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Tsai PJ, Chen MY, Hsu WC, Lin SF, Chan PC, Chen HH, Kao CY, Lin WJ, Chuang TH, Yu GY, Su YW. PTEN acts as a crucial inflammatory checkpoint controlling TLR9/IL-6 axis in B cells. iScience 2024; 27:110388. [PMID: 39092178 PMCID: PMC11292540 DOI: 10.1016/j.isci.2024.110388] [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: 02/16/2024] [Revised: 05/27/2024] [Accepted: 06/24/2024] [Indexed: 08/04/2024] Open
Abstract
Phosphatase and tensin homolog (PTEN) is vital for B cell development, acting as a key negative regulator in the PI3K signaling pathway. We used CD23-cre to generate PTEN-conditional knockout mice (CD23-cKO) to examine the impact of PTEN mutation on peripheral B cells. Unlike mb1-cre-mediated PTEN deletion in early B cells, CD23-cKO mutants exhibited systemic inflammation with increased IL-6 production in mature B cells upon CpG stimulation. Inflammatory B cells in CD23-cKO mice showed elevated phosphatidylinositol 3-phosphate [PI(3)P] levels and increased TLR9 endosomal localization. Pharmacological inhibition of PI(3)P synthesis markedly reduced TLR9-mediated IL-6. Single-cell RNA-sequencing (RNA-seq) revealed altered endocytosis, BANK1, and NF-κB1 expression in PTEN-deficient B cells. Ectopic B cell receptor (BCR) expression on non-inflammatory mb1-cKO B cells restored BANK1 and NF-κB1 expression, enhancing TLR9-mediated IL-6 production. Our study highlights PTEN as a crucial inflammatory checkpoint, regulating TLR9/IL-6 axis by fine-tuning PI(3)P homeostasis. Additionally, BCR downregulation prevents the differentiation of inflammatory B cells in PTEN deficiency.
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Affiliation(s)
- Pei-Ju Tsai
- Immunology Research Center, National Health Research Institutes, Zhunan Town, Miaoli County 350401, Taiwan
| | - Ming-Yu Chen
- Immunology Research Center, National Health Research Institutes, Zhunan Town, Miaoli County 350401, Taiwan
| | - Wei-Chan Hsu
- Immunology Research Center, National Health Research Institutes, Zhunan Town, Miaoli County 350401, Taiwan
| | - Su-Fang Lin
- National Institute of Cancer Research, National Health Research Institutes, Zhunan Town, Miaoli County 350401, Taiwan
| | - Po-Chiang Chan
- Immunology Research Center, National Health Research Institutes, Zhunan Town, Miaoli County 350401, Taiwan
| | - Hsin-Hsin Chen
- Immunology Research Center, National Health Research Institutes, Zhunan Town, Miaoli County 350401, Taiwan
| | - Cheng-Yuan Kao
- Immunology Research Center, National Health Research Institutes, Zhunan Town, Miaoli County 350401, Taiwan
| | - Wen-Jye Lin
- Immunology Research Center, National Health Research Institutes, Zhunan Town, Miaoli County 350401, Taiwan
| | - Tsung-Hsien Chuang
- Immunology Research Center, National Health Research Institutes, Zhunan Town, Miaoli County 350401, Taiwan
| | - Guann-Yi Yu
- National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Zhunan Town, Miaoli County 350401, Taiwan
| | - Yu-Wen Su
- Immunology Research Center, National Health Research Institutes, Zhunan Town, Miaoli County 350401, Taiwan
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2
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Restaino AC, Walz A, Barclay SM, Fettig RR, Vermeer PD. Tumor-associated genetic amplifications impact extracellular vesicle miRNA cargo and their recruitment of nerves in head and neck cancer. FASEB J 2024; 38:e23803. [PMID: 38963404 PMCID: PMC11262563 DOI: 10.1096/fj.202400625rr] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2024] [Revised: 06/19/2024] [Accepted: 06/26/2024] [Indexed: 07/05/2024]
Abstract
Cancer neuroscience is an emerging field of cancer biology focused on defining the interactions and relationships between the nervous system, developing malignancies, and their environments. Our previous work demonstrates that small extracellular vesicles (sEVs) released by head and neck squamous cell carcinomas (HNSCCs) recruit loco-regional nerves to the tumor. sEVs contain a diverse collection of biological cargo, including microRNAs (miRNAs). Here, we asked whether two genes commonly amplified in HNSCC, CCND1, and PIK3CA, impact the sEV miRNA cargo and, subsequently, sEV-mediated tumor innervation. To test this, we individually overexpressed these genes in a syngeneic murine HNSCC cell line, purified their sEVs, and tested their neurite outgrowth activity on dorsal root ganglia (DRG) neurons in vitro. sEVs purified from Ccnd1-overexpressing cells significantly increased neurite outgrowth of DRG compared to sEVs from parental or Pik3ca over-expressing cells. When implanted into C57BL/6 mice, Ccnd1 over-expressing tumor cells promoted significantly more tumor innervation in vivo. qPCR analysis of sEVs shows that increased expression of Ccnd1 altered the packaging of miRNAs (miR-15-5p, miR-17-5p, and miR-21-5p), many of which target transcripts important in regulating axonogenesis. These data indicate that genetic amplifications harbored by malignancies impose changes in sEV miRNA cargo, which can influence tumorc innervation.
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Affiliation(s)
- Anthony C. Restaino
- Cancer Biology and Immunotherapies Group, Sanford Research, 2301 East 60 Street north, Sioux Falls, SD, USA 57104
| | - Austin Walz
- Cancer Biology and Immunotherapies Group, Sanford Research, 2301 East 60 Street north, Sioux Falls, SD, USA 57104
| | - Sarah M. Barclay
- Cancer Biology and Immunotherapies Group, Sanford Research, 2301 East 60 Street north, Sioux Falls, SD, USA 57104
| | - Robin R. Fettig
- Cancer Biology and Immunotherapies Group, Sanford Research, 2301 East 60 Street north, Sioux Falls, SD, USA 57104
| | - Paola D. Vermeer
- Cancer Biology and Immunotherapies Group, Sanford Research, 2301 East 60 Street north, Sioux Falls, SD, USA 57104
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3
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Xu J, He C, Cai Y, Wang X, Yan J, Zhang J, Zhang F, Urbonaviciute V, Cheng Y, Lu S, Holmdahl R. NCF4 regulates antigen presentation of cysteine peptides by intracellular oxidative response and restricts activation of autoreactive and arthritogenic T cells. Redox Biol 2024; 72:103132. [PMID: 38547647 PMCID: PMC11096609 DOI: 10.1016/j.redox.2024.103132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2024] [Revised: 03/12/2024] [Accepted: 03/22/2024] [Indexed: 05/07/2024] Open
Abstract
Autoimmune diseases, such as rheumatoid arthritis (RA) and systemic lupus erythematous, are regulated by polymorphisms in genes contributing to the NOX2 complex. Mutations in both Ncf1 and Ncf4 affect development of arthritis in experimental models of RA, but the different regulatory pathways mediated by NOX2-derived reactive oxygen species (ROS) have not yet been clarified. Here we address the possibility that intracellular ROS, regulated by the NCF4 protein (earlier often denoted p40phox) which interacts with endosomal membranes, could play an important role in the oxidation of cysteine peptides in mononuclear phagocytic cells, thereby regulating antigen presentation and activation of arthritogenic T cells. To study the role of NCF4 we used mice with an amino acid replacing mutation (NCF4R58A), which is known to affect interaction with endosomal membranes, leading to decreased intracellular ROS production. To study the impact of NCF4 on T cell activation, we used the glucose phosphate isomerase peptide GPI325-339, which contains two cysteine residues (325-339c-c). Macrophages from mice with the NCF458A mutation efficiently presented the peptide when the two cysteines were intact and not crosslinked, leading to a strong arthritogenic T cell response. T cell priming occurred in the draining lymph nodes (LNs) within 8 days after immunization. Clodronate treatment, which depletes antigen-presenting mononuclear phagocytes, ameliorated arthritis severity, whereas treatment with FYT720, which traps activated T cells in LNs, prohibited arthritis. We conclude that NCF4-dependent intracellular ROS maintains cysteine peptides in an oxidized crosslinked state, which prevents presentation of peptides recognized by non-tolerized T cells and thereby protects against autoimmune arthritis.
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Affiliation(s)
- Jing Xu
- National Joint Engineering Research Center of Biodiagnostics and Biotherapy, and Department of Rheumatology, Second Affiliated Hospital, Xi'an Jiaotong University, Xi'an, Shaanxi, 710004, PR China; Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi, 710061, PR China; Key Laboratory of Environment and Genes Related to Diseases (Xi'an Jiaotong University), Ministry of Education, Xi'an, Shaanxi, 710061, PR China; Medical Inflammation Research, Division of Immunology, Dept. of Medical Biochemistry and Biophysics, Karolinska Institute, Stockholm, Sweden
| | - Chang He
- Key Laboratory of Environment and Genes Related to Diseases (Xi'an Jiaotong University), Ministry of Education, Xi'an, Shaanxi, 710061, PR China; Medical Inflammation Research, Division of Immunology, Dept. of Medical Biochemistry and Biophysics, Karolinska Institute, Stockholm, Sweden; Department of Cardiology, The Second Affiliated Hospital, Zhejiang University Schoole of Medicine, Zhejiang, Hangzhou, PR China
| | - Yongsong Cai
- Department of Joint Surgery, Xi'an Honghui Hospital, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi, 710061, PR China
| | - Xipeng Wang
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi, 710061, PR China; Key Laboratory of Environment and Genes Related to Diseases (Xi'an Jiaotong University), Ministry of Education, Xi'an, Shaanxi, 710061, PR China
| | - Jidong Yan
- Department of Human Anatomy, Histology and Embryology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, 710061, Xi'an, PR China
| | - Jing Zhang
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi, 710061, PR China; Key Laboratory of Environment and Genes Related to Diseases (Xi'an Jiaotong University), Ministry of Education, Xi'an, Shaanxi, 710061, PR China
| | - Fujun Zhang
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi, 710061, PR China; Key Laboratory of Environment and Genes Related to Diseases (Xi'an Jiaotong University), Ministry of Education, Xi'an, Shaanxi, 710061, PR China
| | - Vilma Urbonaviciute
- Medical Inflammation Research, Division of Immunology, Dept. of Medical Biochemistry and Biophysics, Karolinska Institute, Stockholm, Sweden
| | - Yuanyuan Cheng
- National Joint Engineering Research Center of Biodiagnostics and Biotherapy, and Department of Rheumatology, Second Affiliated Hospital, Xi'an Jiaotong University, Xi'an, Shaanxi, 710004, PR China
| | - Shemin Lu
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi, 710061, PR China; Key Laboratory of Environment and Genes Related to Diseases (Xi'an Jiaotong University), Ministry of Education, Xi'an, Shaanxi, 710061, PR China
| | - Rikard Holmdahl
- National Joint Engineering Research Center of Biodiagnostics and Biotherapy, and Department of Rheumatology, Second Affiliated Hospital, Xi'an Jiaotong University, Xi'an, Shaanxi, 710004, PR China; Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi, 710061, PR China; Key Laboratory of Environment and Genes Related to Diseases (Xi'an Jiaotong University), Ministry of Education, Xi'an, Shaanxi, 710061, PR China; Medical Inflammation Research, Division of Immunology, Dept. of Medical Biochemistry and Biophysics, Karolinska Institute, Stockholm, Sweden.
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4
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Xu J, Zhu Z, Jin Y, Wei C, Wang Y, Li X. Effect of aerobic exercise on brain metabolite profiles in the mouse models of methamphetamine addiction: LC-MS-based metabolomics study. BMC Psychiatry 2023; 23:852. [PMID: 37978352 PMCID: PMC10655403 DOI: 10.1186/s12888-023-05351-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Accepted: 11/06/2023] [Indexed: 11/19/2023] Open
Abstract
Methamphetamine (MA) abuse is recognized as a brain disorder, and physical activity has clear benefits for MA use disorders. The specific mechanisms by which physical activity alleviates MA use disorders are currently not fully understood. Based on this, the present study used untargeted metabolomics using liquid chromatography-mass spectrometry (LC-MS) to analyze the metabolic changes induced by MA in the brains of mice by exercise intervention. It was found that after 2 weeks of treadmill training, aerobic exercise modulated MA-induced brain metabolic disorders, in which 129 metabolites existed that were significantly differentiated in response to MA induction, and 32 metabolites were significantly affected by exercise. These differential metabolites were mainly enriched in glycerophospholipid metabolism, steroid hormone biosynthesis and degradation, and renin-angiotensin system pathways. To our knowledge, this study is the first to use LC-MS to investigate the effects of aerobic exercise on MA-induced brain metabolic profiling. The findings of this study provide new insights into exercise therapy using MA.
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Affiliation(s)
- Jisheng Xu
- School of Sports Medicine and Health, Chengdu Sport University, Chengdu, 610041, P. R. China
| | - Zhicheng Zhu
- School of Sports Medicine and Health, Chengdu Sport University, Chengdu, 610041, P. R. China
| | - Yu Jin
- School of Sports Medicine and Health, Chengdu Sport University, Chengdu, 610041, P. R. China
| | - Changling Wei
- School of Sports Medicine and Health, Chengdu Sport University, Chengdu, 610041, P. R. China
| | - Yi Wang
- Department of Epidemiology and Population Health, Albert Einstein College of Medicine, Bronx, NY, 10461, USA
| | - Xue Li
- School of Sports Medicine and Health, Chengdu Sport University, Chengdu, 610041, P. R. China.
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5
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Rani S, Lai A, Nair S, Sharma S, Handberg A, Carrion F, Möller A, Salomon C. Extracellular vesicles as mediators of cell-cell communication in ovarian cancer and beyond - A lipids focus. Cytokine Growth Factor Rev 2023; 73:52-68. [PMID: 37423866 DOI: 10.1016/j.cytogfr.2023.06.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Accepted: 06/29/2023] [Indexed: 07/11/2023]
Abstract
Extracellular vesicles (EVs) are messengers that carry information in the form of proteins, lipids, and nucleic acids and are not only essential for intercellular communication but also play a critical role in the progression of various pathologies, including ovarian cancer. There has been recent substantial research characterising EV cargo, specifically, the lipid profile of EVs. Lipids are involved in formation and cargo sorting of EVs, their release and cellular uptake. Numerous lipidomic studies demonstrated the enrichment of specific classes of lipids in EVs derived from cancer cells suggesting that the EV associated lipids can potentially be employed as minimally invasive biomarkers for early diagnosis of various malignancies, including ovarian cancer. In this review, we aim to provide a general overview of the heterogeneity of EV, biogenesis, their lipid content, and function in cancer progression focussing on ovarian cancer.
