1
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Hurtado Silva M, van Waardenberg AJ, Mostafa A, Schoch S, Dietrich D, Graham ME. Multiomics of early epileptogenesis in mice reveals phosphorylation and dephosphorylation-directed growth and synaptic weakening. iScience 2024; 27:109534. [PMID: 38600976 PMCID: PMC11005001 DOI: 10.1016/j.isci.2024.109534] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Revised: 01/26/2024] [Accepted: 03/16/2024] [Indexed: 04/12/2024] Open
Abstract
To investigate the phosphorylation-based signaling and protein changes occurring early in epileptogenesis, the hippocampi of mice treated with pilocarpine were examined by quantitative mass spectrometry at 4 and 24 h post-status epilepticus at vast depth. Hundreds of posttranscriptional regulatory proteins were the major early targets of increased phosphorylation. At 24 h, many protein level changes were detected and the phosphoproteome continued to be perturbed. The major targets of decreased phosphorylation at 4 and 24 h were a subset of postsynaptic density scaffold proteins, ion channels, and neurotransmitter receptors. Many proteins targeted by dephosphorylation at 4 h also had decreased protein abundance at 24 h, indicating a phosphatase-mediated weakening of synapses. Increased translation was indicated by protein changes at 24 h. These observations, and many additional indicators within this multiomic resource, suggest that early epileptogenesis is characterized by signaling that stimulates both growth and a homeostatic response that weakens excitability.
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Affiliation(s)
- Mariella Hurtado Silva
- Synapse Proteomics, Children’s Medical Research Institute, The University of Sydney, Westmead, NSW 2145, Australia
| | | | - Aya Mostafa
- Department of Neuropathology, University Hospital Bonn, Synaptic Neuroscience Unit, 53127 Bonn, North Rhine-Westphalia, Germany
| | - Susanne Schoch
- Department of Neuropathology, University Hospital Bonn, Synaptic Neuroscience Unit, 53127 Bonn, North Rhine-Westphalia, Germany
| | - Dirk Dietrich
- Department of Neurosurgery, University Hospital Bonn, Synaptic Neuroscience Unit, 53127 Bonn, North Rhine-Westphalia, Germany
| | - Mark E. Graham
- Synapse Proteomics, Children’s Medical Research Institute, The University of Sydney, Westmead, NSW 2145, Australia
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2
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Huang H, van Waardenberg AJ, Graham ME, Anggono V, Widagdo J. Global quantitative proteomic analysis of aged mouse hippocampus. Proteomics 2024; 24:e2300276. [PMID: 38115172 DOI: 10.1002/pmic.202300276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2023] [Revised: 12/12/2023] [Accepted: 12/13/2023] [Indexed: 12/21/2023]
Abstract
Understanding the molecular changes associated with the aged brain forms the basis for developing potential strategies for slowing cognitive decline associated with normal aging. Focusing on the hippocampus, a critical brain region involved in learning and memory, we employed tandem mass tag methodology to investigate global proteomic changes that occur in advanced-aged (20-month) versus young (3-month) C57BL/6 male mice. Our analysis revealed the upregulation of 236 proteins in the old hippocampal proteome, including those enriched within several age-related processes, such as the adaptive immune response and molecular metabolic pathways, whereas downregulated proteins (88 in total) are mainly involved in axonogenesis and growth cone-related processes. Categorizing proteins by cell-type enrichment in the brain identified a general upregulation of proteins preferentially expressed in microglia, astrocytes, and oligodendrocytes. In contrast, proteins with neuron-specific expression displayed an overall age-related downregulation. By integrating our proteomic with our previously published transcriptomic data, we discovered a mild but significant positive correlation between mRNA and protein expression changes in the aged hippocampus. Therefore, this proteomic data is a valuable additional resource for further understanding age-related molecular mechanisms.
