1
|
Achter JS, Vega ET, Sorrentino A, Kahnert K, Galsgaard KD, Hernandez-Varas P, Wierer M, Holst JJ, Wojtaszewski JFP, Mills RW, Kjøbsted R, Lundby A. In-depth phosphoproteomic profiling of the insulin signaling response in heart tissue and cardiomyocytes unveils canonical and specialized regulation. Cardiovasc Diabetol 2024; 23:258. [PMID: 39026321 PMCID: PMC11264841 DOI: 10.1186/s12933-024-02338-4] [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: 03/12/2024] [Accepted: 06/26/2024] [Indexed: 07/20/2024] Open
Abstract
BACKGROUND Insulin signaling regulates cardiac substrate utilization and is implicated in physiological adaptations of the heart. Alterations in the signaling response within the heart are believed to contribute to pathological conditions such as type-2 diabetes and heart failure. While extensively investigated in several metabolic organs using phosphoproteomic strategies, the signaling response elicited in cardiac tissue in general, and specifically in the specialized cardiomyocytes, has not yet been investigated to the same extent. METHODS Insulin or vehicle was administered to male C57BL6/JRj mice via intravenous injection into the vena cava. Ventricular tissue was extracted and subjected to quantitative phosphoproteomics analysis to evaluate the insulin signaling response. To delineate the cardiomyocyte-specific response and investigate the role of Tbc1d4 in insulin signal transduction, cardiomyocytes from the hearts of cardiac and skeletal muscle-specific Tbc1d4 knockout mice, as well as from wildtype littermates, were studied. The phosphoproteomic studies involved isobaric peptide labeling with Tandem Mass Tags (TMT), enrichment for phosphorylated peptides, fractionation via micro-flow reversed-phase liquid chromatography, and high-resolution mass spectrometry measurements. RESULTS We quantified 10,399 phosphorylated peptides from ventricular tissue and 12,739 from isolated cardiomyocytes, localizing to 3,232 and 3,128 unique proteins, respectively. In cardiac tissue, we identified 84 insulin-regulated phosphorylation events, including sites on the Insulin Receptor (InsrY1351, Y1175, Y1179, Y1180) itself as well as the Insulin receptor substrate protein 1 (Irs1S522, S526). Predicted kinases with increased activity in response to insulin stimulation included Rps6kb1, Akt1 and Mtor. Tbc1d4 emerged as a major phosphorylation target in cardiomyocytes. Despite limited impact on the global phosphorylation landscape, Tbc1d4 deficiency in cardiomyocytes attenuated insulin-induced Glut4 translocation and induced protein remodeling. We observed 15 proteins significantly regulated upon knockout of Tbc1d4. While Glut4 exhibited decreased protein abundance consequent to Tbc1d4-deficiency, Txnip levels were notably increased. Stimulation of wildtype cardiomyocytes with insulin led to the regulation of 262 significant phosphorylation events, predicted to be regulated by kinases such as Akt1, Mtor, Akt2, and Insr. In cardiomyocytes, the canonical insulin signaling response is elicited in addition to regulation on specialized cardiomyocyte proteins, such as Kcnj11Y12 and DspS2597. Details of all phosphorylation sites are provided. CONCLUSION We present a first global outline of the insulin-induced phosphorylation signaling response in heart tissue and in isolated adult cardiomyocytes, detailing the specific residues with changed phosphorylation abundances. Our study marks an important step towards understanding the role of insulin signaling in cardiac diseases linked to insulin resistance.
Collapse
Affiliation(s)
- Jonathan Samuel Achter
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Estefania Torres Vega
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Andrea Sorrentino
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Konstantin Kahnert
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Katrine Douglas Galsgaard
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Pablo Hernandez-Varas
- Core Facility for Integrated Microscopy, Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Michael Wierer
- Proteomics Research Infrastructure, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jens Juul Holst
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- The Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jørgen Frank Pind Wojtaszewski
- The August Krogh Section for Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Robert William Mills
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Rasmus Kjøbsted
- The August Krogh Section for Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Alicia Lundby
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
| |
Collapse
|
2
|
Erol S, Zırh S, Bozdag G, Sokmensuer LK, Muftuoglu SF. In vitro evaluation of exocytosis-associated SNARE molecules in human granulosa cells in polycystic ovary syndrome. J Assist Reprod Genet 2024; 41:49-61. [PMID: 37993579 PMCID: PMC10789710 DOI: 10.1007/s10815-023-02967-w] [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: 06/20/2023] [Accepted: 10/03/2023] [Indexed: 11/24/2023] Open
Abstract
PURPOSE Patients with polycystic ovarian morphology (PCOM) make up 20% cases for assisted reproductive technology (ART). Folliculogenesis is impaired in PCOS. Signaling molecules are involved in follicle development. Dysregulations of intrafollicular environment and signaling molecules are observed in PCOS. Granulosa cells (GCs) and oocytes secrete molecules into follicular fluid by exocytosis of SNAREs. The aim of this study is to evaluate vesicle transport and vesicle fusion proteins (SNAREs) in GCs from PCOS patients who have undergone IVF treatment. METHODS Follicular fluids were collected from patients who undergo IVF/ICSI with the diagnosis of male factor (n = 10) and PCOS (n = 10) patients. GCs were separated and cultured. Each group of GCs was stimulated with FSH-hCG. The cells were examined under electron microscope. Immunofluorescent labeling was performed on cells for Stx6, SNAP25, StxBP1, FSHr, and KITL. Integrated density was analyzed from images of Stx6, SNAP25, StxBP1, FSHr, and KITL. RESULTS Intercellular communication occurs by signal molecules; Stx6, SNAP25, and StxBP1 fusion proteins involved in exocytosis were decreased in the GCs of PCOS. There was no increase in in vitro stimulation with FSH-hCG either. In the electron microscope, it was observed that exocytosis of the vesicles was disrupted. CONCLUSIONS Exocytosis and vesicular dynamics are among the basic physiological functions of human steroidogenic granulosa cells. Follicle development is necessary for production of competent oocytes and ovulation. Understanding the pathophysiology of PCOS at follicular level is important for disease management. According to our findings, deficits in vesicular dynamics of human granulosa cells in may be central to the treatment strategy for PCOS patients.
Collapse
Affiliation(s)
- Suleyman Erol
- Department of Histology and Embryology, School of Medicine, Hacettepe University, Ankara, Turkey
| | - Selim Zırh
- Department of Histology and Embryology, School of Medicine, Hacettepe University, Ankara, Turkey
| | - Gurkan Bozdag
- Department of Obstetrics and Gynecology, School of Medicine, Hacettepe University, Ankara, Turkey
| | - Lale Karakoc Sokmensuer
- Department of Histology and Embryology, School of Medicine, Hacettepe University, Ankara, Turkey
| | - Sevda F Muftuoglu
- Department of Histology and Embryology, School of Medicine, Hacettepe University, Ankara, Turkey.
| |
Collapse
|
3
|
Rashid M, Al Qarni A, Al Mahri S, Mohammad S, Khan A, Abdullah ML, Lehe C, Al Amoudi R, Aldibasi O, Bouchama A. Transcriptome Changes and Metabolic Outcomes After Bariatric Surgery in Adults With Obesity and Type 2 Diabetes. J Endocr Soc 2023; 8:bvad159. [PMID: 38162016 PMCID: PMC10755185 DOI: 10.1210/jendso/bvad159] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2023] [Indexed: 01/03/2024] Open
Abstract
Context Bariatric surgery has been shown to be effective in inducing complete remission of type 2 diabetes in adults with obesity. However, its efficacy in achieving complete diabetes remission remains variable and difficult to predict before surgery. Objective We aimed to characterize bariatric surgery-induced transcriptome changes associated with diabetes remission and the predictive role of the baseline transcriptome. Methods We performed a whole-genome microarray in peripheral mononuclear cells at baseline (before surgery) and 2 and 12 months after bariatric surgery in a prospective cohort of 26 adults with obesity and type 2 diabetes. We applied machine learning to the baseline transcriptome to identify genes that predict metabolic outcomes. We validated the microarray expression profile using a real-time polymerase chain reaction. Results Sixteen patients entered diabetes remission at 12 months and 10 did not. The gene-expression analysis showed similarities and differences between responders and nonresponders. The difference included the expression of critical genes (SKT4, SIRT1, and TNF superfamily), metabolic and signaling pathways (Hippo, Sirtuin, ARE-mediated messenger RNA degradation, MSP-RON, and Huntington), and predicted biological functions (β-cell growth and proliferation, insulin and glucose metabolism, energy balance, inflammation, and neurodegeneration). Modeling the baseline transcriptome identified 10 genes that could hypothetically predict the metabolic outcome before bariatric surgery. Conclusion The changes in the transcriptome after bariatric surgery distinguish patients in whom diabetes enters complete remission from those who do not. The baseline transcriptome can contribute to the prediction of bariatric surgery-induced diabetes remission preoperatively.
Collapse
Affiliation(s)
- Mamoon Rashid
- Department of AI and Bioinformatics, King Abdullah International Medical Research Center, King Saud bin Abdulaziz University for Health Sciences, Ministry of National Guard Health Affairs, Riyadh 11426, Saudi Arabia
| | - Ali Al Qarni
- Endocrinology and Metabolism, Department of Medicine, King Abdulaziz Hospital, King Abdullah International Medical Research Center, King Saud bin Abdulaziz University for Health Sciences, Ministry of National Guard Health Affairs, Al Ahsa 31982, Saudi Arabia
| | - Saeed Al Mahri
- Experimental Medicine Department, King Abdullah International Medical Research Center, King Saud bin Abdulaziz University for Health Sciences, Ministry of National Guard Health Affairs, Riyadh 11426, Saudi Arabia
| | - Sameer Mohammad
- Experimental Medicine Department, King Abdullah International Medical Research Center, King Saud bin Abdulaziz University for Health Sciences, Ministry of National Guard Health Affairs, Riyadh 11426, Saudi Arabia
| | - Altaf Khan
- Department of Biostatistics, King Abdullah International Medical Research Center, King Saud bin Abdulaziz University for Health Sciences, Ministry of National Guard Health Affairs, Riyadh, Saudi Arabia
| | - Mashan L Abdullah
- Experimental Medicine Department, King Abdullah International Medical Research Center, King Saud bin Abdulaziz University for Health Sciences, Ministry of National Guard Health Affairs, Riyadh 11426, Saudi Arabia
| | - Cynthia Lehe
- Experimental Medicine Department, King Abdullah International Medical Research Center, King Saud bin Abdulaziz University for Health Sciences, Ministry of National Guard Health Affairs, Riyadh 11426, Saudi Arabia
| | - Reem Al Amoudi
- Endocrinology and Metabolism, Department of Medicine, King Abdulaziz Hospital, King Abdullah International Medical Research Center, King Saud bin Abdulaziz University for Health Sciences, Ministry of National Guard Health Affairs, Al Ahsa 31982, Saudi Arabia
| | - Omar Aldibasi
- Department of Biostatistics, King Abdullah International Medical Research Center, King Saud bin Abdulaziz University for Health Sciences, Ministry of National Guard Health Affairs, Riyadh, Saudi Arabia
| | - Abderrezak Bouchama
- Experimental Medicine Department, King Abdullah International Medical Research Center, King Saud bin Abdulaziz University for Health Sciences, Ministry of National Guard Health Affairs, Riyadh 11426, Saudi Arabia
| |
Collapse
|
4
|
de las Fuentes L, Schwander KL, Brown MR, Bentley AR, Winkler TW, Sung YJ, Munroe PB, Miller CL, Aschard H, Aslibekyan S, Bartz TM, Bielak LF, Chai JF, Cheng CY, Dorajoo R, Feitosa MF, Guo X, Hartwig FP, Horimoto A, Kolčić I, Lim E, Liu Y, Manning AK, Marten J, Musani SK, Noordam R, Padmanabhan S, Rankinen T, Richard MA, Ridker PM, Smith AV, Vojinovic D, Zonderman AB, Alver M, Boissel M, Christensen K, Freedman BI, Gao C, Giulianini F, Harris SE, He M, Hsu FC, Kühnel B, Laguzzi F, Li X, Lyytikäinen LP, Nolte IM, Poveda A, Rauramaa R, Riaz M, Robino A, Sofer T, Takeuchi F, Tayo BO, van der Most PJ, Verweij N, Ware EB, Weiss S, Wen W, Yanek LR, Zhan Y, Amin N, Arking DE, Ballantyne C, Boerwinkle E, Brody JA, Broeckel U, Campbell A, Canouil M, Chai X, Chen YDI, Chen X, Chitrala KN, Concas MP, de Faire U, de Mutsert R, de Silva HJ, de Vries PS, Do A, Faul JD, Fisher V, Floyd JS, Forrester T, Friedlander Y, Girotto G, Gu CC, Hallmans G, Heikkinen S, Heng CK, Homuth G, Hunt S, Ikram MA, Jacobs DR, Kavousi M, Khor CC, Kilpeläinen TO, Koh WP, Komulainen P, Langefeld CD, Liang J, Liu K, Liu J, Lohman K, Mägi R, Manichaikul AW, McKenzie CA, Meitinger T, Milaneschi Y, Nauck M, Nelson CP, O’Connell JR, Palmer ND, Pereira AC, Perls T, Peters A, Polašek O, Raitakari OT, Rice K, Rice TK, Rich SS, Sabanayagam C, Schreiner PJ, Shu XO, Sidney S, Sims M, Smith JA, Starr JM, Strauch K, Tai ES, Taylor KD, Tsai MY, Uitterlinden AG, van Heemst D, Waldenberger M, Wang YX, Wei WB, Wilson G, Xuan D, Yao J, Yu C, Yuan JM, Zhao W, Becker DM, Bonnefond A, Bowden DW, Cooper RS, Deary IJ, Divers J, Esko T, Franks PW, Froguel P, Gieger C, Jonas JB, Kato N, Lakka TA, Leander K, Lehtimäki T, Magnusson PKE, North KE, Ntalla I, Penninx B, Samani NJ, Snieder H, Spedicati B, van der Harst P, Völzke H, Wagenknecht LE, Weir DR, Wojczynski MK, Wu T, Zheng W, Zhu X, Bouchard C, Chasman DI, Evans MK, Fox ER, Gudnason V, Hayward C, Horta BL, Kardia SLR, Krieger JE, Mook-Kanamori DO, Peyser PA, Province MM, Psaty BM, Rudan I, Sim X, Smith BH, van Dam RM, van Duijn CM, Wong TY, Arnett DK, Rao DC, Gauderman J, Liu CT, Morrison AC, Rotter JI, Fornage M. Gene-educational attainment interactions in a multi-population genome-wide meta-analysis identify novel lipid loci. Front Genet 2023; 14:1235337. [PMID: 38028628 PMCID: PMC10651736 DOI: 10.3389/fgene.2023.1235337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Accepted: 09/27/2023] [Indexed: 12/01/2023] Open
Abstract
Introduction: Educational attainment, widely used in epidemiologic studies as a surrogate for socioeconomic status, is a predictor of cardiovascular health outcomes. Methods: A two-stage genome-wide meta-analysis of low-density lipoprotein cholesterol (LDL), high-density lipoprotein cholesterol (HDL), and triglyceride (TG) levels was performed while accounting for gene-educational attainment interactions in up to 226,315 individuals from five population groups. We considered two educational attainment variables: "Some College" (yes/no, for any education beyond high school) and "Graduated College" (yes/no, for completing a 4-year college degree). Genome-wide significant (p < 5 × 10-8) and suggestive (p < 1 × 10-6) variants were identified in Stage 1 (in up to 108,784 individuals) through genome-wide analysis, and those variants were followed up in Stage 2 studies (in up to 117,531 individuals). Results: In combined analysis of Stages 1 and 2, we identified 18 novel lipid loci (nine for LDL, seven for HDL, and two for TG) by two degree-of-freedom (2 DF) joint tests of main and interaction effects. Four loci showed significant interaction with educational attainment. Two loci were significant only in cross-population analyses. Several loci include genes with known or suggested roles in adipose (FOXP1, MBOAT4, SKP2, STIM1, STX4), brain (BRI3, FILIP1, FOXP1, LINC00290, LMTK2, MBOAT4, MYO6, SENP6, SRGAP3, STIM1, TMEM167A, TMEM30A), and liver (BRI3, FOXP1) biology, highlighting the potential importance of brain-adipose-liver communication in the regulation of lipid metabolism. An investigation of the potential druggability of genes in identified loci resulted in five gene targets shown to interact with drugs approved by the Food and Drug Administration, including genes with roles in adipose and brain tissue. Discussion: Genome-wide interaction analysis of educational attainment identified novel lipid loci not previously detected by analyses limited to main genetic effects.