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Affiliation(s)
- Shikha Rani
- Translational Extracellular Vesicles in Obstetrics and Gynae-Oncology Group, University of Queensland Centre for Clinical Research, Faculty of Medicine, Royal Brisbane and Women's Hospital, The University of Queensland, Brisbane, QLD 4029, Australia
| | - Andrew Lai
- Translational Extracellular Vesicles in Obstetrics and Gynae-Oncology Group, University of Queensland Centre for Clinical Research, Faculty of Medicine, Royal Brisbane and Women's Hospital, The University of Queensland, Brisbane, QLD 4029, Australia
| | - Soumya Nair
- Translational Extracellular Vesicles in Obstetrics and Gynae-Oncology Group, University of Queensland Centre for Clinical Research, Faculty of Medicine, Royal Brisbane and Women's Hospital, The University of Queensland, Brisbane, QLD 4029, Australia
| | - Shayna Sharma
- Translational Extracellular Vesicles in Obstetrics and Gynae-Oncology Group, University of Queensland Centre for Clinical Research, Faculty of Medicine, Royal Brisbane and Women's Hospital, The University of Queensland, Brisbane, QLD 4029, Australia
| | - Aase Handberg
- Department of Clinical Biochemistry, Aalborg University Hospital, Aalborg, Denmark
| | - Flavio Carrion
- Departamento de Investigación, Postgrado y Educación Continua (DIPEC), Facultad de Ciencias de la Salud, Universidad del Alba, Santiago, Chile
| | - Andreas Möller
- Department of Otorhinolaryngology, Li Ka Shing Institute of Health Sciences, Chinese University of Hong Kong, Shatin, Hong Kong
| | - Carlos Salomon
- Translational Extracellular Vesicles in Obstetrics and Gynae-Oncology Group, University of Queensland Centre for Clinical Research, Faculty of Medicine, Royal Brisbane and Women's Hospital, The University of Queensland, Brisbane, QLD 4029, Australia; Departamento de Investigación, Postgrado y Educación Continua (DIPEC), Facultad de Ciencias de la Salud, Universidad del Alba, Santiago, Chile.
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6
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Sarmento MJ, Llorente A, Petan T, Khnykin D, Popa I, Nikolac Perkovic M, Konjevod M, Jaganjac M. The expanding organelle lipidomes: current knowledge and challenges. Cell Mol Life Sci 2023; 80:237. [PMID: 37530856 PMCID: PMC10397142 DOI: 10.1007/s00018-023-04889-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Revised: 06/13/2023] [Accepted: 07/19/2023] [Indexed: 08/03/2023]
Abstract
Lipids in cell membranes and subcellular compartments play essential roles in numerous cellular processes, such as energy production, cell signaling and inflammation. A specific organelle lipidome is characterized by lipid synthesis and metabolism, intracellular trafficking, and lipid homeostasis in the organelle. Over the years, considerable effort has been directed to the identification of the lipid fingerprints of cellular organelles. However, these fingerprints are not fully characterized due to the large variety and structural complexity of lipids and the great variability in the abundance of different lipid species. The process becomes even more challenging when considering that the lipidome differs in health and disease contexts. This review summarizes the information available on the lipid composition of mammalian cell organelles, particularly the lipidome of the nucleus, mitochondrion, endoplasmic reticulum, Golgi apparatus, plasma membrane and organelles in the endocytic pathway. The lipid compositions of extracellular vesicles and lamellar bodies are also described. In addition, several examples of subcellular lipidome dynamics under physiological and pathological conditions are presented. Finally, challenges in mapping organelle lipidomes are discussed.
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Affiliation(s)
- Maria J Sarmento
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, 1649-028, Lisbon, Portugal
| | - Alicia Llorente
- Department of Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital, 0379, Oslo, Norway
- Department for Mechanical, Electronics and Chemical Engineering, Oslo Metropolitan University, 0167, Oslo, Norway
- Faculty of Medicine, Centre for Cancer Cell Reprogramming, University of Oslo, Montebello, 0379, Oslo, Norway
| | - Toni Petan
- Department of Molecular and Biomedical Sciences, Jožef Stefan Institute, Ljubljana, Slovenia
| | - Denis Khnykin
- Department of Pathology, Oslo University Hospital, Oslo, Norway
| | - Iuliana Popa
- Pharmacy Department, Bâtiment Henri Moissan, University Paris-Saclay, 17 Avenue des Sciences, 91400, Orsay, France
| | | | - Marcela Konjevod
- Division of Molecular Medicine, Ruder Boskovic Institute, 10000, Zagreb, Croatia
| | - Morana Jaganjac
- Division of Molecular Medicine, Ruder Boskovic Institute, 10000, Zagreb, Croatia.
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7
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Safaroghli-Azar A, Sanaei MJ, Pourbagheri-Sigaroodi A, Bashash D. Phosphoinositide 3-kinase (PI3K) classes: From cell signaling to endocytic recycling and autophagy. Eur J Pharmacol 2023:175827. [PMID: 37269974 DOI: 10.1016/j.ejphar.2023.175827] [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: 03/13/2023] [Revised: 05/19/2023] [Accepted: 05/31/2023] [Indexed: 06/05/2023]
Abstract
Lipid signaling is defined as any biological signaling action in which a lipid messenger binds to a protein target, converting its effects to specific cellular responses. In this complex biological pathway, the family of phosphoinositide 3-kinase (PI3K) represents a pivotal role and affects many aspects of cellular biology from cell survival, proliferation, and migration to endocytosis, intracellular trafficking, metabolism, and autophagy. While yeasts have a single isoform of phosphoinositide 3-kinase (PI3K), mammals possess eight PI3K types divided into three classes. The class I PI3Ks have set the stage to widen research interest in the field of cancer biology. The aberrant activation of class I PI3Ks has been identified in 30-50% of human tumors, and activating mutations in PIK3CA is one of the most frequent oncogenes in human cancer. In addition to indirect participation in cell signaling, class II and III PI3Ks primarily regulate vesicle trafficking. Class III PI3Ks are also responsible for autophagosome formation and autophagy flux. The current review aims to discuss the original data obtained from international research laboratories on the latest discoveries regarding PI3Ks-mediated cell biological processes. Also, we unravel the mechanisms by which pools of the same phosphoinositides (PIs) derived from different PI3K types act differently.
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Affiliation(s)
- Ava Safaroghli-Azar
- Department of Hematology and Blood Banking, School of Allied Medical Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mohammad-Javad Sanaei
- Department of Hematology and Blood Banking, School of Allied Medical Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Atieh Pourbagheri-Sigaroodi
- Department of Hematology and Blood Banking, School of Allied Medical Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Davood Bashash
- Department of Hematology and Blood Banking, School of Allied Medical Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
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8
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Lungu C, Meyer F, Hörning M, Steudle J, Braun A, Noll B, Benz D, Fränkle F, Schmid S, Eisler SA, Olayioye MA. Golgi screen identifies the RhoGEF Solo as a novel regulator of RhoB and endocytic transport. Traffic 2023; 24:162-176. [PMID: 36562184 DOI: 10.1111/tra.12880] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Accepted: 12/14/2022] [Indexed: 12/24/2022]
Abstract
The control of intracellular membrane trafficking by Rho GTPases is central to cellular homeostasis. How specific guanine nucleotide exchange factors and GTPase-activating proteins locally balance GTPase activation in this process is nevertheless largely unclear. By performing a microscopy-based RNAi screen, we here identify the RhoGEF protein Solo as a functional counterplayer of DLC3, a RhoGAP protein with established roles in membrane trafficking. Biochemical, imaging and optogenetics assays further uncover Solo as a novel regulator of endosomal RhoB. Remarkably, we find that Solo and DLC3 control not only the activity, but also total protein levels of RhoB in an antagonistic manner. Together, the results of our study uncover the first functionally connected RhoGAP-RhoGEF pair at endomembranes, placing Solo and DLC3 at the core of endocytic trafficking.
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Affiliation(s)
- Cristiana Lungu
- Institute of Cell Biology and Immunology, University of Stuttgart, Stuttgart, Germany.,Stuttgart Research Center Systems Biology (SRCSB), University of Stuttgart, Stuttgart, Germany
| | - Florian Meyer
- Institute of Cell Biology and Immunology, University of Stuttgart, Stuttgart, Germany
| | - Marcel Hörning
- Stuttgart Research Center Systems Biology (SRCSB), University of Stuttgart, Stuttgart, Germany.,Institute of Biomaterials and Biomolecular Systems, Biobased Materials Group, University of Stuttgart, Stuttgart, Germany
| | - Jasmin Steudle
- Institute of Cell Biology and Immunology, University of Stuttgart, Stuttgart, Germany
| | - Anja Braun
- Institute of Cell Biology and Immunology, University of Stuttgart, Stuttgart, Germany
| | - Bettina Noll
- Institute of Cell Biology and Immunology, University of Stuttgart, Stuttgart, Germany.,Stuttgart Research Center Systems Biology (SRCSB), University of Stuttgart, Stuttgart, Germany
| | - David Benz
- Institute of Cell Biology and Immunology, University of Stuttgart, Stuttgart, Germany
| | - Felix Fränkle
- Institute of Cell Biology and Immunology, University of Stuttgart, Stuttgart, Germany
| | - Simone Schmid
- Institute of Cell Biology and Immunology, University of Stuttgart, Stuttgart, Germany
| | - Stephan A Eisler
- Institute of Cell Biology and Immunology, University of Stuttgart, Stuttgart, Germany.,Stuttgart Research Center Systems Biology (SRCSB), University of Stuttgart, Stuttgart, Germany
| | - Monilola A Olayioye
- Institute of Cell Biology and Immunology, University of Stuttgart, Stuttgart, Germany.,Stuttgart Research Center Systems Biology (SRCSB), University of Stuttgart, Stuttgart, Germany
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9
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McEwan DG, Ryan KM. ATG2 and VPS13 proteins: molecular highways transporting lipids to drive membrane expansion and organelle communication. FEBS J 2022; 289:7113-7127. [PMID: 34783437 DOI: 10.1111/febs.16280] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Revised: 11/03/2021] [Accepted: 11/15/2021] [Indexed: 01/13/2023]
Abstract
Communication between organelles is an essential process that helps maintain cellular homeostasis and organelle contact sites have recently emerged as crucial mediators of this communication. The emergence of a class of molecular bridges that span the inter-organelle gaps has now been shown to direct the flow of lipid traffic from one lipid bilayer to another. One of the key components of these molecular bridges is the presence of an N-terminal Chorein/VPS13 domain. This is an evolutionarily conserved domain present in multiple proteins within the endocytic and autophagy trafficking pathways. Herein, we discuss the current state-of-the-art of this class of proteins, focusing on the role of these lipid transporters in the autophagy and endocytic pathways. We discuss the recent biochemical and structural advances that have highlighted the essential role Chorein-N domain containing ATG2 proteins play in driving the formation of the autophagosome and how lipids are transported from the endoplasmic reticulum to the growing phagophore. We also consider the VPS13 proteins, their role in organelle contacts and the endocytic pathway and highlight how disease-causing mutations disrupt these contact sites. Finally, we open the door to discuss other Chorein_N domain containing proteins, for instance, UHRF1BP1/1L, their role in disease and look towards prokaryote examples of Chorein_N-like domains. Taken together, recent advances have highlighted an exciting opportunity to delve deeper into inter-organelle communication and understand how lipids are transported between membrane bilayers and how this process is disrupted in multiple diseases.
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Affiliation(s)
| | - Kevin M Ryan
- Cancer Research UK Beatson Institute, Glasgow, UK
- Institute of Cancer Sciences, University of Glasgow, Glasgow, UK
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10
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Yi X, Chen J, Huang D, Feng S, Yang T, Li Z, Wang X, Zhao M, Wu J, Zhong T. Current perspectives on clinical use of exosomes as novel biomarkers for cancer diagnosis. Front Oncol 2022; 12:966981. [PMID: 36119470 PMCID: PMC9472136 DOI: 10.3389/fonc.2022.966981] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2022] [Accepted: 08/01/2022] [Indexed: 12/11/2022] Open
Abstract
Exosomes are a heterogeneous subset of extracellular vesicles (EVs) that biogenesis from endosomes. Besides, exosomes contain a variety of molecular cargoes including proteins, lipids and nucleic acids, which play a key role in the mechanism of exosome formation. Meanwhile, exosomes are involved with physiological and pathological conditions. The molecular profile of exosomes reflects the type and pathophysiological status of the originating cells so could potentially be exploited for diagnostic of cancer. This review aims to describe important molecular cargoes involved in exosome biogenesis. In addition, we highlight exogenous factors, especially autophagy, hypoxia and pharmacology, that regulate the release of exosomes and their corresponding cargoes. Particularly, we also emphasize exosome molecular cargoes as potential biomarkers in liquid biopsy for diagnosis of cancer.
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Affiliation(s)
- Xiaomei Yi
- The First School of Clinical Medicine, Gannan Medical University, Ganzhou, China
- Laboratory Medicine, First Affiliated Hospital of Gannan Medical University, Ganzhou, China
| | - Jie Chen
- The First School of Clinical Medicine, Gannan Medical University, Ganzhou, China
- Laboratory Medicine, First Affiliated Hospital of Gannan Medical University, Ganzhou, China
| | - Defa Huang
- The First School of Clinical Medicine, Gannan Medical University, Ganzhou, China
- Laboratory Medicine, First Affiliated Hospital of Gannan Medical University, Ganzhou, China
| | - Shuo Feng
- English Teaching and Research Section, Gannan Healthcare Vocational College, Ganzhou, China
| | - Tong Yang
- The First School of Clinical Medicine, Gannan Medical University, Ganzhou, China
- Laboratory Medicine, First Affiliated Hospital of Gannan Medical University, Ganzhou, China
| | - Zhengzhe Li
- The First School of Clinical Medicine, Gannan Medical University, Ganzhou, China
- Laboratory Medicine, First Affiliated Hospital of Gannan Medical University, Ganzhou, China
| | - Xiaoxing Wang
- The First School of Clinical Medicine, Gannan Medical University, Ganzhou, China
- Laboratory Medicine, First Affiliated Hospital of Gannan Medical University, Ganzhou, China
| | - Minghong Zhao
- The First School of Clinical Medicine, Gannan Medical University, Ganzhou, China
- Laboratory Medicine, First Affiliated Hospital of Gannan Medical University, Ganzhou, China
| | - Jiyang Wu
- The First School of Clinical Medicine, Gannan Medical University, Ganzhou, China
- Laboratory Medicine, First Affiliated Hospital of Gannan Medical University, Ganzhou, China
| | - Tianyu Zhong
- The First School of Clinical Medicine, Gannan Medical University, Ganzhou, China
- Laboratory Medicine, First Affiliated Hospital of Gannan Medical University, Ganzhou, China
- *Correspondence: Tianyu Zhong,
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11
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Klaus FL, Kirsch C, Müller JP, Huber O, Reiche J. PI3Kγ is a novel regulator of TNFα signaling in the human colon cell line HT29/B6. Ann N Y Acad Sci 2022; 1515:196-207. [PMID: 35725890 DOI: 10.1111/nyas.14842] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Phosphoinositide 3-kinases (PI3Ks) are a family of enzymes phosphorylating phospholipids in the membrane, thereby, promoting the PI3K/AKT signaling cascade. PI3Ks are involved in a variety of fundamental cellular functions, including tumor necrosis factor α (TNFα)-induced tight junction (TJ) impairment-a hallmark of inflammatory bowel diseases. Most of the studies analyzing the role of class I PI3K signaling in epithelial barrier maintenance did not decipher which of the isoforms are responsible for the observed effects. By using wild-type and PI3Kγ-deficient HT-29/B6 cells, we characterized the functional role of PI3Kγ in these cells under inflammatory conditions. Measurement of the transepithelial electrical resistance and the paracellular flux of macromolecules revealed that monolayers of PI3Kγ-deficient cells, compared with wild-type cells, were protected against TNFα-induced barrier dysfunction. This effect was independent of any PI3K activity because treatment with a pan-PI3K inhibitor did not alter this observation. By immunostaining, we found correlative changes in the distribution of the TJ marker ZO-1. Furthermore, the absence of PI3Kγ reduced the basal level of the pore-forming TJ protein claudin-2. Our study suggests a novel noncanonical, kinase-independent scaffolding function of PI3Kγ in TNFα-induced barrier dysfunction.