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Affiliation(s)
- He Huang
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD, Australia
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, USA
| | | | - Mark E Graham
- Synapse Proteomics, Children's Medical Research Institute, The University of Sydney, Sydney, NSW, Australia
| | - Victor Anggono
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD, Australia
| | - Jocelyn Widagdo
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD, Australia
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3
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Longfield SF, Mollazade M, Wallis TP, Gormal RS, Joensuu M, Wark JR, van Waardenberg AJ, Small C, Graham ME, Meunier FA, Martínez-Mármol R. Tau forms synaptic nano-biomolecular condensates controlling the dynamic clustering of recycling synaptic vesicles. Nat Commun 2023; 14:7277. [PMID: 37949856 PMCID: PMC10638352 DOI: 10.1038/s41467-023-43130-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2022] [Accepted: 11/01/2023] [Indexed: 11/12/2023] Open
Abstract
Neuronal communication relies on the release of neurotransmitters from various populations of synaptic vesicles. Despite displaying vastly different release probabilities and mobilities, the reserve and recycling pool of vesicles co-exist within a single cluster suggesting that small synaptic biomolecular condensates could regulate their nanoscale distribution. Here, we performed a large-scale activity-dependent phosphoproteome analysis of hippocampal neurons in vitro and identified Tau as a highly phosphorylated and disordered candidate protein. Single-molecule super-resolution microscopy revealed that Tau undergoes liquid-liquid phase separation to generate presynaptic nanoclusters whose density and number are regulated by activity. This activity-dependent diffusion process allows Tau to translocate into the presynapse where it forms biomolecular condensates, to selectively control the mobility of recycling vesicles. Tau, therefore, forms presynaptic nano-biomolecular condensates that regulate the nanoscale organization of synaptic vesicles in an activity-dependent manner.
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Affiliation(s)
- Shanley F Longfield
- Clem Jones Centre for Ageing Dementia Research (CJCADR), Queensland Brain Institute (QBI), The University of Queensland; St Lucia Campus, Brisbane, QLD, 4072, Australia
| | - Mahdie Mollazade
- Clem Jones Centre for Ageing Dementia Research (CJCADR), Queensland Brain Institute (QBI), The University of Queensland; St Lucia Campus, Brisbane, QLD, 4072, Australia
| | - Tristan P Wallis
- Clem Jones Centre for Ageing Dementia Research (CJCADR), Queensland Brain Institute (QBI), The University of Queensland; St Lucia Campus, Brisbane, QLD, 4072, Australia
| | - Rachel S Gormal
- Clem Jones Centre for Ageing Dementia Research (CJCADR), Queensland Brain Institute (QBI), The University of Queensland; St Lucia Campus, Brisbane, QLD, 4072, Australia
| | - Merja Joensuu
- Clem Jones Centre for Ageing Dementia Research (CJCADR), Queensland Brain Institute (QBI), The University of Queensland; St Lucia Campus, Brisbane, QLD, 4072, Australia
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland; St Lucia Campus, Brisbane, QLD, 4072, Australia
| | - Jesse R Wark
- Synapse Proteomics, Children's Medical Research Institute (CMRI), The University of Sydney, 214 Hawkesbury Road, Westmead, NSW, 2145, Australia
| | | | - Christopher Small
- Clem Jones Centre for Ageing Dementia Research (CJCADR), Queensland Brain Institute (QBI), The University of Queensland; St Lucia Campus, Brisbane, QLD, 4072, Australia
| | - Mark E Graham
- Synapse Proteomics, Children's Medical Research Institute (CMRI), The University of Sydney, 214 Hawkesbury Road, Westmead, NSW, 2145, Australia
| | - Frédéric A Meunier
- Clem Jones Centre for Ageing Dementia Research (CJCADR), Queensland Brain Institute (QBI), The University of Queensland; St Lucia Campus, Brisbane, QLD, 4072, Australia.
