Open
Abstract
Phosphoinositide signaling lipids (PIPs) are key regulators of membrane identity and trafficking. Of these, PI(3,5)P2 is one of the least well-understood, despite key roles in many endocytic pathways including phagocytosis and macropinocytosis. PI(3,5)P2 is generated by the phosphoinositide 5-kinase PIKfyve, which is critical for phagosomal digestion and antimicrobial activity. However PI(3,5)P2 dynamics and regulation remain unclear due to lack of reliable reporters. Using the amoeba Dictyostelium discoideum, we identify SnxA as a highly selective PI(3,5)P2-binding protein and characterize its use as a reporter for PI(3,5)P2 in both Dictyostelium and mammalian cells. Using GFP-SnxA, we demonstrate that Dictyostelium phagosomes and macropinosomes accumulate PI(3,5)P2 3 min after engulfment but are then retained differently, indicating pathway-specific regulation. We further find that PIKfyve recruitment and activity are separable and that PIKfyve activation stimulates its own dissociation. SnxA is therefore a new tool for reporting PI(3,5)P2 in live cells that reveals key mechanistic details of the role and regulation of PIKfyve/PI(3,5)P2.
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Affiliation(s)
- James H. Vines
- School of Biosciences, University of Sheffield, Firth Court Western Bank, Sheffield, UK
| | - Hannes Maib
- Division of Molecular, Cell and Developmental Biology, School of Life Sciences, University of Dundee, Dundee, UK
| | - Catherine M. Buckley
- School of Biosciences, University of Sheffield, Firth Court Western Bank, Sheffield, UK
| | - Aurelie Gueho
- Department of Biochemistry, Faculty of Science, University of Geneva, Geneva, Switzerland
| | - Zhou Zhu
- School of Biosciences, University of Sheffield, Firth Court Western Bank, Sheffield, UK
| | - Thierry Soldati
- Department of Biochemistry, Faculty of Science, University of Geneva, Geneva, Switzerland
| | - David H. Murray
- Division of Molecular, Cell and Developmental Biology, School of Life Sciences, University of Dundee, Dundee, UK
| | - Jason S. King
- School of Biosciences, University of Sheffield, Firth Court Western Bank, Sheffield, UK
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3
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Uzairue LI, Shittu OB, Ojo OE, Obuotor TM, Olanipekun G, Ajose T, Arogbonlo R, Medugu N, Ebruke B, Obaro SK. Antimicrobial resistance and virulence genes of invasive Salmonella enterica from children with bacteremia in north-central Nigeria. SAGE Open Med 2023; 11:20503121231175322. [PMID: 37223673 PMCID: PMC10201152 DOI: 10.1177/20503121231175322] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Accepted: 04/25/2023] [Indexed: 05/25/2023] Open
Abstract
Objectives Bacteremia due to invasive Salmonella enterica has been reported earlier in children in Nigeria. This study aimed to detect the virulence and antibiotic resistance genes of invasive Salmonella enterica from children with bacteremia in north-central Nigeria. Method From June 2015 to June 2018, 4163 blood cultures yielded 83 Salmonella isolates. This is a secondary cross-sectional analysis of the Salmonella isolates. The Salmonella enterica were isolated and identified using standard bacteriology protocol. Biochemical identifications of the Salmonella enterica were made by Phoenix MD 50 identification system. Further identification and confirmation were done with polyvalent antisera O and invA gene. Antimicrobial susceptibility testing was done following clinical and laboratory standard institute guidelines. Resistant genes and virulence genes were determined using a real-time polymerase chain reaction. Result Salmonella typhi 51 (61.4%) was the most prevalent serovar, followed by Salmonella species 13 (15.7%), choleraesuis 8 (9.6%), enteritidis 6 (7.2%), and typhimurium 5 (6.1%). Fifty-one (61.4%) of 83 Salmonella enterica were typhoidal, while 32 (38.6%) were not. Sixty-five (78.3%) of the 83 Salmonella enterica isolates were resistant to ampicillin and trimethoprim-sulfamethoxazole, followed by chloramphenicol 39 (46.7%), tetracycline 41 (41.4%), piperacillin 33 (33.9%), amoxicillin-clavulanate, and streptomycin 21 (25.3%), while cephalothin was 19 (22.9%). Thirty-nine (46.9%) of the 83 Salmonella enterica isolates were multi-drug resistant, and none were extensive drug resistant or pan-drug resistant. A blaTEM 42 (50.6%), floR 32 (38.6%), qnrA 24 (28.9%), tetB 20 (20.1%), tetA 10 (10.0%), and tetG 5 (6.0%) were the antibiotic resistance genes detected. There were perfect agreement between phenotypic and genotypic detection of antimicrobial resistance in tetracycline, ciprofloxacin, and chloramphenicol, while beta-lactam showed κ = 0.60 agreement. All of the Salmonella enterica isolates had the virulence genes invA, sopB, mgtC, and sip4D, while 33 (39.8%), 45 (51.8%), and 2 (2.4%) had ssaQ, spvC, and ljsGI-1, respectively. Conclusion Our findings showed multi-drug resistant Salmonella enterica in children with bacteremia in northern Nigeria. In addition, significant virulence and antimicrobial resistance genes were found in invasive Salmonella enterica in northern Nigeria. Thus, our study emphasizes the need to monitor antimicrobial resistance in Salmonella enterica from invasive sources in Nigeria and supports antibiotic prudence.
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Affiliation(s)
- Leonard I Uzairue
- Department of Microbiology, Federal
University of Agriculture, Abeokuta, Ogun State, Nigeria
- International Foundation Against
Infectious Disease in Nigeria, Abuja, Nigeria
- Department of Medical Laboratory
Sciences, Federal University Oye Ekiti, Ekiti State, Nigeria
| | - Olufunke B Shittu
- Department of Microbiology, Federal
University of Agriculture, Abeokuta, Ogun State, Nigeria
| | - Olufemi E Ojo
- Department of Veterinary Microbiology
and Parasitology, Federal University of Agriculture, Abeokuta, Nigeria
| | - Tolulope M Obuotor
- Department of Microbiology, Federal
University of Agriculture, Abeokuta, Ogun State, Nigeria
| | - Grace Olanipekun
- International Foundation Against
Infectious Disease in Nigeria, Abuja, Nigeria
| | - Theresa Ajose
- International Foundation Against
Infectious Disease in Nigeria, Abuja, Nigeria
| | - Ronke Arogbonlo
- International Foundation Against
Infectious Disease in Nigeria, Abuja, Nigeria
| | - Nubwa Medugu
- International Foundation Against
Infectious Disease in Nigeria, Abuja, Nigeria
- Department of Microbiology and
Parasitology, National Hospital, Abuja, FCT, Nigeria
| | - Bernard Ebruke
- International Foundation Against
Infectious Disease in Nigeria, Abuja, Nigeria
| | - Stephen K Obaro
- International Foundation Against
Infectious Disease in Nigeria, Abuja, Nigeria
- Pediatric Infectious Division, the
University of Nebraska Medical Center, Omaha, NE, USA
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4
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Salloum G, Bresnick AR, Backer JM. Macropinocytosis: mechanisms and regulation. Biochem J 2023; 480:335-362. [PMID: 36920093 DOI: 10.1042/bcj20210584] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 02/22/2023] [Accepted: 02/27/2023] [Indexed: 03/16/2023]
Abstract
Macropinocytosis is defined as an actin-dependent but coat- and dynamin-independent endocytic uptake process, which generates large intracellular vesicles (macropinosomes) containing a non-selective sampling of extracellular fluid. Macropinocytosis provides an important mechanism of immune surveillance by dendritic cells and macrophages, but also serves as an essential nutrient uptake pathway for unicellular organisms and tumor cells. This review examines the cell biological mechanisms that drive macropinocytosis, as well as the complex signaling pathways - GTPases, lipid and protein kinases and phosphatases, and actin regulatory proteins - that regulate macropinosome formation, internalization, and disposition.
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Affiliation(s)
- Gilbert Salloum
- Department of Molecular Pharamacology, Albert Einstein College of Medicine, Bronx, NY, U.S.A
| | - Anne R Bresnick
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY, U.S.A
| | - Jonathan M Backer
- Department of Molecular Pharamacology, Albert Einstein College of Medicine, Bronx, NY, U.S.A
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY, U.S.A
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5
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Luo Z, Liang Y, Tian M, Ruan Z, Su R, Shereen MA, Yin J, Wu K, Guo J, Zhang Q, Li Y, Wu J. Inhibition of PIKFYVE kinase interferes ESCRT pathway to suppress RNA virus replication. J Med Virol 2023; 95:e28527. [PMID: 36695658 DOI: 10.1002/jmv.28527] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Revised: 12/16/2022] [Accepted: 01/14/2023] [Indexed: 01/26/2023]
Abstract
Endosomal sorting complex required for transport (ESCRT) is essential in the functional operation of endosomal transport in envelopment and budding of enveloped RNA viruses. However, in nonenveloped RNA viruses such as enteroviruses of the Picornaviridae family, the precise function of ESCRT pathway in viral replication remains elusive. Here, we initially evaluated that the ESCRT pathway is important for viral replication upon enterovirus 71 (EV71) infection. Furthermore, we discovered that YM201636, a specific inhibitor of phosphoinositide kinase, FYVE finger containing (PIKFYVE) kinase, significantly suppressed EV71 replication and virus-induced inflammation in vitro and in vivo. Mechanistically, YM201636 inhibits PIKFYVE kinase to block the ESCRT pathway and endosomal transport, leading to the disruption of viral entry and replication complex in subcellular components and ultimately repression of intracellular RNA virus replication and virus-induced inflammatory responses. Further studies found that YM201636 broadly represses the replication of other RNA viruses, including coxsackievirus B3 (CVB3), poliovirus 1 (PV1), echovirus 11 (E11), Zika virus (ZIKV), and vesicular stomatitis virus (VSV), rather than DNA viruses, including adenovirus 3 (ADV3) and hepatitis B virus (HBV). Our findings shed light on the mechanism underlying PIKFYVE-modulated ESCRT pathway involved in RNA virus replication, and also provide a prospective antiviral therapy during RNA viruses infections.
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Affiliation(s)
- Zhen Luo
- Guangdong Provincial Key Laboratory of Virology, Institute of Medical Microbiology, Jinan University, Guangzhou, China.,Foshan Institute of Medical Microbiology, Foshan, China
| | - Yicong Liang
- Guangdong Provincial Key Laboratory of Virology, Institute of Medical Microbiology, Jinan University, Guangzhou, China
| | - Mingfu Tian
- Department of Cardiology, The First Affiliated Hospital of Jinan University, Guangzhou, China
| | - Zhihui Ruan
- Guangdong Provincial Key Laboratory of Virology, Institute of Medical Microbiology, Jinan University, Guangzhou, China.,Foshan Institute of Medical Microbiology, Foshan, China
| | - Rui Su
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, China.,Henan Key Laboratory of Immunology and Targeted Drug, School of Basic Medical Science, Xinxiang Medical University, Xinxiang, China
| | - Muhammad Adnan Shereen
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, China.,Department of Microbiology, Kohsar University Murree, Kashmir Point, Pakistan
| | - Jialing Yin
- Guangdong Provincial Key Laboratory of Virology, Institute of Medical Microbiology, Jinan University, Guangzhou, China
| | - Kailang Wu
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, China
| | - Jun Guo
- Department of Cardiology, The First Affiliated Hospital of Jinan University, Guangzhou, China
| | - Qiwei Zhang
- Guangdong Provincial Key Laboratory of Virology, Institute of Medical Microbiology, Jinan University, Guangzhou, China.,Foshan Institute of Medical Microbiology, Foshan, China
| | - Yongkui Li
- Guangdong Provincial Key Laboratory of Virology, Institute of Medical Microbiology, Jinan University, Guangzhou, China.,Foshan Institute of Medical Microbiology, Foshan, China
| | - Jianguo Wu
- Guangdong Provincial Key Laboratory of Virology, Institute of Medical Microbiology, Jinan University, Guangzhou, China.,Foshan Institute of Medical Microbiology, Foshan, China.,Department of Cardiology, The First Affiliated Hospital of Jinan University, Guangzhou, China.,State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, China
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6
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Qiu S, Lavallée-Adam M, Côté M. Proximity Interactome Map of the Vac14-Fig4 Complex Using BioID. J Proteome Res 2021; 20:4959-4973. [PMID: 34554760 DOI: 10.1021/acs.jproteome.1c00408] [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] [Indexed: 12/19/2022]
Abstract
Conversion between phosphatidylinositol-3-phosphate and phosphatidylinositol-3,5-bisphosphate on endosomal membranes is critical for the maturation of early endosomes to late endosomes/lysosomes and is regulated by the PIKfyve-Vac14-Fig4 complex. Despite the importance of this complex for endosomal homeostasis and vesicular trafficking, there is little known about how its activity is regulated or how it interacts with other cellular proteins. Here, we screened for the cellular interactome of Vac14 and Fig4 using proximity-dependent biotin labeling (BioID). After independently screening the interactomes of Vac14 and Fig4, we identified 89 high-confidence protein hits shared by both proteins. Network analysis of these hits revealed pathways with known involvement of the PIKfyve-Vac14-Fig4 complex, including vesicular organization and PI3K/Akt signaling, as well as novel pathways including cell cycle and mitochondrial regulation. We also identified subunits of coatomer complex I (COPI), a Golgi-associated complex with an emerging role in endosomal dynamics. Using proximity ligation assays, we validated the interaction between Vac14 and COPI subunit COPB1 and between Vac14 and Arf1, a GTPase required for COPI assembly. In summary, this study used BioID to comprehensively map the Vac14-Fig4 interactome, revealing potential roles for these proteins in diverse cellular processes and pathways, including preliminary evidence of an interaction between Vac14 and COPI. Data are available via ProteomeXchange with the identifier PXD027917.