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Affiliation(s)
| | - Cornelia Kirsch
- Institute of Biochemistry II, Jena University Hospital, Jena, Germany
| | - Jörg P Müller
- Institute of Molecular Cell Biology, Center for Molecular Biomedicine, Jena University Hospital, Jena, Germany
| | - Otmar Huber
- Institute of Biochemistry II, Jena University Hospital, Jena, Germany.,Center for Sepsis Control and Care, Jena University Hospital, Friedrich-Schiller-University Jena, Jena, Germany
| | - Juliane Reiche
- Institute of Biochemistry II, Jena University Hospital, Jena, Germany
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12
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Laurella LC, Mirakian NT, Garcia MN, Grasso DH, Sülsen VP, Papademetrio DL. Sesquiterpene Lactones as Promising Candidates for Cancer Therapy: Focus on Pancreatic Cancer. Molecules 2022; 27:3492. [PMID: 35684434 PMCID: PMC9182036 DOI: 10.3390/molecules27113492] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Revised: 05/24/2022] [Accepted: 05/24/2022] [Indexed: 11/17/2022] Open
Abstract
Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive disease which confers to patients a poor prognosis at short term. PDAC is the fourth leading cause of death among cancers in the Western world. The rate of new cases of pancreatic cancer (incidence) is 10 per 100,000 but present a 5-year survival of less than 10%, highlighting the poor prognosis of this pathology. Furthermore, 90% of advanced PDAC tumor present KRAS mutations impacting in several oncogenic signaling pathways, many of them associated with cell proliferation and tumor progression. Different combinations of chemotherapeutic agents have been tested over the years without an improvement of significance in its treatment. PDAC remains as one the more challenging biomedical topics thus far. The lack of a proper early diagnosis, the notable mortality statistics and the poor outcome with the available therapies urge the entire scientific community to find novel approaches against PDAC with real improvements in patients' survival and life quality. Natural compounds have played an important role in the process of discovery and development of new drugs. Among them, terpenoids, such as sesquiterpene lactones, stand out due to their biological activities and pharmacological potential as antitumor agents. In this review, we will describe the sesquiterpene lactones with in vitro and in vivo activity against pancreatic tumor cells. We will also discuss the mechanism of action of the compounds as well as the signaling pathways associated with their activity.
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Affiliation(s)
- Laura Cecilia Laurella
- Instituto de Química y Metabolismo del Fármaco (IQUIMEFA), CONICET-Universidad de Buenos Aires, Junín 956, Piso 2, Buenos Aires CP 1113, Argentina;
- Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires CP 1113, Argentina;
| | - Nadia Talin Mirakian
- Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires CP 1113, Argentina;
| | - Maria Noé Garcia
- Cátedra de Inmunología, Departamento de Microbiología, Inmunología, Biotecnología y Genética, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires CP 1113, Argentina;
- Instituto de Estudios de la Inmunidad Humoral (IDEHU), CONICET-Universidad de Buenos Aires, Junín 956, Piso 4, Buenos Aires CP 1113, Argentina;
| | - Daniel Héctor Grasso
- Instituto de Estudios de la Inmunidad Humoral (IDEHU), CONICET-Universidad de Buenos Aires, Junín 956, Piso 4, Buenos Aires CP 1113, Argentina;
- Cátedra de Fisiopatología, Departamento de Ciencias Biológicas, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires CP 1113, Argentina
| | - Valeria Patricia Sülsen
- Instituto de Química y Metabolismo del Fármaco (IQUIMEFA), CONICET-Universidad de Buenos Aires, Junín 956, Piso 2, Buenos Aires CP 1113, Argentina;
- Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires CP 1113, Argentina;
| | - Daniela Laura Papademetrio
- Cátedra de Inmunología, Departamento de Microbiología, Inmunología, Biotecnología y Genética, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires CP 1113, Argentina;
- Instituto de Estudios de la Inmunidad Humoral (IDEHU), CONICET-Universidad de Buenos Aires, Junín 956, Piso 4, Buenos Aires CP 1113, Argentina;
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13
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Liu GT, Kochlamazashvili G, Puchkov D, Müller R, Schultz C, Mackintosh AI, Vollweiter D, Haucke V, Soykan T. Endosomal phosphatidylinositol 3-phosphate controls synaptic vesicle cycling and neurotransmission. EMBO J 2022; 41:e109352. [PMID: 35318705 PMCID: PMC9058544 DOI: 10.15252/embj.2021109352] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 02/24/2022] [Accepted: 03/01/2022] [Indexed: 11/09/2022] Open
Abstract
Neural circuit function requires mechanisms for controlling neurotransmitter release and the activity of neuronal networks, including modulation by synaptic contacts, synaptic plasticity, and homeostatic scaling. However, how neurons intrinsically monitor and feedback control presynaptic neurotransmitter release and synaptic vesicle (SV) recycling to restrict neuronal network activity remains poorly understood at the molecular level. Here, we investigated the reciprocal interplay between neuronal endosomes, organelles of central importance for the function of synapses, and synaptic activity. We show that elevated neuronal activity represses the synthesis of endosomal lipid phosphatidylinositol 3-phosphate [PI(3)P] by the lipid kinase VPS34. Neuronal activity in turn is regulated by endosomal PI(3)P, the depletion of which reduces neurotransmission as a consequence of perturbed SV endocytosis. We find that this mechanism involves Calpain 2-mediated hyperactivation of Cdk5 downstream of receptor- and activity-dependent calcium influx. Our results unravel an unexpected function for PI(3)P-containing neuronal endosomes in the control of presynaptic vesicle cycling and neurotransmission, which may explain the involvement of the PI(3)P-producing VPS34 kinase in neurological disease and neurodegeneration.
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Affiliation(s)
- Guan-Ting Liu
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Berlin, Germany
| | | | - Dmytro Puchkov
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Berlin, Germany
| | - Rainer Müller
- European Molecular Biology Laboratory (EMBL), Cell Biology and Biophysics Unit, Heidelberg, Germany
| | - Carsten Schultz
- European Molecular Biology Laboratory (EMBL), Cell Biology and Biophysics Unit, Heidelberg, Germany.,Department of Chemical Physiology & Biochemistry, Oregon Health & Science University (OHSU), Portland, OR, USA
| | - Albert I Mackintosh
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Berlin, Germany
| | - Dennis Vollweiter
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Berlin, Germany
| | - Volker Haucke
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Berlin, Germany.,Faculty of Biology, Chemistry, Pharmacy, Freie Universität Berlin, Berlin, Germany.,NeuroCure Cluster of Excellence, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Tolga Soykan
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Berlin, Germany
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14
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Ivanova D, Cousin MA. Synaptic Vesicle Recycling and the Endolysosomal System: A Reappraisal of Form and Function. Front Synaptic Neurosci 2022; 14:826098. [PMID: 35280702 PMCID: PMC8916035 DOI: 10.3389/fnsyn.2022.826098] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Accepted: 02/03/2022] [Indexed: 12/15/2022] Open
Abstract
The endolysosomal system is present in all cell types. Within these cells, it performs a series of essential roles, such as trafficking and sorting of membrane cargo, intracellular signaling, control of metabolism and degradation. A specific compartment within central neurons, called the presynapse, mediates inter-neuronal communication via the fusion of neurotransmitter-containing synaptic vesicles (SVs). The localized recycling of SVs and their organization into functional pools is widely assumed to be a discrete mechanism, that only intersects with the endolysosomal system at specific points. However, evidence is emerging that molecules essential for endolysosomal function also have key roles within the SV life cycle, suggesting that they form a continuum rather than being isolated processes. In this review, we summarize the evidence for key endolysosomal molecules in SV recycling and propose an alternative model for membrane trafficking at the presynapse. This includes the hypotheses that endolysosomal intermediates represent specific functional SV pools, that sorting of cargo to SVs is mediated via the endolysosomal system and that manipulation of this process can result in both plastic changes to neurotransmitter release and pathophysiology via neurodegeneration.
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Affiliation(s)
- Daniela Ivanova
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom
- Muir Maxwell Epilepsy Centre, University of Edinburgh, Edinburgh, United Kingdom
- Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh, United Kingdom
- *Correspondence: Daniela Ivanova,
| | - Michael A. Cousin
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom
- Muir Maxwell Epilepsy Centre, University of Edinburgh, Edinburgh, United Kingdom
- Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh, United Kingdom
- Michael A. Cousin,
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15
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Class III PI3K Biology. Curr Top Microbiol Immunol 2022; 436:69-93. [DOI: 10.1007/978-3-031-06566-8_3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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16
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Vieira PH, Benjamim CF, Atella G, Ramos I. VPS38/UVRAG and ATG14, the variant regulatory subunits of the ATG6/Beclin1-PI3K complexes, are crucial for the biogenesis of the yolk organelles and are transcriptionally regulated in the oocytes of the vector Rhodnius prolixus. PLoS Negl Trop Dis 2021; 15:e0009760. [PMID: 34492013 PMCID: PMC8448300 DOI: 10.1371/journal.pntd.0009760] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Revised: 09/17/2021] [Accepted: 08/24/2021] [Indexed: 02/07/2023] Open
Abstract
In insects the reserve proteins are stored in the oocytes into endocytic-originated vesicles named yolk organelles. VPS38/UVRAG and ATG14 are the variant regulatory subunits of two class-III ATG6/Beclin1 PI3K complexes that regulate the recruitment of the endocytic (complex II) and autophagic (complex I) machineries. In a previous work from our group, we found that the silencing of ATG6/Beclin1 resulted in the formation of yolk-deficient oocytes due to defects in the endocytosis of the yolk proteins. Because ATG6/Beclin1 is present in the two above-described PI3K complexes, we could not identify the contributions of each complex to the yolk defective phenotypes. To address this, here we investigated the role of the variant subunits VPS38/UVRAG (complex II, endocytosis) and ATG14 (complex I, autophagy) in the biogenesis of the yolk organelles in the insect vector of Chagas Disease Rhodnius prolixus. Interestingly, the silencing of both genes phenocopied the silencing of ATG6/Beclin1, generating 1) accumulation of yolk proteins in the hemolymph; 2) white, smaller, and yolk-deficient oocytes; 3) abnormal yolk organelles in the oocyte cortex; and 4) unviable F1 embryos. However, we found that the similar phenotypes were the result of a specific cross-silencing effect among the PI3K subunits where the silencing of VPS38/UVRAG and ATG6/Beclin1 resulted in the specific silencing of each other, whereas the silencing of ATG14 triggered the silencing of all three PI3K components. Because the silencing of VPS38/UVRAG and ATG6/Beclin1 reproduced the yolk-deficiency phenotypes without the cross silencing of ATG14, we concluded that the VPS38/UVRAG PI3K complex II was the major contributor to the previously observed phenotypes in silenced insects. Altogether, we found that class-III ATG6/Beclin1 PI3K complex II (VPS38/UVRAG) is essential for the yolk endocytosis and that the subunits of both complexes are under an unknown transcriptional regulatory system.
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Affiliation(s)
- Priscila H Vieira
- Laboratório de Bioquímica de Insetos, Instituto de Bioquímica Médica Leopoldo de Meis. Universidade Federal do Rio de Janeiro, Brazil
| | - Claudia F Benjamim
- Laboratório de Imunologia Molecular e Celular, Instituto de Biofísica Carlos Chagas Filho (IBCCF), Universidade Federal do Rio de Janeiro, Brazil
| | - Georgia Atella
- Laboratório de de Bioquímica de Lipídeos e Lipoproteínas, Instituto de Bioquímica Médica Leopoldo de Meis. Universidade Federal do Rio de Janeiro, Brazil.,Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular-INCT-EM/CNPq. Rio de Janeiro, Brazil
| | - Isabela Ramos
- Laboratório de Bioquímica de Insetos, Instituto de Bioquímica Médica Leopoldo de Meis. Universidade Federal do Rio de Janeiro, Brazil.,Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular-INCT-EM/CNPq. Rio de Janeiro, Brazil
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17
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Donoso‐Quezada J, Ayala‐Mar S, González‐Valdez J. The role of lipids in exosome biology and intercellular communication: Function, analytics and applications. Traffic 2021; 22:204-220. [PMID: 34053166 PMCID: PMC8361711 DOI: 10.1111/tra.12803] [Citation(s) in RCA: 126] [Impact Index Per Article: 42.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2021] [Revised: 05/18/2021] [Accepted: 05/27/2021] [Indexed: 12/16/2022]
Abstract
Exosomes are extracellular vesicles that in recent years have received special attention for their regulatory functions in numerous biological processes. Recent evidence suggests a correlation between the composition of exosomes in body fluids and the progression of some disorders, such as cancer, diabetes and neurodegenerative diseases. In consequence, numerous studies have been performed to evaluate the composition of these vesicles, aiming to develop new biomarkers for diagnosis and to find novel therapeutic targets. On their part, lipids represent one of the most important components of exosomes, with important structural and regulatory functions during exosome biogenesis, release, targeting and cellular uptake. Therefore, exosome lipidomics has emerged as an innovative discipline for the discovery of novel lipid species with biomedical applications. This review summarizes the current knowledge about exosome lipids and their roles in exosome biology and intercellular communication. Furthermore, it presents the state-of-the-art analytical procedures used in exosome lipidomics while emphasizing how this emerging discipline is providing new insights for future applications of exosome lipids in biomedicine.