- School of Biomedical Science, The University of Queensland; St Lucia Campus, Brisbane, QLD, 4072, Australia.
| | - Ramón Martínez-Mármol
- Clem Jones Centre for Ageing Dementia Research (CJCADR), Queensland Brain Institute (QBI), The University of Queensland; St Lucia Campus, Brisbane, QLD, 4072, Australia.
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4
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Yasa J, Reed CE, Bournazos AM, Evesson FJ, Pang I, Graham ME, Wark JR, Nijagal B, Kwan KH, Kwiatkowski T, Jung R, Weisleder N, Cooper ST, Lemckert FA. Minimal expression of dysferlin prevents development of dysferlinopathy in dysferlin exon 40a knockout mice. Acta Neuropathol Commun 2023; 11:15. [PMID: 36653852 PMCID: PMC9847081 DOI: 10.1186/s40478-022-01473-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Accepted: 11/03/2022] [Indexed: 01/19/2023] Open
Abstract
Dysferlin is a Ca2+-activated lipid binding protein implicated in muscle membrane repair. Recessive variants in DYSF result in dysferlinopathy, a progressive muscular dystrophy. We showed previously that calpain cleavage within a motif encoded by alternatively spliced exon 40a releases a 72 kDa C-terminal minidysferlin recruited to injured sarcolemma. Herein we use CRISPR/Cas9 gene editing to knock out murine Dysf exon 40a, to specifically assess its role in membrane repair and development of dysferlinopathy. We created three Dysf exon 40a knockout (40aKO) mouse lines that each express different levels of dysferlin protein ranging from ~ 90%, ~ 50% and ~ 10-20% levels of wild-type. Histopathological analysis of skeletal muscles from all 12-month-old 40aKO lines showed virtual absence of dystrophic features and normal membrane repair capacity for all three 40aKO lines, as compared with dysferlin-null BLAJ mice. Further, lipidomic and proteomic analyses on 18wk old quadriceps show all three 40aKO lines are spared the profound lipidomic/proteomic imbalance that characterises dysferlin-deficient BLAJ muscles. Collective results indicate that membrane repair does not depend upon calpain cleavage within exon 40a and that ~ 10-20% of WT dysferlin protein expression is sufficient to maintain the muscle lipidome, proteome and membrane repair capacity to crucially prevent development of dysferlinopathy.
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Affiliation(s)
- Joe Yasa
- grid.413973.b0000 0000 9690 854XKids Neuroscience Centre, The Children’s Hospital at Westmead, Cnr Hawkesbury Road, Hainsworth Street, Westmead, Sydney, NSW 2145 Australia ,grid.414235.50000 0004 0619 2154Functional Neuromics, Children’s Medical Research Institute, Westmead, Sydney, NSW Australia
| | - Claudia E. Reed
- grid.413973.b0000 0000 9690 854XKids Neuroscience Centre, The Children’s Hospital at Westmead, Cnr Hawkesbury Road, Hainsworth Street, Westmead, Sydney, NSW 2145 Australia ,grid.1013.30000 0004 1936 834XDiscipline of Child and Adolescent Health, Faculty of Medicine, University of Sydney, Sydney, NSW Australia
| | - Adam M. Bournazos
- grid.413973.b0000 0000 9690 854XKids Neuroscience Centre, The Children’s Hospital at Westmead, Cnr Hawkesbury Road, Hainsworth Street, Westmead, Sydney, NSW 2145 Australia ,grid.1013.30000 0004 1936 834XDiscipline of Child and Adolescent Health, Faculty of Medicine, University of Sydney, Sydney, NSW Australia
| | - Frances J. Evesson
- grid.413973.b0000 0000 9690 854XKids Neuroscience Centre, The Children’s Hospital at Westmead, Cnr Hawkesbury Road, Hainsworth Street, Westmead, Sydney, NSW 2145 Australia ,grid.414235.50000 0004 0619 2154Functional Neuromics, Children’s Medical Research Institute, Westmead, Sydney, NSW Australia ,grid.1013.30000 0004 1936 834XDiscipline of Child and Adolescent Health, Faculty of Medicine, University of Sydney, Sydney, NSW Australia
| | - Ignatius Pang