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Affiliation(s)
- Shirley Qiu
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa K1H 8M5, Canada.,Ottawa Institute of Systems Biology, University of Ottawa, Ottawa K1H 8M5, Canada.,Centre for Infection, Immunity, and Inflammation, University of Ottawa, Ottawa K1H 8M5, Canada
| | - Mathieu Lavallée-Adam
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa K1H 8M5, Canada.,Ottawa Institute of Systems Biology, University of Ottawa, Ottawa K1H 8M5, Canada
| | - Marceline Côté
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa K1H 8M5, Canada.,Ottawa Institute of Systems Biology, University of Ottawa, Ottawa K1H 8M5, Canada.,Centre for Infection, Immunity, and Inflammation, University of Ottawa, Ottawa K1H 8M5, Canada
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7
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Genetic factors affect the susceptibility to bacterial infections in diabetes. Sci Rep 2021; 11:9464. [PMID: 33947878 PMCID: PMC8096814 DOI: 10.1038/s41598-021-88273-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Accepted: 03/23/2021] [Indexed: 11/17/2022] Open
Abstract
Diabetes increases the risk of bacterial infections. We investigated whether common genetic variants associate with infection susceptibility in Finnish diabetic individuals. We performed genome-wide association studies and pathway analysis for bacterial infection frequency in Finnish adult diabetic individuals (FinnDiane Study; N = 5092, Diabetes Registry Vaasa; N = 4247) using national register data on antibiotic prescription purchases. Replication analyses were performed in a Swedish diabetic population (ANDIS; N = 9602) and in a Finnish non-diabetic population (FinnGen; N = 159,166). Genome-wide data indicated moderate but significant narrow-sense heritability for infection susceptibility (h2 = 16%, P = 0.02). Variants on chromosome 2 were associated with reduced infection susceptibility (rs62192851, P = 2.23 × 10–7). Homozygotic carriers of the rs62192851 effect allele (N = 44) had a 37% lower median annual antibiotic purchase rate, compared to homozygotic carriers of the reference allele (N = 4231): 0.38 [IQR 0.22–0.90] and 0.60 [0.30–1.20] respectively, P = 0.01). Variants rs6727834 and rs10188087, in linkage disequilibrium with rs62192851, replicated in the FinnGen-cohort (P < 0.05), but no variants replicated in the ANDIS-cohort. Pathway analysis suggested the IRAK1 mediated NF-κB activation through IKK complex recruitment-pathway to be a mediator of the phenotype. Common genetic variants on chromosome 2 may associate with reduced risk of bacterial infections in Finnish individuals with diabetes.
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8
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Soares AC, Ferreira A, Mariën J, Delay C, Lee E, Trojanowski JQ, Moechars D, Annaert W, De Muynck L. PIKfyve activity is required for lysosomal trafficking of tau aggregates and tau seeding. J Biol Chem 2021; 296:100636. [PMID: 33831417 PMCID: PMC8134070 DOI: 10.1016/j.jbc.2021.100636] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 03/01/2021] [Accepted: 04/02/2021] [Indexed: 02/06/2023] Open
Abstract
Tauopathies, such as Alzheimer's disease (AD), are neurodegenerative disorders characterized by the deposition of hyperphosphorylated tau aggregates. Proteopathic tau seeds spread through the brain in a temporospatial pattern, indicative of transsynaptic propagation. It is hypothesized that reducing the uptake of tau seeds and subsequent induction of tau aggregation could be a potential approach for abrogating disease progression in AD. Here, we studied to what extent different endosomal routes play a role in the neuronal uptake of preformed tau seeds. Using pharmacological and genetic tools, we identified dynamin-1, actin, and Rac1 as key players. Furthermore, inhibition of PIKfyve, a protein downstream of Rac1, reduced both the trafficking of tau seeds into lysosomes and the induction of tau aggregation. Our work shows that tau aggregates are internalized by a specific endocytic mechanism and that their fate once internalized can be pharmacologically modulated to reduce tau seeding in neurons.
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Affiliation(s)
- Alberto Carpinteiro Soares
- Neuroscience Department, Janssen Research and Development, a Division of Janssen Pharmaceutica NV, Beerse, Belgium; VIB Center for Brain & Disease Research, Leuven, Belgium; Department of Neurosciences, KU Leuven, Leuven, Belgium
| | - Andreia Ferreira
- Neuroscience Department, Janssen Research and Development, a Division of Janssen Pharmaceutica NV, Beerse, Belgium; VIB Center for Medical Biotechnology, Ghent, Belgium; Department of Biochemistry and Microbiology, Ghent University, Ghent, Belgium
| | - Jonas Mariën
- Neuroscience Department, Janssen Research and Development, a Division of Janssen Pharmaceutica NV, Beerse, Belgium
| | - Charlotte Delay
- Neuroscience Department, Janssen Research and Development, a Division of Janssen Pharmaceutica NV, Beerse, Belgium
| | - Edward Lee
- Department of Pathology and Laboratory Medicine, Institute on Aging and Center for Neurodegenerative Disease Research, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA
| | - John Q Trojanowski
- Department of Pathology and Laboratory Medicine, Institute on Aging and Center for Neurodegenerative Disease Research, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA
| | - Dieder Moechars
- Neuroscience Department, Janssen Research and Development, a Division of Janssen Pharmaceutica NV, Beerse, Belgium
| | - Wim Annaert
- VIB Center for Brain & Disease Research, Leuven, Belgium; Department of Neurosciences, KU Leuven, Leuven, Belgium.
| | - Louis De Muynck
- Neuroscience Department, Janssen Research and Development, a Division of Janssen Pharmaceutica NV, Beerse, Belgium.
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9
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Nguyen JA, Yates RM. Better Together: Current Insights Into Phagosome-Lysosome Fusion. Front Immunol 2021; 12:636078. [PMID: 33717183 PMCID: PMC7946854 DOI: 10.3389/fimmu.2021.636078] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 01/18/2021] [Indexed: 12/15/2022] Open
Abstract
Following phagocytosis, the nascent phagosome undergoes maturation to become a phagolysosome with an acidic, hydrolytic, and often oxidative lumen that can efficiently kill and digest engulfed microbes, cells, and debris. The fusion of phagosomes with lysosomes is a principal driver of phagosomal maturation and is targeted by several adapted intracellular pathogens. Impairment of this process has significant consequences for microbial infection, tissue inflammation, the onset of adaptive immunity, and disease. Given the importance of phagosome-lysosome fusion to phagocyte function and the many virulence factors that target it, it is unsurprising that multiple molecular pathways have evolved to mediate this essential process. While the full range of these pathways has yet to be fully characterized, several pathways involving proteins such as members of the Rab GTPases, tethering factors and SNAREs have been identified. Here, we summarize the current state of knowledge to clarify the ambiguities in the field and construct a more comprehensive phagolysosome formation model. Lastly, we discuss how other cellular pathways help support phagolysosome biogenesis and, consequently, phagocyte function.
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Affiliation(s)
- Jenny A Nguyen
- Department of Biochemistry and Molecular Biology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Robin M Yates
- Department of Biochemistry and Molecular Biology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.,Department of Comparative Biology and Experimental Medicine, Faculty of Veterinary Medicine, University of Calgary, Calgary, AB, Canada.,Cumming School of Medicine, Snyder Institute of Chronic Disease, University of Calgary, Calgary, AB, Canada
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10
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Kehl A, Göser V, Reuter T, Liss V, Franke M, John C, Richter CP, Deiwick J, Hensel M. A trafficome-wide RNAi screen reveals deployment of early and late secretory host proteins and the entire late endo-/lysosomal vesicle fusion machinery by intracellular Salmonella. PLoS Pathog 2020; 16:e1008220. [PMID: 32658937 PMCID: PMC7377517 DOI: 10.1371/journal.ppat.1008220] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2019] [Revised: 07/23/2020] [Accepted: 05/19/2020] [Indexed: 12/17/2022] Open
Abstract
The intracellular lifestyle of Salmonella enterica is characterized by the formation of a replication-permissive membrane-bound niche, the Salmonella-containing vacuole (SCV). As a further consequence of the massive remodeling of the host cell endosomal system, intracellular Salmonella establish a unique network of various Salmonella-induced tubules (SIT). The bacterial repertoire of effector proteins required for the establishment for one type of these SIT, the Salmonella-induced filaments (SIF), is rather well-defined. However, the corresponding host cell proteins are still poorly understood. To identify host factors required for the formation of SIF, we performed a sub-genomic RNAi screen. The analyses comprised high-resolution live cell imaging to score effects on SIF induction, dynamics and morphology. The hits of our functional RNAi screen comprise: i) The late endo-/lysosomal SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) complex, consisting of STX7, STX8, VTI1B, and VAMP7 or VAMP8, which is, in conjunction with RAB7 and the homotypic fusion and protein sorting (HOPS) tethering complex, a complete vesicle fusion machinery. ii) Novel interactions with the early secretory GTPases RAB1A and RAB1B, providing a potential link to coat protein complex I (COPI) vesicles and reinforcing recently identified ties to the endoplasmic reticulum. iii) New connections to the late secretory pathway and/or the recycling endosome via the GTPases RAB3A, RAB8A, and RAB8B and the SNAREs VAMP2, VAMP3, and VAMP4. iv) An unprecedented involvement of clathrin-coated structures. The resulting set of hits allowed us to characterize completely new host factor interactions, and to strengthen observations from several previous studies. The facultative intracellular pathogen Salmonella enterica serovar Typhimurium induces the reorganization of the endosomal system of mammalian host cells. This activity is dependent on translocated effector proteins of the pathogen. The host cell factors required for endosomal remodeling are only partially known. To identify such factors for the formation and dynamics of endosomal compartments in Salmonella-infected cells, we performed a live cell imaging-based RNAi screen to investigate the role of 496 mammalian proteins involved in cellular logistics. We identified that endosomal remodeling by intracellular Salmonella is dependent on host factors in the following functional classes: i) the late endo-/lysosomal SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) complex, ii) the early secretory pathway, represented by regulator GTPases RAB1A and RAB1B, iii) the late secretory pathway and/or recycling endosomes represented by GTPases RAB3A, RAB8A, RAB8B, and the SNAREs VAMP2, VAMP3, and VAMP4, and iv) clathrin-coated structures. The identification of these new host factors provides further evidence for the complex manipulation of host cell transport functions by intracellular Salmonella and should enable detailed follow-up studies on the mechanisms involved.
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Affiliation(s)
- Alexander Kehl
- Division of Microbiology, University of Osnabrück, Osnabrück, Germany
- Division of Biophysics, University of Osnabrück, Osnabrück, Germany
- * E-mail: (AK); (MH)
| | - Vera Göser
- Division of Microbiology, University of Osnabrück, Osnabrück, Germany
| | - Tatjana Reuter
- Division of Microbiology, University of Osnabrück, Osnabrück, Germany
| | - Viktoria Liss
- Division of Microbiology, University of Osnabrück, Osnabrück, Germany
| | - Maximilian Franke
- Division of Microbiology, University of Osnabrück, Osnabrück, Germany
| | - Christopher John
- Division of Microbiology, University of Osnabrück, Osnabrück, Germany
| | | | - Jörg Deiwick
- Division of Microbiology, University of Osnabrück, Osnabrück, Germany
| | - Michael Hensel
- Division of Microbiology, University of Osnabrück, Osnabrück, Germany
- CellNanOs–Center for Cellular Nanoanalytics, Fachbereich Biologie/Chemie, Universität Osnabrück, Osnabrück, Germany
- * E-mail: (AK); (MH)
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11
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Galeev A, Suwandi A, Bakker H, Oktiviyari A, Routier FH, Krone L, Hensel M, Grassl GA. Proteoglycan-Dependent Endo-Lysosomal Fusion Affects Intracellular Survival of Salmonella Typhimurium in Epithelial Cells. Front Immunol 2020; 11:731. [PMID: 32411142 PMCID: PMC7201003 DOI: 10.3389/fimmu.2020.00731] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Accepted: 03/31/2020] [Indexed: 11/28/2022] Open
Abstract
Proteoglycans (PGs) are glycoconjugates which are predominately expressed on cell surfaces and consist of glycosaminoglycans (GAGs) linked to a core protein. An initial step of GAGs assembly is governed by the β-D-xylosyltransferase enzymes encoded in mammals by the XylT1/XylT2 genes. PGs are essential for the interaction of a cell with other cells as well as with the extracellular matrix. A number of studies highlighted a role of PGs in bacterial adhesion, invasion, and immune response. In this work, we investigated a role of PGs in Salmonella enterica serovar Typhimurium (S. Typhimurium) infection of epithelial cells. Gentamicin protection and chloroquine resistance assays were applied to assess invasion and replication of S. Typhimurium in wild-type and xylosyltransferase-deficient (ΔXylT2) Chinese hamster ovary (CHO) cells lacking PGs. We found that S. Typhimurium adheres to and invades CHO WT and CHO ΔXylT2 cells at comparable levels. However, 24 h after infection, proteoglycan-deficient CHO ΔXylT2 cells are significantly less colonized by S. Typhimurium compared to CHO WT cells. This proteoglycan-dependent phenotype could be rescued by addition of PGs to the cell culture medium, as well as by complementation of the XylT2 gene. Chloroquine resistance assay and immunostaining revealed that in the absence of PGs, significantly less bacteria are associated with Salmonella-containing vacuoles (SCVs) due to a re-distribution of endocytosed gentamicin. Inhibition of endo-lysosomal fusion by a specific inhibitor of phosphatidylinositol phosphate kinase PIKfyve significantly increased S. Typhimurium burden in CHO ΔXylT2 cells demonstrating an important role of PGs for PIKfyve dependent vesicle fusion which is modulated by Salmonella to establish infection. Overall, our results demonstrate that PGs influence survival of intracellular Salmonella in epithelial cells via modulation of PIKfyve-dependent endo-lysosomal fusion.