Collapse
Affiliation(s)
- Lisa de las Fuentes
- Cardiovascular Division, Department of Medicine, Washington University School of Medicine, St. Louis, MO, United States
- Division of Biostatistics, Washington University School of Medicine, St. Louis, MO, United States
| | - Karen L. Schwander
- Division of Biostatistics, Washington University School of Medicine, St. Louis, MO, United States
- Division of Statistical Genomics, Department of Genetics, Washington University School of Medicine, St. Louis, MO, United States
| | - Michael R. Brown
- Human Genetics Center, Department of Epidemiology, Human Genetics and Environmental Sciences, School of Public Health, The University of Texas Health Science Center at Houston, Houston, TX, United States
| | - Amy R. Bentley
- Center for Research on Genomics and Global Health, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, United States
| | - Thomas W. Winkler
- Department of Genetic Epidemiology, University of Regensburg, Regensburg, Germany
| | - Yun Ju Sung
- Division of Biostatistics, Washington University School of Medicine, St. Louis, MO, United States
- Department of Psychiatry, Washington University School of Medicine, St. Louis, MO, United States
| | - Patricia B. Munroe
- Clinical Pharmacology, Queen Mary University of London, London, United Kingdom
- National Institute for Health Research Barts Cardiovascular Biomedical Research Unit, Queen Mary University of London, London, United Kingdom
| | - Clint L. Miller
- Center for Public Health Genomics, Department of Public Health Sciences, University of Virginia, Charlottesville, VA, United States
- Biochemistry and Molecular Genetics, Department of Public Health Sciences, University of Virginia, Charlottesville, VA, United States
- Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA, United States
| | - Hugo Aschard
- Department of Epidemiology, Harvard School of Public Health, Boston, MA, United States
- Département de Génomes et Génétique, Institut Pasteur de Lille, Université de Lille, Lille, France
| | - Stella Aslibekyan
- School of Public Health, Epidemiology, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Traci M. Bartz
- Cardiovascular Health Research Unit, University of Washington, Seattle, WA, United States
- Department of Biostatistics, University of Washington, Seattle, WA, United States
| | - Lawrence F. Bielak
- Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, MI, United States
| | - Jin Fang Chai
- Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore, Singapore
| | - Ching-Yu Cheng
- Ocular Epidemiology, Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore
- Ophthalmology and Visual Sciences Academic Clinical Program, Medical School, Duke-National University of Singapore, Singapore, Singapore
| | - Rajkumar Dorajoo
- Genome Institute of Singapore, Agency for Science, Technology and Research, Singapore, Singapore
| | - Mary F. Feitosa
- Division of Statistical Genomics, Department of Genetics, Washington University School of Medicine, St. Louis, MO, United States
| | - Xiuqing Guo
- Department of Pediatrics, The Institute for Translational Genomics and Population Sciences, The Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center, Los Angeles, CA, United States
| | - Fernando P. Hartwig
- Postgraduate Programme in Epidemiology, Faculty of Medicine, Federal University of Pelotas, Pelotas, RS, Brazil
- Medical Research Council Integrative Epidemiology Unit, University of Bristol, Bristol, United Kingdom
| | - Andrea Horimoto
- Laboratory of Genetics and Molecular Cardiology, Heart Institute, University of Sao Paulo Medical School, Sao Paulo, SP, Brazil
| | - Ivana Kolčić
- University of Split School of Medicine, Split, Croatia
- Algebra University College, Zagreb, Croatia
| | - Elise Lim
- Department of Biostatistics, Boston University School of Public Health, Boston, MA, United States
| | - Yongmei Liu
- Division of Cardiology, Department of Medicine, Duke Molecular Physiology Institute, Duke University School of Medicine, Durham, NC, United States
| | - Alisa K. Manning
- Clinical and Translational Epidemiology Unit, Massachusetts General Hospital, Boston, MA, United States
- Department of Medicine, Harvard Medical School, Boston, MA, United States
| | - Jonathan Marten
- Medical Research Council Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh, United Kingdom
| | - Solomon K. Musani
- Jackson Heart Study, Department of Medicine, University of Mississippi Medical Center, Jackson, MS, United States
| | - Raymond Noordam
- Section of Gerontology and Geriatrics, Department of Internal Medicine, Leiden University Medical Center, Leiden, Netherlands
| | - Sandosh Padmanabhan
- Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Tuomo Rankinen
- Human Genomics Laboratory, Pennington Biomedical Research Center, Baton Rouge, LA, United States
| | - Melissa A. Richard
- Brown Foundation Institute of Molecular Medicine, The University of Texas Health Science Center at Houston, Houston, TX, United States
| | - Paul M. Ridker
- Division of Preventive Medicine, Brigham and Women’s Hospital, Boston, MA, United States
- Harvard Medical School, Boston, MA, United States
| | - Albert V. Smith
- Department of Biostatistics, School of Public Health, University of Michigan, Ann Arbor, MI, United States
- Icelandic Heart Association, Kopavogur, Iceland
| | - Dina Vojinovic
- Department of Epidemiology, Erasmus MC, University Medical Center, Rotterdam, Netherlands
- Molecular Epidemiology, Department of Biomedical Data Sciences, Leiden University Medical Center, Leiden, Netherlands
| | - Alan B. Zonderman
- Laboratory of Epidemiology and Population Sciences, National Institute on Aging, National Institutes of Health, Baltimore, MD, United States
- National Institutes of Health, Baltimore, MD, United States
| | - Maris Alver
- Estonian Genome Center, Insititute of Genomics, University of Tartu, Tartu, Estonia
| | - Mathilde Boissel
- European Genomic Institute for Diabetes, Institut Pasteur de Lille, Lille, France
- University of Lille, Lille University Hospital, Lille, France
| | - Kaare Christensen
- Unit of Epidemiology, Biostatistics and Biodemography, Department of Public Health, University of Southern Denmark, Odense, Denmark
| | - Barry I. Freedman
- Nephrology Division, Department of Internal Medicine, Wake Forest School of Medicine, Winston-Salem, NC, United States
| | - Chuan Gao
- Molecular Genetics and Genomics Program, Wake Forest School of Medicine, Winston-Salem, NC, United States
| | - Franco Giulianini
- Division of Preventive Medicine, Brigham and Women’s Hospital, Boston, MA, United States
| | - Sarah E. Harris
- Department of Psychology, The University of Edinburgh, Edinburgh, United Kingdom
- Centre for Cognitive Ageing and Cognitive Epidemiology, The University of Edinburgh, Edinburgh, United Kingdom
| | - Meian He
- Department of Occupational and Environmental Health and State Key Laboratory of Environmental Health for Incubating, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Fang-Chi Hsu
- Department of Biostatistics and Data Science, Division of Public Health Sciences, Wake Forest University School of Medicine, Winston-Salem, NC, United States
| | - Brigitte Kühnel
- Research Unit of Molecular Epidemiology, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
- Institute of Epidemiology, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
| | - Federica Laguzzi
- Cardiovascular and Nutritional Epidemiology, Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Xiaoyin Li
- Department of Population and Quantitative Health Sciences, Cleveland, OH, United States
- Department of Mathematics and Statistics, St. Cloud State University, St. Cloud, MN, United States
| | - Leo-Pekka Lyytikäinen
- Department of Clinical Chemistry, University of Tampere, Tampere, Finland
- Finnish Cardiovascular Research Center, University of Tampere, Tampere, Finland
| | - Ilja M. Nolte
- Unit of Genetic Epidemiology and Bioinformatics, Department of Epidemiology, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Alaitz Poveda
- Genetic and Molecular Epidemiology Unit, Department of Clinical Sciences, Skåne University Hospital, Lund University, Malmö, Sweden
| | - Rainer Rauramaa
- Kuopio Research Institute of Exercise Medicine, Kuopio, Finland
| | - Muhammad Riaz
- Department of Cardiovascular Sciences, University of Leicester, Leicester, United Kingdom
- NIHR Leicester Biomedical Research Centre, Glenfield Hospital, Leicester, United Kingdom
| | - Antonietta Robino
- Institute for Maternal and Child Health-IRCCS Burlo Garofolo, Trieste, Italy
| | - Tamar Sofer
- Biostatistics, Department of Medicine, Brigham and Women’s Hospital, Harvard University, Boston, MA, United States
| | - Fumihiko Takeuchi
- Department of Gene Diagnostics and Therapeutics, Research Institute, National Center for Global Health and Medicine, Tokyo, Japan
| | - Bamidele O. Tayo
- Department of Public Health Sciences, Loyola University Chicago, Maywood, IL, United States
| | - Peter J. van der Most
- Department of Epidemiology, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Niek Verweij
- Department of Cardiology, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Erin B. Ware
- Survey Research Center, Institute for Social Research, University of Michigan, Ann Arbor, MI, United States
| | - Stefan Weiss
- Interfaculty Institute for Genetics and Functional Genomics, University Medicine Greifswald and University of Greifswald, Greifswald, Germany
- German Center for Cardiovascular Research, Greifswald, Germany
| | - Wanqing Wen
- Division of Epidemiology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Lisa R. Yanek
- Division of General Internal Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Yiqiang Zhan
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
| | - Najaf Amin
- Department of Epidemiology, Erasmus MC, University Medical Center, Rotterdam, Netherlands
| | - Dan E. Arking
- Department of Genetic Medicine, McKusick-Nathans Institute, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Christie Ballantyne
- Section of Cardiovascular Research, Baylor College of Medicine, Houston, TX, United States
- Houston Methodist Debakey Heart and Vascular Center, Houston, TX, United States
| | - Eric Boerwinkle
- Human Genetics Center, Department of Epidemiology, Human Genetics and Environmental Sciences, School of Public Health, The University of Texas Health Science Center at Houston, Houston, TX, United States
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX, United States
| | - Jennifer A. Brody
- Cardiovascular Health Research Unit, University of Washington, Seattle, WA, United States
| | - Ulrich Broeckel
- Section on Genomic Pediatrics, Department of Pediatrics, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Archie Campbell
- Centre for Genomic and Experimental Medicine, Institute of Genetics & Cancer, University of Edinburgh, Edinburgh, United Kingdom
- Usher Institute for Population Health Sciences and Informatics, University of Edinburgh, Edinburgh, United Kingdom
| | - Mickaël Canouil
- European Genomic Institute for Diabetes, Institut Pasteur de Lille, Lille, France
- University of Lille, Lille University Hospital, Lille, France
| | - Xiaoran Chai
- Data Science Unit, Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore
| | - Yii-Der Ida Chen
- Department of Pediatrics, The Institute for Translational Genomics and Population Sciences, The Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center, Los Angeles, CA, United States
| | - Xu Chen
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
| | - Kumaraswamy Naidu Chitrala
- Laboratory of Epidemiology and Population Sciences, National Institute on Aging, National Institutes of Health, Baltimore, MD, United States
| | - Maria Pina Concas
- Institute for Maternal and Child Health-IRCCS Burlo Garofolo, Trieste, Italy
| | - Ulf de Faire
- Cardiovascular and Nutritional Epidemiology, Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Renée de Mutsert
- Department of Clinical Epidemiology, Leiden University Medical Center, Leiden, Netherlands
| | - H. Janaka de Silva
- Department of Medicine, Faculty of Medicine, University of Kelaniya, Ragama, Sri Lanka
| | - Paul S. de Vries
- Human Genetics Center, Department of Epidemiology, Human Genetics and Environmental Sciences, School of Public Health, The University of Texas Health Science Center at Houston, Houston, TX, United States
| | - Ahn Do
- Division of Biostatistics, Washington University School of Medicine, St. Louis, MO, United States
- Division of Statistical Genomics, Department of Genetics, Washington University School of Medicine, St. Louis, MO, United States
| | - Jessica D. Faul
- Survey Research Center, Institute for Social Research, University of Michigan, Ann Arbor, MI, United States
| | - Virginia Fisher
- Department of Biostatistics, Boston University School of Public Health, Boston, MA, United States
| | - James S. Floyd
- Cardiovascular Health Research Unit, University of Washington, Seattle, WA, United States
| | - Terrence Forrester
- Tropical Medicine Research Institute, University of the West Indies, Mona, Jamaica
| | - Yechiel Friedlander
- Braun School of Public Health, Hadassah Medical Center, Hebrew University, Jerusalem, Israel
| | - Giorgia Girotto
- Institute for Maternal and Child Health-IRCCS Burlo Garofolo, Trieste, Italy
| | - C. Charles Gu
- Division of Biostatistics, Washington University School of Medicine, St. Louis, MO, United States
| | - Göran Hallmans
- Section for Nutritional Research, Department of Public Health and Clinical Medicine, Umeå University, Umeå, Sweden
| | - Sami Heikkinen
- Institute of Biomedicine, School of Medicine, University of Eastern Finland, Kuopio, Finland
| | - Chew-Kiat Heng
- Department of Paediatrics, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
- Khoo Teck Puat National University Children’s Medical Institute, National University Health System, Singapore, Singapore
| | - Georg Homuth
- Interfaculty Institute for Genetics and Functional Genomics, University Medicine Greifswald and University of Greifswald, Greifswald, Germany
| | - Steven Hunt
- Department of Internal Medicine, University of Utah, Salt Lake City, UT, United States
- Department of Genetic Medicine, Weill Cornell Medicine in Qatar, Doha, Qatar
| | - M. Arfan Ikram
- Department of Epidemiology, Erasmus MC, University Medical Center, Rotterdam, Netherlands
| | - David R. Jacobs
- Division of Epidemiology and Community Health, School of Public Health, University of Minnesota, Minneapolis, MN, United States
| | - Maryam Kavousi
- Department of Epidemiology, Erasmus MC, University Medical Center, Rotterdam, Netherlands
| | - Chiea Chuen Khor
- Genome Institute of Singapore, Agency for Science, Technology and Research, Singapore, Singapore
| | - Tuomas O. Kilpeläinen
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Department of Environmental Medicine and Public Health, The Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Woon-Puay Koh
- Healthy Longevity Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
- Singapore Institute for Clinical Sciences, Agency for Science Technology and Research (A*STAR), Singapore, Singapore
| | | | - Carl D. Langefeld
- Department of Biostatistics and Data Science, Division of Public Health Sciences, Wake Forest University School of Medicine, Winston-Salem, NC, United States
| | - Jingjing Liang
- Department of Population and Quantitative Health Sciences, Cleveland, OH, United States
| | - Kiang Liu
- Epidemiology, Department of Preventive Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL, United States
| | - Jianjun Liu
- Genome Institute of Singapore, Agency for Science, Technology and Research, Singapore, Singapore
| | - Kurt Lohman
- Division of Cardiology, Department of Medicine, Duke Molecular Physiology Institute, Duke University School of Medicine, Durham, NC, United States
| | - Reedik Mägi
- Estonian Genome Center, Insititute of Genomics, University of Tartu, Tartu, Estonia
| | - Ani W. Manichaikul
- Center for Public Health Genomics, Department of Public Health Sciences, University of Virginia, Charlottesville, VA, United States
| | - Colin A. McKenzie
- Tropical Medicine Research Institute, University of the West Indies, Mona, Jamaica
| | - Thomas Meitinger
- Institute of Human Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
- Institute of Human Genetics, Technische Universität München, Munich, Germany
| | | | - Matthias Nauck
- German Center for Cardiovascular Research, Greifswald, Germany
- Institute of Clinical Chemistry and Laboratory Medicine, University Medicine Greifswald, Greifswald, Germany
| | - Christopher P. Nelson
- Department of Cardiovascular Sciences, University of Leicester, Leicester, United Kingdom
- NIHR Leicester Biomedical Research Centre, Glenfield Hospital, Leicester, United Kingdom
| | - Jeffrey R. O’Connell
- Division of Endocrinology, Diabetes, and Nutrition, University of Maryland School of Medicine, Baltimore, MD, United States
- Program for Personalized and Genomic Medicine, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Nicholette D. Palmer
- Department of Biochemistry, Wake Forest School of Medicine, Winston-Salem, NC, United States
| | - Alexandre C. Pereira
- Laboratory of Genetics and Molecular Cardiology, Heart Institute, University of Sao Paulo Medical School, Sao Paulo, SP, Brazil
| | - Thomas Perls
- Geriatrics Section, Department of Medicine, Boston University School of Medicine, Boston, MA, United States
| | - Annette Peters
- Institute of Epidemiology, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
- German Center for Cardiovascular Research, Neuherberg, Germany
| | - Ozren Polašek
- University of Split School of Medicine, Split, Croatia
- Algebra University College, Zagreb, Croatia
| | - Olli T. Raitakari
- Centre for Population Health Research, University of Turku and Turku University Hospital, Turku, Finland
- Research Centre of Applied and Preventive Cardiovascular Medicine, University of Turku, Turku, Finland
- Department of Clinical Physiology and Nuclear Medicine, Turku University Hospital, Turku, Finland
| | - Kenneth Rice
- Department of Biostatistics, University of Washington, Seattle, WA, United States