- grid.414235.50000 0004 0619 2154Synapse Proteomics, Children’s Medical Research Institute, The University of Sydney, Westmead, NSW Australia
| | - Mark E. Graham
- grid.414235.50000 0004 0619 2154Synapse Proteomics, Children’s Medical Research Institute, The University of Sydney, Westmead, NSW Australia
| | - Jesse R. Wark
- grid.1013.30000 0004 1936 834XOperations, Children’s Medical Research Institute, The University of Sydney, Westmead, NSW Australia
| | - Brunda Nijagal
- grid.1008.90000 0001 2179 088XMetabolomics Australia, Bio21 Institute, The University of Melbourne, Victoria, Australia
| | - Kim H. Kwan
- grid.1008.90000 0001 2179 088XMetabolomics Australia, Bio21 Institute, The University of Melbourne, Victoria, Australia
| | - Thomas Kwiatkowski
- grid.268132.c0000 0001 0701 2416West Chester University, West Chester, PA 19383 USA
| | - Rachel Jung
- grid.412332.50000 0001 1545 0811Department of Physiology and Cell Biology, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH 43210-1252 USA
| | - Noah Weisleder
- grid.412332.50000 0001 1545 0811Department of Physiology and Cell Biology, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH 43210-1252 USA
| | - Sandra T. Cooper
- grid.413973.b0000 0000 9690 854XKids Neuroscience Centre, The Children’s Hospital at Westmead, Cnr Hawkesbury Road, Hainsworth Street, Westmead, Sydney, NSW 2145 Australia ,grid.414235.50000 0004 0619 2154Functional Neuromics, Children’s Medical Research Institute, Westmead, Sydney, NSW Australia ,grid.1013.30000 0004 1936 834XDiscipline of Child and Adolescent Health, Faculty of Medicine, University of Sydney, Sydney, NSW Australia
| | - Frances A. Lemckert
- grid.413973.b0000 0000 9690 854XKids Neuroscience Centre, The Children’s Hospital at Westmead, Cnr Hawkesbury Road, Hainsworth Street, Westmead, Sydney, NSW 2145 Australia ,grid.414235.50000 0004 0619 2154Functional Neuromics, Children’s Medical Research Institute, Westmead, Sydney, NSW Australia ,grid.1013.30000 0004 1936 834XDiscipline of Child and Adolescent Health, Faculty of Medicine, University of Sydney, Sydney, NSW Australia
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5
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Royero P, Quatraccioni A, Früngel R, Silva MH, Bast A, Ulas T, Beyer M, Opitz T, Schultze JL, Graham ME, Oberlaender M, Becker A, Schoch S, Beck H. Circuit-selective cell-autonomous regulation of inhibition in pyramidal neurons by Ste20-like kinase. Cell Rep 2022; 41:111757. [PMID: 36476865 PMCID: PMC9756112 DOI: 10.1016/j.celrep.2022.111757] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Revised: 10/18/2022] [Accepted: 11/09/2022] [Indexed: 12/12/2022] Open
Abstract
Maintaining an appropriate balance between excitation and inhibition is critical for neuronal information processing. Cortical neurons can cell-autonomously adjust the inhibition they receive to individual levels of excitatory input, but the underlying mechanisms are unclear. We describe that Ste20-like kinase (SLK) mediates cell-autonomous regulation of excitation-inhibition balance in the thalamocortical feedforward circuit, but not in the feedback circuit. This effect is due to regulation of inhibition originating from parvalbumin-expressing interneurons, while inhibition via somatostatin-expressing interneurons is unaffected. Computational modeling shows that this mechanism promotes stable excitatory-inhibitory ratios across pyramidal cells and ensures robust and sparse coding. Patch-clamp RNA sequencing yields genes differentially regulated by SLK knockdown, as well as genes associated with excitation-inhibition balance participating in transsynaptic communication and cytoskeletal dynamics. These data identify a mechanism for cell-autonomous regulation of a specific inhibitory circuit that is critical to ensure that a majority of cortical pyramidal cells participate in information coding.