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Affiliation(s)
- Alibek Galeev
- Institute of Medical Microbiology and Hospital Epidemiology, Hannover Medical School and German Center for Infection Research (DZIF), Hanover, Germany
| | - Abdulhadi Suwandi
- Institute of Medical Microbiology and Hospital Epidemiology, Hannover Medical School and German Center for Infection Research (DZIF), Hanover, Germany
| | - Hans Bakker
- Institute of Clinical Biochemistry, Hannover Medical School, Hanover, Germany
| | - Ade Oktiviyari
- Institute of Medical Microbiology and Hospital Epidemiology, Hannover Medical School and German Center for Infection Research (DZIF), Hanover, Germany
| | - Françoise H Routier
- Institute of Clinical Biochemistry, Hannover Medical School, Hanover, Germany
| | - Lena Krone
- Division of Microbiology, University of Osnabrück, Osnabrück, Germany
| | - Michael Hensel
- Division of Microbiology, University of Osnabrück, Osnabrück, Germany
| | - Guntram A Grassl
- Institute of Medical Microbiology and Hospital Epidemiology, Hannover Medical School and German Center for Infection Research (DZIF), Hanover, Germany
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12
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RAB5A and TRAPPC6B are novel targets for Shiga toxin 2a inactivation in kidney epithelial cells. Sci Rep 2020; 10:4945. [PMID: 32188865 PMCID: PMC7080763 DOI: 10.1038/s41598-020-59694-w] [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: 11/05/2019] [Accepted: 01/30/2020] [Indexed: 12/21/2022] Open
Abstract
The cardinal virulence factor of human-pathogenic enterohaemorrhagic Escherichia coli (EHEC) is Shiga toxin (Stx), which causes severe extraintestinal complications including kidney failure by damaging renal endothelial cells. In EHEC pathogenesis, the disturbance of the kidney epithelium by Stx becomes increasingly recognised, but how this exactly occurs is unknown. To explore this molecularly, we investigated the Stx receptor content and transcriptomic profile of two human renal epithelial cell lines: highly Stx-sensitive ACHN cells and largely Stx-insensitive Caki-2 cells. Though both lines exhibited the Stx receptor globotriaosylceramide, RNAseq revealed strikingly different transcriptomic responses to an Stx challenge. Using RNAi to silence factors involved in ACHN cells’ Stx response, the greatest protection occurred when silencing RAB5A and TRAPPC6B, two host factors that we newly link to Stx trafficking. Silencing these factors alongside YKT6 fully prevented the cytotoxic Stx effect. Overall, our approach reveals novel subcellular targets for potential therapies against Stx-mediated kidney failure.
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13
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Göser V, Kehl A, Röder J, Hensel M. Role of the ESCRT‐III complex in controlling integrity of the
Salmonella
‐containing vacuole. Cell Microbiol 2020; 22:e13176. [DOI: 10.1111/cmi.13176] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 12/27/2019] [Accepted: 01/20/2020] [Indexed: 12/21/2022]
Affiliation(s)
- Vera Göser
- Abt. MikrobiologieFachbereich Biologie/Chemie, Universität Osnabrück Osnabrück Germany
| | - Alexander Kehl
- Abt. MikrobiologieFachbereich Biologie/Chemie, Universität Osnabrück Osnabrück Germany
- Institut für HygieneUniversität Münster Münster Germany
- CellNanOs, Center for Cellular NanoanalyticsFachbereich Biologie/Chemie, Universität Osnabrück Osnabrück Germany
| | - Jennifer Röder
- Abt. MikrobiologieFachbereich Biologie/Chemie, Universität Osnabrück Osnabrück Germany
| | - Michael Hensel
- Abt. MikrobiologieFachbereich Biologie/Chemie, Universität Osnabrück Osnabrück Germany
- CellNanOs, Center for Cellular NanoanalyticsFachbereich Biologie/Chemie, Universität Osnabrück Osnabrück Germany
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14
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Min SH, Suzuki A, Weaver L, Guzman J, Chung Y, Jin H, Gonzalez F, Trasorras C, Zhao L, Spruce LA, Seeholzer SH, Behrens EM, Abrams CS. PIKfyve Deficiency in Myeloid Cells Impairs Lysosomal Homeostasis in Macrophages and Promotes Systemic Inflammation in Mice. Mol Cell Biol 2019; 39:e00158-19. [PMID: 31427458 PMCID: PMC6791654 DOI: 10.1128/mcb.00158-19] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Revised: 04/29/2019] [Accepted: 08/12/2019] [Indexed: 01/15/2023] Open
Abstract
Macrophages are professional phagocytes that are essential for host defense and tissue homeostasis. Proper membrane trafficking and degradative functions of the endolysosomal system are known to be critical for the function of these cells. We have found that PIKfyve, the kinase that synthesizes the endosomal phosphoinositide phosphatidylinositol-3,5-bisphosphate, is an essential regulator of lysosomal biogenesis and degradative functions in macrophages. Genetically engineered mice lacking PIKfyve in their myeloid cells (PIKfyvefl/fl LysM-Cre) develop diffuse tissue infiltration of foamy macrophages, hepatosplenomegaly, and systemic inflammation. PIKfyve loss in macrophages causes enlarged endolysosomal compartments and impairs the lysosomal degradative function. Moreover, PIKfyve deficiency increases the cellular levels of lysosomal proteins. Although PIKfyve deficiency reduced the activation of mTORC1 pathway and was associated with increased cleavage of TFEB proteins, this does not translate into transcriptional activation of lysosomal genes, suggesting that PIKfyve modulates the abundance of lysosomal proteins by affecting the degradation of these proteins. Our study shows that PIKfyve modulation of lysosomal degradative activity and protein expression is essential to maintain lysosomal homeostasis in macrophages.
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Affiliation(s)
- Sang Hee Min
- Department of Medicine, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, USA
- Department of Medicine, University of Michigan, Ann Arbor, Michigan, USA
| | - Aae Suzuki
- Department of Medicine, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, USA
| | - Lehn Weaver
- Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Jessica Guzman
- Department of Medicine, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, USA
| | - Yutein Chung
- Department of Medicine, University of Michigan, Ann Arbor, Michigan, USA
| | - Huiyan Jin
- Department of Medicine, University of Michigan, Ann Arbor, Michigan, USA
| | - Francina Gonzalez
- Department of Medicine, University of Michigan, Ann Arbor, Michigan, USA
| | - Claire Trasorras
- Department of Medicine, University of Michigan, Ann Arbor, Michigan, USA
| | - Liang Zhao
- Department of Medicine, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, USA
| | - Lynn A Spruce
- Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | | | - Edward M Behrens
- Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Charles S Abrams
- Department of Medicine, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, USA
- Department of Pathology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, USA
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15
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Ikonomov OC, Sbrissa D, Shisheva A. Small molecule PIKfyve inhibitors as cancer therapeutics: Translational promises and limitations. Toxicol Appl Pharmacol 2019; 383:114771. [PMID: 31628917 DOI: 10.1016/j.taap.2019.114771] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2019] [Revised: 09/27/2019] [Accepted: 09/29/2019] [Indexed: 11/20/2022]
Abstract
Through synthesis of two rare phosphoinositides, PtdIns(3,5)P2 and PtdIns5P, the ubiquitously expressed phosphoinositide kinase PIKfyve is implicated in pleiotropic cellular functions. Small molecules specifically inhibiting PIKfyve activity cause cytoplasmic vacuolation in all dividing cells in culture yet trigger non-apoptotic death through excessive vacuolation only in cancer cells. Intriguingly, cancer cell toxicity appears to be inhibitor-specific suggesting that additional targets beyond PIKfyve are affected. One PIKfyve inhibitor - apilimod - is already in clinical trials for treatment of B-cell malignancies. However, apilimod is inactivated in cultured cells and exhibits unexpectedly low plasma levels in patients treated with maximum oral dosage. Thus, the potential widespread use of PIKfyve inhibitors as cancer therapeutics requires progress on multiple fronts: (i) advances in methods for isolating relevant cancer cells from individual patients; (ii) delineation of the molecular mechanisms potentiating the vacuolation induced by PIKfyve inhibitors in sensitive cancer cells; (iii) design of PIKfyve inhibitors with favorable pharmacokinetics; and (iv) development of effective drug combinations.
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Affiliation(s)
- Ognian C Ikonomov
- Department of Physiology, Wayne State University School of Medicine, Detroit, MI 48201, USA.
| | - Diego Sbrissa
- Department of Urology, Wayne State University School of Medicine, Detroit, MI 48201, USA.
| | - Assia Shisheva
- Department of Physiology, Wayne State University School of Medicine, Detroit, MI 48201, USA.
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16
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Buckley CM, Heath VL, Guého A, Bosmani C, Knobloch P, Sikakana P, Personnic N, Dove SK, Michell RH, Meier R, Hilbi H, Soldati T, Insall RH, King JS. PIKfyve/Fab1 is required for efficient V-ATPase and hydrolase delivery to phagosomes, phagosomal killing, and restriction of Legionella infection. PLoS Pathog 2019; 15:e1007551. [PMID: 30730983 PMCID: PMC6382210 DOI: 10.1371/journal.ppat.1007551] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Revised: 02/20/2019] [Accepted: 01/03/2019] [Indexed: 12/11/2022] Open
Abstract
By engulfing potentially harmful microbes, professional phagocytes are continually at risk from intracellular pathogens. To avoid becoming infected, the host must kill pathogens in the phagosome before they can escape or establish a survival niche. Here, we analyse the role of the phosphoinositide (PI) 5-kinase PIKfyve in phagosome maturation and killing, using the amoeba and model phagocyte Dictyostelium discoideum. PIKfyve plays important but poorly understood roles in vesicular trafficking by catalysing formation of the lipids phosphatidylinositol (3,5)-bisphosphate (PI(3,5)2) and phosphatidylinositol-5-phosphate (PI(5)P). Here we show that its activity is essential during early phagosome maturation in Dictyostelium. Disruption of PIKfyve inhibited delivery of both the vacuolar V-ATPase and proteases, dramatically reducing the ability of cells to acidify newly formed phagosomes and digest their contents. Consequently, PIKfyve- cells were unable to generate an effective antimicrobial environment and efficiently kill captured bacteria. Moreover, we demonstrate that cells lacking PIKfyve are more susceptible to infection by the intracellular pathogen Legionella pneumophila. We conclude that PIKfyve-catalysed phosphoinositide production plays a crucial and general role in ensuring early phagosomal maturation, protecting host cells from diverse pathogenic microbes.
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Affiliation(s)
- Catherine M. Buckley
- Centre for Membrane Interactions and Dynamics, Department of Biomedical Sciences, University of Sheffield, Firth Court, Western Bank, Sheffield, United Kingdom
- Bateson Centre, University of Sheffield, Firth Court, Western Bank, Sheffield, United Kingdom
| | - Victoria L. Heath
- Institute of Cardiovascular Sciences, Institute for Biomedical Research, College of Medical and Dental Sciences, University of Birmingham, Edgbaston, Birmingham, United Kingdom
| | - Aurélie Guého
- Department of Biochemistry, Faculty of Sciences, University of Geneva, Geneva, Switzerland
| | - Cristina Bosmani
- Department of Biochemistry, Faculty of Sciences, University of Geneva, Geneva, Switzerland
| | - Paulina Knobloch
- Institute of Medical Microbiology, University of Zürich, Zürich, Switzerland
| | - Phumzile Sikakana
- Centre for Membrane Interactions and Dynamics, Department of Biomedical Sciences, University of Sheffield, Firth Court, Western Bank, Sheffield, United Kingdom
| | - Nicolas Personnic
- Institute of Medical Microbiology, University of Zürich, Zürich, Switzerland
| | - Stephen K. Dove
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, United Kingdom
| | - Robert H. Michell
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, United Kingdom
| | - Roger Meier
- Institute of Molecular Life Sciences, University of Zürich, Zürich, Switzerland
| | - Hubert Hilbi
- Institute of Medical Microbiology, University of Zürich, Zürich, Switzerland
| | - Thierry Soldati
- Department of Biochemistry, Faculty of Sciences, University of Geneva, Geneva, Switzerland
| | - Robert H. Insall
- CRUK Beatson Institute, Switchback Road, Bearsden, Glasgow, United Kingdom
| | - Jason S. King
- Centre for Membrane Interactions and Dynamics, Department of Biomedical Sciences, University of Sheffield, Firth Court, Western Bank, Sheffield, United Kingdom
- Bateson Centre, University of Sheffield, Firth Court, Western Bank, Sheffield, United Kingdom
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17
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Baranov MV, Bianchi F, Schirmacher A, van Aart MAC, Maassen S, Muntjewerff EM, Dingjan I, Ter Beest M, Verdoes M, Keyser SGL, Bertozzi CR, Diederichsen U, van den Bogaart G. The Phosphoinositide Kinase PIKfyve Promotes Cathepsin-S-Mediated Major Histocompatibility Complex Class II Antigen Presentation. iScience 2018; 11:160-177. [PMID: 30612035 PMCID: PMC6319320 DOI: 10.1016/j.isci.2018.12.015] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Revised: 11/28/2018] [Accepted: 12/14/2018] [Indexed: 02/07/2023] Open
Abstract
Antigen presentation to T cells in major histocompatibility complex class II (MHC class II) requires the conversion of early endo/phagosomes into lysosomes by a process called maturation. Maturation is driven by the phosphoinositide kinase PIKfyve. Blocking PIKfyve activity by small molecule inhibitors caused a delay in the conversion of phagosomes into lysosomes and in phagosomal acidification, whereas production of reactive oxygen species (ROS) increased. Elevated ROS resulted in reduced activity of cathepsin S and B, but not X, causing a proteolytic defect of MHC class II chaperone invariant chain Ii processing. We developed a novel universal MHC class II presentation assay based on a bio-orthogonal "clickable" antigen and showed that MHC class II presentation was disrupted by the inhibition of PIKfyve, which in turn resulted in reduced activation of CD4+ T cells. Our results demonstrate a key role of PIKfyve in the processing and presentation of antigens, which should be taken into consideration when targeting PIKfyve in autoimmune disease and cancer.