| | - Treva K. Rice
- Division of Biostatistics, Washington University School of Medicine, St. Louis, MO, United States
| | - Stephen S. Rich
- Center for Public Health Genomics, Department of Public Health Sciences, University of Virginia, Charlottesville, VA, United States
| | - Charumathi Sabanayagam
- Ocular Epidemiology, Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore
- Ophthalmology and Visual Sciences Academic Clinical Program, Medical School, Duke-National University of Singapore, Singapore, Singapore
| | - Pamela J. Schreiner
- Division of Epidemiology and Community Health, School of Public Health, University of Minnesota, Minneapolis, MN, United States
| | - Xiao-Ou Shu
- Division of Epidemiology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Stephen Sidney
- Division of Research, Kaiser Permanente of Northern California, Oakland, CA, United States
| | - Mario Sims
- Jackson Heart Study, Department of Medicine, University of Mississippi Medical Center, Jackson, MS, United States
| | - Jennifer A. Smith
- Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, MI, United States
- Survey Research Center, Institute for Social Research, University of Michigan, Ann Arbor, MI, United States
| | - John M. Starr
- Centre for Cognitive Ageing and Cognitive Epidemiology, The University of Edinburgh, Edinburgh, United Kingdom
- Alzheimer Scotland Dementia Research Centre, The University of Edinburgh, Edinburgh, United Kingdom
| | - Konstantin Strauch
- German Research Center for Environmental Health, Helmholtz Zentrum München, Institute of Genetic Epidemiology, Neuherberg, Germany
- Institute of Medical Informatics Biometry and Epidemiology, Ludwig-Maximilians-Universität München, Munich, Germany
| | - E. Shyong Tai
- Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore, Singapore
- Yong Loo Lin School of Medicine, National University of Singapore and National University Health System, Singapore, Singapore
- Duke-National University of Singapore Medical School, Singapore, Singapore
| | - Kent D. Taylor
- Department of Pediatrics, The Institute for Translational Genomics and Population Sciences, The Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center, Los Angeles, CA, United States
| | - Michael Y. Tsai
- Department of Laboratory Medicine and Pathology, Minneapolis, MN, United States
| | - André G. Uitterlinden
- Department of Epidemiology, Erasmus MC, University Medical Center, Rotterdam, Netherlands
- Department of Internal Medicine, Erasmus MC, University Medical Center, Rotterdam, Netherlands
| | - Diana van Heemst
- Section of Gerontology and Geriatrics, Department of Internal Medicine, Leiden University Medical Center, Leiden, Netherlands
| | - Melanie Waldenberger
- Research Unit of Molecular Epidemiology, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
- Institute of Epidemiology, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
- German Center for Cardiovascular Research (DZHK), Partner Site Munich Heart Alliance, Munich, Germany
| | - Ya-Xing Wang
- Beijing Ophthalmology and Visual Science Key Lab, Beijing Tongren Eye Center, Beijing Tongren Hospital, Beijing Institute of Ophthalmology, Capital Medical University, Beijing, China
| | - Wen-Bin Wei
- Beijing Ophthalmology and Visual Science Key Lab, Beijing Tongren Eye Center, Beijing Tongren Hospital, Beijing Institute of Ophthalmology, Capital Medical University, Beijing, China
| | - Gregory Wilson
- Jackson Heart Study Graduate Training Center, School of Public, Jackson State University, Jackson, MS, United States
| | - Deng Xuan
- Department of Biostatistics, Boston University School of Public Health, Boston, MA, United States
| | - Jie Yao
- Department of Pediatrics, The Institute for Translational Genomics and Population Sciences, The Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center, Los Angeles, CA, United States
| | - Caizheng Yu
- Department of Occupational and Environmental Health and State Key Laboratory of Environmental Health for Incubating, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Jian-Min Yuan
- Department of Epidemiology, School of Public Health, University of Pittsburgh, Pittsburgh, PA, United States
- Division of Cancer Control and Population Sciences, University of Pittsburgh Medical Center (UPMC) Hillman Cancer Center, Pittsburgh, PA, United States
| | - Wei Zhao
- Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, MI, United States
| | - Diane M. Becker
- Division of General Internal Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Amélie Bonnefond
- European Genomic Institute for Diabetes, Institut Pasteur de Lille, Lille, France
- University of Lille, Lille University Hospital, Lille, France
- Department of Metabolism, Digestion and Reproduction, Imperial College London, London, United Kingdom
| | - Donald W. Bowden
- Department of Biochemistry, Wake Forest School of Medicine, Winston-Salem, NC, United States
| | - Richard S. Cooper
- Department of Public Health Sciences, Loyola University Chicago, Maywood, IL, United States
| | - Ian J. Deary
- Department of Psychology, The University of Edinburgh, Edinburgh, United Kingdom
- Centre for Cognitive Ageing and Cognitive Epidemiology, The University of Edinburgh, Edinburgh, United Kingdom
| | - Jasmin Divers
- Department of Biostatistics and Data Science, Division of Public Health Sciences, Wake Forest University School of Medicine, Winston-Salem, NC, United States
| | - Tõnu Esko
- Estonian Genome Center, Insititute of Genomics, University of Tartu, Tartu, Estonia
- Broad Institute, Massachusetts Institute of Technology and Harvard University, Boston, MA, United States
| | - Paul W. Franks
- Genetic and Molecular Epidemiology Unit, Department of Clinical Sciences, Skåne University Hospital, Lund University, Malmö, Sweden
- Department of Public Health and Clinical Medicine, Umeå University, Umeå, Sweden
- Department of Nutrition, Harvard Chan School of Public Health, Boston, MA, United States
| | - Philippe Froguel
- European Genomic Institute for Diabetes, Institut Pasteur de Lille, Lille, France
- University of Lille, Lille University Hospital, Lille, France
- Department of Metabolism, Digestion and Reproduction, Imperial College London, London, United Kingdom
| | - Christian Gieger
- Research Unit of Molecular Epidemiology, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
- German Center for Diabetes Research, Neuherberg, Germany
| | - Jost B. Jonas
- Beijing Ophthalmology and Visual Science Key Lab, Beijing Tongren Eye Center, Beijing Tongren Hospital, Beijing Institute of Ophthalmology, Capital Medical University, Beijing, China
- Department of Ophthalmology, Medical Faculty Mannheim, University Heidelberg, Mannheim, Germany
- Institute of Molecular and Clinical Ophthalmology, Basel, Switzerland
| | - Norihiro Kato
- Department of Gene Diagnostics and Therapeutics, Research Institute, National Center for Global Health and Medicine, Tokyo, Japan
| | - Timo A. Lakka
- Kuopio Research Institute of Exercise Medicine, Kuopio, Finland
- Institute of Biomedicine, School of Medicine, University of Eastern Finland, Kuopio, Finland
- Department of Clinical Physiology and Nuclear Medicine, Kuopio University Hospital, Kuopio, Finland
| | - Karin Leander
- Cardiovascular and Nutritional Epidemiology, Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Terho Lehtimäki
- Department of Clinical Chemistry, University of Tampere, Tampere, Finland
- Finnish Cardiovascular Research Center, University of Tampere, Tampere, Finland
| | - Patrik K. E. Magnusson
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
| | - Kari E. North
- Department of Epidemiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Ioanna Ntalla
- Clinical Pharmacology, Queen Mary University of London, London, United Kingdom
- Celgene, Bristol Myers Squibb, Mississauga, ON, Canada
| | | | - Nilesh J. Samani
- Department of Cardiovascular Sciences, University of Leicester, Leicester, United Kingdom
- NIHR Leicester Biomedical Research Centre, Glenfield Hospital, Leicester, United Kingdom
| | - Harold Snieder
- Unit of Genetic Epidemiology and Bioinformatics, Department of Epidemiology, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Beatrice Spedicati
- Department of Medicine, Surgery and Health Sciences, University of Trieste, Trieste, Italy
| | - Pim van der Harst
- Division Heart and Lungs, Department of Cardiology, University Medical Center Utrecht, University of Utrecht, Utrecht, Netherlands
| | - Henry Völzke
- German Center for Cardiovascular Research, Greifswald, Germany
- Institute for Community Medicine, University Medicine Greifswald, Greifswald, Germany
| | - Lynne E. Wagenknecht
- Department of Biostatistics and Data Science, Division of Public Health Sciences, Wake Forest University School of Medicine, Winston-Salem, NC, United States
| | - David R. Weir
- Survey Research Center, Institute for Social Research, University of Michigan, Ann Arbor, MI, United States
| | - Mary K. Wojczynski
- Division of Statistical Genomics, Department of Genetics, Washington University School of Medicine, St. Louis, MO, United States
| | - Tangchun Wu
- Department of Occupational and Environmental Health and State Key Laboratory of Environmental Health for Incubating, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Wei Zheng
- Division of Epidemiology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Xiaofeng Zhu
- Department of Population and Quantitative Health Sciences, Cleveland, OH, United States
| | - Claude Bouchard
- Human Genomics Laboratory, Pennington Biomedical Research Center, Baton Rouge, LA, United States
| | - Daniel I. Chasman
- Division of Preventive Medicine, Brigham and Women’s Hospital, Boston, MA, United States
- Harvard Medical School, Boston, MA, United States
| | - Michele K. Evans
- Laboratory of Epidemiology and Population Sciences, National Institute on Aging, National Institutes of Health, Baltimore, MD, United States
- National Institute on Aging, National Institutes of Health, Bethesda, MD, United States
| | - Ervin R. Fox
- Division of Cardiology, Department of Medicine, University of Mississippi Medical Center, Jackson, MS, United States
| | - Vilmundur Gudnason
- Icelandic Heart Association, Kopavogur, Iceland
- Faculty of Medicine, University of Iceland, Reykjavik, Iceland
| | - Caroline Hayward
- Medical Research Council Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh, United Kingdom
| | - Bernardo L. Horta
- Postgraduate Programme in Epidemiology, Faculty of Medicine, Federal University of Pelotas, Pelotas, RS, Brazil
| | - Sharon L. R. Kardia
- Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, MI, United States
| | - Jose Eduardo Krieger
- Laboratory of Genetics and Molecular Cardiology, Heart Institute, University of Sao Paulo Medical School, Sao Paulo, SP, Brazil
| | - Dennis O. Mook-Kanamori
- Department of Clinical Epidemiology, Leiden University Medical Center, Leiden, Netherlands
- Department of Public Health and Primary Care, Leiden University Medical Center, Leiden, Netherlands
| | - Patricia A. Peyser
- Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, MI, United States
| | - Michael M. Province
- Division of Statistical Genomics, Department of Genetics, Washington University School of Medicine, St. Louis, MO, United States
| | - Bruce M. Psaty
- Cardiovascular Health Research Unit, University of Washington, Seattle, WA, United States
- Department of Epidemiology, University of Washington, Seattle, WA, United States
- Department of Health Systems and Population Health, University of Washington, Seattle, WA, United States
| | - Igor Rudan
- Centre for Global Health, The Usher Institute, The University of Edinburgh, Edinburgh, United Kingdom
| | - Xueling Sim
- Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore, Singapore
| | - Blair H. Smith
- Division of Population Health and Genomics, Ninewells Hospital and Medical School, University of Dundee, Dundee, United Kingdom
| | - Rob M. van Dam
- Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore, Singapore
- Department of Exercise and Nutrition Sciences, Milken Institute School of Public Health, The George Washington University, Washington, DC, United States
| | - Cornelia M. van Duijn
- Department of Epidemiology, Erasmus MC, University Medical Center, Rotterdam, Netherlands
- Nuffield Department of Population Health, University of Oxford, Oxford, United Kingdom
| | - Tien Yin Wong
- Ocular Epidemiology, Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore
- Ophthalmology and Visual Sciences Academic Clinical Program, Medical School, Duke-National University of Singapore, Singapore, Singapore
| | - Donna K. Arnett
- College of Public Health, Dean’s Office, University of Kentucky, Lexington, KY, United States
| | - Dabeeru C. Rao
- Division of Biostatistics, Washington University School of Medicine, St. Louis, MO, United States
| | - James Gauderman
- Division of Biostatistics, Population and Public Health Sciences, University of Southern California, Los Angeles, CA, United States
| | - Ching-Ti Liu
- Department of Biostatistics, Boston University School of Public Health, Boston, MA, United States
| | - Alanna C. Morrison
- Human Genetics Center, Department of Epidemiology, Human Genetics and Environmental Sciences, School of Public Health, The University of Texas Health Science Center at Houston, Houston, TX, United States
| | - Jerome I. Rotter
- Department of Pediatrics, The Institute for Translational Genomics and Population Sciences, The Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center, Los Angeles, CA, United States
| | - Myriam Fornage
- Human Genetics Center, Department of Epidemiology, Human Genetics and Environmental Sciences, School of Public Health, The University of Texas Health Science Center at Houston, Houston, TX, United States
- Brown Foundation Institute of Molecular Medicine, The University of Texas Health Science Center at Houston, Houston, TX, United States
| |
Collapse
|
5
|
Bremner SK, Berends R, Kaupisch A, Roccisana J, Sutherland C, Bryant NJ, Gould GW. Phosphorylation of the N-terminus of Syntaxin-16 controls interaction with mVps45 and GLUT4 trafficking in adipocytes. PeerJ 2023; 11:e15630. [PMID: 37520260 PMCID: PMC10373645 DOI: 10.7717/peerj.15630] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Accepted: 06/02/2023] [Indexed: 08/01/2023] Open
Abstract
The ability of insulin to stimulate glucose transport in muscle and fat cells is mediated by the regulated delivery of intracellular vesicles containing glucose transporter-4 (GLUT4) to the plasma membrane, a process known to be defective in disease such as Type 2 diabetes. In the absence of insulin, GLUT4 is sequestered in tubules and vesicles within the cytosol, collectively known as the GLUT4 storage compartment. A subset of these vesicles, known as the 'insulin responsive vesicles' are selectively delivered to the cell surface in response to insulin. We have previously identified Syntaxin16 (Sx16) and its cognate Sec1/Munc18 protein family member mVps45 as key regulatory proteins involved in the delivery of GLUT4 into insulin responsive vesicles. Here we show that mutation of a key residue within the Sx16 N-terminus involved in mVps45 binding, and the mutation of the Sx16 binding site in mVps45 both perturb GLUT4 sorting, consistent with an important role of the interaction of these two proteins in GLUT4 trafficking. We identify Threonine-7 (T7) as a site of phosphorylation of Sx16 in vitro. Mutation of T7 to D impairs Sx16 binding to mVps45 in vitro and overexpression of T7D significantly impaired insulin-stimulated glucose transport in adipocytes. We show that both AMP-activated protein kinase (AMPK) and its relative SIK2 phosphorylate this site. Our data suggest that Sx16 T7 is a potentially important regulatory site for GLUT4 trafficking in adipocytes.
Collapse
Affiliation(s)
| | - Rebecca Berends
- Institute of Molecular, Cell and Systems Biology, University of Glasgow, Glasgow, United Kingdom
| | - Alexandra Kaupisch
- Institute of Molecular, Cell and Systems Biology, University of Glasgow, Glasgow, United Kingdom
| | - Jennifer Roccisana
- Institute of Molecular, Cell and Systems Biology, University of Glasgow, Glasgow, United Kingdom
| | - Calum Sutherland
- Department of Cellular Medicine, University of Dundee, Dundee, United Kingdom
| | - Nia J. Bryant
- Department of Biology, University of York, York, United Kingdom
| | - Gwyn W. Gould
- SIPBS, University of Strathclyde, Glasgow, United Kingdom
| |
Collapse
|
6
|
Diaz-Vegas A, Norris DM, Jall-Rogg S, Cooke KC, Conway OJ, Shun-Shion AS, Duan X, Potter M, van Gerwen J, Baird HJ, Humphrey SJ, James DE, Fazakerley DJ, Burchfield JG. A high-content endogenous GLUT4 trafficking assay reveals new aspects of adipocyte biology. Life Sci Alliance 2023; 6:e202201585. [PMID: 36283703 PMCID: PMC9595207 DOI: 10.26508/lsa.202201585] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Revised: 10/10/2022] [Accepted: 10/10/2022] [Indexed: 11/06/2022] Open
Abstract
Insulin-induced GLUT4 translocation to the plasma membrane in muscle and adipocytes is crucial for whole-body glucose homeostasis. Currently, GLUT4 trafficking assays rely on overexpression of tagged GLUT4. Here we describe a high-content imaging platform for studying endogenous GLUT4 translocation in intact adipocytes. This method enables high fidelity analysis of GLUT4 responses to specific perturbations, multiplexing of other trafficking proteins and other features including lipid droplet morphology. Using this multiplexed approach we showed that Vps45 and Rab14 are selective regulators of GLUT4, but Trarg1, Stx6, Stx16, Tbc1d4 and Rab10 knockdown affected both GLUT4 and TfR translocation. Thus, GLUT4 and TfR translocation machinery likely have some overlap upon insulin-stimulation. In addition, we identified Kif13A, a Rab10 binding molecular motor, as a novel regulator of GLUT4 traffic. Finally, comparison of endogenous to overexpressed GLUT4 highlights that the endogenous GLUT4 methodology has an enhanced sensitivity to genetic perturbations and emphasises the advantage of studying endogenous protein trafficking for drug discovery and genetic analysis of insulin action in relevant cell types.