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Affiliation(s)
| | - Sergio Ayala‐Mar
- Tecnologico de MonterreySchool of Engineering and ScienceMonterreyNuevo LeónMexico
| | - José González‐Valdez
- Tecnologico de MonterreySchool of Engineering and ScienceMonterreyNuevo LeónMexico
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18
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Phosphatidylinositol 3-Phosphate Mediates the Establishment of Infectious Bursal Disease Virus Replication Complexes in Association with Early Endosomes. J Virol 2021; 95:JVI.02313-20. [PMID: 33361427 DOI: 10.1128/jvi.02313-20] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Accepted: 12/15/2020] [Indexed: 12/13/2022] Open
Abstract
Infectious bursal disease virus (IBDV) is the archetypal member of the family Birnaviridae and the etiological agent of Gumboro disease, a highly contagious immunosuppressive infection of concern to the global poultry sector for its adverse health effects in chicks. Unlike most double-stranded RNA (dsRNA) viruses, which enclose their genomes within specialized cores throughout their viral replication cycle, birnaviruses organize their bisegmented dsRNA genome in ribonucleoprotein (RNP) structures. Recently, we demonstrated that IBDV exploits endosomal membranes for replication. The establishment of IBDV replication machinery on the cytosolic leaflet of endosomal compartments is mediated by the viral protein VP3 and its intrinsic ability to target endosomes. In this study, we identified the early endosomal phosphatidylinositol 3-phosphate [PtdIns(3)P] as a key host factor of VP3 association with endosomal membranes and consequent establishment of IBDV replication complexes in early endosomes. Indeed, our data reveal a crucial role for PtdIns(3)P in IBDV replication. Overall, our findings provide new insights into the replicative strategy of birnaviruses and strongly suggest that it resembles those of positive-strand RNA (+ssRNA) viruses, which replicate in association with host membranes. Furthermore, our findings support the role of birnaviruses as evolutionary intermediaries between +ssRNA and dsRNA viruses and, importantly, demonstrate a novel role for PtdIns(3)P in the replication of a dsRNA virus.IMPORTANCE Infectious bursal disease virus (IBDV) infects chicks and is the causative agent of Gumboro disease. During IBDV outbreaks in recent decades, the emergence of very virulent variants and the lack of effective prevention/treatment strategies to fight this disease have had devastating consequences for the poultry industry. IBDV belongs to the peculiar family Birnaviridae Unlike most dsRNA viruses, birnaviruses organize their genomes in ribonucleoprotein complexes and replicate in a core-independent manner. We recently demonstrated that IBDV exploits host cell endosomes as platforms for viral replication, a process that depends on the VP3 viral protein. In this study, we delved deeper into the molecular characterization of IBDV-endosome association and investigated the role of host cell phosphatidylinositide lipids in VP3 protein localization and IBDV infection. Together, our findings demonstrate that PtdIns(3)P serves as a scaffold for the association of VP3 to endosomes and reveal its essential role for IBDV replication.
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19
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Lee MF, Trotman LC. PTEN: Bridging Endocytosis and Signaling. Cold Spring Harb Perspect Med 2020; 10:cshperspect.a036103. [PMID: 31818848 DOI: 10.1101/cshperspect.a036103] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
The transduction of signals in the PTEN/PI3-kinase (PI3K) pathway is built around a phosphoinositide (PIP) lipid messenger, phosphatidylinositol trisphosphate, PI(3,4,5)P3 or PIP3 Another, more ancient role of this family of messengers is the control of endocytosis, where a handful of separate PIPs act like postal codes. Prominent among them is PI(3)P, which helps to ensure that endocytic vesicles, their cargo, and membranes themselves reach their correct destinations. Traditionally, the cancer and the endocytic functions of the PI3K signaling pathway have been studied by cancer and membrane biologists, respectively, with some notable but overall minimal overlap. Modern microscopy has enabled monitoring of the PTEN/PI3K pathway in action. Here, we explore the flurry of groundbreaking concepts emerging from those efforts. The discovery that PTEN contains an autonomous PI(3)P reader domain, fused to the catalytic PIP3 eraser domain has prompted us to explore the relationship between PI3K signaling and endocytosis. This revealed how PTEN can achieve signal termination in a precisely controlled fashion, because endocytosis can package the PIP3 signal into discrete units that PTEN will erase. We explore how PTEN can bridge the worlds of endocytosis and PI3K signaling and discuss progress on how PI3K/AKT signaling can be acting from internal membranes. We discuss how the PTEN/PI3K system for growth control may have emerged from principles of endocytosis, and how this development could have affected the evolution of multicellular organisms.
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Affiliation(s)
- Matthew F Lee
- Watson School of Biological Sciences, Cold Spring Harbor, New York 11724, USA
| | - Lloyd C Trotman
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York 11724, USA
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20
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Char R, Pierre P. The RUFYs, a Family of Effector Proteins Involved in Intracellular Trafficking and Cytoskeleton Dynamics. Front Cell Dev Biol 2020; 8:779. [PMID: 32850870 PMCID: PMC7431699 DOI: 10.3389/fcell.2020.00779] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Accepted: 07/24/2020] [Indexed: 12/12/2022] Open
Abstract
Intracellular trafficking is essential for cell structure and function. In order to perform key tasks such as phagocytosis, secretion or migration, cells must coordinate their intracellular trafficking, and cytoskeleton dynamics. This relies on certain classes of proteins endowed with specialized and conserved domains that bridge membranes with effector proteins. Of particular interest are proteins capable of interacting with membrane subdomains enriched in specific phosphatidylinositol lipids, tightly regulated by various kinases and phosphatases. Here, we focus on the poorly studied RUFY family of adaptor proteins, characterized by a RUN domain, which interacts with small GTP-binding proteins, and a FYVE domain, involved in the recognition of phosphatidylinositol 3-phosphate. We report recent findings on this protein family that regulates endosomal trafficking, cell migration and upon dysfunction, can lead to severe pathology at the organismal level.
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Affiliation(s)
- Rémy Char
- Aix Marseille Université, Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale, Centre d'Immunologie de Marseille-Luminy, Marseille, France
| | - Philippe Pierre
- Aix Marseille Université, Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale, Centre d'Immunologie de Marseille-Luminy, Marseille, France.,Institute for Research in Biomedicine and Ilidio Pinho Foundation, Department of Medical Sciences, University of Aveiro, Aveiro, Portugal.,Shanghai Institute of Immunology, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
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21
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Shorning BY, Dass MS, Smalley MJ, Pearson HB. The PI3K-AKT-mTOR Pathway and Prostate Cancer: At the Crossroads of AR, MAPK, and WNT Signaling. Int J Mol Sci 2020; 21:E4507. [PMID: 32630372 PMCID: PMC7350257 DOI: 10.3390/ijms21124507] [Citation(s) in RCA: 287] [Impact Index Per Article: 71.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 06/22/2020] [Accepted: 06/22/2020] [Indexed: 12/13/2022] Open
Abstract
Oncogenic activation of the phosphatidylinositol-3-kinase (PI3K), protein kinase B (PKB/AKT), and mammalian target of rapamycin (mTOR) pathway is a frequent event in prostate cancer that facilitates tumor formation, disease progression and therapeutic resistance. Recent discoveries indicate that the complex crosstalk between the PI3K-AKT-mTOR pathway and multiple interacting cell signaling cascades can further promote prostate cancer progression and influence the sensitivity of prostate cancer cells to PI3K-AKT-mTOR-targeted therapies being explored in the clinic, as well as standard treatment approaches such as androgen-deprivation therapy (ADT). However, the full extent of the PI3K-AKT-mTOR signaling network during prostate tumorigenesis, invasive progression and disease recurrence remains to be determined. In this review, we outline the emerging diversity of the genetic alterations that lead to activated PI3K-AKT-mTOR signaling in prostate cancer, and discuss new mechanistic insights into the interplay between the PI3K-AKT-mTOR pathway and several key interacting oncogenic signaling cascades that can cooperate to facilitate prostate cancer growth and drug-resistance, specifically the androgen receptor (AR), mitogen-activated protein kinase (MAPK), and WNT signaling cascades. Ultimately, deepening our understanding of the broader PI3K-AKT-mTOR signaling network is crucial to aid patient stratification for PI3K-AKT-mTOR pathway-directed therapies, and to discover new therapeutic approaches for prostate cancer that improve patient outcome.
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Affiliation(s)
| | | | | | - Helen B. Pearson
- The European Cancer Stem Cell Research Institute, Cardiff University, Hadyn Ellis Building, Maindy Road, Cardiff CF24 4HQ, Wales, UK; (B.Y.S.); (M.S.D.); (M.J.S.)
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22
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PX Domain-Containing Kinesin KIF16B and Microtubule-Dependent Intracellular Movements. J Membr Biol 2020; 253:101-108. [PMID: 32140737 DOI: 10.1007/s00232-020-00110-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Accepted: 02/16/2020] [Indexed: 01/03/2023]
Abstract
As a member of the kinesin-3 family, kinesin family member 16B (KIF16B) has a characteristic PhoX homology (PX) domain that binds to membranes containing phosphatidylinositol-3-phosphate (PI(3)P) and moves along microtubule filaments to the plus end via a process regulated by coiled coils in the stalk region in various cell types. The physiological function of KIF16B supports the transport of intracellular cargo and the formation of endosomal tubules. Ras-related protein (Rab) coordinates many steps of membrane transport and are involved in the regulation of KIF16B-mediated vesicle trafficking. Data obtained from clinical research suggest that KIF16B has a potential effect on the disease processes in intellectual disability, abnormal lipid metabolism, and tumor brain metastasis. In this review, we summarize recent advances in the structural and physiological characteristics of KIF16B as well as diseases associated with KIF16B disorders, and speculating its role as a potential adaptor for intracellular cholesterol trafficking.
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23
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Kilisch M, Mayer S, Mitkovski M, Roehse H, Hentrich J, Schwappach B, Papadopoulos T. A GTPase-induced switch in phospholipid affinity of collybistin contributes to synaptic gephyrin clustering. J Cell Sci 2020; 133:jcs.232835. [PMID: 31932505 DOI: 10.1242/jcs.232835] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Accepted: 12/19/2019] [Indexed: 11/20/2022] Open
Abstract
Synaptic transmission between neurons relies on the exact spatial organization of postsynaptic transmitter receptors, which are recruited and positioned by dedicated scaffolding and regulatory proteins. At GABAergic synapses, the regulatory protein collybistin (Cb, also known as ARHGEF9) interacts with small GTPases, cell adhesion proteins and phosphoinositides to recruit the scaffolding protein gephyrin and GABAA receptors to nascent synapses. We dissected the interaction of Cb with the small Rho-like GTPase TC10 (also known as RhoQ) and phospholipids. Our data define a protein-lipid interaction network that controls the clustering of gephyrin at synapses. Within this network, TC10 and monophosphorylated phosphoinositides, particulary phosphatidylinositol 3-phosphate (PI3P), provide a coincidence detection platform that allows the accumulation and activation of Cb in endomembranes. Upon activation, TC10 induces a phospholipid affinity switch in Cb, which allows Cb to specifically interact with phosphoinositide species present at the plasma membrane. We propose that this GTPase-based regulatory switch mechanism represents an important step in the process of tethering of Cb-dependent scaffolds and receptors at nascent postsynapses.
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Affiliation(s)
- Markus Kilisch
- Department of Molecular Biology, Universitätsmedizin Göttingen, Humboldtallee 23, Göttingen 37073, Germany
| | - Simone Mayer
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, Hermann-Rein Str. 3, Göttingen 37075, Germany
| | - Miso Mitkovski
- MPI-EM Light Microscopy Facility, Max Planck Institute of Experimental Medicine, Hermann-Rein Str. 3, Göttingen 37075, Germany
| | - Heiko Roehse
- MPI-EM Light Microscopy Facility, Max Planck Institute of Experimental Medicine, Hermann-Rein Str. 3, Göttingen 37075, Germany
| | - Jennifer Hentrich
- Department of Molecular Biology, Universitätsmedizin Göttingen, Humboldtallee 23, Göttingen 37073, Germany
| | - Blanche Schwappach
- Department of Molecular Biology, Universitätsmedizin Göttingen, Humboldtallee 23, Göttingen 37073, Germany
| | - Theofilos Papadopoulos
- Department of Molecular Biology, Universitätsmedizin Göttingen, Humboldtallee 23, Göttingen 37073, Germany
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24
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Matthew-Onabanjo AN, Janusis J, Mercado-Matos J, Carlisle AE, Kim D, Levine F, Cruz-Gordillo P, Richards R, Lee MJ, Shaw LM. Beclin 1 Promotes Endosome Recruitment of Hepatocyte Growth Factor Tyrosine Kinase Substrate to Suppress Tumor Proliferation. Cancer Res 2019; 80:249-262. [PMID: 31744816 DOI: 10.1158/0008-5472.can-19-1555] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Revised: 10/01/2019] [Accepted: 11/13/2019] [Indexed: 12/24/2022]
Abstract
Beclin 1 has nonautophagic functions that include its ability to regulate endocytic receptor trafficking. However, the contribution of this function to tumor suppression is poorly understood. Here, we provide in vivo evidence that Beclin 1 suppresses tumor proliferation by regulating the endocytic trafficking and degradation of the EGFR and transferrin (TFR1) receptors. Beclin 1 promoted endosomal recruitment of hepatocyte growth factor tyrosine kinase substrate (HRS), which was necessary for sorting surface receptors to intraluminal vesicles for signal silencing and lysosomal degradation. In tumors with low Beclin 1 expression, endosomal HRS recruitment was diminished and receptor function was sustained. Collectively, our results demonstrate a novel role for Beclin 1 in impeding tumor growth by coordinating the regulation of key growth factor and nutrient receptors. These data provide an explanation for how low levels of Beclin 1 facilitate tumor proliferation and contribute to poor cancer outcomes. SIGNIFICANCE: Beclin 1 controls the trafficking fate of growth regulatory receptors to suppress tumor proliferation.
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Affiliation(s)
- Asia N Matthew-Onabanjo
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, Massachusetts.,Medical Scientist Training Program, University of Massachusetts Medical School, Worcester, Massachusetts
| | - Jenny Janusis
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, Massachusetts
| | - Jose Mercado-Matos
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, Massachusetts.,Medical Scientist Training Program, University of Massachusetts Medical School, Worcester, Massachusetts
| | - Anne E Carlisle
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, Massachusetts
| | - Dohoon Kim
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, Massachusetts
| | - Fayola Levine
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, Massachusetts
| | - Peter Cruz-Gordillo
- Medical Scientist Training Program, University of Massachusetts Medical School, Worcester, Massachusetts.,Program in Systems Biology, University of Massachusetts Medical School, Worcester, Massachusetts
| | - Ryan Richards
- Program in Systems Biology, University of Massachusetts Medical School, Worcester, Massachusetts
| | - Michael J Lee
- Program in Systems Biology, University of Massachusetts Medical School, Worcester, Massachusetts
| | - Leslie M Shaw
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, Massachusetts.