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Affiliation(s)
- Maksim V Baranov
- Department of Tumor Immunology, Radboud University Medical Center, Radboud Institute for Molecular Life Sciences, Geert Grooteplein 28, 6525GA Nijmegen, the Netherlands
| | - Frans Bianchi
- Department of Tumor Immunology, Radboud University Medical Center, Radboud Institute for Molecular Life Sciences, Geert Grooteplein 28, 6525GA Nijmegen, the Netherlands; Department of Molecular Immunology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 7, Groningen 9747 AG, the Netherlands
| | - Anastasiya Schirmacher
- Institute of Organic and Biomolecular Chemistry, Georg-August-University of Göttingen, Tammannstr. 2, 37077 Göttingen, Germany
| | - Melissa A C van Aart
- Department of Tumor Immunology, Radboud University Medical Center, Radboud Institute for Molecular Life Sciences, Geert Grooteplein 28, 6525GA Nijmegen, the Netherlands
| | - Sjors Maassen
- Department of Tumor Immunology, Radboud University Medical Center, Radboud Institute for Molecular Life Sciences, Geert Grooteplein 28, 6525GA Nijmegen, the Netherlands; Department of Molecular Immunology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 7, Groningen 9747 AG, the Netherlands
| | - Elke M Muntjewerff
- Department of Tumor Immunology, Radboud University Medical Center, Radboud Institute for Molecular Life Sciences, Geert Grooteplein 28, 6525GA Nijmegen, the Netherlands
| | - Ilse Dingjan
- Department of Tumor Immunology, Radboud University Medical Center, Radboud Institute for Molecular Life Sciences, Geert Grooteplein 28, 6525GA Nijmegen, the Netherlands
| | - Martin Ter Beest
- Department of Tumor Immunology, Radboud University Medical Center, Radboud Institute for Molecular Life Sciences, Geert Grooteplein 28, 6525GA Nijmegen, the Netherlands
| | - Martijn Verdoes
- Department of Tumor Immunology, Radboud University Medical Center, Radboud Institute for Molecular Life Sciences, Geert Grooteplein 28, 6525GA Nijmegen, the Netherlands
| | | | - Carolyn R Bertozzi
- Department of Chemistry and Howard Hughes Medical Institute, Stanford University, Stanford, CA 94305, USA
| | - Ulf Diederichsen
- Institute of Organic and Biomolecular Chemistry, Georg-August-University of Göttingen, Tammannstr. 2, 37077 Göttingen, Germany
| | - Geert van den Bogaart
- Department of Tumor Immunology, Radboud University Medical Center, Radboud Institute for Molecular Life Sciences, Geert Grooteplein 28, 6525GA Nijmegen, the Netherlands; Department of Molecular Immunology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 7, Groningen 9747 AG, the Netherlands.
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18
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Isobe Y, Nigorikawa K, Tsurumi G, Takemasu S, Takasuga S, Kofuji S, Hazeki K. PIKfyve accelerates phagosome acidification through activation of TRPML1 while arrests aberrant vacuolation independent of the Ca2+ channel. J Biochem 2018; 165:75-84. [DOI: 10.1093/jb/mvy084] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Accepted: 10/05/2018] [Indexed: 01/17/2023] Open
Affiliation(s)
- Yuri Isobe
- Graduate School of Biomedical & Health Sciences, Hiroshima University, Minamiku Kasumi 1-2-3, Hiroshima, Japan
| | - Kiyomi Nigorikawa
- Graduate School of Biomedical & Health Sciences, Hiroshima University, Minamiku Kasumi 1-2-3, Hiroshima, Japan
| | - Go Tsurumi
- Graduate School of Biomedical & Health Sciences, Hiroshima University, Minamiku Kasumi 1-2-3, Hiroshima, Japan
| | - Shinya Takemasu
- Graduate School of Biomedical & Health Sciences, Hiroshima University, Minamiku Kasumi 1-2-3, Hiroshima, Japan
| | - Shunsuke Takasuga
- Department of Pathology and Immunology, Akita University School of Medicine, Akita, Japan
| | - Satoshi Kofuji
- Graduate School of Biomedical & Health Sciences, Hiroshima University, Minamiku Kasumi 1-2-3, Hiroshima, Japan
| | - Kaoru Hazeki
- Graduate School of Biomedical & Health Sciences, Hiroshima University, Minamiku Kasumi 1-2-3, Hiroshima, Japan
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19
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Freeman SA, Grinstein S. Resolution of macropinosomes, phagosomes and autolysosomes: Osmotically driven shrinkage enables tubulation and vesiculation. Traffic 2018; 19:965-974. [DOI: 10.1111/tra.12614] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2018] [Revised: 08/15/2018] [Accepted: 08/16/2018] [Indexed: 12/14/2022]
Affiliation(s)
- Spencer A. Freeman
- Program in Cell Biology; Peter Gilgan Centre for Research and Learning, Hospital for Sick Children; Toronto Ontario Canada
| | - Sergio Grinstein
- Program in Cell Biology; Peter Gilgan Centre for Research and Learning, Hospital for Sick Children; Toronto Ontario Canada
- Keenan Research Centre of the Li Ka Shing Knowledge Institute, St. Michael's Hospital; Toronto Ontario Canada
- Department of Biochemistry; University of Toronto; Toronto Ontario Canada
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20
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Qiu S, Côté M. From hitchhiker to hijacker: pathogen exploitation of endosomal phosphoinositides 1. Biochem Cell Biol 2018; 97:1-9. [PMID: 29746785 DOI: 10.1139/bcb-2017-0317] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Signalling through phosphoinositide lipids is essential for regulating many cellular processes, including endosomal trafficking. A number of intracellular pathogens have found ways to subvert host trafficking pathways via exploitation of endosomal phosphoinositides. This review will discuss how pathogens such as bacteria, viruses, and eukaryotic parasites depend on endosomal phosphoinositides for infection as well as the mechanisms through which some are able to actively manipulate these signalling lipids to facilitate invasion, survival, replication, and immune evasion.
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Affiliation(s)
- Shirley Qiu
- a Department of Biochemistry, Microbiology, and Immunology, University of Ottawa, Ottawa, ON K1H 8M5, Canada.,b Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, ON K1H 8M5, Canada.,c Center for Infection, Immunity and Inflammation, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Marceline Côté
- a Department of Biochemistry, Microbiology, and Immunology, University of Ottawa, Ottawa, ON K1H 8M5, Canada.,b Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, ON K1H 8M5, Canada.,c Center for Infection, Immunity and Inflammation, University of Ottawa, Ottawa, ON K1H 8M5, Canada
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21
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Fogarty K, Kashem M, Bauer A, Bernardino A, Brennan D, Cook B, Farrow N, Molinaro T, Nelson R. Development of Three Orthogonal Assays Suitable for the Identification and Qualification of PIKfyve Inhibitors. Assay Drug Dev Technol 2018; 15:210-219. [PMID: 28723271 DOI: 10.1089/adt.2017.790] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
FYVE-type zinc finger-containing phosphoinositide kinase (PIKfyve) catalyzes the formation of phosphatidylinositol 3,5-bisphosphate (PI(3,5)P2) from phosphatidylinositol 3-phosphate (PI(3)P). PIKfyve has been implicated in multiple cellular processes, and its role in the regulation of toll-like receptor (TLR) pathways and the production of proinflammatory cytokines has sparked interest in developing small-molecule PIKfyve inhibitors as potential therapeutics to treat autoimmune and inflammatory diseases. We developed three orthogonal assays to identify and qualify small-molecule inhibitors of PIKfyve: (1) a purified component microfluidic enzyme assay that measures the conversion of fluorescently labeled PI(3)P to PI(3,5)P2 by purified recombinant full-length human 6His-PIKfyve (rPIKfyve); (2) an intracellular protein stabilization assay using the kinase domain of PIKfyve expressed in HEK293 cells; and (3) a cell-based functional assay that measures the production of interleukin (IL)-12p70 in human peripheral blood mononuclear cells stimulated with TLR agonists lipopolysaccharide and R848. We determined apparent Km values for both ATP and labeled PI(3)P in the rPIKfyve enzyme assay and evaluated the enzyme's ability to use phosphatidylinositol as a substrate. We also tested four reference compounds in the three assays and showed that together these assays provide a platform that is suitable to select promising inhibitors having appropriate functional activity and confirmed cellular target engagement to advance into preclinical models of inflammation.
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Affiliation(s)
- Kylie Fogarty
- 1 Department of Small Molecule Discovery Research, Boehringer Ingelheim Pharmaceuticals, Inc. , Ridgefield, Connecticut
| | - Mohammed Kashem
- 1 Department of Small Molecule Discovery Research, Boehringer Ingelheim Pharmaceuticals, Inc. , Ridgefield, Connecticut
| | - Andras Bauer
- 2 Department of Immunology and Inflammation, Boehringer Ingelheim Pharmaceuticals, Inc. , Ridgefield, Connecticut
| | - Alexandra Bernardino
- 2 Department of Immunology and Inflammation, Boehringer Ingelheim Pharmaceuticals, Inc. , Ridgefield, Connecticut
| | - Debra Brennan
- 1 Department of Small Molecule Discovery Research, Boehringer Ingelheim Pharmaceuticals, Inc. , Ridgefield, Connecticut
| | - Brian Cook
- 1 Department of Small Molecule Discovery Research, Boehringer Ingelheim Pharmaceuticals, Inc. , Ridgefield, Connecticut
| | - Neil Farrow
- 1 Department of Small Molecule Discovery Research, Boehringer Ingelheim Pharmaceuticals, Inc. , Ridgefield, Connecticut
| | - Teresa Molinaro
- 1 Department of Small Molecule Discovery Research, Boehringer Ingelheim Pharmaceuticals, Inc. , Ridgefield, Connecticut
| | - Richard Nelson
- 1 Department of Small Molecule Discovery Research, Boehringer Ingelheim Pharmaceuticals, Inc. , Ridgefield, Connecticut
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22
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Liggins MC, Flesher JL, Jahid S, Vasudeva P, Eby V, Takasuga S, Sasaki J, Sasaki T, Boissy RE, Ganesan AK. PIKfyve regulates melanosome biogenesis. PLoS Genet 2018; 14:e1007290. [PMID: 29584722 PMCID: PMC5889185 DOI: 10.1371/journal.pgen.1007290] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Revised: 04/06/2018] [Accepted: 03/05/2018] [Indexed: 12/18/2022] Open
Abstract
PIKfyve, VAC14, and FIG4 form a complex that catalyzes the production of PI(3,5)P2, a signaling lipid implicated in process ranging from lysosome maturation to neurodegeneration. While previous studies have identified VAC14 and FIG4 mutations that lead to both neurodegeneration and coat color defects, how PIKfyve regulates melanogenesis is unknown. In this study, we sought to better understand the role of PIKfyve in melanosome biogenesis. Melanocyte-specific PIKfyve knockout mice exhibit greying of the mouse coat and the accumulation of single membrane vesicle structures in melanocytes resembling multivesicular endosomes. PIKfyve inhibition blocks melanosome maturation, the processing of the melanosome protein PMEL, and the trafficking of the melanosome protein TYRP1. Taken together, these studies identify a novel role for PIKfyve in controlling the delivery of proteins from the endosomal compartment to the melanosome, a role that is distinct from the role of PIKfyve in the reformation of lysosomes from endolysosomes.