Collapse
Affiliation(s)
- Alexis Diaz-Vegas
- Charles Perkins Centre, School of Life and Environmental Sciences, University of Sydney, Sydney, Australia
| | - Dougall M Norris
- Metabolic Research Laboratories, Wellcome-Medical Research Council Institute of Metabolic Science, University of Cambridge, Cambridge, UK
| | - Sigrid Jall-Rogg
- Charles Perkins Centre, School of Life and Environmental Sciences, University of Sydney, Sydney, Australia
| | - Kristen C Cooke
- Charles Perkins Centre, School of Life and Environmental Sciences, University of Sydney, Sydney, Australia
| | - Olivia J Conway
- Metabolic Research Laboratories, Wellcome-Medical Research Council Institute of Metabolic Science, University of Cambridge, Cambridge, UK
| | - Amber S Shun-Shion
- Metabolic Research Laboratories, Wellcome-Medical Research Council Institute of Metabolic Science, University of Cambridge, Cambridge, UK
| | - Xiaowen Duan
- Metabolic Research Laboratories, Wellcome-Medical Research Council Institute of Metabolic Science, University of Cambridge, Cambridge, UK
| | - Meg Potter
- Charles Perkins Centre, School of Life and Environmental Sciences, University of Sydney, Sydney, Australia
| | - Julian van Gerwen
- Charles Perkins Centre, School of Life and Environmental Sciences, University of Sydney, Sydney, Australia
| | - Harry Jm Baird
- Metabolic Research Laboratories, Wellcome-Medical Research Council Institute of Metabolic Science, University of Cambridge, Cambridge, UK
| | - Sean J Humphrey
- Charles Perkins Centre, School of Life and Environmental Sciences, University of Sydney, Sydney, Australia
| | - David E James
- Charles Perkins Centre, School of Life and Environmental Sciences, University of Sydney, Sydney, Australia
- School of Medical Sciences, University of Sydney, Sydney, Australia
| | - Daniel J Fazakerley
- Metabolic Research Laboratories, Wellcome-Medical Research Council Institute of Metabolic Science, University of Cambridge, Cambridge, UK
| | - James G Burchfield
- Charles Perkins Centre, School of Life and Environmental Sciences, University of Sydney, Sydney, Australia
| |
Collapse
|
7
|
Bremner SK, Al Shammari WS, Milligan RS, Hudson BD, Sutherland C, Bryant NJ, Gould GW. Pleiotropic effects of Syntaxin16 identified by gene editing in cultured adipocytes. Front Cell Dev Biol 2022; 10:1033501. [PMID: 36467416 PMCID: PMC9716095 DOI: 10.3389/fcell.2022.1033501] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Accepted: 11/02/2022] [Indexed: 08/01/2023] Open
Abstract
Adipocytes play multiple roles in the regulation of glucose metabolism which rely on the regulation of membrane traffic. These include secretion of adipokines and serving as an energy store. Central to their energy storing function is the ability to increase glucose uptake in response to insulin, mediated through translocation of the facilitative glucose transporter GLUT4 to the cell surface. The trans-Golgi reticulum localized SNARE protein syntaxin 16 (Sx16) has been identified as a key component of the secretory pathway required for insulin-regulated trafficking of GLUT4. We used CRISPR/Cas9 technology to generate 3T3-L1 adipocytes lacking Sx16 to understand the role of the secretory pathway on adipocyte function. GLUT4 mRNA and protein levels were reduced in Sx16 knockout adipocytes and insulin stimulated GLUT4 translocation to the cell surface was reduced. Strikingly, neither basal nor insulin-stimulated glucose transport were affected. By contrast, GLUT1 levels were upregulated in Sx16 knockout cells. Levels of sortilin and insulin regulated aminopeptidase were also increased in Sx16 knockout adipocytes which may indicate an upregulation of an alternative GLUT4 sorting pathway as a compensatory mechanism for the loss of Sx16. In response to chronic insulin stimulation, Sx16 knockout adipocytes exhibit elevated insulin-independent glucose transport and significant alterations in lactate metabolism. We further show that the adipokine secretory pathways are impaired in Sx16 knockout cells. Together this demonstrates a role for Sx16 in the control of glucose transport, the response to elevated insulin, cellular metabolic profiles and adipocytokine secretion.
Collapse
Affiliation(s)
- Shaun K. Bremner
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, United Kingdom
| | - Woroud S. Al Shammari
- The Centre for Translational Pharmacology, Institute of Molecular, Cell and Systems Biology, University of Glasgow, Glasgow, United Kingdom
| | - Roderick S. Milligan
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, United Kingdom
| | - Brian D. Hudson
- The Centre for Translational Pharmacology, Institute of Molecular, Cell and Systems Biology, University of Glasgow, Glasgow, United Kingdom
| | - Calum Sutherland
- Department of Cellular Medicine, Ninewells Hospital, University of Dundee, Glasgow, United Kingdom
| | - Nia J. Bryant
- Department of Biology, University of York, York, United Kingdom
| | - Gwyn W. Gould
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, United Kingdom
| |
Collapse
|
8
|
Matsui K, Emoto M, Fukuda N, Nomiyama R, Yamada K, Tanizawa Y. SNARE-binding protein synaptosomal-associated protein of 29 kDa (SNAP29) regulates the intracellular sequestration of glucose transporter 4 (GLUT4) vesicles in adipocytes. J Diabetes Investig 2022; 14:19-27. [PMID: 36181414 PMCID: PMC9807150 DOI: 10.1111/jdi.13912] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/23/2022] [Revised: 08/16/2022] [Accepted: 09/07/2022] [Indexed: 01/07/2023] Open
Abstract
AIMS/INTRODUCTION Insulin stimulates translocation of glucose transporter 4 (GLUT4) from the perinuclear location to the plasma membrane. In the unstimulated state, intracellular vesicles containing GLUT4 are sequestered into specialized storage vesicles that have come to be known as the insulin-responsive compartment (IRC). The IRC is a functional compartment in the perinuclear region that is a target of the insulin signaling cascade, although its precise nature is unclear. Here, we report a novel molecular mechanism facilitating formation of the IRC. MATERIALS AND METHODS We determined synaptosomal-associated protein of 29 kDa (SNAP29) by mass spectrometry to be an EH domain-containing protein 1 (EHD1)-binding protein. Then, its expression was confirmed by western blotting. Subcellular localization of SNAP29 was determined by immunofluorescent microscopy. Interactions between SNAP29 and syntaxins were determined by immunoprecipitation. We measured glucose uptake and GLUT4 translocation in 3T3-L1 adipocyte expressing SNAP29 or silencing SNAP29. RESULTS We found SNAP29 to be localized in the perinuclear region and to show partial co-localization with GLUT4 under basal conditions. We also found that SNAP29 binds to syntaxin6, a Qc-SNARE, in adipocytes. In SNAP29-expressing cells, vesicles containing GLUT4 were observed to aggregate around the perinuclear region. In contrast, when SNAP29 was silenced, perinuclear GLUT4 vesicles were dispersed throughout the cytosol. Insulin-stimulated glucose uptake was inhibited in both SNAP29-expressing and SNAP29-silenced cells. CONCLUSIONS These data suggest that SNAP29 sequesters and anchors GLUT4-containing vesicles in the perinuclear region, and might have a role in the biogenesis of the perinuclear IRC.
Collapse
Affiliation(s)
- Kumiko Matsui
- Department of Endocrinology, Metabolism, Hematological Sciences and TherapeuticsYamaguchi University Graduate School of MedicineUbeJapan
| | - Masahiro Emoto
- Department of Endocrinology, Metabolism, Hematological Sciences and TherapeuticsYamaguchi University Graduate School of MedicineUbeJapan,Emoto ClinicUbeJapan
| | - Naofumi Fukuda
- Department of Endocrinology, Metabolism, Hematological Sciences and TherapeuticsYamaguchi University Graduate School of MedicineUbeJapan
| | - Ryuta Nomiyama
- Department of Endocrinology, Metabolism, Hematological Sciences and TherapeuticsYamaguchi University Graduate School of MedicineUbeJapan
| | - Kyoko Yamada
- Department of Endocrinology, Metabolism, Hematological Sciences and TherapeuticsYamaguchi University Graduate School of MedicineUbeJapan
| | - Yukio Tanizawa
- Department of Endocrinology, Metabolism, Hematological Sciences and TherapeuticsYamaguchi University Graduate School of MedicineUbeJapan
| |
Collapse
|
9
|
Human Cytomegalovirus Manipulates Syntaxin 6 for Successful Trafficking and Subsequent Infection of Monocytes. J Virol 2022; 96:e0081922. [PMID: 35862696 PMCID: PMC9327712 DOI: 10.1128/jvi.00819-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Human cytomegalovirus (HCMV) exhibits a complex host-pathogen interaction with peripheral blood monocytes. We have identified a unique, cell-type specific retrograde-like intracellular trafficking pattern that HCMV utilizes to gain access to the monocyte nucleus and for productive infection. We show that infection of primary human monocytes, epithelial cells, and fibroblasts leads to an increase in the amount of the trafficking protein Syntaxin 6 (Stx6). However, only knockdown (KD) of Stx6 in monocytes inhibited viral trafficking to the trans-Golgi network (TGN), a requisite step for nuclear translocation in monocytes. Conversely, KD of Stx6 in epithelial cells and fibroblasts did not change the kinetics of nuclear translocation and productive infection. Stx6 predominantly functions at the level of the TGN where it facilitates retrograde transport, a trafficking pathway used by only a few cellular proteins and seldom by pathogens. We also newly identify that in monocytes, Stx6 exhibits an irregular vesicular localization rather than being concentrated at the TGN as seen in other cell-types. Lastly, we implicate that viral particles that associate with both Stx6 and EEA1 early in infection are the viral population that successfully traffics to the TGN at later time points and undergo nuclear translocation. Additionally, we show for the first time that HCMV enters the TGN, and that lack of Stx6 prevents viral trafficking to this organelle. We argue that we have identified an essential cell-type specific regulator that controls early steps in efficient productive infection of a cell-type required for viral persistence and disease. IMPORTANCE Human cytomegalovirus (HCMV) infection causes severe and often fatal disease in the immunocompromised. It is one of the leading infectious causes of birth defects and causes severe complications in transplant recipients. By uncovering the unique pathways used by the virus to infect key cells, such as monocytes, responsible for dissemination and persistence, we provide new potential targets for therapeutic intervention.
Collapse
|
10
|
Roberts BS, Yang CQ, Neher SB. Characterization of lipoprotein lipase storage vesicles in 3T3-L1 adipocytes. J Cell Sci 2022; 135:jcs258734. [PMID: 34382637 PMCID: PMC8403984 DOI: 10.1242/jcs.258734] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Accepted: 07/10/2021] [Indexed: 12/12/2022] Open
Abstract
Lipoprotein lipase (LPL) is a secreted triglyceride lipase involved in the clearance of very-low-density lipoproteins and chylomicrons from circulation. LPL is expressed primarily in adipose and muscle tissues and transported to the capillary lumen. LPL secretion is regulated by insulin in adipose tissue; however, few studies have examined the regulatory and trafficking steps involved in secretion. Here, we describe the intracellular localization and insulin-dependent trafficking of LPL in 3T3-L1 adipocytes. We compared LPL trafficking to the better characterized trafficking pathways taken by leptin and GLUT4 (also known as SLC2A4). We show that the LPL trafficking pathway shares some characteristics of these other pathways, but that LPL subcellular localization and trafficking are distinct from those of GLUT4 and leptin. LPL secretion occurs slowly in response to insulin and rapidly in response to the Ca2+ ionophore ionomycin. This regulated trafficking is dependent on Golgi protein kinase D and the ADP-ribosylation factor GTPase ARF1. Together, these data give support to a new trafficking pathway for soluble cargo that is active in adipocytes.
Collapse
Affiliation(s)
| | | | - Saskia B. Neher
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| |
Collapse
|
11
|
Fazakerley DJ, Koumanov F, Holman GD. GLUT4 On the move. Biochem J 2022; 479:445-462. [PMID: 35147164 PMCID: PMC8883492 DOI: 10.1042/bcj20210073] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Revised: 01/11/2022] [Accepted: 01/14/2022] [Indexed: 12/16/2022]
Abstract
Insulin rapidly stimulates GLUT4 translocation and glucose transport in fat and muscle cells. Signals from the occupied insulin receptor are translated into downstream signalling changes in serine/threonine kinases within timescales of seconds, and this is followed by delivery and accumulation of the glucose transporter GLUT4 at the plasma membrane. Kinetic studies have led to realisation that there are distinct phases of this stimulation by insulin. There is a rapid initial burst of GLUT4 delivered to the cell surface from a subcellular reservoir compartment and this is followed by a steady-state level of continuing stimulation in which GLUT4 recycles through a large itinerary of subcellular locations. Here, we provide an overview of the phases of insulin stimulation of GLUT4 translocation and the molecules that are currently considered to activate these trafficking steps. Furthermore, we suggest how use of new experimental approaches together with phospho-proteomic data may help to further identify mechanisms for activation of these trafficking processes.
Collapse
Affiliation(s)
- Daniel J Fazakerley
- Metabolic Research Laboratories, Wellcome-Medical Research Council Institute of Metabolic Science, University of Cambridge, Cambridge CB2 0QQ, U.K
| | - Francoise Koumanov
- Department for Health, Centre for Nutrition, Exercise, and Metabolism, University of Bath, Bath, Somerset BA2 7AY, U.K
| | - Geoffrey D Holman
- Department of Biology and Biochemistry, University of Bath, Bath, Somerset BA2 7AY, U.K
| |
Collapse
|
12
|
Heckmann M, Klanert G, Sandner G, Lanzerstorfer P, Auer M, Weghuber J. Fluorescence Microscopy-Based Quantitation of GLUT4 Translocation. Methods Appl Fluoresc 2022; 10. [PMID: 35008072 DOI: 10.1088/2050-6120/ac4998] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Accepted: 01/10/2022] [Indexed: 11/11/2022]
Abstract
Postprandial insulin-stimulated glucose uptake into target tissue is crucial for the maintenance of normal blood glucose homeostasis. This step is rate-limited by the number of facilitative glucose transporters type 4 (GLUT4) present in the plasma membrane. Since insulin resistance and impaired GLUT4 translocation are associated with the development of metabolic disorders such as type 2 diabetes, this transporter has become an important target of antidiabetic drug research. The application of screening approaches that are based on the analysis of GLUT4 translocation to the plasma membrane to identify substances with insulinomimetic properties has gained global research interest in recent years. Here, we review methods that have been implemented to quantitate the translocation of GLUT4 to the plasma membrane. These methods can be broadly divided into two sections: microscopy-based technologies (e.g., immunoelectron, confocal or total internal reflection fluorescence microscopy) and biochemical and spectrometric approaches (e.g., membrane fractionation, photoaffinity labeling or flow cytometry). In this review, we discuss the most relevant approaches applied to GLUT4 thus far, highlighting the advantages and disadvantages of these approaches, and we provide a critical discussion and outlook into new methodological opportunities.
Collapse
Affiliation(s)
- Mara Heckmann
- University of Applied Sciences Upper Austria, Stelzhamerstrasse 23, Wels, Oberösterreich, 4600, AUSTRIA
| | - Gerald Klanert
- FFoQSI GmbH-Austrian Competence Centre for Feed and Food Quality, Safety and Innovation, Technopark 1C, Tulln, 3430, AUSTRIA
| | - Georg Sandner
- University of Applied Sciences Upper Austria, Stelzhamerstrasse 23, Wels, Oberösterreich, 4600, AUSTRIA
| | - Peter Lanzerstorfer
- University of Applied Sciences Upper Austria, Stelzhamerstrasse 23, Wels, Oberösterreich, 4600, AUSTRIA
| | - Manfred Auer
- Division of Pathway Medicine, University of Edinburgh, University of Edinburgh Medical School, The Chancellor's Building, 49 Little France Crescent, Edinburgh, EH16 4SB, Edinburgh, EH8 9AB, UNITED KINGDOM OF GREAT BRITAIN AND NORTHERN IRELAND
| | - Julian Weghuber
- University of Applied Sciences Upper Austria, Stelzhamerstrasse 23, Wels, Oberösterreich, 4600, AUSTRIA
| |
Collapse
|
13
|
Black HL, Livingstone R, Mastick CC, Al Tobi M, Taylor H, Geiser A, Stirrat L, Kioumourtzoglou D, Petrie JR, Boyle JG, Bryant NJ, Gould GW. Knockout of Syntaxin-4 in 3T3-L1 adipocytes reveals new insight into GLUT4 trafficking and adiponectin secretion. J Cell Sci 2021; 135:273617. [PMID: 34859814 PMCID: PMC8767277 DOI: 10.1242/jcs.258375] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Accepted: 11/18/2021] [Indexed: 11/20/2022] Open
Abstract
Adipocytes are key to metabolic regulation, exhibiting insulin-stimulated glucose transport that is underpinned by the insulin-stimulated delivery of glucose transporter type 4 (SLC2A4, also known and hereafter referred to as GLUT4)-containing vesicles to the plasma membrane where they dock and fuse, and increase cell surface GLUT4 levels. Adipocytokines, such as adiponectin, are secreted via a similar mechanism. We used genome editing to knock out syntaxin-4, a protein reported to mediate fusion between GLUT4-containing vesicles and the plasma membrane in 3T3-L1 adipocytes. Syntaxin-4 knockout reduced insulin-stimulated glucose transport and adiponectin secretion by ∼50% and reduced GLUT4 levels. Ectopic expression of haemagglutinin (HA)-tagged GLUT4 conjugated to GFP showed that syntaxin-4-knockout cells retain significant GLUT4 translocation capacity, demonstrating that syntaxin-4 is dispensable for insulin-stimulated GLUT4 translocation. Analysis of recycling kinetics revealed only a modest reduction in the exocytic rate of GLUT4 in knockout cells, and little effect on endocytosis. These analyses demonstrate that syntaxin-4 is not always rate limiting for GLUT4 delivery to the cell surface. In sum, we show that syntaxin-4 knockout results in reduced insulin-stimulated glucose transport, depletion of cellular GLUT4 levels and inhibition of adiponectin secretion but has only modest effects on the translocation capacity of the cells. This article has an associated First Person interview with Hannah L. Black and Rachel Livingstone, joint first authors of the paper. Summary: Syntaxin-4 knockout reduces insulin-stimulated glucose transport, depletes levels of cellular GLUT4 and inhibits secretion of adiponectin but only modestly affects the translocation capacity of the cells.