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25
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Singla A, Fedoseienko A, Giridharan SSP, Overlee BL, Lopez A, Jia D, Song J, Huff-Hardy K, Weisman L, Burstein E, Billadeau DD. Endosomal PI(3)P regulation by the COMMD/CCDC22/CCDC93 (CCC) complex controls membrane protein recycling. Nat Commun 2019; 10:4271. [PMID: 31537807 PMCID: PMC6753146 DOI: 10.1038/s41467-019-12221-6] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Accepted: 08/21/2019] [Indexed: 01/04/2023] Open
Abstract
Protein recycling through the endolysosomal system relies on molecular assemblies that interact with cargo proteins, membranes, and effector molecules. Among them, the COMMD/CCDC22/CCDC93 (CCC) complex plays a critical role in recycling events. While CCC is closely associated with retriever, a cargo recognition complex, its mechanism of action remains unexplained. Herein we show that CCC and retriever are closely linked through sharing a common subunit (VPS35L), yet the integrity of CCC, but not retriever, is required to maintain normal endosomal levels of phosphatidylinositol-3-phosphate (PI(3)P). CCC complex depletion leads to elevated PI(3)P levels, enhanced recruitment and activation of WASH (an actin nucleation promoting factor), excess endosomal F-actin and trapping of internalized receptors. Mechanistically, we find that CCC regulates the phosphorylation and endosomal recruitment of the PI(3)P phosphatase MTMR2. Taken together, we show that the regulation of PI(3)P levels by the CCC complex is critical to protein recycling in the endosomal compartment. Recycling of proteins that have entered the endosome is essential to homeostasis. The COMMD/CCDC22/CCDC93 (CCC) complex is regulator of recycling but the molecular mechanisms are unclear. Here, the authors report that the CCC complex regulates endosomal recycling by maintaining PI3P levels on endosomal membranes.
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Affiliation(s)
- Amika Singla
- Department of Internal Medicine, and Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Alina Fedoseienko
- Division of Oncology Research and Department of Biochemistry and Molecular Biology, College of Medicine, Mayo Clinic, Rochester, MN, 55905, USA
| | - Sai S P Giridharan
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Brittany L Overlee
- Division of Oncology Research and Department of Biochemistry and Molecular Biology, College of Medicine, Mayo Clinic, Rochester, MN, 55905, USA
| | - Adam Lopez
- Department of Internal Medicine, and Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Da Jia
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Department of Paediatrics, Division of Neurology, West China Second University Hospital, State Key Laboratory of Biotherapy and Collaborative Innovation Center of Biotherapy, Sichuan University, Chengdu, 610041, China
| | - Jie Song
- Department of Internal Medicine, and Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Kayci Huff-Hardy
- Department of Internal Medicine, and Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Lois Weisman
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Ezra Burstein
- Department of Internal Medicine, and Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA.
| | - Daniel D Billadeau
- Division of Oncology Research and Department of Biochemistry and Molecular Biology, College of Medicine, Mayo Clinic, Rochester, MN, 55905, USA.
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26
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Jin Y, Shang Y, Zhang D, An J, Pan D. Hexabromocyclododecanes promoted autophagy through the PI3K/Akt/mTOR pathway in L02 cells. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2019; 244:77-82. [PMID: 31108313 DOI: 10.1016/j.jenvman.2019.05.031] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Revised: 04/22/2019] [Accepted: 05/06/2019] [Indexed: 06/09/2023]
Abstract
As additive brominated flame retardants, hexabromocyclododecanes (HBCDs) are being widely used in diverse artificial materials and products, including thermal insulation building materials, housings of electronic equipment, and upholstery textiles. Toxicology studies have shown that HBCDs exposure are closely related to hepatotoxicity and liver diseases. The present study is designed to explore how HBCDs affect cell apoptosis and autophagy process in a human hepatocyte cell line (L02) and to reveal the underline molecular mechanisms. Firstly, HBCDs could elevate the apoptosis rate of L02 cells dose-dependently. Three apoptosis related proteins (apoptotic protease activating factor 1 (Apaf-1), cysteinyl aspartate specific proteinase 3 (caspase-3) and cysteinyl aspartate specific proteinase 9 (caspase-9)) were observed to be up-regulated using western blotting method. Autophagy process was also started by HBCDs in L02 cells as indicated by the increased expressions of LC3-phosphatidylethanolamine conjugate (LC3-II) and other autophagic protein markers (Beclin-1, autophagy related protein 3 (Atg3), autophagy related protein 5 (Atg5), autophagy related protein 7 (Atg7) and autophagy related protein 16L1(Atg16L1)). The results of the green fluorescent protein (GFP)-microtubule-associated protein 1 light chain 3 (LC3) intracellular localization and fluorescence intensity further evidenced the activation of autophagy in L02 cells after treated with HBCDs. In addition, phosphatidylinositide 3-kinases/protein kinase B/mammalian target of rapamycin (PI3K/Akt/mTOR) pathway was activated in L02 cells by HBCDs, suggested by the increased expressions of related proteins. The inhibitors of PI3K (LY294002), DNA-activated protein kinase catalytic subunit (DNA-PKcs) (NU7441), Akt (MK2206), and mTOR (KU0063794) could obviously reduce the autophagic proteins prompted by HBCDs. The fluorescence intensities of GFP-LC3 transfected L02 cells were also decreased significantly after the application of these inhibitors. These results indicated that PI3K/Akt/mTOR pathway was participated in regulating autophagy process promoted by HBCDs. In above, HBCDs could induce mitochondrial-dependent apoptosis and autophagy in L02 cells, which was modulated by PI3K/Akt/mTOR pathway.
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Affiliation(s)
- Yingying Jin
- School of Environmental and Chemical Engineering, Shanghai University, Shanghai, 200444, China
| | - Yu Shang
- School of Environmental and Chemical Engineering, Shanghai University, Shanghai, 200444, China
| | - Dongping Zhang
- School of Environmental and Chemical Engineering, Shanghai University, Shanghai, 200444, China
| | - Jing An
- School of Environmental and Chemical Engineering, Shanghai University, Shanghai, 200444, China
| | - Dongyan Pan
- Department of Ophthalmology, Changhai Hospital, Second Military Medical University, Shanghai, 200433, China.
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27
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Robinson DC, Mammel AE, Logan AM, Larson AA, Schmidt EJ, Condon AF, Robinson FL. An In Vitro Model of Charcot-Marie-Tooth Disease Type 4B2 Provides Insight Into the Roles of MTMR13 and MTMR2 in Schwann Cell Myelination. ASN Neuro 2019; 10:1759091418803282. [PMID: 30419760 PMCID: PMC6236487 DOI: 10.1177/1759091418803282] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Charcot-Marie-Tooth Disorder Type 4B (CMT4B) is a demyelinating
peripheral neuropathy caused by mutations in myotubularin-related
(MTMR) proteins 2, 13, or 5 (CMT4B1/2/3), which regulate
phosphoinositide turnover and endosomal trafficking. Although mouse
models of CMT4B2 exist, an in vitro model would make
possible pharmacological and reverse genetic experiments needed to
clarify the role of MTMR13 in myelination. We have generated such a
model using Schwann cell-dorsal root ganglion (SC-DRG) explants from
Mtmr13−/− mice. Myelin sheaths
in mutant cultures contain outfoldings highly reminiscent of those
observed in the nerves of Mtmr13−/− mice
and CMT4B2 patients. Mtmr13−/− SC-DRG
explants also contain reduced Mtmr2, further supporting a role of
Mtmr13 in stabilizing Mtmr2. Elevated PI(3,5)P2 has been
implicated as a cause of myelin outfoldings in
Mtmr2−/− models. In contrast,
the role of elevated PI3P or PI(3,5)P2 in promoting
outfoldings in Mtmr13−/− models is
unclear. We found that over-expression of MTMR2 in
Mtmr13−/− SC-DRGs moderately
reduced the prevalence of myelin outfoldings. Thus, a manipulation
predicted to lower PI3P and PI(3,5)P2 partially suppressed
the phenotype caused by Mtmr13 deficiency. We also explored the
relationship between CMT4B2-like myelin outfoldings and kinases that
produce PI3P and PI(3,5)P2 by analyzing nerve pathology in
mice lacking both Mtmr13 and one of two specific PI 3-kinases.
Intriguingly, the loss of vacuolar protein sorting 34 or PI3K-C2β in
Mtmr13−/− mice had no impact
on the prevalence of myelin outfoldings. In aggregate, our findings
suggest that the MTMR13 scaffold protein likely has critical functions
other than stabilizing MTMR2 to achieve an adequate level of PI
3-phosphatase activity.
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Affiliation(s)
- Danielle C Robinson
- 1 Department of Neurology, Jungers Center for Neurosciences Research, Oregon Health & Science University, Portland, OR, USA.,2 Neuroscience Graduate Program, Oregon Health & Science University, Portland, OR, USA
| | - Anna E Mammel
- 1 Department of Neurology, Jungers Center for Neurosciences Research, Oregon Health & Science University, Portland, OR, USA.,3 Cell, Developmental & Cancer Biology Graduate Program, Oregon Health & Science University, Portland, OR, USA
| | - Anne M Logan
- 1 Department of Neurology, Jungers Center for Neurosciences Research, Oregon Health & Science University, Portland, OR, USA.,2 Neuroscience Graduate Program, Oregon Health & Science University, Portland, OR, USA
| | - Aubree A Larson
- 1 Department of Neurology, Jungers Center for Neurosciences Research, Oregon Health & Science University, Portland, OR, USA
| | - Eric J Schmidt
- 1 Department of Neurology, Jungers Center for Neurosciences Research, Oregon Health & Science University, Portland, OR, USA
| | - Alec F Condon
- 1 Department of Neurology, Jungers Center for Neurosciences Research, Oregon Health & Science University, Portland, OR, USA.,2 Neuroscience Graduate Program, Oregon Health & Science University, Portland, OR, USA
| | - Fred L Robinson
- 1 Department of Neurology, Jungers Center for Neurosciences Research, Oregon Health & Science University, Portland, OR, USA.,4 Vollum Institute, Oregon Health & Science University, Portland, OR, USA
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28
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Sbrissa D, Naisan G, Ikonomov OC, Shisheva A. Apilimod, a candidate anticancer therapeutic, arrests not only PtdIns(3,5)P2 but also PtdIns5P synthesis by PIKfyve and induces bafilomycin A1-reversible aberrant endomembrane dilation. PLoS One 2018; 13:e0204532. [PMID: 30240452 PMCID: PMC6150535 DOI: 10.1371/journal.pone.0204532] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2018] [Accepted: 09/10/2018] [Indexed: 01/02/2023] Open
Abstract
PIKfyve, an evolutionarily conserved kinase synthesizing PtdIns5P and PtdIns(3,5)P2, is crucial for mammalian cell proliferation and viability. Accordingly, PIKfyve inhibitors are now in clinical trials as anti-cancer drugs. Among those, apilimod is the most promising, yet its potency to inhibit PIKfyve and affect endomembrane homeostasis is only partially characterized. We demonstrate here for the first time that apilimod powerfully inhibited in vitro synthesis of PtdIns5P along with that of PtdIns(3,5)P2. HPLC-based resolution of intracellular phosphoinositides (PIs) revealed that apilimod triggered a marked reduction of both lipids in the context of intact cells. Notably, there was also a profound rise in PtdIns3P resulting from arrested PtdIns3P consumption for PtdIns(3,5)P2 synthesis. As typical for PIKfyve inhibition and the concomitant PtdIns(3,5)P2 reduction, apilimod induced the appearance of dilated endomembrane structures in the form of large translucent cytoplasmic vacuoles. Remarkably, bafilomycin A1 (BafA1) fully reversed the aberrant cell phenotype back to normal and completely precluded the appearance of cytoplasmic vacuoles when added prior to apilimod. Inspection of the PI profiles ruled out restoration of the reduced PtdIns(3,5)P2 pool as a molecular mechanism underlying BafA1 rescue. Rather, we found that BafA1 markedly attenuated the PtdIns3P elevation under PIKfyve inhibition. This was accompanied by profoundly decreased endosomal recruitment of fusogenic EEA1. Together, our data demonstrate that apilimod inhibits not only PtdIns(3,5)P2 but also PtdIns5P synthesis and that the cytoplasmic vacuolization triggered by the inhibitor is precluded or reversed by BafA1 through a mechanism associated, in part, with reduction in both PtdIns3P levels and EEA1 membrane recruitment.
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Affiliation(s)
- Diego Sbrissa
- Department of Physiology, Wayne State University School of Medicine, Detroit, Michigan, United States of America
| | - Ghassan Naisan
- Department of Physiology, Wayne State University School of Medicine, Detroit, Michigan, United States of America
| | - Ognian C. Ikonomov
- Department of Physiology, Wayne State University School of Medicine, Detroit, Michigan, United States of America
| | - Assia Shisheva
- Department of Physiology, Wayne State University School of Medicine, Detroit, Michigan, United States of America
- * E-mail:
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29
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Vieira PH, Bomfim L, Atella GC, Masuda H, Ramos I. Silencing of RpATG6 impaired the yolk accumulation and the biogenesis of the yolk organelles in the insect vector R. prolixus. PLoS Negl Trop Dis 2018; 12:e0006507. [PMID: 29768406 PMCID: PMC5973624 DOI: 10.1371/journal.pntd.0006507] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Revised: 05/29/2018] [Accepted: 05/08/2018] [Indexed: 12/11/2022] Open
Abstract
In oviparous animals, the egg yolk is synthesized by the mother in a major metabolic challenge, where the different yolk components are secreted to the hemolymph and delivered to the oocytes mostly by endocytosis. The yolk macromolecules are then stored in a wide range of endocytic-originated vesicles which are collectively referred to as yolk organelles and occupy most of the mature oocytes cytoplasm. After fertilization, the contents of these organelles are degraded in a regulated manner to supply the embryo cells with fundamental molecules for de novo synthesis. Yolk accumulation and its regulated degradation are therefore crucial for successful development, however, most of the molecular mechanisms involved in the biogenesis, sorting and degradation of targeted yolk organelles are still poorly understood. ATG6 is part of two PI3P-kinase complexes that can regulate the recruitment of the endocytic or the autophagy machineries. Here, we investigate the role of RpATG6 in the endocytosis of the yolk macromolecules and in the biogenesis of the yolk organelles in the insect vector Rhodnius prolixus. We found that vitellogenic females express high levels of RpATG6 in the ovaries, when compared to the levels detected in the midgut and fat body. RNAi silencing of RpATG6 resulted in yolk proteins accumulated in the vitellogenic hemolymph, as a consequence of poor uptake by the oocytes. Accordingly, the silenced oocytes are unviable, white (contrasting to the control pink oocytes), smaller (62% of the control oocyte volume) and accumulate only 40% of the yolk proteins, 80% of the TAG and 50% of the polymer polyphosphate quantified in control oocytes. The cortex of silenced oocytes present atypical smaller vesicles indicating that the yolk organelles were not properly formed and/or sorted, which was supported by the lack of endocytic vesicles near the plasma membrane of silenced oocytes as seen by TEM. Altogether, we found that RpATG6 is central for the mechanisms of yolk accumulation, emerging as an important target for further investigations on oogenesis and, therefore, reproduction of this vector.