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Affiliation(s)
- Marc C. Liggins
- Department of Dermatology, University of California, San Diego, San Diego, CA, United States of America
| | - Jessica L. Flesher
- Department of Biological Chemistry, University of California, Irvine, Irvine, CA, United States of America
| | - Sohail Jahid
- Department of Dermatology, University of California, Irvine, Irvine, CA, United States of America
| | - Priya Vasudeva
- Department of Dermatology, University of California, Irvine, Irvine, CA, United States of America
| | - Victoria Eby
- Department of Dermatology, University of Cincinnati, Cincinnati, OH, United States of America
| | - Shunsuke Takasuga
- Department of Medical Biology, Akita University School of Medicine, Akita, Japan
| | - Junko Sasaki
- Department of Medical Biology, Akita University School of Medicine, Akita, Japan
| | - Takehiko Sasaki
- Department of Medical Biology, Akita University School of Medicine, Akita, Japan
| | - Raymond E. Boissy
- Department of Dermatology, University of Cincinnati, Cincinnati, OH, United States of America
| | - Anand K. Ganesan
- Department of Biological Chemistry, University of California, Irvine, Irvine, CA, United States of America
- Department of Dermatology, University of California, Irvine, Irvine, CA, United States of America
- * E-mail:
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23
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Qiu S, Leung A, Bo Y, Kozak RA, Anand SP, Warkentin C, Salambanga FDR, Cui J, Kobinger G, Kobasa D, Côté M. Ebola virus requires phosphatidylinositol (3,5) bisphosphate production for efficient viral entry. Virology 2017; 513:17-28. [PMID: 29031163 DOI: 10.1016/j.virol.2017.09.028] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Revised: 09/28/2017] [Accepted: 09/30/2017] [Indexed: 12/11/2022]
Abstract
For entry, Ebola virus (EBOV) requires the interaction of its viral glycoprotein with the cellular protein Niemann-Pick C1 (NPC1) which resides in late endosomes and lysosomes. How EBOV is trafficked and delivered to NPC1 and whether this is positively regulated during entry remain unclear. Here, we show that the PIKfyve-ArPIKfyve-Sac3 cellular complex, which is involved in the metabolism of phosphatidylinositol (3,5) bisphosphate (PtdIns(3,5)P2), is critical for EBOV infection. Although the expression of all subunits of the complex was required for efficient entry, PIKfyve kinase activity was specifically critical for entry by all pathogenic filoviruses. Inhibition of PIKfyve prevented colocalization of EBOV with NPC1 and led to virus accumulation in intracellular vesicles with characteristics of early endosomes. Importantly, genetically-encoded phosphoinositide probes revealed an increase in PtdIns(3,5)P2-positive vesicles in cells during EBOV entry. Taken together, our studies suggest that EBOV requires PtdIns(3,5)P2 production in cells to promote efficient delivery to NPC1.
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Affiliation(s)
- Shirley Qiu
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Canada; Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, Canada
| | - Anders Leung
- Special Pathogens Program, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Canada
| | - Yuxia Bo
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Canada; Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, Canada
| | - Robert A Kozak
- Special Pathogens Program, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Canada
| | - Sai Priya Anand
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Canada; Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, Canada
| | - Corina Warkentin
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Canada; Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, Canada
| | - Fabiola D R Salambanga
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Canada; Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, Canada
| | - Jennifer Cui
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Canada; Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, Canada
| | - Gary Kobinger
- Special Pathogens Program, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Canada
| | - Darwyn Kobasa
- Special Pathogens Program, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Canada; Department of Medical Microbiology, University of Manitoba, Winnipeg, Canada
| | - Marceline Côté
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Canada; Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, Canada.
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24
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Sui ZH, Xu H, Wang H, Jiang S, Chi H, Sun L. Intracellular Trafficking Pathways of Edwardsiella tarda: From Clathrin- and Caveolin-Mediated Endocytosis to Endosome and Lysosome. Front Cell Infect Microbiol 2017; 7:400. [PMID: 28932708 PMCID: PMC5592743 DOI: 10.3389/fcimb.2017.00400] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2017] [Accepted: 08/24/2017] [Indexed: 11/24/2022] Open
Abstract
Edwardsiella tarda is a Gram-negative bacterium that can infect a broad range of hosts including humans and fish. Accumulating evidences have indicated that E. tarda is able to survive and replicate in host phagocytes. However, the pathways involved in the intracellular infection of E. tarda are unclear. In this study, we examined the entry and endocytic trafficking of E. tarda in the mouse macrophage cell line RAW264.7. We found that E. tarda entered RAW264.7 and multiplied intracellularly in a robust manner. Cellular invasion of E. tarda was significantly impaired by inhibition of clathrin- and caveolin-mediated endocytic pathways and by inhibition of endosome acidification, but not by inhibition of macropinocytosis. Consistently, RAW264.7-infecting E. tarda was co-localized with clathrin, caveolin, and hallmarks of early and late endosomes, and intracellular E. tarda was found to exist in acid organelles. In addition, E. tarda in RAW264.7 was associated with actin and microtubule, and blocking of the functions of these cytoskeletons by inhibitors significantly decreased E. tarda infection. Furthermore, formaldehyde-killed E. tarda exhibited routes of cellular uptake and intracellular trafficking similar to that of live E. tarda. Together these results provide the first evidence that entry of live E. tarda into macrophages is probably a passive, virulence-independent process of phagocytosis effected by clathrin- and caveolin-mediated endocytosis and cytoskeletons, and that the intracellular traffic of E. tarda involves endosomes and endolysosomes.
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Affiliation(s)
- Zhi-hai Sui
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of SciencesQingdao, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and TechnologyQingdao, China
- University of Chinese Academy of SciencesBeijing, China
| | - Haijiao Xu
- State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of SciencesChangchun, China
| | - Hongda Wang
- State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of SciencesChangchun, China
| | - Shuai Jiang
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of SciencesQingdao, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and TechnologyQingdao, China
| | - Heng Chi
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of SciencesQingdao, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and TechnologyQingdao, China
| | - Li Sun
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of SciencesQingdao, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and TechnologyQingdao, China
- *Correspondence: Li Sun
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25
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Liebl D, Qi X, Zhe Y, Barnett TC, Teasdale RD. SopB-Mediated Recruitment of SNX18 Facilitates Salmonella Typhimurium Internalization by the Host Cell. Front Cell Infect Microbiol 2017; 7:257. [PMID: 28664153 PMCID: PMC5471308 DOI: 10.3389/fcimb.2017.00257] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Accepted: 05/31/2017] [Indexed: 11/16/2022] Open
Abstract
To invade epithelial cells, Salmonella enterica serovar Typhimurium (S. Typhimurium) induces macropinocytosis through the action of virulence proteins delivered across the host cell membrane via a type III secretion system. We show that after docking at the plasma membrane S. Typhimurium triggers rapid recruitment of cytosolic SNX18, a SH3-PX-BAR domain sorting nexin protein, to the bacteria-induced membrane ruffles and to the nascent Salmonella-containing vacuole. SNX18 recruitment required the inositol-phosphatase activity of the Salmonella effector SopB and an intact phosphoinositide-binding site within the PX domain of SNX18, but occurred independently of Rho-GTPases Rac1 and Cdc42 activation. SNX18 promotes formation of the SCV from the plasma membrane by acting as a scaffold to recruit Dynamin-2 and N-WASP in a process dependent on the SH3 domain of SNX18. Quantification of bacteria uptake revealed that overexpression of SNX18 increased bacteria internalization, whereas a decrease was detected in cells overexpressing the phosphoinositide-binding mutant R303Q, the ΔSH3 mutant, and in cells where endogenous levels of SNX18 were knocked-down. This study identifies SNX18 as a novel target of SopB and suggests a mechanism where S. Typhimurium engages host factors via local manipulation of phosphoinositide composition at the site of invasion to orchestrate the internalization process.
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Affiliation(s)
- David Liebl
- Institute for Molecular Bioscience, The University of QueenslandBrisbane, QLD, Australia
| | - Xiaying Qi
- Institute for Molecular Bioscience, The University of QueenslandBrisbane, QLD, Australia
| | - Yang Zhe
- Institute for Molecular Bioscience, The University of QueenslandBrisbane, QLD, Australia
| | - Timothy C Barnett
- Australian Infectious Diseases Research Centre, The University of QueenslandBrisbane, QLD, Australia.,School of Chemistry and Molecular Biosciences, The University of QueenslandBrisbane, QLD, Australia
| | - Rohan D Teasdale
- Institute for Molecular Bioscience, The University of QueenslandBrisbane, QLD, Australia.,Australian Infectious Diseases Research Centre, The University of QueenslandBrisbane, QLD, Australia.,School of Biomedical Sciences, The University of QueenslandBrisbane, QLD, Australia
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26
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Cuesta-Geijo MÁ, Barrado-Gil L, Galindo I, Muñoz-Moreno R, Alonso C. Redistribution of Endosomal Membranes to the African Swine Fever Virus Replication Site. Viruses 2017; 9:v9060133. [PMID: 28587154 PMCID: PMC5490810 DOI: 10.3390/v9060133] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Revised: 05/19/2017] [Accepted: 05/25/2017] [Indexed: 12/14/2022] Open
Abstract
African swine fever virus (ASFV) infection causes endosomal reorganization. Here, we show that the virus causes endosomal congregation close to the nucleus as the infection progresses, which is necessary to build a compact viral replication organelle. ASFV enters the cell by the endosomal pathway and reaches multivesicular late endosomes. Upon uncoating and fusion, the virus should exit to the cytosol to start replication. ASFV remodels endosomal traffic and redistributes endosomal membranes to the viral replication site. Virus replication also depends on endosomal membrane phosphoinositides (PtdIns) synthesized by PIKfyve. Endosomes could act as platforms providing membranes and PtdIns, necessary for ASFV replication. Our study has revealed that ASFV reorganizes endosome dynamics, in order to ensure a productive infection.
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Affiliation(s)
- Miguel Ángel Cuesta-Geijo
- Department of Biotechnology, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, INIA, Ctra. de la Coruña Km 7.5, 28040 Madrid, Spain.
- Department of Infectious Diseases, King's College London School of Medicine, Guy's Hospital, London SE1 9RT, UK.
| | - Lucía Barrado-Gil
- Department of Biotechnology, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, INIA, Ctra. de la Coruña Km 7.5, 28040 Madrid, Spain.
| | - Inmaculada Galindo
- Department of Biotechnology, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, INIA, Ctra. de la Coruña Km 7.5, 28040 Madrid, Spain.
| | - Raquel Muñoz-Moreno
- Department of Microbiology and Global Health and Emerging Pathogens Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.
| | - Covadonga Alonso
- Department of Biotechnology, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, INIA, Ctra. de la Coruña Km 7.5, 28040 Madrid, Spain.
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27
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Teo WX, Yang Z, Kerr MC, Luo L, Guo Z, Alexandrov K, Stow JL, Teasdale RD. Salmonella effector SopD2 interferes with Rab34 function. Cell Biol Int 2017; 41:433-446. [PMID: 28185347 DOI: 10.1002/cbin.10739] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Accepted: 01/31/2017] [Indexed: 11/10/2022]
Abstract
Many intracellular pathogens have evolved highly specialized mechanisms to isolate themselves from the host cell's innate immune response while still obtaining the necessary nutrients to survive. Salmonella utilizes type 3 secretion systems (T3SSs) to deliver bacterial proteins called effectors, across the encompassing Salmonella Containing vacuole (SCV) membrane, to subvert the host's membrane trafficking pathways and alter other cellular processes. The Salmonella Pathogenicity Island (SPI)-2 effector SopD2 has recently been demonstrated to modulate multiple members of the Rab GTPase family such as Rab7, Rab8, Rab10, and Rab32 (D'Costa et al., , Cell Reports, 12:1508-18; Spano et al., , Cell Host & Microbe, 19:216-26). Here, we demonstrate the additional capacity of SopD2 to bind Rab34 and modulate its function. Our data indicate that depletion of Rab34 delays maturation of the SCV, and consequently, inhibits intracellular Salmonella enterica serotype typhimurium (S. typhimurium) growth. Interestingly, intracellular growth of the S. typhimurium lacking SopD2 was severely impaired in Rab34-depleted cells, suggesting a compounding virulence effect. Overall this study reveals an additional member of the Rab GTPase family, Rab34, that is modulated by SopD2 and provides insight into its role in Salmonella biology.
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Affiliation(s)
- Wei Xuan Teo
- Institute for Molecular Biosciences, University of Queensland, St. Lucia, QLD, 4072, Australia
| | - Zhe Yang
- Institute for Molecular Biosciences, University of Queensland, St. Lucia, QLD, 4072, Australia
| | - Markus Charles Kerr
- Institute for Molecular Biosciences, University of Queensland, St. Lucia, QLD, 4072, Australia
| | - Lin Luo
- Institute for Molecular Biosciences, University of Queensland, St. Lucia, QLD, 4072, Australia
| | - Zhong Guo
- Institute for Molecular Biosciences, University of Queensland, St. Lucia, QLD, 4072, Australia
| | - Kirill Alexandrov
- Institute for Molecular Biosciences, University of Queensland, St. Lucia, QLD, 4072, Australia
| | - Jenny Lea Stow
- Institute for Molecular Biosciences, University of Queensland, St. Lucia, QLD, 4072, Australia
| | - Rohan David Teasdale
- Institute for Molecular Biosciences, University of Queensland, St. Lucia, QLD, 4072, Australia
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28
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Thornbrough JM, Gopinath A, Hundley T, Worley MJ. Human Genome-Wide RNAi Screen for Host Factors That Facilitate Salmonella Invasion Reveals a Role for Potassium Secretion in Promoting Internalization. PLoS One 2016; 11:e0166916. [PMID: 27880807 PMCID: PMC5120809 DOI: 10.1371/journal.pone.0166916] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2016] [Accepted: 11/07/2016] [Indexed: 02/06/2023] Open
Abstract
Salmonella enterica can actively invade the gastro-intestinal epithelium. This frequently leads to diarrheal disease, and also gives the pathogen access to phagocytes that can serve as vehicles for dissemination into deeper tissue. The ability to invade host cells is also important in maintaining the carrier state. While much is known about the bacterial factors that promote invasion, relatively little is known about the host factors involved. To gain insight into how Salmonella enterica serovar Typhimurium is able to invade normally non-phagocytic cells, we undertook a global RNAi screen with S. Typhimurium-infected human epithelial cells. In all, we identified 633 genes as contributing to bacterial internalization. These genes fall into a diverse group of functional categories revealing that cytoskeletal regulators are not the only factors that modulate invasion. In fact, potassium ion transport was the most enriched molecular function category in our screen, reinforcing a link between potassium and internalization. In addition to providing new insights into the molecular mechanisms underlying the ability of pathogens to invade host cells, all 633 host factors identified are candidates for new anti-microbial targets for treating Salmonella infections, and may be useful in curtailing infections with other pathogens as well.