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Affiliation(s)
- Pedro Royero
- Institute of Experimental Epileptology and Cognition Research, University of Bonn, University of Bonn Medical Center, Venusberg-Campus 1, 53105 Bonn, Germany,International Max Planck Research School for Brain and Behavior, Bonn, Germany
| | - Anne Quatraccioni
- Department of Neuropathology, University Hospital Bonn, Section for Translational Epilepsy Research, 53127 Bonn, Germany,International Max Planck Research School for Brain and Behavior, Bonn, Germany
| | - Rieke Früngel
- In Silico Brain Sciences Group, Max-Planck Institute for Neurobiology of Behavior – Caesar, Bonn, Germany,International Max Planck Research School for Brain and Behavior, Bonn, Germany
| | - Mariella Hurtado Silva
- Synapse Proteomics, Children’s Medical Research Institute, The University of Sydney, Sydney, NSW, Australia
| | - Arco Bast
- In Silico Brain Sciences Group, Max-Planck Institute for Neurobiology of Behavior – Caesar, Bonn, Germany,International Max Planck Research School for Brain and Behavior, Bonn, Germany
| | - Thomas Ulas
- Systems Medicine, Deutsches Zentrum für Neurodegenerative Erkrankungen (DZNE) e.V., Bonn, Germany,PRECISE Platform for Single Cell Genomics and Epigenomics, Deutsches Zentrum für Neurodegenerative Erkrankungen (DZNE) e.V. and University of Bonn, Bonn, Germany,Genomics & Immunoregulation, LIMES Institute, University of Bonn, Bonn, Germany
| | - Marc Beyer
- PRECISE Platform for Single Cell Genomics and Epigenomics, Deutsches Zentrum für Neurodegenerative Erkrankungen (DZNE) e.V. and University of Bonn, Bonn, Germany,Immunogenomics & Neurodegeneration, Deutsches Zentrum für Neurodegenerative Erkrankungen e.V., Bonn, Germany
| | - Thoralf Opitz
- Institute of Experimental Epileptology and Cognition Research, University of Bonn, University of Bonn Medical Center, Venusberg-Campus 1, 53105 Bonn, Germany
| | - Joachim L. Schultze
- Systems Medicine, Deutsches Zentrum für Neurodegenerative Erkrankungen (DZNE) e.V., Bonn, Germany,PRECISE Platform for Single Cell Genomics and Epigenomics, Deutsches Zentrum für Neurodegenerative Erkrankungen (DZNE) e.V. and University of Bonn, Bonn, Germany,Genomics & Immunoregulation, LIMES Institute, University of Bonn, Bonn, Germany
| | - Mark E. Graham
- Institute of Experimental Epileptology and Cognition Research, University of Bonn, University of Bonn Medical Center, Venusberg-Campus 1, 53105 Bonn, Germany
| | - Marcel Oberlaender
- In Silico Brain Sciences Group, Max-Planck Institute for Neurobiology of Behavior – Caesar, Bonn, Germany
| | - Albert Becker
- Department of Neuropathology, University Hospital Bonn, Section for Translational Epilepsy Research, 53127 Bonn, Germany
| | - Susanne Schoch
- Department of Neuropathology, University Hospital Bonn, Section for Translational Epilepsy Research, 53127 Bonn, Germany
| | - Heinz Beck
- Institute of Experimental Epileptology and Cognition Research, University of Bonn, University of Bonn Medical Center, Venusberg-Campus 1, 53105 Bonn, Germany,Deutsches Zentrum für Neurodegenerative Erkrankungen e.V., Bonn, Germany,Corresponding author
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6
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Müller JA, Betzin J, Santos-Tejedor J, Mayer A, Oprişoreanu AM, Engholm-Keller K, Paulußen I, Gulakova P, McGovern TD, Gschossman LJ, Schönhense E, Wark JR, Lamprecht A, Becker AJ, Waardenberg AJ, Graham ME, Dietrich D, Schoch S. A presynaptic phosphosignaling hub for lasting homeostatic plasticity. Cell Rep 2022; 39:110696. [PMID: 35443170 DOI: 10.1016/j.celrep.2022.110696] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 11/26/2021] [Accepted: 03/29/2022] [Indexed: 11/29/2022] Open