Collapse
Affiliation(s)
- Hannah L Black
- Department of Biology and York Biomedical Research Institute, University of York. Heslington, York, YO10 5DD, UK
| | - Rachel Livingstone
- Henry Welcome Laboratory for Cell Biology, Institute for Molecular, Cellular and Systems Biology, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
| | - Cynthia C Mastick
- Henry Welcome Laboratory for Cell Biology, Institute for Molecular, Cellular and Systems Biology, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK.,Department of Biology, University of Nevada Reno, 1664 N. Virginia Street, Reno, NV 89557, USA
| | - Mohammed Al Tobi
- Henry Welcome Laboratory for Cell Biology, Institute for Molecular, Cellular and Systems Biology, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
| | - Holly Taylor
- Strathclyde Institute for Pharmacy and Biomedical Sciences, 161 Cathedral Street, University of Strathclyde, Glasgow G4 0RE, UK
| | - Angéline Geiser
- Strathclyde Institute for Pharmacy and Biomedical Sciences, 161 Cathedral Street, University of Strathclyde, Glasgow G4 0RE, UK
| | - Laura Stirrat
- Strathclyde Institute for Pharmacy and Biomedical Sciences, 161 Cathedral Street, University of Strathclyde, Glasgow G4 0RE, UK
| | - Dimitrios Kioumourtzoglou
- Department of Biology and York Biomedical Research Institute, University of York. Heslington, York, YO10 5DD, UK
| | - John R Petrie
- Institute of Cardiovascular and Medical Sciences, University of Glasgow. Glasgow G12 8QQ, UK
| | - James G Boyle
- Institute of Cardiovascular and Medical Sciences, University of Glasgow. Glasgow G12 8QQ, UK.,School of Medicine, Dentistry and Nursing, University of Glasgow. Glasgow G12 8QQ, UK
| | - Nia J Bryant
- Department of Biology and York Biomedical Research Institute, University of York. Heslington, York, YO10 5DD, UK
| | - Gwyn W Gould
- Strathclyde Institute for Pharmacy and Biomedical Sciences, 161 Cathedral Street, University of Strathclyde, Glasgow G4 0RE, UK
| |
Collapse
|
14
|
Neuregulin 4 Downregulation Induces Insulin Resistance in 3T3-L1 Adipocytes through Inflammation and Autophagic Degradation of GLUT4 Vesicles. Int J Mol Sci 2021; 22:ijms222312960. [PMID: 34884763 PMCID: PMC8657571 DOI: 10.3390/ijms222312960] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Revised: 11/25/2021] [Accepted: 11/25/2021] [Indexed: 11/17/2022] Open
Abstract
The adipokine Neuregulin 4 (Nrg4) protects against obesity-induced insulin resistance. Here, we analyze how the downregulation of Nrg4 influences insulin action and the underlying mechanisms in adipocytes. Validated shRNA lentiviral vectors were used to generate scramble (Scr) and Nrg4 knockdown (KD) 3T3-L1 adipocytes. Adipogenesis was unaffected in Nrg4 KD adipocytes, but there was a complete impairment of the insulin-induced 2-deoxyglucose uptake, which was likely the result of reduced insulin receptor and Glut4 protein. Downregulation of Nrg4 enhanced the expression of proinflammatory cytokines. Anti-inflammatory agents recovered the insulin receptor, but not Glut4, content. Proteins enriched in Glut4 storage vesicles such as the insulin-responsive aminopeptidase (IRAP) and Syntaxin-6 as well as TBC1D4, a protein involved in the intracellular retention of Glut4 vesicles, also decreased by Nrg4 KD. Insulin failed to reduce autophagy in Nrg4 KD adipocytes, observed by a minor effect on mTOR phosphorylation, at the time that proteins involved in autophagy such as LC3-II, Rab11, and Clathrin were markedly upregulated. The lysosomal activity inhibitor bafilomycin A1 restored Glut4, IRAP, Syntaxin-6, and TBC1D4 content to those found in control adipocytes. Our study reveals that Nrg4 preserves the insulin responsiveness by preventing inflammation and, in turn, benefits the insulin regulation of autophagy.
Collapse
|
15
|
Camus SM, Camus MD, Figueras-Novoa C, Boncompain G, Sadacca LA, Esk C, Bigot A, Gould GW, Kioumourtzoglou D, Perez F, Bryant NJ, Mukherjee S, Brodsky FM. CHC22 clathrin mediates traffic from early secretory compartments for human GLUT4 pathway biogenesis. J Cell Biol 2020; 219:133472. [PMID: 31863584 PMCID: PMC7039200 DOI: 10.1083/jcb.201812135] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2018] [Revised: 08/02/2019] [Accepted: 10/09/2019] [Indexed: 12/29/2022] Open
Abstract
Blood glucose clearance relies on insulin-stimulated exocytosis of glucose transporter 4 (GLUT4) from sites of sequestration in muscle and fat. This work demonstrates that, in humans, CHC22 clathrin controls GLUT4 traffic from the ER-to-Golgi intermediate compartment to sites of sequestration during GLUT4 pathway biogenesis. Glucose transporter 4 (GLUT4) is sequestered inside muscle and fat and then released by vesicle traffic to the cell surface in response to postprandial insulin for blood glucose clearance. Here, we map the biogenesis of this GLUT4 traffic pathway in humans, which involves clathrin isoform CHC22. We observe that GLUT4 transits through the early secretory pathway more slowly than the constitutively secreted GLUT1 transporter and localize CHC22 to the ER-to-Golgi intermediate compartment (ERGIC). CHC22 functions in transport from the ERGIC, as demonstrated by an essential role in forming the replication vacuole of Legionella pneumophila bacteria, which requires ERGIC-derived membrane. CHC22 complexes with ERGIC tether p115, GLUT4, and sortilin, and downregulation of either p115 or CHC22, but not GM130 or sortilin, abrogates insulin-responsive GLUT4 release. This indicates that CHC22 traffic initiates human GLUT4 sequestration from the ERGIC and defines a role for CHC22 in addition to retrograde sorting of GLUT4 after endocytic recapture, enhancing pathways for GLUT4 sequestration in humans relative to mice, which lack CHC22.
Collapse
Affiliation(s)
- Stéphane M Camus
- Department of Bioengineering and Therapeutic Sciences and Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA.,Department of Microbiology and Immunology and the G.W. Hooper Foundation, University of California, San Francisco, San Francisco, CA.,Division of Biosciences, University College London, London, UK
| | - Marine D Camus
- Department of Bioengineering and Therapeutic Sciences and Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA.,Department of Microbiology and Immunology and the G.W. Hooper Foundation, University of California, San Francisco, San Francisco, CA.,Division of Biosciences, University College London, London, UK
| | | | - Gaelle Boncompain
- Institut Curie, PSL Research University, CNRS UMR 144, Paris, France
| | | | - Christopher Esk
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences, Vienna, Austria
| | - Anne Bigot
- Sorbonne Université, Institut National de la Santé et de la Recherche Médicale, Association Institut de Myologie, UMR S974 Centre for Research in Myology, Paris, France
| | - Gwyn W Gould
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Dimitrios Kioumourtzoglou
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK.,Department of Biology and York Biomedical Research Institute, University of York, York, UK
| | - Franck Perez
- Institut Curie, PSL Research University, CNRS UMR 144, Paris, France
| | - Nia J Bryant
- Department of Biology and York Biomedical Research Institute, University of York, York, UK
| | - Shaeri Mukherjee
- Department of Microbiology and Immunology and the G.W. Hooper Foundation, University of California, San Francisco, San Francisco, CA
| | - Frances M Brodsky
- Department of Bioengineering and Therapeutic Sciences and Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA.,Department of Microbiology and Immunology and the G.W. Hooper Foundation, University of California, San Francisco, San Francisco, CA.,Division of Biosciences, University College London, London, UK
| |
Collapse
|
16
|
Building GLUT4 Vesicles: CHC22 Clathrin's Human Touch. Trends Cell Biol 2020; 30:705-719. [PMID: 32620516 DOI: 10.1016/j.tcb.2020.05.007] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Revised: 05/24/2020] [Accepted: 05/27/2020] [Indexed: 12/18/2022]
Abstract
Insulin stimulates glucose transport by triggering regulated delivery of intracellular vesicles containing the GLUT4 glucose transporter to the plasma membrane. This process is defective in diseases such as type 2 diabetes (T2DM). While studies in rodent cells have been invaluable in understanding GLUT4 traffic, evolutionary plasticity must be considered when extrapolating these findings to humans. Recent work has identified species-specific distinctions in GLUT4 traffic, notably the participation of a novel clathrin isoform, CHC22, in humans but not rodents. Here, we discuss GLUT4 sorting in different species and how studies of CHC22 have identified new routes for GLUT4 trafficking. We further consider how different sorting-protein complexes relate to these routes and discuss other implications of these pathways in cell biology and disease.
Collapse
|
17
|
Jones E, Mead S. Genetic risk factors for Creutzfeldt-Jakob disease. Neurobiol Dis 2020; 142:104973. [PMID: 32565065 DOI: 10.1016/j.nbd.2020.104973] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Revised: 05/18/2020] [Accepted: 06/13/2020] [Indexed: 10/24/2022] Open
Abstract
Prion diseases are a group of fatal neurodegenerative disorders of mammals that share a central role for prion protein (PrP, gene PRNP) in their pathogenesis. Prions are infectious agents that account for the observed transmission of prion diseases between humans and animals in certain circumstances. The prion mechanism invokes a misfolded and multimeric assembly of PrP (a prion) that grows by templating of the normal protein and propagates by fission. Aside from the medical and public health notoriety of acquired prion diseases, the conditions have attracted interest as it has been realized that common neurodegenerative disorders share so-called prion-like mechanisms. In this article we will expand on recent evidence for new genetic loci that alter the risk of human prion disease. The most common human prion disease, sporadic Creutzfeldt-Jakob disease (sCJD), is characterized by the seemingly spontaneous appearance of prions in the brain. Genetic variation within PRNP is associated with all types of prion diseases, in particular, heterozygous genotypes at codons 129 and 219 have long been known to be strong protective factors against sCJD. A large number of rare mutations have been described in PRNP that cause autosomal dominant inherited prion diseases. Two loci recently identified by genome-wide association study increase sCJD risk, including variants in or near to STX6 and GAL3ST1. STX6 encodes syntaxin-6, a component of SNARE complexes with cellular roles that include the fusion of intracellular vesicles with target membranes. GAL3ST1 encodes cerebroside sulfotransferase, the only enzyme that sulfates sphingolipids to make sulfatides, a major lipid component of myelin. We discuss how these roles may modify the pathogenesis of prion diseases and their relevance for other neurodegenerative disorders.
Collapse
Affiliation(s)
- Emma Jones
- MRC Prion Unit at University College London (UCL), UCL Institute of Prion Diseases, 33 Cleveland Street, W1W 7FF, United Kingdom
| | - Simon Mead
- MRC Prion Unit at University College London (UCL), UCL Institute of Prion Diseases, 33 Cleveland Street, W1W 7FF, United Kingdom.
| |
Collapse
|
18
|
Minami S, Yokota N, Kawahara H. BAG6 contributes to glucose uptake by supporting the cell surface translocation of the glucose transporter GLUT4. Biol Open 2020; 9:bio.047324. [PMID: 31911483 PMCID: PMC6994957 DOI: 10.1242/bio.047324] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Defective translocation of glucose transporter 4 (GLUT4) to the cell surface is a key feature of insulin resistance in type 2 diabetes. Therefore, elucidating the mechanism of GLUT4 translocation is of primary importance. The mammalian Bag6/Bat3 gene has been suggested to be linked with potential obesity- and diabetes-associated loci, while its function in the control of glucose incorporation into the cytoplasm has not been investigated. In this study, we established a series of cell lines that stably expressed GLUT4 with three tandem repeats of the antigenic peptide inserted into its 1st extracellular loop. With these cell lines, we found that the depletion of endogenous BAG6 downregulated the cell surface expression of GLUT4, concomitant with the reduced incorporation of a glucose analog into the cells. Defective intracellular translocation of GLUT4 in BAG6-depleted cells is similar to the case observed for the depletion of Rab8a, an essential regulator of insulin-stimulated GLUT4 translocation. In addition, we observed that the assembly of syntaxin 6 into the endoplasmic reticulum membrane was slightly disturbed under BAG6 depletion. Given that Rab8a and syntaxin 6 are critical for GLUT4 translocation, we suggest that BAG6 may play multiple roles in the trafficking of glucose transporters to the cell surface. This article has an associated First Person interview with the first author of the paper. Summary: BAG6 is critical for the insulin-stimulated translocation of GLUT4 from its peri-nuclear storage compartments to the cell surface.
Collapse
Affiliation(s)
- Setsuya Minami
- Laboratory of Cell Biology and Biochemistry, Department of Biological Sciences, Tokyo Metropolitan University, Tokyo 192-0397, Japan
| | - Naoto Yokota
- Laboratory of Cell Biology and Biochemistry, Department of Biological Sciences, Tokyo Metropolitan University, Tokyo 192-0397, Japan
| | - Hiroyuki Kawahara
- Laboratory of Cell Biology and Biochemistry, Department of Biological Sciences, Tokyo Metropolitan University, Tokyo 192-0397, Japan
| |
Collapse
|
19
|
Li DT, Habtemichael EN, Julca O, Sales CI, Westergaard XO, DeVries SG, Ruiz D, Sayal B, Bogan JS. GLUT4 Storage Vesicles: Specialized Organelles for Regulated Trafficking. THE YALE JOURNAL OF BIOLOGY AND MEDICINE 2019; 92:453-470. [PMID: 31543708 PMCID: PMC6747935] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
Fat and muscle cells contain a specialized, intracellular organelle known as the GLUT4 storage vesicle (GSV). Insulin stimulation mobilizes GSVs, so that these vesicles fuse at the cell surface and insert GLUT4 glucose transporters into the plasma membrane. This example is likely one instance of a broader paradigm for regulated, non-secretory exocytosis, in which intracellular vesicles are translocated in response to diverse extracellular stimuli. GSVs have been studied extensively, yet these vesicles remain enigmatic. Data support the view that in unstimulated cells, GSVs are present as a pool of preformed small vesicles, which are distinct from endosomes and other membrane-bound organelles. In adipocytes, GSVs contain specific cargoes including GLUT4, IRAP, LRP1, and sortilin. They are formed by membrane budding, involving sortilin and probably CHC22 clathrin in humans, but the donor compartment from which these vesicles form remains uncertain. In unstimulated cells, GSVs are trapped by TUG proteins near the endoplasmic reticulum - Golgi intermediate compartment (ERGIC). Insulin signals through two main pathways to mobilize these vesicles. Signaling by the Akt kinase modulates Rab GTPases to target the GSVs to the cell surface. Signaling by the Rho-family GTPase TC10α stimulates Usp25m-mediated TUG cleavage to liberate the vesicles from the Golgi. Cleavage produces a ubiquitin-like protein modifier, TUGUL, that links the GSVs to KIF5B kinesin motors to promote their movement to the cell surface. In obesity, attenuation of these processes results in insulin resistance and contributes to type 2 diabetes and may simultaneously contribute to hypertension and dyslipidemia in the metabolic syndrome.
Collapse
Affiliation(s)
- Don T. Li
- Section of Endocrinology and Metabolism, Department of Internal Medicine, Yale University School of Medicine, Yale University, New Haven, CT,Department of Cell Biology, Yale University School of Medicine, Yale University, New Haven, CT
| | - Estifanos N. Habtemichael
- Section of Endocrinology and Metabolism, Department of Internal Medicine, Yale University School of Medicine, Yale University, New Haven, CT
| | - Omar Julca
- Section of Endocrinology and Metabolism, Department of Internal Medicine, Yale University School of Medicine, Yale University, New Haven, CT
| | - Chloe I. Sales
- Section of Endocrinology and Metabolism, Department of Internal Medicine, Yale University School of Medicine, Yale University, New Haven, CT
| | - Xavier O. Westergaard
- Section of Endocrinology and Metabolism, Department of Internal Medicine, Yale University School of Medicine, Yale University, New Haven, CT
| | - Stephen G. DeVries
- Section of Endocrinology and Metabolism, Department of Internal Medicine, Yale University School of Medicine, Yale University, New Haven, CT
| | - Diana Ruiz
- Section of Endocrinology and Metabolism, Department of Internal Medicine, Yale University School of Medicine, Yale University, New Haven, CT
| | - Bhavesh Sayal
- Section of Endocrinology and Metabolism, Department of Internal Medicine, Yale University School of Medicine, Yale University, New Haven, CT
| | - Jonathan S. Bogan
- Section of Endocrinology and Metabolism, Department of Internal Medicine, Yale University School of Medicine, Yale University, New Haven, CT,Department of Cell Biology, Yale University School of Medicine, Yale University, New Haven, CT,To whom all correspondence should be addressed: Jonathan S. Bogan, Section of Endocrinology and Metabolism, Department of Internal Medicine, Yale University School of Medicine, P.O. Box 208020, New Haven, CT 06520-8020; Tel: 203-785-6319; Fax: 203-785-6462;
| |
Collapse
|
20
|
Fischer AW, Albers K, Schlein C, Sass F, Krott LM, Schmale H, Gordts PLSM, Scheja L, Heeren J. PID1 regulates insulin-dependent glucose uptake by controlling intracellular sorting of GLUT4-storage vesicles. Biochim Biophys Acta Mol Basis Dis 2019; 1865:1592-1603. [PMID: 30904610 PMCID: PMC6624118 DOI: 10.1016/j.bbadis.2019.03.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Revised: 02/28/2019] [Accepted: 03/19/2019] [Indexed: 12/26/2022]
Abstract
The phosphotyrosine interacting domain-containing protein 1 (PID1) serves as a cytosolic adaptor protein of the LDL receptor-related protein 1 (LRP1). By regulating its intracellular trafficking, PID1 controls the hepatic, LRP1-dependent clearance of pro-atherogenic lipoproteins. In adipose and muscle tissues, LRP1 is present in endosomal storage vesicles containing the insulin-responsive glucose transporter 4 (GLUT4). This prompted us to investigate whether PID1 modulates GLUT4 translocation and function via its interaction with the LRP1 cytosolic domain. We initially evaluated this in primary brown adipocytes as we observed an inverse correlation between brown adipose tissue glucose uptake and expression of LRP1 and PID1. Insulin stimulation in wild type brown adipocytes induced LRP1 and GLUT4 translocation from endosomal storage vesicles to the cell surface. Loss of PID1 expression in brown adipocytes prompted LRP1 and GLUT4 sorting to the plasma membrane independent of insulin signaling. When placed on a diabetogenic high fat diet, systemic and adipocyte-specific PID1-deficient mice presented with improved hyperglycemia and glucose tolerance as well as reduced basal plasma insulin levels compared to wild type control mice. Moreover, the improvements in glucose parameters associated with increased glucose uptake in adipose and muscle tissues from PID1-deficient mice. The data provide evidence that PID1 serves as an insulin-regulated retention adaptor protein controlling translocation of LRP1 in conjunction with GLUT4 to the plasma membrane of adipocytes. Notably, loss of PID1 corrects for insulin resistance-associated hyperglycemia emphasizing its pivotal role and therapeutic potential in the regulation of glucose homeostasis.