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Affiliation(s)
- Joshua M. Thornbrough
- Department of Biology, University of Louisville, Louisville, KY, 40292, United States of America
| | - Adarsh Gopinath
- Department of Biology, University of Louisville, Louisville, KY, 40292, United States of America
| | - Tom Hundley
- Department of Biology, University of Louisville, Louisville, KY, 40292, United States of America
| | - Micah J. Worley
- Department of Biology, University of Louisville, Louisville, KY, 40292, United States of America
- Department of Microbiology and Immunology, University of Louisville, Louisville, KY, 40202, United States of America
- * E-mail:
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29
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Kim SM, Roy SG, Chen B, Nguyen TM, McMonigle RJ, McCracken AN, Zhang Y, Kofuji S, Hou J, Selwan E, Finicle BT, Nguyen TT, Ravi A, Ramirez MU, Wiher T, Guenther GG, Kono M, Sasaki AT, Weisman LS, Potma EO, Tromberg BJ, Edwards RA, Hanessian S, Edinger AL. Targeting cancer metabolism by simultaneously disrupting parallel nutrient access pathways. J Clin Invest 2016; 126:4088-4102. [PMID: 27669461 PMCID: PMC5096903 DOI: 10.1172/jci87148] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Accepted: 08/16/2016] [Indexed: 12/23/2022] Open
Abstract
Oncogenic mutations drive anabolic metabolism, creating a dependency on nutrient influx through transporters, receptors, and macropinocytosis. While sphingolipids suppress tumor growth by downregulating nutrient transporters, macropinocytosis and autophagy still provide cancer cells with fuel. Therapeutics that simultaneously disrupt these parallel nutrient access pathways have potential as powerful starvation agents. Here, we describe a water-soluble, orally bioavailable synthetic sphingolipid, SH-BC-893, that triggers nutrient transporter internalization and also blocks lysosome-dependent nutrient generation pathways. SH-BC-893 activated protein phosphatase 2A (PP2A), leading to mislocalization of the lipid kinase PIKfyve. The concomitant mislocalization of the PIKfyve product PI(3,5)P2 triggered cytosolic vacuolation and blocked lysosomal fusion reactions essential for LDL, autophagosome, and macropinosome degradation. By simultaneously limiting access to both extracellular and intracellular nutrients, SH-BC-893 selectively killed cells expressing an activated form of the anabolic oncogene Ras in vitro and in vivo. However, slower-growing, autochthonous PTEN-deficient prostate tumors that did not exhibit a classic Warburg phenotype were equally sensitive. Remarkably, normal proliferative tissues were unaffected by doses of SH-BC-893 that profoundly inhibited tumor growth. These studies demonstrate that simultaneously blocking parallel nutrient access pathways with sphingolipid-based drugs is broadly effective and cancer selective, suggesting a potential strategy for overcoming the resistance conferred by tumor heterogeneity.
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Affiliation(s)
- Seong M. Kim
- Department of Developmental and Cell Biology, University of California Irvine (UCI), Irvine, California, USA
| | - Saurabh G. Roy
- Department of Developmental and Cell Biology, University of California Irvine (UCI), Irvine, California, USA
| | - Bin Chen
- Department of Chemistry, Université de Montréal, Montréal, Québec, Canada
| | - Tiffany M. Nguyen
- Department of Developmental and Cell Biology, University of California Irvine (UCI), Irvine, California, USA
| | - Ryan J. McMonigle
- Department of Developmental and Cell Biology, University of California Irvine (UCI), Irvine, California, USA
| | - Alison N. McCracken
- Department of Developmental and Cell Biology, University of California Irvine (UCI), Irvine, California, USA
| | - Yanling Zhang
- Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, Michigan, USA
| | - Satoshi Kofuji
- Departments of Internal Medicine, Neurosurgery, and Cancer Biology, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | - Jue Hou
- Department of Biomedical Engineering, UCI, Irvine, California, USA
| | - Elizabeth Selwan
- Department of Developmental and Cell Biology, University of California Irvine (UCI), Irvine, California, USA
| | - Brendan T. Finicle
- Department of Developmental and Cell Biology, University of California Irvine (UCI), Irvine, California, USA
| | - Tricia T. Nguyen
- Department of Developmental and Cell Biology, University of California Irvine (UCI), Irvine, California, USA
| | - Archna Ravi
- Department of Developmental and Cell Biology, University of California Irvine (UCI), Irvine, California, USA
| | - Manuel U. Ramirez
- Department of Developmental and Cell Biology, University of California Irvine (UCI), Irvine, California, USA
| | - Tim Wiher
- Department of Developmental and Cell Biology, University of California Irvine (UCI), Irvine, California, USA
| | - Garret G. Guenther
- Department of Developmental and Cell Biology, University of California Irvine (UCI), Irvine, California, USA
| | - Mari Kono
- National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), Bethesda, Maryland, USA
| | - Atsuo T. Sasaki
- Departments of Internal Medicine, Neurosurgery, and Cancer Biology, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | - Lois S. Weisman
- Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, Michigan, USA
| | - Eric O. Potma
- Department of Biomedical Engineering, UCI, Irvine, California, USA
| | | | - Robert A. Edwards
- Department of Pathology, University of California Irvine School of Medicine, Irvine, California, USA
| | - Stephen Hanessian
- Department of Chemistry, Université de Montréal, Montréal, Québec, Canada
- Department of Pharmaceutical Sciences, UCI, Irvine, California, USA
| | - Aimee L. Edinger
- Department of Developmental and Cell Biology, University of California Irvine (UCI), Irvine, California, USA
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30
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Krishna S, Palm W, Lee Y, Yang W, Bandyopadhyay U, Xu H, Florey O, Thompson CB, Overholtzer M. PIKfyve Regulates Vacuole Maturation and Nutrient Recovery following Engulfment. Dev Cell 2016; 38:536-47. [PMID: 27623384 PMCID: PMC5046836 DOI: 10.1016/j.devcel.2016.08.001] [Citation(s) in RCA: 86] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Revised: 05/20/2016] [Accepted: 08/08/2016] [Indexed: 12/20/2022]
Abstract
The scavenging of extracellular macromolecules by engulfment can sustain cell growth in a nutrient-depleted environment. Engulfed macromolecules are contained within vacuoles that are targeted for lysosome fusion to initiate degradation and nutrient export. We have shown that vacuoles containing engulfed material undergo mTORC1-dependent fission that redistributes degraded cargo back into the endosomal network. Here we identify the lipid kinase PIKfyve as a regulator of an alternative pathway that distributes engulfed contents in support of intracellular macromolecular synthesis during macropinocytosis, entosis, and phagocytosis. We find that PIKfyve regulates vacuole size in part through its downstream effector, the cationic transporter TRPML1. Furthermore, PIKfyve promotes recovery of nutrients from vacuoles, suggesting a potential link between PIKfyve activity and lysosomal nutrient export. During nutrient depletion, PIKfyve activity protects Ras-mutant cells from starvation-induced cell death and supports their proliferation. These data identify PIKfyve as a critical regulator of vacuole maturation and nutrient recovery during engulfment.
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Affiliation(s)
- Shefali Krishna
- Gerstner Sloan Kettering Graduate School of Biomedical Sciences, New York, NY 10065, USA; Cell Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Wilhelm Palm
- Cancer Biology and Genetics Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Yongchan Lee
- Cell Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Wendy Yang
- Cell Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Urmi Bandyopadhyay
- Cell Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Haoxing Xu
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, 3089 National Science Building (Kraus), 830 North University, Ann Arbor, MI 48109, USA
| | - Oliver Florey
- Signalling Programme, The Babraham Institute, Cambridge CB22 3AT, UK
| | - Craig B Thompson
- Cancer Biology and Genetics Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Michael Overholtzer
- Cell Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA.
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31
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Teo WX, Kerr MC, Teasdale RD. MTMR4 Is Required for the Stability of the Salmonella-Containing Vacuole. Front Cell Infect Microbiol 2016; 6:91. [PMID: 27625994 PMCID: PMC5003867 DOI: 10.3389/fcimb.2016.00091] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2016] [Accepted: 08/15/2016] [Indexed: 12/22/2022] Open
Abstract
The intracellular pathogen Salmonella enterica servovar Typhimurium (S.typhimurium) modulates the host cell's phosphoinositide (PI) metabolism to establish its intracellular replicative niche, the Salmonella-containing vacuole (SCV). Upon invasion, phosphoinositide 3-phosphate (PI(3)P) and other early endosomal markers are rapidly recruited to and remain associated with the SCV throughout its early maturation. While the phosphoinositide 3-phosphatase myotubularin 4 (MTMR4) has an established role in regulating autophagy and cellular PI(3)P-content, two processes associated with the intracellular survival of S. typhimurium, a direct role for MTMR4 in Salmonella biology has not been examined. Here we demonstrate that GFP-tagged MTMR4 is recruited to the SCV and infection of cells depleted of endogenous MTMR4 results in a decrease in viable intracellular Salmonella. This reflects a significant increase in the proportion of SCVs with compromised integrity, which targets the compartment for autophagy and consequent bacterial cell death. These findings highlight the importance of PI(3)P regulation to the integrity of the SCV and reveal a novel role for the myotubularins in bacterial pathogenesis.
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Affiliation(s)
- Wei X Teo
- Institute for Molecular Bioscience, University of Queensland Brisbane, QLD, Australia
| | - Markus C Kerr
- Institute for Molecular Bioscience, University of Queensland Brisbane, QLD, Australia
| | - Rohan D Teasdale
- Institute for Molecular Bioscience, University of Queensland Brisbane, QLD, Australia
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32
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Dolat L, Spiliotis ET. Septins promote macropinosome maturation and traffic to the lysosome by facilitating membrane fusion. J Cell Biol 2016; 214:517-27. [PMID: 27551056 PMCID: PMC5004444 DOI: 10.1083/jcb.201603030] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Accepted: 07/21/2016] [Indexed: 11/22/2022] Open
Abstract
How macropinosomes traffic to lysosomes is poorly understood. Dolat and Spiliotis show that septins associate preferentially with mature macropinosomes in a PI(3,5)P2-dependent manner and regulate fluid-phase cargo traffic to lysosomes by promoting macropinosome/endosome fusion. Macropinocytosis, the internalization of extracellular fluid and material by plasma membrane ruffles, is critical for antigen presentation, cell metabolism, and signaling. Macropinosomes mature through homotypic and heterotypic fusion with endosomes and ultimately merge with lysosomes. The molecular underpinnings of this clathrin-independent endocytic pathway are largely unknown. Here, we show that the filamentous septin GTPases associate preferentially with maturing macropinosomes in a phosphatidylinositol 3,5-bisphosphate–dependent manner and localize to their contact/fusion sites with macropinosomes/endosomes. Septin knockdown results in large clusters of docked macropinosomes, which persist longer and exhibit fewer fusion events. Septin depletion and overexpression down-regulates and enhances, respectively, the delivery of fluid-phase cargo to lysosomes, without affecting Rab5 and Rab7 recruitment to macropinosomes/endosomes. In vitro reconstitution assays show that fusion of macropinosomes/endosomes is abrogated by septin immunodepletion and function-blocking antibodies and is induced by recombinant septins in the absence of cytosol and polymerized actin. Thus, septins regulate fluid-phase cargo traffic to lysosomes by promoting macropinosome maturation and fusion with endosomes/lysosomes.
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Affiliation(s)
- Lee Dolat
- Department of Biology, Drexel University, Philadelphia, PA 19104
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33
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Selwan EM, Finicle BT, Kim SM, Edinger AL. Attacking the supply wagons to starve cancer cells to death. FEBS Lett 2016; 590:885-907. [PMID: 26938658 DOI: 10.1002/1873-3468.12121] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Revised: 02/10/2016] [Accepted: 02/29/2016] [Indexed: 12/14/2022]
Abstract
The constitutive anabolism of cancer cells not only supports proliferation but also addicts tumor cells to a steady influx of exogenous nutrients. Limiting access to metabolic substrates could be an effective and selective means to block cancer growth. In this review, we define the pathways by which cancer cells acquire the raw materials for anabolism, highlight the actionable proteins in each pathway, and discuss the status of therapeutic interventions that disrupt nutrient acquisition. Critical open questions to be answered before apical metabolic inhibitors can be successfully and safely deployed in the clinic are also outlined. In summary, recent studies provide strong support that substrate limitation is a powerful therapeutic strategy to effectively, and safely, starve cancer cells to death.
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Affiliation(s)
- Elizabeth M Selwan
- Department of Developmental and Cell Biology, University of California Irvine, CA, USA
| | - Brendan T Finicle
- Department of Developmental and Cell Biology, University of California Irvine, CA, USA
| | - Seong M Kim
- Department of Developmental and Cell Biology, University of California Irvine, CA, USA
| | - Aimee L Edinger
- Department of Developmental and Cell Biology, University of California Irvine, CA, USA
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34
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Chan ASM, Clairfeuille T, Landao-Bassonga E, Kinna G, Ng PY, Loo LS, Cheng TS, Zheng M, Hong W, Teasdale RD, Collins BM, Pavlos NJ. Sorting nexin 27 couples PTHR trafficking to retromer for signal regulation in osteoblasts during bone growth. Mol Biol Cell 2016; 27:1367-82. [PMID: 26912788 PMCID: PMC4831889 DOI: 10.1091/mbc.e15-12-0851] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Accepted: 02/10/2016] [Indexed: 12/26/2022] Open
Abstract
The parathyroid hormone 1 receptor (PTHR) is central to the process of bone formation and remodeling. PTHR signaling requires receptor internalization into endosomes, which is then terminated by recycling or degradation. Here we show that sorting nexin 27 (SNX27) functions as an adaptor that couples PTHR to the retromer trafficking complex. SNX27 binds directly to the C-terminal PDZ-binding motif of PTHR, wiring it to retromer for endosomal sorting. The structure of SNX27 bound to the PTHR motif reveals a high-affinity interface involving conserved electrostatic interactions. Mechanistically, depletion of SNX27 or retromer augments intracellular PTHR signaling in endosomes. Osteoblasts genetically lacking SNX27 show similar disruptions in PTHR signaling and greatly reduced capacity for bone mineralization, contributing to profound skeletal deficits in SNX27-knockout mice. Taken together, our data support a critical role for SNX27-retromer mediated transport of PTHR in normal bone development.