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Affiliation(s)
- Priscila H. Vieira
- Laboratório de Bioquímica de Insetos, Instituto de Bioquímica Médica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Larissa Bomfim
- Laboratório de Bioquímica de Insetos, Instituto de Bioquímica Médica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Georgia C. Atella
- Laboratório de Bioquímica de lipídeos e lipoproteínas, Instituto de Bioquímica Médica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Hatisaburo Masuda
- Laboratório de Bioquímica de Insetos, Instituto de Bioquímica Médica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Isabela Ramos
- Laboratório de Bioquímica de Insetos, Instituto de Bioquímica Médica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
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30
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Bilanges B, Alliouachene S, Pearce W, Morelli D, Szabadkai G, Chung YL, Chicanne G, Valet C, Hill JM, Voshol PJ, Collinson L, Peddie C, Ali K, Ghazaly E, Rajeeve V, Trichas G, Srinivas S, Chaussade C, Salamon RS, Backer JM, Scudamore CL, Whitehead MA, Keaney EP, Murphy LO, Semple RK, Payrastre B, Tooze SA, Vanhaesebroeck B. Vps34 PI 3-kinase inactivation enhances insulin sensitivity through reprogramming of mitochondrial metabolism. Nat Commun 2017; 8:1804. [PMID: 29180704 PMCID: PMC5703854 DOI: 10.1038/s41467-017-01969-4] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2016] [Accepted: 10/30/2017] [Indexed: 12/13/2022] Open
Abstract
Vps34 PI3K is thought to be the main producer of phosphatidylinositol-3-monophosphate, a lipid that controls intracellular vesicular trafficking. The organismal impact of systemic inhibition of Vps34 kinase activity is not completely understood. Here we show that heterozygous Vps34 kinase-dead mice are healthy and display a robustly enhanced insulin sensitivity and glucose tolerance, phenotypes mimicked by a selective Vps34 inhibitor in wild-type mice. The underlying mechanism of insulin sensitization is multifactorial and not through the canonical insulin/Akt pathway. Vps34 inhibition alters cellular energy metabolism, activating the AMPK pathway in liver and muscle. In liver, Vps34 inactivation mildly dampens autophagy, limiting substrate availability for mitochondrial respiration and reducing gluconeogenesis. In muscle, Vps34 inactivation triggers a metabolic switch from oxidative phosphorylation towards glycolysis and enhanced glucose uptake. Our study identifies Vps34 as a new drug target for insulin resistance in Type-2 diabetes, in which the unmet therapeutic need remains substantial.
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Affiliation(s)
- Benoit Bilanges
- UCL Cancer Institute, University College London, 72 Huntley Street, London, WC1E 6DD, UK.
| | - Samira Alliouachene
- UCL Cancer Institute, University College London, 72 Huntley Street, London, WC1E 6DD, UK
| | - Wayne Pearce
- UCL Cancer Institute, University College London, 72 Huntley Street, London, WC1E 6DD, UK
| | - Daniele Morelli
- UCL Cancer Institute, University College London, 72 Huntley Street, London, WC1E 6DD, UK
| | - Gyorgy Szabadkai
- Department of Cell and Developmental Biology, Consortium for Mitochondrial Research, University College London, Gower Street, London, WC1E 6BT, UK
- Department of Biomedical Sciences, University of Padua, Padua, 58/B via Ugo, Bassi, 35121, Italy
| | - Yuen-Li Chung
- Cancer Research UK Cancer Imaging Centre, Division of Radiotherapy and Imaging, The Institute of Cancer Research London, 123 Old Brompton Road, London, SW7 3RP, UK
| | - Gaëtan Chicanne
- Inserm/UPS UMR 1048, Institut des Maladies Métaboliques et Cardiovasculaires, 1 Avenue Jean Poulhès BP 84225, 31432, Toulouse Cedex 4, France
| | - Colin Valet
- Inserm/UPS UMR 1048, Institut des Maladies Métaboliques et Cardiovasculaires, 1 Avenue Jean Poulhès BP 84225, 31432, Toulouse Cedex 4, France
| | - Julia M Hill
- Department of Cell and Developmental Biology, Consortium for Mitochondrial Research, University College London, Gower Street, London, WC1E 6BT, UK
| | - Peter J Voshol
- Metabolic Research Laboratories, MRC Metabolic Diseases Unit, Wellcome Trust-MRC Institute of Metabolic Science, Level 4, Box 289, Addenbrooke's Hospital, Cambridge, CB2 0QQ, UK
| | - Lucy Collinson
- The Francis Crick Institute, Lincoln's Inn Fields Laboratories, 44 Lincoln's Inn Fields, London, WC2A 3LY, UK
| | - Christopher Peddie
- The Francis Crick Institute, Lincoln's Inn Fields Laboratories, 44 Lincoln's Inn Fields, London, WC2A 3LY, UK
| | - Khaled Ali
- UCL Cancer Institute, University College London, 72 Huntley Street, London, WC1E 6DD, UK
| | - Essam Ghazaly
- Centre of Haemato-Oncology, Barts Cancer Institute, Queen Mary University of London, London, EC1M 6BQ, UK
| | - Vinothini Rajeeve
- Centre of Haemato-Oncology, Barts Cancer Institute, Queen Mary University of London, London, EC1M 6BQ, UK
| | - Georgios Trichas
- Department of Physiology Anatomy and Genetics, University of Oxford, Oxford, OX1 3PT, UK
| | - Shankar Srinivas
- Department of Physiology Anatomy and Genetics, University of Oxford, Oxford, OX1 3PT, UK
| | - Claire Chaussade
- UCL Cancer Institute, University College London, 72 Huntley Street, London, WC1E 6DD, UK
| | - Rachel S Salamon
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, 10461, NY, USA
| | - Jonathan M Backer
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, 10461, NY, USA
| | - Cheryl L Scudamore
- Mary Lyon Centre, MRC Harwell, Harwell Science and Innovation Campus, Harwell, OX11 0RD, UK
| | - Maria A Whitehead
- UCL Cancer Institute, University College London, 72 Huntley Street, London, WC1E 6DD, UK
| | - Erin P Keaney
- Novartis Institutes for BioMedical Research, 181 Massachusetts Avenue, Cambridge, MA, 02139, USA
| | - Leon O Murphy
- Novartis Institutes for BioMedical Research, 181 Massachusetts Avenue, Cambridge, MA, 02139, USA
| | - Robert K Semple
- Institute of Metabolic Science, University of Cambridge, Addenbrooke's Hospital, Cambridge, CB2 0QQ, UK
| | - Bernard Payrastre
- Inserm/UPS UMR 1048, Institut des Maladies Métaboliques et Cardiovasculaires, 1 Avenue Jean Poulhès BP 84225, 31432, Toulouse Cedex 4, France
| | - Sharon A Tooze
- The Francis Crick Institute, Lincoln's Inn Fields Laboratories, 44 Lincoln's Inn Fields, London, WC2A 3LY, UK
| | - Bart Vanhaesebroeck
- UCL Cancer Institute, University College London, 72 Huntley Street, London, WC1E 6DD, UK.
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31
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Schoijet AC, Miranda K, Sternlieb T, Barrera NM, Girard-Dias W, de Souza W, Alonso GD. TbVps15 is required for vesicular transport and cytokinesis in Trypanosoma brucei. Mol Biochem Parasitol 2017; 219:33-41. [PMID: 29155083 DOI: 10.1016/j.molbiopara.2017.11.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Revised: 11/10/2017] [Accepted: 11/11/2017] [Indexed: 01/20/2023]
Abstract
The class III phosphatidylinositol 3-kinase (PI3K) Vps34 is an important regulator of key cellular functions, including cell growth, survival, intracellular trafficking, autophagy and nutrient sensing. In yeast, Vps34 is associated with the putative serine/threonine protein kinase Vps15, however, its role in signaling has not been deeply evaluated. Here, we have identified the Vps15 orthologue in Trypanosoma brucei, named TbVps15. Knockdown of TbVps15 expression by interference RNA resulted in inhibition of cell growth and blockage of cytokinesis. Scanning electron microcopy revealed a variety of morphological abnormalities, with enlarged parasites and dividing cells that often exhibited a detached flagellum. Transmission electron microscopy analysis of TbVps15 RNAi cells showed an increase in intracellular vacuoles of the endomembrane system and some cells displayed an enlargement of the flagellar pocket, a common feature of cells defective in endocytosis. Moreover, uptake of dextran, transferrin and Concanavalin A was impaired. Finally, TbVps15 downregulation affected the PI3K activity, supporting the hypothesis that TbVps15 and TbVps34 form a complex as occurs in other organisms. In summary, we propose that TbVps15 has a role in the maintenance of cytokinesis, endocytosis and intracellular trafficking in T. brucei.
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Affiliation(s)
- Alejandra C Schoijet
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres" (INGEBI-CONICET), Buenos Aires, Argentina; Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Fisiología, Biología Molecular y Celular, Buenos Aires, Argentina
| | - Kildare Miranda
- Laboratorio de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho and Centro Nacional de Biologia Estrutural e Bioimagem (CENABIO), Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil; Instituto Nacional de Biologia Estrutural e Bioimagem, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Tamara Sternlieb
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres" (INGEBI-CONICET), Buenos Aires, Argentina
| | - Nadia M Barrera
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres" (INGEBI-CONICET), Buenos Aires, Argentina
| | - Wendell Girard-Dias
- Laboratorio de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho and Centro Nacional de Biologia Estrutural e Bioimagem (CENABIO), Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil; Plataforma de Microscopia Eletrônica Rudolf Barth IOC, Fiocruz, Rio de Janeiro, Brazil
| | - Wanderley de Souza
- Laboratorio de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho and Centro Nacional de Biologia Estrutural e Bioimagem (CENABIO), Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil; Instituto Nacional de Biologia Estrutural e Bioimagem, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Guillermo D Alonso
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres" (INGEBI-CONICET), Buenos Aires, Argentina; Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Fisiología, Biología Molecular y Celular, Buenos Aires, Argentina.
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32
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Class III phosphatidylinositol-3-OH kinase controls epithelial integrity through endosomal LKB1 regulation. Nat Cell Biol 2017; 19:1412-1423. [DOI: 10.1038/ncb3631] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2016] [Accepted: 09/18/2017] [Indexed: 12/18/2022]
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Mutant Huntingtin Is Secreted via a Late Endosomal/Lysosomal Unconventional Secretory Pathway. J Neurosci 2017; 37:9000-9012. [PMID: 28821645 DOI: 10.1523/jneurosci.0118-17.2017] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Revised: 06/26/2017] [Accepted: 08/09/2017] [Indexed: 12/22/2022] Open
Abstract
Huntington's disease (HD) is an autosomal-dominant neurodegenerative disorder caused by the expansion of a CAG triplet in the gene encoding for huntingtin (Htt). The resulting mutant protein (mHtt) with extended polyglutamine (polyQ) sequence at the N terminus leads to neuronal degeneration both in a cell-autonomous and a non-cell-autonomous manner. Recent studies identified mHtt in the extracellular environment and suggested that its spreading contributes to toxicity, but the mechanism of mHtt release from the cell of origin remains unknown. In this study, we performed a comprehensive, unbiased analysis of secretory pathways and identified an unconventional lysosomal pathway as an important mechanism for mHtt secretion in mouse neuroblastoma and striatal cell lines, as well as in primary neurons. mHtt secretion was dependent on synaptotagmin 7, a regulator of lysosomal secretion, and inhibited by chemical ablation of late endosomes/lysosomes, suggesting a lysosomal secretory pattern. mHtt was targeted preferentially to the late endosomes/lysosomes compared with wild-type Htt. Importantly, we found that late endosomal/lysosomal targeting and secretion of mHtt could be inhibited efficiently by the phosphatidylinositol 3-kinase and neutral sphingomyelinase chemical inhibitors, Ly294002 and GW4869, respectively. Together, our data suggest a lysosomal mechanism of mHtt secretion and offer potential strategies for pharmacological modulation of its neuronal secretion.SIGNIFICANCE STATEMENT This is the first study examining the mechanism of mutant huntingtin (mHTT) secretion in an unbiased manner. We found that the protein is secreted via a late endosomal/lysosomal unconventional secretory pathway. Moreover, mHtt secretion can be reduced significantly by phosphatidylinositol 3-kinase and neutral sphingomyelinase inhibitors. Understanding and manipulating the secretion of mHtt is important because of its potentially harmful propagation in the brain.
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34
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Logan AM, Mammel AE, Robinson DC, Chin AL, Condon AF, Robinson FL. Schwann cell-specific deletion of the endosomal PI 3-kinase Vps34 leads to delayed radial sorting of axons, arrested myelination, and abnormal ErbB2-ErbB3 tyrosine kinase signaling. Glia 2017; 65:1452-1470. [PMID: 28617998 DOI: 10.1002/glia.23173] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2016] [Revised: 05/04/2017] [Accepted: 05/10/2017] [Indexed: 12/12/2022]
Abstract
The PI 3-kinase Vps34 (Pik3c3) synthesizes phosphatidylinositol 3-phosphate (PI3P), a lipid critical for both endosomal membrane traffic and macroautophagy. Human genetics have implicated PI3P dysregulation, and endosomal trafficking in general, as a recurring cause of demyelinating Charcot-Marie-Tooth (CMT) peripheral neuropathy. Here, we investigated the role of Vps34, and PI3P, in mouse Schwann cells by selectively deleting Vps34 in this cell type. Vps34-Schwann cell knockout (Vps34SCKO ) mice show severe hypomyelination in peripheral nerves. Vps34-/- Schwann cells interact abnormally with axons, and there is a delay in radial sorting, a process by which large axons are selected for myelination. Upon reaching the promyelinating stage, Vps34-/- Schwann cells are significantly impaired in the elaboration of myelin. Nerves from Vps34SCKO mice contain elevated levels of the LC3 and p62 proteins, indicating impaired autophagy. However, in the light of recent demonstrations that autophagy is dispensable for myelination, it is unlikely that hypomyelination in Vps34SCKO mice is caused by impaired autophagy. Endosomal trafficking is also disturbed in Vps34-/- Schwann cells. We investigated the activation of the ErbB2/3 receptor tyrosine kinases in Vps34SCKO nerves, as these proteins, which play essential roles in Schwann cell myelination, are known to traffic through endosomes. In Vps34SCKO nerves, ErbB3 was hyperphosphorylated on a tyrosine known to be phosphorylated in response to neuregulin 1 exposure. ErbB2 protein levels were also decreased during myelination. Our findings suggest that the loss of Vps34 alters the trafficking of ErbB2/3 through endosomes. Abnormal ErbB2/3 signaling to downstream targets may contribute to the hypomyelination observed in Vps34SCKO mice.