Collapse
Affiliation(s)
- Alexander W Fischer
- Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg Eppendorf, 20246 Hamburg, Germany
| | - Kirstin Albers
- Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg Eppendorf, 20246 Hamburg, Germany
| | - Christian Schlein
- Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg Eppendorf, 20246 Hamburg, Germany
| | - Frederike Sass
- Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg Eppendorf, 20246 Hamburg, Germany
| | - Lucia M Krott
- Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg Eppendorf, 20246 Hamburg, Germany
| | - Hartwig Schmale
- Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg Eppendorf, 20246 Hamburg, Germany
| | - Philip L S M Gordts
- Department of Medicine, University of California, San Diego, La Jolla, CA 92093, USA; Glycobiology Research and Training Center, University of California, San Diego, La Jolla, CA 92093, USA
| | - Ludger Scheja
- Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg Eppendorf, 20246 Hamburg, Germany
| | - Joerg Heeren
- Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg Eppendorf, 20246 Hamburg, Germany.
| |
Collapse
|
21
|
Bowman PRT, Smith GL, Gould GW. Cardiac SNARE Expression in Health and Disease. Front Endocrinol (Lausanne) 2019; 10:881. [PMID: 31920989 PMCID: PMC6930865 DOI: 10.3389/fendo.2019.00881] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Accepted: 12/03/2019] [Indexed: 12/16/2022] Open
Abstract
SNARE proteins are integral to intracellular vesicular trafficking, which in turn is the process underlying the regulated expression of substrate transporters such as the glucose transporter GLUT4 at the cell surface of insulin target tissues. Impaired insulin stimulated GLUT4 trafficking is associated with reduced cardiac function in many disease states, most notably diabetes. Despite this, our understanding of the expression and regulation of SNARE proteins in cardiac tissue and how these may change in diabetes is limited. Here we characterize the array of SNARE proteins expressed in cardiac tissue, and quantify the levels of expression of VAMP2, SNAP23, and Syntaxin4-key proteins involved in insulin-stimulated GLUT4 translocation. We examined SNARE protein levels in cardiac tissue from two rodent models of insulin resistance, db/db mice and high-fat fed mice, and show alterations in patterns of expression are evident. Such changes may have implications for cardiac function.
Collapse
Affiliation(s)
- Peter R. T. Bowman
- Henry Wellcome Laboratory of Cell Biology, College of Medical, Veterinary and Life Sciences, Institute of Molecular Cell and Systems Biology, University of Glasgow, Glasgow, United Kingdom
| | - Godfrey L. Smith
- College of Medical, Veterinary and Life Sciences, Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Gwyn W. Gould
- Henry Wellcome Laboratory of Cell Biology, College of Medical, Veterinary and Life Sciences, Institute of Molecular Cell and Systems Biology, University of Glasgow, Glasgow, United Kingdom
- *Correspondence: Gwyn W. Gould
| |
Collapse
|
22
|
Nozawa T, Minowa-Nozawa A, Aikawa C, Nakagawa I. The STX6-VTI1B-VAMP3 complex facilitates xenophagy by regulating the fusion between recycling endosomes and autophagosomes. Autophagy 2016; 13:57-69. [PMID: 27791468 DOI: 10.1080/15548627.2016.1241924] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Macroautophagy/autophagy plays a critical role in immunity by directly degrading invading pathogens such as Group A Streptococcus (GAS), through a process that has been named xenophagy. We previously demonstrated that autophagic vacuoles directed against GAS, termed GAS-containing autophagosome-like vacuoles (GcAVs), use recycling endosomes (REs) as a membrane source. However, the precise molecular mechanism that facilitates the fusion between GcAVs and REs remains unclear. Here, we demonstrate that STX6 (syntaxin 6) is recruited to GcAVs and forms a complex with VTI1B and VAMP3 to regulate the GcAV-RE fusion that is required for xenophagy. STX6 targets the GcAV membrane through its tyrosine-based sorting motif and transmembrane domain, and localizes to TFRC (transferrin receptor)-positive punctate structures on GcAVs through its H2 SNARE domain. Knockdown and knockout experiments revealed that STX6 is required for the fusion between GcAVs and REs to promote clearance of intracellular GAS by autophagy. Moreover, VAMP3 and VTI1B interact with STX6 and localize on the TFRC-positive puncta on GcAVs, and are also involved in the RE-GcAV fusion. Furthermore, knockout of RABGEF1 impairs the RE-GcAV fusion and STX6-VAMP3 interaction. These findings demonstrate that RABGEF1 mediates RE fusion with GcAVs through the STX6-VAMP3-VTI1B complex, and reveal the SNARE dynamics involved in autophagosome formation in response to bacterial infection.
Collapse
Affiliation(s)
- Takashi Nozawa
- a Department of Microbiology , Graduate School of Medicine, Kyoto University , Kyoto , Japan
| | - Atsuko Minowa-Nozawa
- a Department of Microbiology , Graduate School of Medicine, Kyoto University , Kyoto , Japan
| | - Chihiro Aikawa
- a Department of Microbiology , Graduate School of Medicine, Kyoto University , Kyoto , Japan
| | - Ichiro Nakagawa
- a Department of Microbiology , Graduate School of Medicine, Kyoto University , Kyoto , Japan
| |
Collapse
|
23
|
Bruno J, Brumfield A, Chaudhary N, Iaea D, McGraw TE. SEC16A is a RAB10 effector required for insulin-stimulated GLUT4 trafficking in adipocytes. J Cell Biol 2016; 214:61-76. [PMID: 27354378 PMCID: PMC4932369 DOI: 10.1083/jcb.201509052] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Accepted: 06/08/2016] [Indexed: 12/19/2022] Open
Abstract
Sec16A is known to be required for COPII vesicle formation from the ER. Here, Bruno et al. show that, independent of its role at the ER, Sec16A is a RAB10 effector involved in the insulin-stimulated formation of specialized transport vesicles that ferry the GLUT4 glucose transporter to the plasma membrane of adipocytes. RAB10 is a regulator of insulin-stimulated translocation of the GLUT4 glucose transporter to the plasma membrane (PM) of adipocytes, which is essential for whole-body glucose homeostasis. We establish SEC16A as a novel RAB10 effector in this process. Colocalization of SEC16A with RAB10 is augmented by insulin stimulation, and SEC16A knockdown attenuates insulin-induced GLUT4 translocation, phenocopying RAB10 knockdown. We show that SEC16A and RAB10 promote insulin-stimulated mobilization of GLUT4 from a perinuclear recycling endosome/TGN compartment. We propose RAB10–SEC16A functions to accelerate formation of the vesicles that ferry GLUT4 to the PM during insulin stimulation. Because GLUT4 continually cycles between the PM and intracellular compartments, the maintenance of elevated cell-surface GLUT4 in the presence of insulin requires accelerated biogenesis of the specialized GLUT4 transport vesicles. The function of SEC16A in GLUT4 trafficking is independent of its previously characterized activity in ER exit site formation and therefore independent of canonical COPII-coated vesicle function. However, our data support a role for SEC23A, but not the other COPII components SEC13, SEC23B, and SEC31, in the insulin stimulation of GLUT4 trafficking, suggesting that vesicles derived from subcomplexes of COPII coat proteins have a role in the specialized trafficking of GLUT4.
Collapse
Affiliation(s)
- Joanne Bruno
- Department of Biochemistry, Weill Cornell Medical College, New York, NY 10065 Weill Cornell/Rockefeller/Sloan Kettering Tri-Institutional MD-PhD Program, New York, NY 10065
| | | | - Natasha Chaudhary
- Department of Biochemistry, Weill Cornell Medical College, New York, NY 10065
| | - David Iaea
- Department of Biochemistry, Weill Cornell Medical College, New York, NY 10065
| | - Timothy E McGraw
- Department of Biochemistry, Weill Cornell Medical College, New York, NY 10065 Department of Cardiothoracic Surgery, Weill Cornell Medical College, New York, NY 10065
| |
Collapse
|
24
|
TUSC5 regulates insulin-mediated adipose tissue glucose uptake by modulation of GLUT4 recycling. Mol Metab 2015; 4:795-810. [PMID: 26629404 PMCID: PMC4632119 DOI: 10.1016/j.molmet.2015.08.003] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2015] [Revised: 08/11/2015] [Accepted: 08/18/2015] [Indexed: 12/26/2022] Open
Abstract
Objective Failure to properly dispose of glucose in response to insulin is a serious health problem, occurring during obesity and is associated with type 2 diabetes development. Insulin-stimulated glucose uptake is facilitated by the translocation and plasma membrane fusion of vesicles containing glucose transporter 4 (GLUT4), the rate-limiting step of post-prandial glucose disposal. Methods We analyzed the role of Tusc5 in the regulation of insulin-stimulated Glut4-mediated glucose uptake in vitro and in vivo. Furthermore, we measured Tusc5 expression in two patient cohorts. Results Herein, we report that TUSC5 controls insulin-stimulated glucose uptake in adipocytes, in vitro and in vivo. TUSC5 facilitates the proper recycling of GLUT4 and other key trafficking proteins during prolonged insulin stimulation, thereby enabling proper protein localization and complete vesicle formation, processes that ultimately enable insulin-stimulated glucose uptake. Tusc5 knockout mice exhibit impaired glucose disposal and TUSC5 expression is predictive of glucose tolerance in obese individuals, independent of body weight. Furthermore, we show that TUSC5 is a PPARγ target and in its absence the anti-diabetic effects of TZDs are significantly blunted. Conclusions Collectively, these findings establish TUSC5 as an adipose tissue-specific protein that enables proper protein recycling, linking the ubiquitous vesicle traffic machinery with tissue-specific insulin-mediated glucose uptake into adipose tissue and the maintenance of a healthy metabolic phenotype in mice and humans. Tusc5 regulates glucose uptake in adipose tissue by modulating the GSV recycling machinery. Tusc5 knockout mice develop insulin resistance due to impaired adipose tissue glucose uptake. Rosiglitazone improves glucose homeostasis in part through the induction of Tusc5. Tusc5 is a novel adipose specific adaptor protein linking Glut4 trafficking to the ubiquitous machinery.
Collapse
|
25
|
Expression of syntaxin 8 in visceral adipose tissue is increased in obese patients with type 2 diabetes and related to markers of insulin resistance and inflammation. Arch Med Res 2014; 46:47-53. [PMID: 25523146 DOI: 10.1016/j.arcmed.2014.12.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2014] [Accepted: 12/09/2014] [Indexed: 11/22/2022]
Abstract
BACKGROUND AND AIMS Obesity is associated with increased adipose tissue inflammation as well as with the development of type 2 diabetes (T2D). Syntaxin 8 (STX8) is a protein required for the transport of endosomes. In this study we analyzed the relationship of STX8 with the presence of T2D in the context of obesity. METHODS With this purpose, 21 subjects (seven lean [LN], eight obese normoglycemic [OB-NG] and six obese with type 2 diabetes [OB-T2D]) were included in the study. Gene and protein expression levels of STX8 and GLUT4 were analyzed in visceral adipose tissue (VAT). RESULTS mRNA (p = 0.008) and protein (p <0.001) expression levels of STX8 were significantly increased in VAT of OB-T2D patients. Moreover, gene expression levels of SLC2A4 (GLUT4) were downregulated (p = 0.002) in VAT of obese patients. We found that STX8 was positively correlated (p <0.05) with fasting glucose concentrations, plasma glucose 2 h after an OGTT and C-reactive protein. Interestingly, the expression of STX8 was negatively correlated (p <0.05) with the expression of SLC2A4 in VAT. CONCLUSIONS Increased STX8 expression in VAT appears to be associated with the presence of T2D in obese patients through a mechanism that may involve GLUT4.
Collapse
|
26
|
Sadler JBA, Bryant NJ, Gould GW. Characterization of VAMP isoforms in 3T3-L1 adipocytes: implications for GLUT4 trafficking. Mol Biol Cell 2014; 26:530-6. [PMID: 25501368 PMCID: PMC4310743 DOI: 10.1091/mbc.e14-09-1368] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
The levels of expression, distribution, and association of all of the VAMPs expressed in 3T3-L1 adipocytes are characterized. This is the first systematic analysis of all members of this protein family for any cell type. The fusion of GLUT4-containing vesicles with the plasma membrane of adipocytes is a key facet of insulin action. This process is mediated by the formation of functional soluble N-ethylmaleimide–sensitive factor attachment protein receptor (SNARE) complexes between the plasma membrane t-SNARE complex and the vesicle v-SNARE or VAMP. The t-SNARE complex consists of Syntaxin4 and SNAP23, and whereas many studies identify VAMP2 as the v-SNARE, others suggest that either VAMP3 or VAMP8 may also fulfil this role. Here we characterized the levels of expression, distribution, and association of all the VAMPs expressed in 3T3-L1 adipocytes to provide the first systematic analysis of all members of this protein family for any cell type. Despite our finding that all VAMP isoforms form SDS-resistant SNARE complexes with Syntaxin4/SNAP23 in vitro, a combination of levels of expression (which vary by >30-fold), subcellular distribution, and coimmunoprecipitation analyses lead us to propose that VAMP2 is the major v-SNARE involved in GLUT4 trafficking to the surface of 3T3-L1 adipocytes.
Collapse
Affiliation(s)
- Jessica B A Sadler
- Henry Wellcome Laboratory of Cell Biology, Institute for Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - Nia J Bryant
- Department of Biology, University of York, Heslington YO10 5DD, United Kingdom
| | - Gwyn W Gould
- Henry Wellcome Laboratory of Cell Biology, Institute for Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| |
Collapse
|
27
|
Govers R. Molecular mechanisms of GLUT4 regulation in adipocytes. DIABETES & METABOLISM 2014; 40:400-10. [DOI: 10.1016/j.diabet.2014.01.005] [Citation(s) in RCA: 82] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2013] [Revised: 01/24/2014] [Accepted: 01/26/2014] [Indexed: 01/28/2023]
|
28
|
Klip A, Sun Y, Chiu TT, Foley KP. Signal transduction meets vesicle traffic: the software and hardware of GLUT4 translocation. Am J Physiol Cell Physiol 2014; 306:C879-86. [DOI: 10.1152/ajpcell.00069.2014] [Citation(s) in RCA: 124] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Skeletal muscle is the major tissue disposing of dietary glucose, a function regulated by insulin-elicited signals that impart mobilization of GLUT4 glucose transporters to the plasma membrane. This phenomenon, also central to adipocyte biology, has been the subject of intense and productive research for decades. We focus on muscle cell studies scrutinizing insulin signals and vesicle traffic in a spatiotemporal manner. Using the analogy of an integrated circuit to approach the intersection between signal transduction and vesicle mobilization, we identify signaling relays (“software”) that engage structural/mechanical elements (“hardware”) to enact the rapid mobilization and incorporation of GLUT4 into the cell surface. We emphasize how insulin signal transduction switches from tyrosine through lipid and serine phosphorylation down to activation of small G proteins of the Rab and Rho families, describe key negative regulation step of Rab GTPases through the GTPase-activating protein activity of the Akt substrate of 160 kDa (AS160), and focus on the mechanical effectors engaged by Rabs 8A and 10 (the molecular motor myosin Va), and the Rho GTPase Rac1 (actin filament branching and severing through Arp2/3 and cofilin). Finally, we illustrate how actin filaments interact with myosin 1c and α-Actinin4 to promote vesicle tethering as preamble to fusion with the membrane.