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Affiliation(s)
- Audrey S M Chan
- Cellular Orthopaedic Laboratory, School of Surgery, University of Western Australia, Nedlands 6009, Australia
| | - Thomas Clairfeuille
- Institute for Molecular Bioscience, University of Queensland, St. Lucia 4072, Australia
| | - Euphemie Landao-Bassonga
- Cellular Orthopaedic Laboratory, School of Surgery, University of Western Australia, Nedlands 6009, Australia
| | - Genevieve Kinna
- Institute for Molecular Bioscience, University of Queensland, St. Lucia 4072, Australia
| | - Pei Ying Ng
- Cellular Orthopaedic Laboratory, School of Surgery, University of Western Australia, Nedlands 6009, Australia
| | - Li Shen Loo
- Institute of Molecular and Cell Biology, A*STAR, Singapore 138673
| | - Tak Sum Cheng
- Cellular Orthopaedic Laboratory, School of Surgery, University of Western Australia, Nedlands 6009, Australia
| | - Minghao Zheng
- Cellular Orthopaedic Laboratory, School of Surgery, University of Western Australia, Nedlands 6009, Australia
| | - Wanjin Hong
- Institute of Molecular and Cell Biology, A*STAR, Singapore 138673
| | - Rohan D Teasdale
- Institute for Molecular Bioscience, University of Queensland, St. Lucia 4072, Australia
| | - Brett M Collins
- Institute for Molecular Bioscience, University of Queensland, St. Lucia 4072, Australia
| | - Nathan J Pavlos
- Cellular Orthopaedic Laboratory, School of Surgery, University of Western Australia, Nedlands 6009, Australia
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35
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Lim JP, Gosavi P, Mintern JD, Ross EM, Gleeson PA. Sorting nexin 5 selectively regulates dorsal-ruffle-mediated macropinocytosis in primary macrophages. J Cell Sci 2015; 128:4407-19. [PMID: 26459636 DOI: 10.1242/jcs.174359] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Accepted: 10/05/2015] [Indexed: 02/01/2023] Open
Abstract
The regulation of macropinocytosis, a specialised endocytosis pathway, is important for immune cell function. However, it is not known whether the biogenesis of macropinosomes involves one or more distinct pathways. We previously identified sorting nexin 5 (SNX5) as a regulator of macropinocytosis in macrophages. Here, we show that bone-marrow-derived macrophages from SNX5-knockout mice had a 60-70% reduction in macropinocytic uptake of dextran or ovalbumin, whereas phagocytosis and retrograde transport from the plasma membrane to the Golgi was unaffected. In contrast, deficiency of SNX5 had no effect on macropinocytosis or antigen presentation by dendritic cells. Activation of macrophages with CSF-1 resulted in a localisation of SNX5 to actin-rich ruffles in a manner dependent on receptor tyrosine kinases. SNX5-deficient macrophages showed a dramatic reduction in ruffling on the dorsal surface following CSF-1 receptor activation, whereas peripheral ruffling and cell migration were unaffected. We demonstrate that SNX5 is acting upstream of actin polymerisation following CSF-1 receptor activation. Overall, our findings reveal the important contribution of dorsal ruffing to receptor-activated macropinocytosis in primary macrophages and show that SNX5 selectively regulates macropinosomes derived from the dorsal ruffles.
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Affiliation(s)
- Jet Phey Lim
- The Department of Biochemistry and Molecular Biology and Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Prajakta Gosavi
- The Department of Biochemistry and Molecular Biology and Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Justine D Mintern
- The Department of Biochemistry and Molecular Biology and Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Ellen M Ross
- The Department of Biochemistry and Molecular Biology and Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Paul A Gleeson
- The Department of Biochemistry and Molecular Biology and Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Melbourne, Victoria 3010, Australia
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Rizopoulos Z, Balistreri G, Kilcher S, Martin CK, Syedbasha M, Helenius A, Mercer J. Vaccinia Virus Infection Requires Maturation of Macropinosomes. Traffic 2015; 16:814-31. [PMID: 25869659 PMCID: PMC4973667 DOI: 10.1111/tra.12290] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Revised: 04/08/2015] [Accepted: 04/09/2015] [Indexed: 01/11/2023]
Abstract
The prototypic poxvirus, vaccinia virus (VACV), occurs in two infectious forms, mature virions (MVs) and extracellular virions (EVs). Both enter HeLa cells by inducing macropinocytic uptake. Using confocal microscopy, live-cell imaging, targeted RNAi screening and perturbants of endosome maturation, we analyzed the properties and maturation pathway of the macropinocytic vacuoles containing VACV MVs in HeLa cells. The vacuoles first acquired markers of early endosomes [Rab5, early endosome antigen 1 and phosphatidylinositol(3)P]. Prior to release of virus cores into the cytoplasm, they contained markers of late endosomes and lysosomes (Rab7a, lysosome-associated membrane protein 1 and sorting nexin 3). RNAi screening of endocytic cell factors emphasized the importance of late compartments for VACV infection. Follow-up perturbation analysis showed that infection required Rab7a and PIKfyve, confirming that VACV is a late-penetrating virus dependent on macropinosome maturation. VACV EV infection was inhibited by depletion of many of the same factors, indicating that both infectious particle forms share the need for late vacuolar conditions for penetration.
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Affiliation(s)
- Zaira Rizopoulos
- ETH Zürich Institute of Biochemistry, Otto-Stern-Weg 3, 8093 Zürich, Switzerland
| | - Giuseppe Balistreri
- ETH Zürich Institute of Biochemistry, Otto-Stern-Weg 3, 8093 Zürich, Switzerland
| | - Samuel Kilcher
- MRC-Laboratory for Molecular Cell Biology, University College London, Gower Street, London WC1E 6BT, UK
| | - Caroline K Martin
- MRC-Laboratory for Molecular Cell Biology, University College London, Gower Street, London WC1E 6BT, UK
| | | | - Ari Helenius
- ETH Zürich Institute of Biochemistry, Otto-Stern-Weg 3, 8093 Zürich, Switzerland
| | - Jason Mercer
- MRC-Laboratory for Molecular Cell Biology, University College London, Gower Street, London WC1E 6BT, UK
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Phosphatidylinositol 4-phosphate and phosphatidylinositol 3-phosphate regulate phagolysosome biogenesis. Proc Natl Acad Sci U S A 2015; 112:4636-41. [PMID: 25825728 DOI: 10.1073/pnas.1423456112] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Professional phagocytic cells ingest microbial intruders by engulfing them into phagosomes, which subsequently mature into microbicidal phagolysosomes. Phagosome maturation requires sequential fusion of the phagosome with early endosomes, late endosomes, and lysosomes. Although various phosphoinositides (PIPs) have been detected on phagosomes, it remained unclear which PIPs actually govern phagosome maturation. Here, we analyzed the involvement of PIPs in fusion of phagosomes with various endocytic compartments and identified phosphatidylinositol 4-phosphate [PI(4)P], phosphatidylinositol 3-phosphate [PI(3)P], and the lipid kinases that generate these PIPs, as mediators of phagosome-lysosome fusion. Phagosome-early endosome fusion required PI(3)P, yet did not depend on PI(4)P. Thus, PI(3)P regulates phagosome maturation at early and late stages, whereas PI(4)P is selectively required late in the pathway.
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38
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Egami Y, Taguchi T, Maekawa M, Arai H, Araki N. Small GTPases and phosphoinositides in the regulatory mechanisms of macropinosome formation and maturation. Front Physiol 2014; 5:374. [PMID: 25324782 PMCID: PMC4179697 DOI: 10.3389/fphys.2014.00374] [Citation(s) in RCA: 104] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2014] [Accepted: 09/10/2014] [Indexed: 12/26/2022] Open
Abstract
Macropinosome formation requires the sequential activation of numerous signaling pathways that coordinate the actin-driven formation of plasma membrane protrusions (ruffles) and circular ruffles (macropinocytic cups), followed by the closure of these macropinocytic cups into macropinosomes. In the process of macropinosome formation, localized productions of phosphoinositides such as PI(4,5)P2 and PI(3,4,5)P3 spatiotemporally orchestrate actin polymerization and rearrangement through recruiting and activating a variety of actin-associated proteins. In addition, the sequential activation of small GTPases, which are known to be master regulators of the actin cytoskeleton, plays a pivotal role in parallel with phosphoinositides. To complete macropinosome formation, phosphoinositide breakdown and Rho GTPase deactivation must occur in appropriate timings. After the nascent macropinosomes are formed, phosphoinositides and several Rab GTPases control macropinosome maturation by regulating vesicle trafficking and membrane fusion. In this review, we summarize recent advances in our understanding of the critical functions of phosphoinositide metabolism and small GTPases in association with their downstream effectors in macropinocytosis.
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Affiliation(s)
- Youhei Egami
- Department of Histology and Cell Biology, School of Medicine, Kagawa University Miki, Japan
| | - Tomohiko Taguchi
- Department of Health Chemistry, Graduate School of Pharmaceutical Sciences, University of Tokyo Tokyo, Japan ; Pathological Cell Biology Laboratory, Graduate School of Pharmaceutical Sciences, University of Tokyo Tokyo, Japan
| | - Masashi Maekawa
- Department of Health Chemistry, Graduate School of Pharmaceutical Sciences, University of Tokyo Tokyo, Japan ; Keenan Research Centre, Li Ka Shing Knowledge Institute, St. Michael's Hospital Toronto, ON, Canada
| | - Hiroyuki Arai
- Department of Health Chemistry, Graduate School of Pharmaceutical Sciences, University of Tokyo Tokyo, Japan ; Pathological Cell Biology Laboratory, Graduate School of Pharmaceutical Sciences, University of Tokyo Tokyo, Japan
| | - Nobukazu Araki
- Department of Histology and Cell Biology, School of Medicine, Kagawa University Miki, Japan
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39
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Thieleke-Matos C, da Silva ML, Cabrita-Santos L, Pires CF, Ramalho JS, Ikonomov O, Seixas E, Shisheva A, Seabra MC, Barral DC. Host PI(3,5)P2 activity is required for Plasmodium berghei growth during liver stage infection. Traffic 2014; 15:1066-82. [PMID: 24992508 DOI: 10.1111/tra.12190] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2013] [Revised: 06/26/2014] [Accepted: 06/29/2014] [Indexed: 01/18/2023]
Abstract
Malaria parasites go through an obligatory liver stage before they infect erythrocytes and cause disease symptoms. In the host hepatocytes, the parasite is enclosed by a parasitophorous vacuole membrane (PVM). Here, we dissected the interaction between the Plasmodium parasite and the host cell late endocytic pathway and show that parasite growth is dependent on the phosphoinositide 5-kinase (PIKfyve) that converts phosphatidylinositol 3-phosphate [PI(3)P] into phosphatidylinositol 3,5-bisphosphate [PI(3,5)P2 ] in the endosomal system. We found that inhibition of PIKfyve by either pharmacological or non-pharmacological means causes a delay in parasite growth. Moreover, we show that the PI(3,5)P2 effector protein TRPML1 that is involved in late endocytic membrane fusion, is present in vesicles closely contacting the PVM and is necessary for parasite growth. Thus, our studies suggest that the parasite PVM is able to fuse with host late endocytic vesicles in a PI(3,5)P2 -dependent manner, allowing the exchange of material between the host and the parasite, which is essential for successful infection.
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Affiliation(s)
- Carolina Thieleke-Matos
- CEDOC, Faculdade de Ciências Médicas, Universidade Nova de Lisboa, 1169-056, Lisboa, Portugal; IGC, Instituto Gulbenkian de Ciência, 2780-156, Oeiras, Portugal
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40
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Kim GH, Dayam RM, Prashar A, Terebiznik M, Botelho RJ. PIKfyve Inhibition Interferes with Phagosome and Endosome Maturation in Macrophages. Traffic 2014; 15:1143-63. [DOI: 10.1111/tra.12199] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2013] [Revised: 07/11/2014] [Accepted: 07/14/2014] [Indexed: 01/17/2023]
Affiliation(s)
- Grace H.E. Kim
- Deparment of Chemistry and Biology and the Molecular Science Program; Ryerson University; Toronto Ontario M5B2K3 Canada
| | - Roya M. Dayam
- Deparment of Chemistry and Biology and the Molecular Science Program; Ryerson University; Toronto Ontario M5B2K3 Canada
| | - Akriti Prashar
- Department of Cell and Systems Biology; University of Toronto at Scarborough; Toronto Ontario M1C 1A4 Canada
| | - Mauricio Terebiznik
- Department of Cell and Systems Biology; University of Toronto at Scarborough; Toronto Ontario M1C 1A4 Canada
| | - Roberto J. Botelho
- Deparment of Chemistry and Biology and the Molecular Science Program; Ryerson University; Toronto Ontario M5B2K3 Canada
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41
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Kerr M, Teasdale RD. Live imaging of endosome dynamics. Semin Cell Dev Biol 2014; 31:11-9. [PMID: 24704360 DOI: 10.1016/j.semcdb.2014.03.027] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2014] [Revised: 03/21/2014] [Accepted: 03/25/2014] [Indexed: 11/26/2022]
Abstract
When studying the living endosome one must first recognise that we are not studying a single discrete organelle but rather a highly dynamic interconnected network of membrane-bound compartments. Endocytosed molecules are sorted and transported through various polymorphic intracellular organelles that mature and interact with one another via fusion and fission events in a highly spatially and temporally co-ordinated manner. As such, we recognise that being a dynamic system, it must be studied in a dynamic fashion. Videomicroscopy has provided profound insights into the cell, and its use in the study of the living endosome has exemplified this supplying a unique perspective on this elusive organelle. In this review we will examine some of the seminal observations that this technology has contributed as well as survey the various assays, tools and technologies that can be applied to understanding the living endosome.