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Affiliation(s)
- Anne M Logan
- Department of Neurology, Jungers Center for Neurosciences Research, Oregon Health and Science University, Mail Code L623, Portland, Oregon, 97239.,Neuroscience Graduate Program, Oregon Health and Science University, Portland, Oregon, 97239
| | - Anna E Mammel
- Department of Neurology, Jungers Center for Neurosciences Research, Oregon Health and Science University, Mail Code L623, Portland, Oregon, 97239.,Cell, Developmental and Cancer Biology Graduate Program, Oregon Health and Science University, Portland, Oregon, 97239
| | - Danielle C Robinson
- Department of Neurology, Jungers Center for Neurosciences Research, Oregon Health and Science University, Mail Code L623, Portland, Oregon, 97239.,Neuroscience Graduate Program, Oregon Health and Science University, Portland, Oregon, 97239
| | - Andrea L Chin
- Department of Neurology, Jungers Center for Neurosciences Research, Oregon Health and Science University, Mail Code L623, Portland, Oregon, 97239
| | - Alec F Condon
- Department of Neurology, Jungers Center for Neurosciences Research, Oregon Health and Science University, Mail Code L623, Portland, Oregon, 97239.,Neuroscience Graduate Program, Oregon Health and Science University, Portland, Oregon, 97239
| | - Fred L Robinson
- Department of Neurology, Jungers Center for Neurosciences Research, Oregon Health and Science University, Mail Code L623, Portland, Oregon, 97239.,Vollum Institute, Oregon Health and Science University, Portland, Oregon, 97239
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35
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The intricate regulation and complex functions of the Class III phosphoinositide 3-kinase Vps34. Biochem J 2017; 473:2251-71. [PMID: 27470591 DOI: 10.1042/bcj20160170] [Citation(s) in RCA: 156] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Accepted: 03/30/2016] [Indexed: 11/17/2022]
Abstract
The Class III phosphoinositide 3-kinase Vps34 (vacuolar protein sorting 34) plays important roles in endocytic trafficking, macroautophagy, phagocytosis, cytokinesis and nutrient sensing. Recent studies have provided exciting new insights into the structure and regulation of this lipid kinase, and new cellular functions for Vps34 have emerged. This review critically examines the wealth of new data on this important enzyme, and attempts to integrate these findings with current models of Vps34 signalling.
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36
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Phosphatidylinositol 3-phosphate-binding protein AtPH1 controls the localization of the metal transporter NRAMP1 in Arabidopsis. Proc Natl Acad Sci U S A 2017; 114:E3354-E3363. [PMID: 28373552 DOI: 10.1073/pnas.1702975114] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
"Too much of a good thing" perfectly describes the dilemma that living organisms face with metals. The tight control of metal homeostasis in cells depends on the trafficking of metal transporters between membranes of different compartments. However, the mechanisms regulating the location of transport proteins are still largely unknown. Developing Arabidopsis thaliana seedlings require the natural resistance-associated macrophage proteins (NRAMP3 and NRAMP4) transporters to remobilize iron from seed vacuolar stores and thereby acquire photosynthetic competence. Here, we report that mutations in the pleckstrin homology (PH) domain-containing protein AtPH1 rescue the iron-deficient phenotype of nramp3nramp4 Our results indicate that AtPH1 binds phosphatidylinositol 3-phosphate (PI3P) in vivo and acts in the late endosome compartment. We further show that loss of AtPH1 function leads to the mislocalization of the metal uptake transporter NRAMP1 to the vacuole, providing a rationale for the reversion of nramp3nramp4 phenotypes. This work identifies a PH domain protein as a regulator of plant metal transporter localization, providing evidence that PH domain proteins may be effectors of PI3P for protein sorting.
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37
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Latré de Laté P, Pineda M, Harnett M, Harnett W, Besteiro S, Langsley G. Apicomplexan autophagy and modulation of autophagy in parasite-infected host cells. Biomed J 2017; 40:23-30. [PMID: 28411879 PMCID: PMC6138587 DOI: 10.1016/j.bj.2017.01.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Revised: 01/05/2017] [Accepted: 01/11/2017] [Indexed: 11/18/2022] Open
Abstract
Apicomplexan parasites are responsible for a number of important human pathologies. Obviously, as Eukaryotes they share a number of cellular features and pathways with their respective host cells. One of them is autophagy, a process involved in the degradation of the cell's own components. These intracellular parasites nonetheless seem to present a number of original features compared to their very evolutionarily distant host cells. In mammals and other metazoans, autophagy has been identified as an important contributor to the defence against microbial pathogens. Thus, host autophagy also likely plays a key role in the control of apicomplexan parasites, although its potential manipulation and subversion by intracellular parasites creates a complex interplay in the regulation of host and parasite autophagy. In this mini-review, we summarise current knowledge on autophagy in both parasites and their host cells, in the context of infection by three Apicomplexa: Plasmodium, Toxoplasma, and Theileria.
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Affiliation(s)
- Perle Latré de Laté
- Inserm U1016, Cnrs UMR8104, Cochin Institute, Paris, France; Comparative Cellbiology of Apicomplexan Parasites, Faculty of Medicine, Paris-Descartes University, Paris, France
| | - Miguel Pineda
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, Glasgow Biomedical Research Centre, University of Glasgow, Glasgow, UK
| | - Margaret Harnett
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, Glasgow Biomedical Research Centre, University of Glasgow, Glasgow, UK.
| | - William Harnett
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, UK
| | | | - Gordon Langsley
- Inserm U1016, Cnrs UMR8104, Cochin Institute, Paris, France; Comparative Cellbiology of Apicomplexan Parasites, Faculty of Medicine, Paris-Descartes University, Paris, France.
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38
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Yakhine-Diop S, Martínez-Chacón G, González-Polo R, Fuentes J, Niso-Santano M. Fluorescent FYVE Chimeras to Quantify PtdIns3P Synthesis During Autophagy. Methods Enzymol 2017; 587:257-269. [DOI: 10.1016/bs.mie.2016.09.060] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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39
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Papadopoulos T, Rhee HJ, Subramanian D, Paraskevopoulou F, Mueller R, Schultz C, Brose N, Rhee JS, Betz H. Endosomal Phosphatidylinositol 3-Phosphate Promotes Gephyrin Clustering and GABAergic Neurotransmission at Inhibitory Postsynapses. J Biol Chem 2016; 292:1160-1177. [PMID: 27941024 DOI: 10.1074/jbc.m116.771592] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Indexed: 11/06/2022] Open
Abstract
The formation of neuronal synapses and the dynamic regulation of their efficacy depend on the proper assembly of the postsynaptic neurotransmitter receptor apparatus. Receptor recruitment to inhibitory GABAergic postsynapses requires the scaffold protein gephyrin and the guanine nucleotide exchange factor collybistin (Cb). In vitro, the pleckstrin homology domain of Cb binds phosphoinositides, specifically phosphatidylinositol 3-phosphate (PI3P). However, whether PI3P is required for inhibitory postsynapse formation is currently unknown. Here, we investigated the role of PI3P at developing GABAergic postsynapses by using a membrane-permeant PI3P derivative, time-lapse confocal imaging, electrophysiology, as well as knockdown and overexpression of PI3P-metabolizing enzymes. Our results provide the first in cellula evidence that PI3P located at early/sorting endosomes regulates the postsynaptic clustering of gephyrin and GABAA receptors and the strength of inhibitory, but not excitatory, postsynapses in cultured hippocampal neurons. In human embryonic kidney 293 cells, stimulation of gephyrin cluster formation by PI3P depends on Cb. We therefore conclude that the endosomal pool of PI3P, generated by the class III phosphatidylinositol 3-kinase, is important for the Cb-mediated recruitment of gephyrin and GABAA receptors to developing inhibitory postsynapses and thus the formation of postsynaptic membrane specializations.
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Affiliation(s)
- Theofilos Papadopoulos
- From the Department of Molecular Biology, Center of Biochemistry and Molecular Cell Biology, Universitätsmedizin Göttingen, Humboldtallee 23, 37073 Göttingen, Germany,
| | - Hong Jun Rhee
- the Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, Hermann-Rein-Strasse 3, 37075 Göttingen, Germany
| | - Devaraj Subramanian
- the European Molecular Biology Laboratory (EMBL), Cell Biology and Biophysics Unit, Meyerhofstrasse 1, 69117 Heidelberg, Germany
| | - Foteini Paraskevopoulou
- From the Department of Molecular Biology, Center of Biochemistry and Molecular Cell Biology, Universitätsmedizin Göttingen, Humboldtallee 23, 37073 Göttingen, Germany
| | - Rainer Mueller
- the European Molecular Biology Laboratory (EMBL), Cell Biology and Biophysics Unit, Meyerhofstrasse 1, 69117 Heidelberg, Germany
| | - Carsten Schultz
- the European Molecular Biology Laboratory (EMBL), Cell Biology and Biophysics Unit, Meyerhofstrasse 1, 69117 Heidelberg, Germany.,the Department of Physiology and Pharmacology, Oregon Health and Science University, Portland, Oregon 97239-3098
| | - Nils Brose
- the Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, Hermann-Rein-Strasse 3, 37075 Göttingen, Germany
| | - Jeong-Seop Rhee
- the Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, Hermann-Rein-Strasse 3, 37075 Göttingen, Germany
| | - Heinrich Betz
- the Department of Neurochemistry, Max Planck Institute for Brain Research, Deutschordenstrasse 46, 60528 Frankfurt am Main, Germany, and.,the Max Planck Institute of Medical Research, Jahnstrasse 29, 69120 Heidelberg, Germany
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40
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Fassy F, Dureuil C, Lamberton A, Mathieu M, Michot N, Ronan B, Pasquier B. In Vitro Characterization of VPS34 Lipid Kinase Inhibition by Small Molecules. Methods Enzymol 2016; 587:447-464. [PMID: 28253972 DOI: 10.1016/bs.mie.2016.09.070] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
VPS34 is a class III phosphoinositide 3-kinase that acts on vesicle trafficking. This kinase has recently attracted significant attention because of the function it plays in the machinery involved in the early steps of autophagy. Moreover, because significant progress had been made in the optimization of specific kinase inhibitors, its potential to be targeted by catalytic inhibitors has been investigated by different groups. The aim of this review is to present the key in vitro assays necessary for characterizing inhibitors of the catalytic activity of VPS34. The review covers catalytic (IC50 on purified recombinant protein) and binding assays (KD, ka, kd on purified recombinant protein), and a cell-based assay (IC50 in GFP-FYVE expressing cell line). The methodology for crystallization of VPS34 protein is also presented as it can provide guidance for the design by medicinal chemistry of small molecular mass kinase inhibitor.
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Affiliation(s)
- F Fassy
- Sanofi, Quai Jules Guesde, Vitry Sur Seine, Paris, France
| | - C Dureuil
- Sanofi, Quai Jules Guesde, Vitry Sur Seine, Paris, France
| | - A Lamberton
- Sanofi, Quai Jules Guesde, Vitry Sur Seine, Paris, France
| | - M Mathieu
- Sanofi, Quai Jules Guesde, Vitry Sur Seine, Paris, France
| | - N Michot
- Sanofi, Quai Jules Guesde, Vitry Sur Seine, Paris, France
| | - B Ronan
- Sanofi, Quai Jules Guesde, Vitry Sur Seine, Paris, France
| | - B Pasquier
- Sanofi, Quai Jules Guesde, Vitry Sur Seine, Paris, France.
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41
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Uchida Y, Rutaganira FU, Jullié D, Shokat KM, von Zastrow M. Endosomal Phosphatidylinositol 3-Kinase Is Essential for Canonical GPCR Signaling. Mol Pharmacol 2016; 91:65-73. [PMID: 27821547 DOI: 10.1124/mol.116.106252] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Accepted: 11/04/2016] [Indexed: 02/04/2023] Open
Abstract
G protein-coupled receptors (GPCRs), the largest family of signaling receptors, are critically regulated by endosomal trafficking, suggesting that endosomes might provide new strategies for manipulating GPCR signaling. Here we test this hypothesis by focusing on class III phosphatidylinositol 3-kinase (Vps34), which is an essential regulator of endosomal trafficking. We verify that Vps34 is required for recycling of the β2-adrenoceptor (β2AR), a prototypical GPCR, and then investigate the effects of Vps34 inhibition on the canonical cAMP response elicited by β2AR activation. Vps34 inhibition impairs the ability of cells to recover this response after prolonged activation, which is in accord with the established role of recycling in GPCR resensitization. In addition, Vps34 inhibition also attenuates the short-term cAMP response, and its effect begins several minutes after initial agonist application. These results establish Vps34 as an essential determinant of both short-term and long-term canonical GPCR signaling, and support the potential utility of the endosomal system as a druggable target for signaling.
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Affiliation(s)
- Yasunori Uchida
- Department of Psychiatry (Y.U., D.J., and M.Z.), Department of Cellular and Molecular Pharmacology (F.U.R., K.M.S., and M.Z.), and Howard Hughes Medical Institute (F.U.R. and K.M.S.), University of California, San Francisco, San Francisco, California
| | - Florentine U Rutaganira
- Department of Psychiatry (Y.U., D.J., and M.Z.), Department of Cellular and Molecular Pharmacology (F.U.R., K.M.S., and M.Z.), and Howard Hughes Medical Institute (F.U.R. and K.M.S.), University of California, San Francisco, San Francisco, California
| | - Damien Jullié
- Department of Psychiatry (Y.U., D.J., and M.Z.), Department of Cellular and Molecular Pharmacology (F.U.R., K.M.S., and M.Z.), and Howard Hughes Medical Institute (F.U.R. and K.M.S.), University of California, San Francisco, San Francisco, California
| | - Kevan M Shokat
- Department of Psychiatry (Y.U., D.J., and M.Z.), Department of Cellular and Molecular Pharmacology (F.U.R., K.M.S., and M.Z.), and Howard Hughes Medical Institute (F.U.R. and K.M.S.), University of California, San Francisco, San Francisco, California
| | - Mark von Zastrow
- Department of Psychiatry (Y.U., D.J., and M.Z.), Department of Cellular and Molecular Pharmacology (F.U.R., K.M.S., and M.Z.), and Howard Hughes Medical Institute (F.U.R. and K.M.S.), University of California, San Francisco, San Francisco, California
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42
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Ohashi Y, Soler N, García Ortegón M, Zhang L, Kirsten ML, Perisic O, Masson GR, Burke JE, Jakobi AJ, Apostolakis AA, Johnson CM, Ohashi M, Ktistakis NT, Sachse C, Williams RL. Characterization of Atg38 and NRBF2, a fifth subunit of the autophagic Vps34/PIK3C3 complex. Autophagy 2016; 12:2129-2144. [PMID: 27630019 PMCID: PMC5103362 DOI: 10.1080/15548627.2016.1226736] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The phosphatidylinositol 3-kinase Vps34 is part of several protein complexes. The structural organization of heterotetrameric complexes is starting to emerge, but little is known about organization of additional accessory subunits that interact with these assemblies. Combining hydrogen-deuterium exchange mass spectrometry (HDX-MS), X-ray crystallography and electron microscopy (EM), we have characterized Atg38 and its human ortholog NRBF2, accessory components of complex I consisting of Vps15-Vps34-Vps30/Atg6-Atg14 (yeast) and PIK3R4/VPS15-PIK3C3/VPS34-BECN1/Beclin 1-ATG14 (human). HDX-MS shows that Atg38 binds the Vps30-Atg14 subcomplex of complex I, using mainly its N-terminal MIT domain and bridges the coiled-coil I regions of Atg14 and Vps30 in the base of complex I. The Atg38 C-terminal domain is important for localization to the phagophore assembly site (PAS) and homodimerization. Our 2.2 Å resolution crystal structure of the Atg38 C-terminal homodimerization domain shows 2 segments of α-helices assembling into a mushroom-like asymmetric homodimer with a 4-helix cap and a parallel coiled-coil stalk. One Atg38 homodimer engages a single complex I. This is in sharp contrast to human NRBF2, which also forms a homodimer, but this homodimer can bridge 2 complex I assemblies.