Collapse
Affiliation(s)
- Amira Klip
- Cell Biology Program, The Hospital for Sick Children, Toronto, Ontario, Canada; and
- Department of Biochemistry, The University of Toronto, Ontario, Canada
| | - Yi Sun
- Cell Biology Program, The Hospital for Sick Children, Toronto, Ontario, Canada; and
| | - Tim Ting Chiu
- Cell Biology Program, The Hospital for Sick Children, Toronto, Ontario, Canada; and
- Department of Biochemistry, The University of Toronto, Ontario, Canada
| | - Kevin P. Foley
- Cell Biology Program, The Hospital for Sick Children, Toronto, Ontario, Canada; and
- Department of Biochemistry, The University of Toronto, Ontario, Canada
| |
Collapse
|
29
|
Foley KP, Klip A. Dynamic GLUT4 sorting through a syntaxin-6 compartment in muscle cells is derailed by insulin resistance-causing ceramide. Biol Open 2014; 3:314-25. [PMID: 24705014 PMCID: PMC4021353 DOI: 10.1242/bio.20147898] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
GLUT4 constitutively recycles between the plasma membrane and intracellular depots. Insulin shifts this dynamic equilibrium towards the plasma membrane by recruiting GLUT4 to the plasma membrane from insulin-responsive vesicles. Muscle is the primary site for dietary glucose deposition; however, how GLUT4 sorts into insulin-responsive vesicles, and if and how insulin resistance affects this process, is unknown. In L6 myoblasts stably expressing myc-tagged GLUT4, we analyzed the intracellular itinerary of GLUT4 as it internalizes from the cell surface and examined if such sorting is perturbed by C2-ceramide, a lipid metabolite causing insulin resistance. Surface-labeled GLUT4myc that internalized for 30 min accumulated in a Syntaxin-6 (Stx6)- and Stx16-positive perinuclear sub-compartment devoid of furin or internalized transferrin, and displayed insulin-responsive re-exocytosis. C2-ceramide dispersed the Stx6-positive sub-compartment and prevented insulin-responsive re-exocytosis of internalized GLUT4myc, even under conditions not affecting insulin-stimulated signaling towards Akt. Microtubule disruption with nocodazole prevented pre-internalized GLUT4myc from reaching the Stx6-positive perinuclear sub-compartment and from undergoing insulin-responsive exocytosis. Removing nocodazole allowed both parameters to recover, suggesting that the Stx6-positive perinuclear sub-compartment was required for GLUT4 insulin-responsiveness. Accordingly, Stx6 knockdown inhibited by ∼50% the ability of internalized GLUT4myc to undergo insulin-responsive re-exocytosis without altering its overall perinuclear accumulation. We propose that Stx6 defines the insulin-responsive compartment in muscle cells. Our data are consistent with a model where ceramide could cause insulin resistance by altering intracellular GLUT4 sorting.
Collapse
Affiliation(s)
- Kevin P Foley
- Program in Cell Biology, The Hospital for Sick Children, Toronto, ON M5G 1X8, Canada Department of Biochemistry, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Amira Klip
- Program in Cell Biology, The Hospital for Sick Children, Toronto, ON M5G 1X8, Canada Department of Biochemistry, University of Toronto, Toronto, ON M5S 1A8, Canada
| |
Collapse
|
30
|
Abstract
GLUT4 is regulated by its intracellular localization. In the absence of insulin, GLUT4 is efficiently retained intracellularly within storage compartments in muscle and fat cells. Upon insulin stimulation (and contraction in muscle), GLUT4 translocates from these compartments to the cell surface where it transports glucose from the extracellular milieu into the cell. Its implication in insulin-regulated glucose uptake makes GLUT4 not only a key player in normal glucose homeostasis but also an important element in insulin resistance and type 2 diabetes. Nevertheless, how GLUT4 is retained intracellularly and how insulin acts on this retention mechanism is largely unclear. In this review, the current knowledge regarding the various molecular processes that govern GLUT4 physiology is discussed as well as the questions that remain.
Collapse
|
31
|
Yang P, Patrick E, Tan SX, Fazakerley DJ, Burchfield J, Gribben C, Prior MJ, James DE, Hwa Yang Y. Direction pathway analysis of large-scale proteomics data reveals novel features of the insulin action pathway. ACTA ACUST UNITED AC 2013; 30:808-14. [PMID: 24167158 DOI: 10.1093/bioinformatics/btt616] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
MOTIVATION With the advancement of high-throughput techniques, large-scale profiling of biological systems with multiple experimental perturbations is becoming more prevalent. Pathway analysis incorporates prior biological knowledge to analyze genes/proteins in groups in a biological context. However, the hypotheses under investigation are often confined to a 1D space (i.e. up, down, either or mixed regulation). Here, we develop direction pathway analysis (DPA), which can be applied to test hypothesis in a high-dimensional space for identifying pathways that display distinct responses across multiple perturbations. RESULTS Our DPA approach allows for the identification of pathways that display distinct responses across multiple perturbations. To demonstrate the utility and effectiveness, we evaluated DPA under various simulated scenarios and applied it to study insulin action in adipocytes. A major action of insulin in adipocytes is to regulate the movement of proteins from the interior to the cell surface membrane. Quantitative mass spectrometry-based proteomics was used to study this process on a large-scale. The combined dataset comprises four separate treatments. By applying DPA, we identified that several insulin responsive pathways in the plasma membrane trafficking are only partially dependent on the insulin-regulated kinase Akt. We subsequently validated our findings through targeted analysis of key proteins from these pathways using immunoblotting and live cell microscopy. Our results demonstrate that DPA can be applied to dissect pathway networks testing diverse hypotheses and integrating multiple experimental perturbations. AVAILABILITY AND IMPLEMENTATION The R package 'directPA' is distributed from CRAN under GNU General Public License (GPL)-3 and can be downloaded from: http://cran.r-project.org/web/packages/directPA/index.html CONTACT jean.yang@sydney.edu.au SUPPLEMENTARY INFORMATION Supplementary data are available at Bioinformatics online.
Collapse
Affiliation(s)
- Pengyi Yang
- Systems Biology Group, Biostatistics Branch, National Institute of Environmental Health Sciences, National Institute of Health, Research Triangle Park, NC 27709, USA, School of Mathematics and Statistics, University of Sydney, Diabetes and Obesity Program, Garvan Institute of Medical Research, NSW 2006, Australia and Metabolism in Human Disease Unit, Institute of Molecular and Cellular Biology, A*Star, 61 Biopolis Drive, Proteos 138673, Singapore
| | | | | | | | | | | | | | | | | |
Collapse
|
32
|
Neto H, Kaupisch A, Collins LL, Gould GW. Syntaxin 16 is a master recruitment factor for cytokinesis. Mol Biol Cell 2013; 24:3663-74. [PMID: 24109596 PMCID: PMC3842993 DOI: 10.1091/mbc.e13-06-0302] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Syntaxin 16 is a key regulator of cytokinesis, as it is required for the recruitment of both recycling endosome–associated Exocyst and ESCRT machinery during late telophase. Therefore these two distinct facets of cytokinesis are inextricably linked. Recently it was shown that both recycling endosome and endosomal sorting complex required for transport (ESCRT) components are required for cytokinesis, in which they are believed to act in a sequential manner to bring about secondary ingression and abscission, respectively. However, it is not clear how either of these complexes is targeted to the midbody and whether their delivery is coordinated. The trafficking of membrane vesicles between different intracellular organelles involves the formation of soluble N-ethylmaleimide–sensitive factor attachment protein receptor (SNARE) complexes. Although membrane traffic is known to play an important role in cytokinesis, the contribution and identity of intracellular SNAREs to cytokinesis remain unclear. Here we demonstrate that syntaxin 16 is a key regulator of cytokinesis, as it is required for recruitment of both recycling endosome–associated Exocyst and ESCRT machinery during late telophase, and therefore that these two distinct facets of cytokinesis are inextricably linked.
Collapse
Affiliation(s)
- Hélia Neto
- Henry Wellcome Laboratory of Cell Biology, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | | | | | | |
Collapse
|
33
|
Roccisana J, Sadler JBA, Bryant NJ, Gould GW. Sorting of GLUT4 into its insulin-sensitive store requires the Sec1/Munc18 protein mVps45. Mol Biol Cell 2013; 24:2389-97. [PMID: 23741049 PMCID: PMC3727931 DOI: 10.1091/mbc.e13-01-0011] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2013] [Revised: 05/24/2013] [Accepted: 05/29/2013] [Indexed: 01/15/2023] Open
Abstract
Insulin stimulates glucose transport in fat and muscle cells by regulating delivery of the facilitative glucose transporter, glucose transporter isoform 4 (GLUT4), to the plasma membrane. In the absence of insulin, GLUT4 is sequestered away from the general recycling endosomal pathway into specialized vesicles, referred to as GLUT4-storage vesicles. Understanding the sorting of GLUT4 into this store is a major challenge. Here we examine the role of the Sec1/Munc18 protein mVps45 in GLUT4 trafficking. We show that mVps45 is up-regulated upon differentiation of 3T3-L1 fibroblasts into adipocytes and is expressed at stoichiometric levels with its cognate target-soluble N-ethylmaleimide-sensitive factor attachment protein receptor, syntaxin 16. Depletion of mVps45 in 3T3-L1 adipocytes results in decreased GLUT4 levels and impaired insulin-stimulated glucose transport. Using sub-cellular fractionation and an in vitro assay for GLUT4-storage vesicle formation, we show that mVps45 is required to correctly traffic GLUT4 into this compartment. Collectively our data reveal a crucial role for mVps45 in the delivery of GLUT4 into its specialized, insulin-regulated compartment.
Collapse
Affiliation(s)
- Jennifer Roccisana
- Henry Wellcome Laboratory of Cell Biology, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - Jessica B. A. Sadler
- Henry Wellcome Laboratory of Cell Biology, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - Nia J. Bryant
- Henry Wellcome Laboratory of Cell Biology, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - Gwyn W. Gould
- Henry Wellcome Laboratory of Cell Biology, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| |
Collapse
|
34
|
Sadler JBA, Bryant NJ, Gould GW, Welburn CR. Posttranslational modifications of GLUT4 affect its subcellular localization and translocation. Int J Mol Sci 2013; 14:9963-78. [PMID: 23665900 PMCID: PMC3676823 DOI: 10.3390/ijms14059963] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2013] [Revised: 05/02/2013] [Accepted: 05/02/2013] [Indexed: 01/05/2023] Open
Abstract
The facilitative glucose transporter type 4 (GLUT4) is expressed in adipose and muscle and plays a vital role in whole body glucose homeostasis. In the absence of insulin, only ~1% of cellular GLUT4 is present at the plasma membrane, with the vast majority localizing to intracellular organelles. GLUT4 is retained intracellularly by continuous trafficking through two inter-related cycles. GLUT4 passes through recycling endosomes, the trans Golgi network and an insulin-sensitive intracellular compartment, termed GLUT4-storage vesicles or GSVs. It is from GSVs that GLUT4 is mobilized to the cell surface in response to insulin, where it increases the rate of glucose uptake into the cell. As with many physiological responses to external stimuli, this regulated trafficking event involves multiple posttranslational modifications. This review outlines the roles of posttranslational modifications of GLUT4 on its function and insulin-regulated trafficking.
Collapse
Affiliation(s)
| | - Nia J. Bryant
- Institute of Molecular, Cell and Systems Biology, Davidson Building, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK; E-Mails: (J.B.A.S.); (N.J.B.); (G.W.G.)
| | - Gwyn W. Gould
- Institute of Molecular, Cell and Systems Biology, Davidson Building, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK; E-Mails: (J.B.A.S.); (N.J.B.); (G.W.G.)
| | - Cassie R. Welburn
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +44-141-330-6454; Fax: +44-141-330-5481
| |
Collapse
|
35
|
Jung JJ, Inamdar SM, Tiwari A, Ye D, Lin F, Choudhury A. Syntaxin 16 regulates lumen formation during epithelial morphogenesis. PLoS One 2013; 8:e61857. [PMID: 23626741 PMCID: PMC3633931 DOI: 10.1371/journal.pone.0061857] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2012] [Accepted: 03/15/2013] [Indexed: 11/19/2022] Open
Abstract
The formation and maintenance of cell-cell junctions, both under physiological and pathological conditions, requires the targeting and trafficking of junctional proteins. Proteins of the syntaxin (Stx)-family localize to a variety of subcellular membranes and contribute to intracellular transport of cargo by regulating vesicle fusion events at these sites. Unlike plasma membrane localized Stxs, the roles of endosome- and Golgi-localized stx proteins in epithelial morphogenesis are less understood. Here we show that Stx16- an endosome- and Golgi-localized target-membrane soluble N-ethylmaleimide attachment protein receptor (t-SNARE) that plays a role in membrane trafficking between these compartments - is essential for lumen development. In cultured Madin Darby Canine Kidney (MDCK) cells, Stx16 was selectively upregulated as sparsely plated cells attained confluency. Stx16-depleted confluent monolayers consistently showed lower transepithelial resistance than control monolayers, and failed to maintain endogenous and ectopically expressed E-cadherin at the adherens junctions due to decreased recycling. We further found that whereas cysts formed by MDCK cells cultured in Matrigel have a single hollow lumen, those formed by stx16-depleted counterparts had multiple lumens, due to abnormal orientiation of the mitotic spindle. Finally, a similar role for stx16 function in vivo is indicated by our analysis of pronephric-duct development in zebrafish expressing the claudinB:lynGFP transgene; lack of stx16 function in this structure (in stx16-morphant embryos) led to the development of enlarged, torturous pronephric ducts with more than one lumen. Taken together, our in vitro and in vivo studies establish a role for Stx16 in maintaining the integrity of cell-cell junctions, and thereby in morphogenesis of the kidney epithelial lumen.
Collapse
Affiliation(s)
- Jae-Joon Jung
- Department of Anatomy and Cell Biology, University of Iowa, Iowa City, Iowa, United States of America
| | | | | | | | | | | |
Collapse
|
36
|
Abstract
Intracellular membrane trafficking along endocytic and secretory transport pathways plays a critical role in diverse cellular functions including both developmental and pathological processes. Briefly, proteins and lipids destined for transport to distinct locations are collectively assembled into vesicles and delivered to their target site by vesicular fusion. SNARE (soluble N-ethylmaleimide-sensitive factor-attachment protein receptor) proteins are required for these events, during which v-SNAREs (vesicle SNAREs) interact with t-SNAREs (target SNAREs) to allow transfer of cargo from donor vesicle to target membrane. Recently, the t-SNARE family member, syntaxin-6, has been shown to play an important role in the transport of proteins that are key to diverse cellular dynamic processes. In this paper, we briefly discuss the specific role of SNAREs in various mammalian cell types and comprehensively review the various roles of the Golgi- and endosome-localized t-SNARE, syntaxin-6, in membrane trafficking during physiological as well as pathological conditions.
Collapse
|
37
|
Bogan JS, Rubin BR, Yu C, Löffler MG, Orme CM, Belman JP, McNally LJ, Hao M, Cresswell JA. Endoproteolytic cleavage of TUG protein regulates GLUT4 glucose transporter translocation. J Biol Chem 2012; 287:23932-47. [PMID: 22610098 DOI: 10.1074/jbc.m112.339457] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
To promote glucose uptake into fat and muscle cells, insulin causes the translocation of GLUT4 glucose transporters from intracellular vesicles to the cell surface. Previous data support a model in which TUG traps GLUT4-containing vesicles and tethers them intracellularly in unstimulated cells and in which insulin mobilizes this pool of vesicles by releasing this tether. Here we show that TUG undergoes site-specific endoproteolytic cleavage, which separates a GLUT4-binding, N-terminal region of TUG from a C-terminal region previously suggested to bind an intracellular anchor. Cleavage is accelerated by insulin stimulation in 3T3-L1 adipocytes and is highly dependent upon adipocyte differentiation. The N-terminal TUG cleavage product has properties of a novel 18-kDa ubiquitin-like modifier, which we call TUGUL. The C-terminal product is observed at the expected size of 42 kDa and also as a 54-kDa form that is released from membranes into the cytosol. In transfected cells, intact TUG links GLUT4 to PIST and also binds Golgin-160 through its C-terminal region. PIST is an effector of TC10α, a GTPase previously shown to transmit an insulin signal required for GLUT4 translocation, and we show using RNAi that TC10α is required for TUG proteolytic processing. Finally, we demonstrate that a cleavage-resistant form of TUG does not support highly insulin-responsive GLUT4 translocation or glucose uptake in 3T3-L1 adipocytes. Together with previous results, these data support a model whereby insulin stimulates TUG cleavage to liberate GLUT4 storage vesicles from the Golgi matrix, which promotes GLUT4 translocation to the cell surface and enhances glucose uptake.
Collapse
Affiliation(s)
- Jonathan S Bogan
- Section of Endocrinology and Metabolism, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut 06520-8020, USA.
| | | | | | | | | | | | | | | | | |
Collapse
|
38
|
Riggs KA, Hasan N, Humphrey D, Raleigh C, Nevitt C, Corbin D, Hu C. Regulation of integrin endocytic recycling and chemotactic cell migration by syntaxin 6 and VAMP3 interaction. J Cell Sci 2012; 125:3827-39. [PMID: 22573826 DOI: 10.1242/jcs.102566] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Integrins are the primary receptors of cells adhering to the extracellular matrix, and play key roles in various cellular processes including migration, proliferation and survival. The expression and distribution of integrins at the cell surface is controlled by endocytosis and recycling. The present study examines the function of syntaxin 6 (STX6), a t-SNARE located in the trans-Golgi network, in integrin trafficking. STX6 is overexpressed in many types of human cancer. We show that depletion of STX6 inhibits chemotactic cell migration and the delivery of the laminin receptor α3β1 integrin to the cell surface, whereas STX6 overexpression stimulates chemotactic cell migration, integrin delivery, and integrin-initiated activation of focal adhesion kinase. These data indicate that STX6 plays a rate-limiting role in cell migration and integrin trafficking. In STX6-depleted cells, α3β1 integrin is accumulated in recycling endosomes that contain the v-SNARE VAMP3. Importantly, we show that STX6 and VAMP3 form a v-/t-SNARE complex, VAMP3 is required in α3β1 integrin delivery to the cell surface, and endocytosed α3β1 integrin traffics to both VAMP3 and STX6 compartments. Collectively, our data suggest a new integrin trafficking pathway in which endocytosed integrins are transported from VAMP3-containing recycling endosomes to STX6-containing trans-Golgi network before being recycled to the plasma membrane.