Abstract
Stable function of networks requires that synapses adapt their strength to levels of neuronal activity, and failure to do so results in cognitive disorders. How such homeostatic regulation may be implemented in mammalian synapses remains poorly understood. Here we show that the phosphorylation status of several positions of the active-zone (AZ) protein RIM1 are relevant for synaptic glutamate release. Position RIMS1045 is necessary and sufficient for expression of silencing-induced homeostatic plasticity and is kept phosphorylated by serine arginine protein kinase 2 (SRPK2). SRPK2-induced upscaling of synaptic release leads to additional RIM1 nanoclusters and docked vesicles at the AZ and is not observed in the absence of RIM1 and occluded by RIMS1045E. Our data suggest that SRPK2 and RIM1 represent a presynaptic phosphosignaling hub that is involved in the homeostatic balance of synaptic coupling of neuronal networks.
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Affiliation(s)
- Johannes Alexander Müller
- Section for Translational Epilepsy Research, Department of Neuropathology, University Hospital Bonn, Bonn, Germany; Department of Neurosurgery, University Hospital Bonn, Bonn, Germany
| | - Julia Betzin
- Section for Translational Epilepsy Research, Department of Neuropathology, University Hospital Bonn, Bonn, Germany
| | - Jorge Santos-Tejedor
- Section for Translational Epilepsy Research, Department of Neuropathology, University Hospital Bonn, Bonn, Germany
| | - Annika Mayer
- Section for Translational Epilepsy Research, Department of Neuropathology, University Hospital Bonn, Bonn, Germany
| | - Ana-Maria Oprişoreanu
- Section for Translational Epilepsy Research, Department of Neuropathology, University Hospital Bonn, Bonn, Germany
| | - Kasper Engholm-Keller
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark; Synapse Proteomics, Children's Medical Research Institute, The University of Sydney, Westmead, NSW, Australia
| | | | - Polina Gulakova
- Section for Translational Epilepsy Research, Department of Neuropathology, University Hospital Bonn, Bonn, Germany; Department of Neurosurgery, University Hospital Bonn, Bonn, Germany
| | | | - Lena Johanna Gschossman
- Section for Translational Epilepsy Research, Department of Neuropathology, University Hospital Bonn, Bonn, Germany; Department of Neurosurgery, University Hospital Bonn, Bonn, Germany
| | - Eva Schönhense
- Section for Translational Epilepsy Research, Department of Neuropathology, University Hospital Bonn, Bonn, Germany
| | - Jesse R Wark
- Synapse Proteomics, Children's Medical Research Institute, The University of Sydney, Westmead, NSW, Australia
| | - Alf Lamprecht
- Department of Pharmaceutics, Bonn University, Bonn, Germany
| | - Albert J Becker
- Section for Translational Epilepsy Research, Department of Neuropathology, University Hospital Bonn, Bonn, Germany
| | - Ashley J Waardenberg
- Australian Institute for Tropical Health and Medicine, James Cook University, Smithfield, QLD 4878, Australia; i-Synapse, Cairns, QLD, Australia
| | - Mark E Graham
- Synapse Proteomics, Children's Medical Research Institute, The University of Sydney, Westmead, NSW, Australia
| | - Dirk Dietrich
- Department of Neurosurgery, University Hospital Bonn, Bonn, Germany.
| | - Susanne Schoch
- Section for Translational Epilepsy Research, Department of Neuropathology, University Hospital Bonn, Bonn, Germany.