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Affiliation(s)
- Yohei Ohashi
- a MRC Laboratory of Molecular Biology , Cambridge , United Kingdom
| | - Nicolas Soler
- a MRC Laboratory of Molecular Biology , Cambridge , United Kingdom
| | | | - Lufei Zhang
- a MRC Laboratory of Molecular Biology , Cambridge , United Kingdom
| | - Marie L Kirsten
- b European Molecular Biology Laboratory , Structural and Computational Biology Unit , Heidelberg , Germany
| | - Olga Perisic
- a MRC Laboratory of Molecular Biology , Cambridge , United Kingdom
| | - Glenn R Masson
- a MRC Laboratory of Molecular Biology , Cambridge , United Kingdom
| | - John E Burke
- b European Molecular Biology Laboratory , Structural and Computational Biology Unit , Heidelberg , Germany
| | - Arjen J Jakobi
- b European Molecular Biology Laboratory , Structural and Computational Biology Unit , Heidelberg , Germany.,c European Molecular Biology Laboratory, Hamburg Unit , Hamburg , Germany
| | | | | | - Maki Ohashi
- a MRC Laboratory of Molecular Biology , Cambridge , United Kingdom
| | | | - Carsten Sachse
- b European Molecular Biology Laboratory , Structural and Computational Biology Unit , Heidelberg , Germany
| | - Roger L Williams
- a MRC Laboratory of Molecular Biology , Cambridge , United Kingdom
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Abstract
Most functions of eukaryotic cells are controlled by cellular membranes, which are not static entities but undergo frequent budding, fission, fusion, and sculpting reactions collectively referred to as membrane dynamics. Consequently, regulation of membrane dynamics is crucial for cellular functions. A key mechanism in such regulation is the reversible recruitment of cytosolic proteins or protein complexes to specific membranes at specific time points. To a large extent this recruitment is orchestrated by phosphorylated derivatives of the membrane lipid phosphatidylinositol, known as phosphoinositides. The seven phosphoinositides found in nature localize to distinct membrane domains and recruit distinct effectors, thereby contributing strongly to the maintenance of membrane identity. Many of the phosphoinositide effectors are proteins that control membrane dynamics, and in this review we discuss the functions of phosphoinositides in membrane dynamics during exocytosis, endocytosis, autophagy, cell division, cell migration, and epithelial cell polarity, with emphasis on protein effectors that are recruited by specific phosphoinositides during these processes.
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Affiliation(s)
- Kay O Schink
- Centre for Cancer Biomedicine, Faculty of Medicine, University of Oslo, Montebello, N-0379 Oslo, Norway; , .,Department of Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital, Montebello, N-0379 Oslo, Norway
| | - Kia-Wee Tan
- Centre for Cancer Biomedicine, Faculty of Medicine, University of Oslo, Montebello, N-0379 Oslo, Norway; , .,Department of Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital, Montebello, N-0379 Oslo, Norway
| | - Harald Stenmark
- Centre for Cancer Biomedicine, Faculty of Medicine, University of Oslo, Montebello, N-0379 Oslo, Norway; , .,Department of Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital, Montebello, N-0379 Oslo, Norway.,Centre of Molecular Inflammation Research, Faculty of Medicine, Norwegian University of Science and Technology, N-7491 Trondheim, Norway
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Overexpression of Plasmodium berghei ATG8 by Liver Forms Leads to Cumulative Defects in Organelle Dynamics and to Generation of Noninfectious Merozoites. mBio 2016; 7:mBio.00682-16. [PMID: 27353755 PMCID: PMC4937212 DOI: 10.1128/mbio.00682-16] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED Plasmodium parasites undergo continuous cellular renovation to adapt to various environments in the vertebrate host and insect vector. In hepatocytes, Plasmodium berghei discards unneeded organelles for replication, such as micronemes involved in invasion. Concomitantly, intrahepatic parasites expand organelles such as the apicoplast that produce essential metabolites. We previously showed that the ATG8 conjugation system is upregulated in P. berghei liver forms and that P. berghei ATG8 (PbATG8) localizes to the membranes of the apicoplast and cytoplasmic vesicles. Here, we focus on the contribution of PbATG8 to the organellar changes that occur in intrahepatic parasites. We illustrated that micronemes colocalize with PbATG8-containing structures before expulsion from the parasite. Interference with PbATG8 function by overexpression results in poor development into late liver stages and production of small merosomes that contain immature merozoites unable to initiate a blood infection. At the cellular level, PbATG8-overexpressing P. berghei exhibits a delay in microneme compartmentalization into PbATG8-containing autophagosomes and elimination compared to parasites from the parental strain. The apicoplast, identifiable by immunostaining of the acyl carrier protein (ACP), undergoes an abnormally fast proliferation in mutant parasites. Over time, the ACP staining becomes diffuse in merosomes, indicating a collapse of the apicoplast. PbATG8 is not incorporated into the progeny of mutant parasites, in contrast to parental merozoites in which PbATG8 and ACP localize to the apicoplast. These observations reveal that Plasmodium ATG8 is a key effector in the development of merozoites by controlling microneme clearance and apicoplast proliferation and that dysregulation in ATG8 levels is detrimental for malaria infectivity. IMPORTANCE Malaria is responsible for more mortality than any other parasitic disease. Resistance to antimalarial medicines is a recurring problem; new drugs are urgently needed. A key to the parasite's successful intracellular development in the liver is the metabolic changes necessary to convert the parasite from a sporozoite to a replication-competent, metabolically active trophozoite form. Our study reinforces the burgeoning concept that organellar changes during parasite differentiation are mediated by an autophagy-like process. We have identified ATG8 in Plasmodium liver forms as an important effector that controls the development and fate of organelles, e.g., the clearance of micronemes that are required for hepatocyte invasion and the expansion of the apicoplast that produces many metabolites indispensable for parasite replication. Given the unconventional properties and the importance of ATG8 for parasite development in hepatocytes, targeting the parasite's autophagic pathway may represent a novel approach to control malarial infections.
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Dobrenel T, Caldana C, Hanson J, Robaglia C, Vincentz M, Veit B, Meyer C. TOR Signaling and Nutrient Sensing. ANNUAL REVIEW OF PLANT BIOLOGY 2016; 67:261-85. [PMID: 26905651 DOI: 10.1146/annurev-arplant-043014-114648] [Citation(s) in RCA: 243] [Impact Index Per Article: 30.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
All living organisms rely on nutrients to sustain cell metabolism and energy production, which in turn need to be adjusted based on available resources. The evolutionarily conserved target of rapamycin (TOR) protein kinase is a central regulatory hub that connects environmental information about the quantity and quality of nutrients to developmental and metabolic processes in order to maintain cellular homeostasis. TOR is activated by both nitrogen and carbon metabolites and promotes energy-consuming processes such as cell division, mRNA translation, and anabolism in times of abundance while repressing nutrient remobilization through autophagy. In animals and yeasts, TOR acts antagonistically to the starvation-induced AMP-activated kinase (AMPK)/sucrose nonfermenting 1 (Snf1) kinase, called Snf1-related kinase 1 (SnRK1) in plants. This review summarizes the immense knowledge on the relationship between TOR signaling and nutrients in nonphotosynthetic organisms and presents recent findings in plants that illuminate the crucial role of this pathway in conveying nutrient-derived signals and regulating many aspects of metabolism and growth.
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Affiliation(s)
- Thomas Dobrenel
- Institut Jean-Pierre Bourgin, UMR 1318 INRA AgroParisTech, ERL CNRS 3559, Saclay Plant Sciences, Versailles 78026, France;
- Umeå Plant Science Center, Department of Plant Physiology, Umeå University, Umeå 90187, Sweden
| | - Camila Caldana
- Molecular Physiology of Plant Biomass Production Group, Max Planck Partner Group, Brazilian Bioethanol Science and Technology Laboratory, CEP 13083-100 Campinas, São Paulo, Brazil
| | - Johannes Hanson
- Umeå Plant Science Center, Department of Plant Physiology, Umeå University, Umeå 90187, Sweden
| | - Christophe Robaglia
- Laboratoire de Génétique et Biophysique des Plantes, UMR 7265, DSV, IBEB, SBVME, CEA, CNRS, Aix Marseille Université, Faculté des Sciences de Luminy, Marseille 13009, France
| | - Michel Vincentz
- Laboratório de Genética de Plantas, Centro de Biologia Molecular e Engenharia Genética, Universidade Estadual de Campinas, CEP 13083-875 Campinas, São Paulo, Brazil
| | - Bruce Veit
- Forage Improvement, AgResearch, Institute of Fundamental Sciences, Massey University, Palmerston North 4442, New Zealand
| | - Christian Meyer
- Institut Jean-Pierre Bourgin, UMR 1318 INRA AgroParisTech, ERL CNRS 3559, Saclay Plant Sciences, Versailles 78026, France;
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Deciphering the roles of phosphoinositide lipids in phagolysosome biogenesis. Commun Integr Biol 2016; 9:e1174798. [PMID: 27489580 PMCID: PMC4951175 DOI: 10.1080/19420889.2016.1174798] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Revised: 03/29/2016] [Accepted: 03/31/2016] [Indexed: 01/01/2023] Open
Abstract
Professional phagocytes engulf microbial invaders into plasma membrane-derived phagosomes. These mature into microbicidal phagolysosomes, leading to killing of the ingested microbe. Phagosome maturation involves sequential fusion of the phagosome with early endosomes, late endosomes, and the main degradative compartments in cells, lysosomes. Some bacterial pathogens manipulate the phosphoinositide (PIP) composition of phagosome membranes and are not delivered to phagolysosomes, pointing at a role of PIPs in phagosome maturation. This hypothesis is supported by comprehensive microscopic studies. Recently, cell-free reconstitution of fusion between phagosomes and endo(lyso)somes identified phosphatidylinositol 4-phosphate [PI(4)P] and phosphatidylinositol 3-phosphate [PI(3)P] as key regulators of phagolysosome biogenesis. Here, we describe the emerging roles of PIPs in phagosome maturation and we present tools to study PIP involvement in phagosome trafficking using intact cells or purified compartments.
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Abstract
Autophagy is a lysosome-dependent mechanism of intracellular degradation. The cellular and molecular mechanisms underlying this process are highly complex and involve multiple proteins, including the kinases ULK1 and Vps34. The main function of autophagy is the maintenance of cell survival when modifications occur in the cellular environment. During the past decade, extensive studies have greatly improved our knowledge and autophagy has exploded as a research field. This process is now widely implicated in pathophysiological processes such as cancer, metabolic, and neurodegenerative disorders, making it an attractive target for drug discovery. In this review, we will summarize the different types of inhibitors that affect the autophagy machinery and provide some potential therapeutic perspectives.
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Affiliation(s)
- Benoit Pasquier
- Sanofi, 13, Quai Jules Guesde, 94403, Vitry Sur Seine, France.
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Marat AL, Haucke V. Phosphatidylinositol 3-phosphates-at the interface between cell signalling and membrane traffic. EMBO J 2016; 35:561-79. [PMID: 26888746 DOI: 10.15252/embj.201593564] [Citation(s) in RCA: 177] [Impact Index Per Article: 22.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Accepted: 01/26/2016] [Indexed: 12/31/2022] Open
Abstract
Phosphoinositides (PIs) form a minor class of phospholipids with crucial functions in cell physiology, ranging from cell signalling and motility to a role as signposts of compartmental membrane identity. Phosphatidylinositol 3-phosphates are present at the plasma membrane and within the endolysosomal system, where they serve as key regulators of both cell signalling and of intracellular membrane traffic. Here, we provide an overview of the metabolic pathways that regulate cellular synthesis of PI 3-phosphates at distinct intracellular sites and discuss the mechanisms by which these lipids regulate cell signalling and membrane traffic. Finally, we provide a framework for how PI 3-phosphate metabolism is integrated into the cellular network.
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Affiliation(s)
- Andrea L Marat
- Leibniz Institut für Molekulare Pharmakologie (FMP), Berlin, Germany
| | - Volker Haucke
- Leibniz Institut für Molekulare Pharmakologie (FMP), Berlin, Germany
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Manna PT, Field MC. Phosphoinositides, kinases and adaptors coordinating endocytosis in Trypanosoma brucei. Commun Integr Biol 2016; 8:e1082691. [PMID: 27064836 PMCID: PMC4802737 DOI: 10.1080/19420889.2015.1082691] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Accepted: 08/08/2015] [Indexed: 01/01/2023] Open
Abstract
In the kinetoplastid parasite Trypanosoma brucei clathrin-mediated endocytosis is essential for survival and aids immune evasion in the mammalian host. The formation of endocytic clathrin coated vesicles in T. brucei is via a unique mechanism owing to an evolutionarily recent loss of the adaptor protein (AP)2 complex, a central hub in endocytic vesicle assembly. Despite this loss, recent studies examining endocytic clathrin coat assembly have highlighted a high degree of conservation between trypanosomes and their mammalian hosts. In particular phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2) and its putative effectors, TbCALM and TbEpsinR, are central to clathrin-mediated endocytosis in the trypanosome, just as they are in animal cells. In addition to providing insights into the cell biology of T. brucei, these studies also suggest an ancient, possibly pan-eukaryotic connection between PtdIns(4,5)P2 and endocytosis.
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Affiliation(s)
- Paul T Manna
- Cambridge Institute for Medical Research; University of Cambridge ; Cambridge, UK
| | - Mark C Field
- Division of Biological Chemistry and Drug Discovery; University of Dundee ; Dundee, UK
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Ketel K, Krauss M, Nicot AS, Puchkov D, Wieffer M, Müller R, Subramanian D, Schultz C, Laporte J, Haucke V. A phosphoinositide conversion mechanism for exit from endosomes. Nature 2016; 529:408-12. [DOI: 10.1038/nature16516] [Citation(s) in RCA: 129] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Accepted: 12/04/2015] [Indexed: 12/12/2022]
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