Collapse
Affiliation(s)
- Krista A Riggs
- Department of Biochemistry and Molecular Biology, University of Louisville School of Medicine, Louisville, KY 40202, USA
| | | | | | | | | | | | | |
Collapse
|
39
|
Abstract
To enhance glucose uptake into muscle and fat cells, insulin stimulates the translocation of GLUT4 glucose transporters from intracellular membranes to the cell surface. This response requires the intersection of insulin signaling and vesicle trafficking pathways, and it is compromised in the setting of overnutrition to cause insulin resistance. Insulin signals through AS160/Tbc1D4 and Tbc1D1 to modulate Rab GTPases and through the Rho GTPase TC10α to act on other targets. In unstimulated cells, GLUT4 is incorporated into specialized storage vesicles containing IRAP, LRP1, sortilin, and VAMP2, which are sequestered by TUG, Ubc9, and other proteins. Insulin mobilizes these vesicles directly to the plasma membrane, and it modulates the trafficking itinerary so that cargo recycles from endosomes during ongoing insulin exposure. Knowledge of how signaling and trafficking pathways are coordinated will be essential to understanding the pathogenesis of diabetes and the metabolic syndrome and may also inform a wide range of other physiologies.
Collapse
Affiliation(s)
- Jonathan S Bogan
- Section of Endocrinology and Metabolism, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut 06520-8020, USA.
| |
Collapse
|
40
|
Nakayama T, Kamiguchi H, Akagawa K. Syntaxin 1C, a soluble form of syntaxin, attenuates membrane recycling by destabilizing microtubules. J Cell Sci 2012; 125:817-30. [PMID: 22421360 DOI: 10.1242/jcs.081943] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Syntaxin 1C (STX1C), produced by alternative splicing of the stx1A gene, is a soluble syntaxin lacking a SNARE domain and a transmembrane domain. It is unclear how soluble syntaxin can control intracellular membrane trafficking. We found that STX1C affected microtubule (MT) dynamics through its tubulin-binding domain (TBD) and regulated recycling of intracellular vesicles carrying glucose transporter-1 (GLUT1). We demonstrated that the amino acid sequence VRSK of the TBD was important for the interaction between STX1C and tubulin and that wild-type STX1C (STX1C-WT), but not the TBD mutant, reduced the V(max) of glucose transport and GLUT1 translocation to the plasma membrane in FRSK cells. Moreover, by time-lapse analysis, we revealed that STX1C-WT suppressed MT stability and vesicle-transport motility in cells expressing GFP-α-tubulin, whereas TBD mutants had no effect. We also identified that GLUT1 was recycled in the 45 minutes after endocytosis and that GLUT1 vesicles moved along with MTs. Finally, we showed, by a recycling assay and FCM analysis, that STX1C-WT delayed the recycling phase of GLUT1 to PM, without affecting the endocytotic process of GLUT1. These data indicate that STX1C delays the GLUT1 recycling phase by suppressing MT stability and vesicle-transport motility through its TBD, providing the first insight into how soluble syntaxin controls membrane trafficking.
Collapse
Affiliation(s)
- Takahiro Nakayama
- Department of Cell Physiology, Kyorin University School of Medicine, Tokyo, 181-8611, Japan.
| | | | | |
Collapse
|
41
|
Kim JY, Kandror KV. The first luminal loop confers insulin responsiveness to glucose transporter 4. Mol Biol Cell 2012; 23:910-7. [PMID: 22262463 PMCID: PMC3290648 DOI: 10.1091/mbc.e11-10-0839] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Glucose transporter isoform 4 (GLUT4) is the sole glucose transporter responsible for the effect of insulin on postprandial blood glucose clearance. It is translocated to the plasma membrane by specialized insulin-responsive vesicles. Targeting of GLUT4 to these vesicles is mediated by sortilin, which interacts with the first luminal loop of the transporter. Glucose transporter isoform 4 (GLUT4), is the sole glucose transporter responsible for the effect of insulin on postprandial blood glucose clearance. However, the nature of the insulin sensitivity of GLUT4 remains unknown. In this study, we replaced the first luminal loop of cellugyrin, a 4-transmembrane protein that does not respond to insulin, with that of GLUT4. The chimera protein is targeted to the intracellular insulin-responsive vesicles and is translocated to the plasma membrane upon insulin stimulation. The faithful targeting of the chimera depends on the expression of the sorting receptor sortilin, which interacts with the unique amino acid residues in the first luminal loop of GLUT4. Thus the first luminal loop may confer insulin responsiveness to the GLUT4 molecule.
Collapse
Affiliation(s)
- Ju Youn Kim
- Department of Biochemistry, Boston University School of Medicine, Boston, MA 02118, USA
| | | |
Collapse
|
42
|
Wang X, Liu X, Sim X, Xu H, Khor CC, Ong RTH, Tay WT, Suo C, Poh WT, Ng DPK, Liu J, Aung T, Chia KS, Wong TY, Tai ES, Teo YY. A statistical method for region-based meta-analysis of genome-wide association studies in genetically diverse populations. Eur J Hum Genet 2011; 20:469-75. [PMID: 22126751 PMCID: PMC3306862 DOI: 10.1038/ejhg.2011.219] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Genome-wide association studies (GWAS) have become the preferred experimental design in exploring the genetic etiology of complex human traits and diseases. Standard SNP-based meta-analytic approaches have been utilized to integrate the results from multiple experiments. This fundamentally assumes that the patterns of linkage disequilibrium (LD) between the underlying causal variants and the directly genotyped SNPs are similar across the populations for the same SNPs to emerge with surrogate evidence of disease association. We introduce a novel strategy for assessing regional evidence of phenotypic association that explicitly incorporates the extent of LD in the region. This provides a natural framework for combining evidence from multi-ethnic studies of both dichotomous and quantitative traits that (i) accommodates different patterns of LD, (ii) integrates different genotyping platforms and (iii) allows for the presence of allelic heterogeneity between the populations. Our method can also be generalized to perform gene-based or pathway-based analyses. Applying this method on real GWAS data in type 2 diabetes (T2D) boosted the association evidence in regions well-established for T2D etiology in three diverse South-East Asian populations, as well as identified two novel gene regions and a biologically convincing pathway that are subsequently validated with data from the Wellcome Trust Case Control Consortium.
Collapse
Affiliation(s)
- Xu Wang
- Department of Epidemiology and Public Health, National University of Singapore, Singapore
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
43
|
Hatakeyama H, Kanzaki M. Molecular basis of insulin-responsive GLUT4 trafficking systems revealed by single molecule imaging. Traffic 2011; 12:1805-20. [PMID: 21910807 DOI: 10.1111/j.1600-0854.2011.01279.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Development of a 'static retention' property of GLUT4, the insulin-responsive glucose transporter, has emerged as being essential for achieving its maximal insulin-induced surface exposure. Herein, employing quantum-dot-based nanometrology of intracellular GLUT4 behavior, we reveal the molecular basis of its systematization endowed upon adipogenic differentiation of 3T3L1 cells. Specifically, (i) the endosomes-to-trans-Golgi network (TGN) retrieval system specialized for GLUT4 develops in response to sortilin expression, which requires an intricately balanced interplay among retromers, golgin-97 and syntaxin-6, the housekeeping vesicle trafficking machinery. (ii) The Golgin-97-localizing subdomain of the differentiated TGN apparently serves as an intermediate transit route by which GLUT4 can further proceed to the stationary GLUT4 storage compartment. (iii) AS160/Tbc1d4 then renders the 'static retention' property insulin responsive, i.e. insulin liberates GLUT4 from the static state only in the presence of functional AS160/Tbc1d4. (iv) Moreover, sortilin malfunction and the resulting GLUT4 sorting defects along with retarded TGN function might be etiologically related to insulin resistance. Together, these observations provide a conceptual framework for understanding maturation/retardation of the insulin-responsive GLUT4 trafficking system that relies on the specialized subdomain of differentiated TGN.
Collapse
Affiliation(s)
- Hiroyasu Hatakeyama
- Graduate School of Biomedical Engineering, Tohoku University, Sendai, Miyagi 980-8575, Japan
| | | |
Collapse
|
44
|
Tiwari A, Jung JJ, Inamdar SM, Brown CO, Goel A, Choudhury A. Endothelial cell migration on fibronectin is regulated by syntaxin 6-mediated alpha5beta1 integrin recycling. J Biol Chem 2011; 286:36749-61. [PMID: 21880737 DOI: 10.1074/jbc.m111.260828] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
The α5β1 integrin heterodimer regulates many processes that contribute to embryonic development and angiogenesis, in both physiological and pathological contexts. As one of the major adhesion complexes on endothelial cells, it plays a vital role in adhesion and migration along the extracellular matrix. We recently showed that angiogenesis is modulated by syntaxin 6, a Golgi- and endosome-localized t-SNARE, and that it does so by regulating the post-Golgi trafficking of VEGFR2. Here we show that syntaxin 6 is also required for α5β1 integrin-mediated adhesion of endothelial cells to, and migration along, fibronectin. We demonstrate that syntaxin 6 and α5β1 integrin colocalize in EEA1-containing early endosomes, and that functional inhibition of syntaxin 6 leads to misrouting of β1 integrin to the degradation pathway (late endosomes and lysosomes) rather transport along recycling pathway from early endosomes; an increase in the pool of ubiquitinylated α5 integrin and its lysosome-dependent degradation; reduced cell spreading on fibronectin; decreased Rac1 activation; and altered Rac1 localization. Collectively, our data show that functional syntaxin 6 is required for the regulation of α5β1-mediated endothelial cell movement on fibronectin. These syntaxin 6-regulated membrane trafficking events control outside-in signaling via haptotactic and chemotactic mechanisms.
Collapse
Affiliation(s)
- Ajit Tiwari
- Department of Anatomy and Cell Biology, University of Iowa, Iowa City, Iowa 52242, USA
| | | | | | | | | | | |
Collapse
|
45
|
Pelaseyed T, Hansson GC. CFTR anion channel modulates expression of human transmembrane mucin MUC3 through the PDZ protein GOPC. J Cell Sci 2011; 124:3074-83. [PMID: 21852426 DOI: 10.1242/jcs.076943] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The transmembrane mucins in the enterocyte are type 1 transmembrane proteins with long and rigid mucin domains, rich in proline, threonine and serine residues that carry numerous O-glycans. Three of these mucins, MUC3, MUC12 and MUC17 are unique in harboring C-terminal class I PDZ motifs, making them suitable ligands for PDZ proteins. A screening of 123 different human PDZ domains for binding to MUC3 identified a strong interaction with the PDZ protein GOPC (Golgi-associated PDZ and coiled-coil motif-containing protein). This interaction was mediated by the C-terminal PDZ motif of MUC3, binding to the single GOPC PDZ domain. GOPC is also a binding partner for cystic fibrosis transmembrane conductance regulator (CFTR) that directs CFTR for degradation. Overexpression of GOPC downregulated the total levels of MUC3, an effect that was reversed by introducing CFTR. The results suggest that CFTR and MUC3 compete for binding to GOPC, which in turn can regulate levels of these two proteins. For the first time a direct coupling between mucins and the CFTR channel is demonstrated, a finding that will shed further light on the still poorly understood relationship between cystic fibrosis and the mucus phenotype of this disease.
Collapse
Affiliation(s)
- Thaher Pelaseyed
- Department of Medical Biochemistry, University of Gothenburg, Gothenburg, Sweden
| | | |
Collapse
|
46
|
Abstract
Delivery of the glucose transporter type 4 (GLUT4) from an intracellular location to the cell surface in response to insulin represents a specialized form of membrane traffic, known to be impaired in the disease states of insulin resistance and type 2 diabetes. Like all membrane trafficking events, this translocation of GLUT4 requires members of the SNARE family of proteins. Here, we discuss two SNARE complexes that have been implicated in insulin-regulated GLUT4 traffic: one regulating the final delivery of GLUT4 to the cell surface in response to insulin and the other controlling GLUT4's intracellular trafficking.
Collapse
Affiliation(s)
- Nia J Bryant
- Henry Wellcome Laboratory of Cell Biology, Institute of Molecular, Cell and Systems Biology, Davidson Building, College of Medicine, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
| | | |
Collapse
|
47
|
Brewer PD, Romenskaia I, Kanow MA, Mastick CC. Loss of AS160 Akt substrate causes Glut4 protein to accumulate in compartments that are primed for fusion in basal adipocytes. J Biol Chem 2011; 286:26287-97. [PMID: 21613213 DOI: 10.1074/jbc.m111.253880] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
The Akt substrate AS160 (TCB1D4) regulates Glut4 exocytosis; shRNA knockdown of AS160 increases surface Glut4 in basal adipocytes. AS160 knockdown is only partially insulin-mimetic; insulin further stimulates Glut4 translocation in these cells. Insulin regulates translocation as follows: 1) by releasing Glut4 from retention in a slowly cycling/noncycling storage pool, increasing the actively cycling Glut4 pool, and 2) by increasing the intrinsic rate constant for exocytosis of the actively cycling pool (k(ex)). Kinetic studies were performed in 3T3-L1 adipocytes to measure the effects of AS160 knockdown on the rate constants of exocytosis (k(ex)), endocytosis (k(en)), and release from retention into the cycling pool. AS160 knockdown released Glut4 into the actively cycling pool without affecting k(ex) or k(en). Insulin increased k(ex) in the knockdown cells, further increasing cell surface Glut4. Inhibition of phosphatidylinositol 3-kinase or Akt affected both k(ex) and release from retention in control cells but only k(ex) in AS160 knockdown cells. Glut4 vesicles accumulate in a primed pre-fusion pool in basal AS160 knockdown cells. Akt regulates the rate of exocytosis of the primed vesicles through an AS160-independent mechanism. Therefore, there is an additional Akt substrate that regulates the fusion of Glut4 vesicles that remain to be identified. Mathematical modeling was used to test the hypothesis that this substrate regulates vesicle priming (release from retention), whereas AS160 regulates the reverse step by stimulating GTP turnover of a Rab protein required for vesicle tethering/docking/fusion. Our analysis indicates that fusion of the primed vesicles with the plasma membrane is an additional non-Akt-dependent insulin-regulated step.
Collapse
Affiliation(s)
- Paul Duffield Brewer
- Department of Biochemistry and Molecular Biology, University of Nevada School of Medicine, Reno, Nevada 89557, USA
| | | | | | | |
Collapse
|
48
|
Chat S, Layani S, Mahaut C, Henry C, Chanat E, Truchet S. Characterisation of the potential SNARE proteins relevant to milk product release by mouse mammary epithelial cells. Eur J Cell Biol 2011; 90:401-13. [DOI: 10.1016/j.ejcb.2011.01.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2010] [Revised: 12/28/2010] [Accepted: 01/05/2011] [Indexed: 11/28/2022] Open
|
49
|
Regulation of vascular endothelial growth factor receptor 2 trafficking and angiogenesis by Golgi localized t-SNARE syntaxin 6. Blood 2010; 117:1425-35. [PMID: 21063020 DOI: 10.1182/blood-2010-06-291690] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Vascular endothelial growth factor receptor 2 (VEGFR2) plays a key role in physiologic and pathologic angiogenesis. Plasma membrane (PM) levels of VEGFR2 are regulated by endocytosis and secretory transport through the Golgi apparatus. To date, the mechanism whereby the VEGFR2 traffics through the Golgi apparatus remains incompletely characterized. We show in human endothelial cells that binding of VEGF to the cell surface localized VEGFR2 stimulates exit of intracellular VEGFR2 from the Golgi apparatus. Brefeldin A treatment reduced the level of surface VEGFR2, confirming that VEGFR2 traffics through the Golgi apparatus en route to the PM. Mechanistically, we show that inhibition of syntaxin 6, a Golgi-localized target membrane-soluble N-ethylmaleimide attachment protein receptor (t-SNARE) protein, interferes with VEGFR2 trafficking to the PM and facilitates lysosomal degradation of the VEGFR2. In cell culture, inhibition of syntaxin 6 also reduced VEGF-induced cell proliferation, cell migration, and vascular tube formation. Furthermore, in a mouse ear model of angiogenesis, an inhibitory form of syntaxin 6 reduced VEGF-induced neovascularization and permeability. Our data demonstrate the importance of syntaxin 6 in the maintenance of cellular VEGFR2 levels, and suggest that the inhibitory form of syntaxin 6 has good potential as an antiangiogenic agent.
Collapse
|
50
|
Chen Y, Gan BQ, Tang BL. Syntaxin 16: Unraveling cellular physiology through a ubiquitous SNARE molecule. J Cell Physiol 2010; 225:326-32. [DOI: 10.1002/jcp.22286] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
|