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Affiliation(s)
- Markus Kerr
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Queensland, Australia.
| | - Rohan D Teasdale
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Queensland, Australia
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42
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Follett J, Norwood SJ, Hamilton NA, Mohan M, Kovtun O, Tay S, Zhe Y, Wood SA, Mellick GD, Silburn PA, Collins BM, Bugarcic A, Teasdale RD. The Vps35 D620N Mutation Linked to Parkinson's Disease Disrupts the Cargo Sorting Function of Retromer. Traffic 2013; 15:230-44. [DOI: 10.1111/tra.12136] [Citation(s) in RCA: 161] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2013] [Revised: 10/21/2013] [Accepted: 10/21/2013] [Indexed: 12/13/2022]
Affiliation(s)
- Jordan Follett
- Institute for Molecular Bioscience; The University of Queensland; St Lucia Queensland, Australia
| | - Suzanne J. Norwood
- Institute for Molecular Bioscience; The University of Queensland; St Lucia Queensland, Australia
| | - Nicholas A. Hamilton
- Institute for Molecular Bioscience; The University of Queensland; St Lucia Queensland, Australia
| | - Megha Mohan
- Eskitis Institute for Drug Discovery; Griffith University; Nathan Queensland, Australia
| | - Oleksiy Kovtun
- Institute for Molecular Bioscience; The University of Queensland; St Lucia Queensland, Australia
| | - Stephanie Tay
- Institute for Molecular Bioscience; The University of Queensland; St Lucia Queensland, Australia
| | - Yang Zhe
- Institute for Molecular Bioscience; The University of Queensland; St Lucia Queensland, Australia
| | - Stephen A. Wood
- Eskitis Institute for Drug Discovery; Griffith University; Nathan Queensland, Australia
| | - George D. Mellick
- Eskitis Institute for Drug Discovery; Griffith University; Nathan Queensland, Australia
| | - Peter A. Silburn
- Eskitis Institute for Drug Discovery; Griffith University; Nathan Queensland, Australia
- The University of Queensland Centre for Clinical Research; Herston Queensland, Australia
| | - Brett M. Collins
- Institute for Molecular Bioscience; The University of Queensland; St Lucia Queensland, Australia
| | - Andrea Bugarcic
- Institute for Molecular Bioscience; The University of Queensland; St Lucia Queensland, Australia
| | - Rohan D. Teasdale
- Institute for Molecular Bioscience; The University of Queensland; St Lucia Queensland, Australia
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43
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McCartney AJ, Zhang Y, Weisman LS. Phosphatidylinositol 3,5-bisphosphate: low abundance, high significance. Bioessays 2013; 36:52-64. [PMID: 24323921 DOI: 10.1002/bies.201300012] [Citation(s) in RCA: 155] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Recent studies of the low abundant signaling lipid, phosphatidylinositol 3,5-bisphosphate (PI(3,5)P2 ), reveal an intriguingly diverse list of downstream pathways, the intertwined relationship between PI(3,5)P2 and PI5P, as well as links to neurodegenerative diseases. Derived from the structural lipid phosphatidylinositol, PI(3,5)P2 is dynamically generated on multiple cellular compartments where interactions with an increasing list of effectors regulate many cellular pathways. A complex of proteins that includes Fab1/PIKfyve, Vac14, and Fig4/Sac3 mediates the biosynthesis of PI(3,5)P2 , and mutations that disrupt complex function and/or formation cause profound consequences in cells. Surprisingly, mutations in this pathway are linked with neurological diseases, including Charcot-Marie-Tooth syndrome and amyotrophic lateral sclerosis. Future studies of PI(3,5)P2 and PI5P are likely to expand the roles of these lipids in regulation of cellular functions, as well as provide new approaches for treatment of some neurological diseases.
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Affiliation(s)
- Amber J McCartney
- Neuroscience Graduate Program, University of Michigan, Ann Arbor, MI, USA
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44
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PIKfyve regulates the endosomal localization of CpG oligodeoxynucleotides to elicit TLR9-dependent cellular responses. PLoS One 2013; 8:e73894. [PMID: 24040108 PMCID: PMC3767827 DOI: 10.1371/journal.pone.0073894] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2013] [Accepted: 07/25/2013] [Indexed: 12/25/2022] Open
Abstract
TLR9 is a receptor for oligodeoxynucleotides that contain unmethylated CpG motifs (CpG). Because TLR9 resides in the endoplasmic reticulum during the quiescence state, CpG binding to TLR9 requires membrane trafficking, which includes the maturation of the CpG-containing endosome. In the present study, we examined the role of PIKfyve, a phosphatidylinositol 3-phosphate 5-kinase, in the regulation of TLR9 signaling. The PIKfyve inhibitor YM201636 inhibited co-localization of the CpG-containing endosome with LysoTracker, which stains acidic organelle, and with TLR9. YM201636 increased the co-localization of CpG with the early endosome marker EEA1 but decreased co-localization with the late endosome marker LAMP1. Similar results were obtained in Raw264.7 cells containing shRNA that targets PIKfyve. CpG-mediated phosphorylation but not lipopolysaccharide (LPS)-mediated phosphorylation of IKK, p38 MAPK, JNK and Stat3 was severely impaired by the loss of PIKfyve function. CpG-mediated expression of cytokine mRNA was also decreased in the absence of PIKfyve. These findings demonstrate a novel role of PIKfyve in TLR9 signaling.
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45
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Li X, Garrity AG, Xu H. Regulation of membrane trafficking by signalling on endosomal and lysosomal membranes. J Physiol 2013; 591:4389-401. [PMID: 23878375 DOI: 10.1113/jphysiol.2013.258301] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Endosomal and lysosomal membrane trafficking requires the coordination of multiple signalling events to control cargo sorting and processing, and endosome maturation. The initiation and termination of signalling events in endosomes and lysosomes is not well understood, but several key regulators have been identified, which include small GTPases, phosphoinositides, and Ca2+. Small GTPases act as master regulators and molecular switches in a GTP-dependent manner, initiating signalling cascades to regulate the direction and specificity of endosomal trafficking. Phosphoinositides are membrane-bound lipids that indicate vesicular identities for recruiting specific cytoplasmic proteins to endosomal membranes, thus allowing specificity of membrane fusion, fission, and cargo sorting to occur within and between specific vesicle compartments. In addition, phosphoinositides regulate the function of membrane proteins such as ion channels and transporters in a compartment-specific manner to mediate transport and signalling. Finally, Ca2+, a locally acting second messenger released from intracellular ion channels, may provide precise spatiotemporal regulation of endosomal signalling and trafficking events. Small GTPase signalling can regulate phosphoinositide conversion during endosome maturation, and electrophysiological studies on isolated endosomes have shown that endosomal and lysosomal Ca2+ channels are directly modulated by endosomal lipids. Thus trafficking and maturation of endosomes and lysosomes can be precisely regulated by dynamic changes in GTPases and membrane lipids, as well as Ca2+ signalling. Importantly, impaired phosphoinositide and Ca2+ signalling can cause endosomal and lysosomal trafficking defects at the cellular level, and a spectrum of lysosome storage diseases.
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Affiliation(s)
- Xinran Li
- H. Xu: University of Michigan, MCDB, 3089 Natural Science Building (Kraus), 830 North University, Ann Arbor, MI 48109, USA.
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46
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Abstract
Intracellular membrane trafficking requires the complex interplay of several classes of trafficking proteins. Rab proteins, the largest subfamily of the Ras superfamily of small G-proteins, are central regulators of all aspects of intracellular trafficking processes including vesicle budding and uncoating, motility, tethering and fusion. In the present paper, we discuss the discovery, evolution and characterization of the Rab GTPase family. We examine their basic functional roles, their important structural features and the regulatory proteins which mediate Rab function. We speculate on outstanding issues in the field, such as the mechanisms of Rab membrane association and the co-ordinated interplay between distinct Rab proteins. Finally, we summarize the data implicating Rab proteins in an ever increasing number of diseases.
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47
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Martin S, Harper CB, May LM, Coulson EJ, Meunier FA, Osborne SL. Inhibition of PIKfyve by YM-201636 dysregulates autophagy and leads to apoptosis-independent neuronal cell death. PLoS One 2013; 8:e60152. [PMID: 23544129 PMCID: PMC3609765 DOI: 10.1371/journal.pone.0060152] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2012] [Accepted: 02/21/2013] [Indexed: 12/21/2022] Open
Abstract
The lipid phosphatidylinositol 3,5-bisphosphate (PtdIns(3,5)P2), synthesised by PIKfyve, regulates a number of intracellular membrane trafficking pathways. Genetic alteration of the PIKfyve complex, leading to even a mild reduction in PtdIns(3,5)P2, results in marked neurodegeneration via an uncharacterised mechanism. In the present study we have shown that selectively inhibiting PIKfyve activity, using YM-201636, significantly reduces the survival of primary mouse hippocampal neurons in culture. YM-201636 treatment promoted vacuolation of endolysosomal membranes followed by apoptosis-independent cell death. Many vacuoles contained intravacuolar membranes and inclusions reminiscent of autolysosomes. Accordingly, YM-201636 treatment increased the level of the autophagosomal marker protein LC3-II, an effect that was potentiated by inhibition of lysosomal proteases, suggesting that alterations in autophagy could be a contributing factor to neuronal cell death.
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Affiliation(s)
- Sally Martin
- The University of Queensland, Queensland Brain Institute, Brisbane, Queensland, Australia
| | - Callista B. Harper
- The University of Queensland, Queensland Brain Institute, Brisbane, Queensland, Australia
| | - Linda M. May
- The University of Queensland, Queensland Brain Institute, Brisbane, Queensland, Australia
| | - Elizabeth J. Coulson
- The University of Queensland, Queensland Brain Institute, Brisbane, Queensland, Australia
| | - Frederic A. Meunier
- The University of Queensland, Queensland Brain Institute, Brisbane, Queensland, Australia
- * E-mail: (FAM); (SLO)
| | - Shona L. Osborne
- The University of Queensland, Queensland Brain Institute, Brisbane, Queensland, Australia
- * E-mail: (FAM); (SLO)
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48
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Harper CB, Popoff MR, McCluskey A, Robinson PJ, Meunier FA. Targeting membrane trafficking in infection prophylaxis: dynamin inhibitors. Trends Cell Biol 2013; 23:90-101. [DOI: 10.1016/j.tcb.2012.10.007] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2012] [Revised: 10/11/2012] [Accepted: 10/11/2012] [Indexed: 12/01/2022]
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Abstract
Phosphoinositide 3-kinases (PI3Ks) control many important aspects of immune cell development, differentiation, and function. Mammals have eight PI3K catalytic subunits that are divided into three classes based on similarities in structure and function. Specific roles for the class I PI3Ks have been broadly investigated and are relatively well understood, as is the function of their corresponding phosphatases. More recently, specific roles for the class II and class III PI3Ks have emerged. Through vertebrate evolution and in parallel with the evolution of adaptive immunity, there has been a dramatic increase not only in the genes for PI3K subunits but also in genes for phosphatases that act on 3-phosphoinositides and in 3-phosphoinositide-binding proteins. Our understanding of the PI3Ks in immunity is guided by fundamental discoveries made in simpler model organisms as well as by appreciating new adaptations of this signaling module in mammals in general and in immune cells in particular.
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Affiliation(s)
- Klaus Okkenhaug
- Laboratory of Lymphocyte Signaling and Development, The Babraham Institute, Cambridge, CB22 3AT, United Kingdom.
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Bohdanowicz M, Grinstein S. Role of Phospholipids in Endocytosis, Phagocytosis, and Macropinocytosis. Physiol Rev 2013; 93:69-106. [DOI: 10.1152/physrev.00002.2012] [Citation(s) in RCA: 198] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Endocytosis, phagocytosis, and macropinocytosis are fundamental processes that enable cells to sample their environment, eliminate pathogens and apoptotic bodies, and regulate the expression of surface components. While a great deal of effort has been devoted over many years to understanding the proteins involved in these processes, the important contribution of phospholipids has only recently been appreciated. This review is an attempt to collate and analyze the rapidly emerging evidence documenting the role of phospholipids in clathrin-mediated endocytosis, phagocytosis, and macropinocytosis. A primer on phospholipid biosynthesis, catabolism, subcellular distribution, and transport is presented initially, for reference, together with general considerations of the effects of phospholipids on membrane curvature and charge. This is followed by a detailed analysis of the critical functions of phospholipids in the internalization processes and in the maturation of the resulting vesicles and vacuoles as they progress along the endo-lysosomal pathway.
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Affiliation(s)
- Michal Bohdanowicz
- Division of Cell Biology, Hospital for Sick Children, and Institute of Medical Sciences, University of Toronto, Toronto, Canada
| | - Sergio Grinstein
- Division of Cell Biology, Hospital for Sick Children, and Institute of Medical Sciences, University of Toronto, Toronto, Canada
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