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7
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Fernando M, Lee S, Wark JR, Xiao D, Lim BY, O'Hara-Wright M, Kim HJ, Smith GC, Wong T, Teber ET, Ali RR, Yang P, Graham ME, Gonzalez-Cordero A. Differentiation of brain and retinal organoids from confluent cultures of pluripotent stem cells connected by nerve-like axonal projections of optic origin. Stem Cell Reports 2022; 17:1476-1492. [PMID: 35523177 PMCID: PMC9213828 DOI: 10.1016/j.stemcr.2022.04.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Revised: 04/04/2022] [Accepted: 04/05/2022] [Indexed: 10/25/2022] Open
Abstract
Advances in the study of neurological conditions have been possible because of pluripotent stem cell technologies and organoids. Studies have described the generation of neural ectoderm-derived retinal and brain structures from pluripotent stem cells. However, the field is still troubled by technical challenges, including high culture costs and variability. Here, we describe a simple and economical protocol that reproducibly gives rise to the neural retina and cortical brain regions from confluent cultures of stem cells. The spontaneously generated cortical organoids are transcriptionally comparable with organoids generated by other methods. Furthermore, these organoids showed spontaneous functional network activity and proteomic analysis confirmed organoids maturity. The generation of retinal and brain organoids in close proximity enabled their mutual isolation. Suspension culture of this complex organoid system demonstrated the formation of nerve-like structures connecting retinal and brain organoids, which might facilitate the investigation of neurological diseases of the eye and brain.
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Affiliation(s)
- Milan Fernando
- Stem Cell Medicine and Stem Cell and Organoid Facility, University of Sydney, Westmead, 2145 NSW, Australia
| | - Scott Lee
- Stem Cell Medicine and Stem Cell and Organoid Facility, University of Sydney, Westmead, 2145 NSW, Australia
| | - Jesse R Wark
- Stem Cell Medicine and Stem Cell and Organoid Facility, University of Sydney, Westmead, 2145 NSW, Australia; Synapse Proteomics, University of Sydney, Westmead, 2145 NSW, Australia
| | - Di Xiao
- Computational Systems Biology, University of Sydney, Westmead, 2145 NSW, Australia; Charles Perkins Centre, School of Mathematics and Statistics, University of Sydney, Sydney, NSW 2006, Australia; School of Medical Sciences, Faculty of Medicine and Health, University of Sydney, NSW 2006, Australia
| | - Benjamin Y Lim
- Stem Cell Medicine and Stem Cell and Organoid Facility, University of Sydney, Westmead, 2145 NSW, Australia
| | - Michelle O'Hara-Wright
- Stem Cell Medicine and Stem Cell and Organoid Facility, University of Sydney, Westmead, 2145 NSW, Australia; School of Medical Sciences, Faculty of Medicine and Health, University of Sydney, NSW 2006, Australia
| | - Hani J Kim
- Computational Systems Biology, University of Sydney, Westmead, 2145 NSW, Australia; Charles Perkins Centre, School of Mathematics and Statistics, University of Sydney, Sydney, NSW 2006, Australia; School of Medical Sciences, Faculty of Medicine and Health, University of Sydney, NSW 2006, Australia
| | - Grady C Smith
- Stem Cell Medicine and Stem Cell and Organoid Facility, University of Sydney, Westmead, 2145 NSW, Australia
| | - Ted Wong
- Bioinformatics, Children's Medical Research Institute, University of Sydney, Westmead, 2145 NSW, Australia
| | - Erdahl T Teber
- Bioinformatics, Children's Medical Research Institute, University of Sydney, Westmead, 2145 NSW, Australia; School of Medical Sciences, Faculty of Medicine and Health, University of Sydney, NSW 2006, Australia
| | - Robin R Ali
- Gene and Cell Therapy Group, UCL Institute of Ophthalmology, London EC1V 9EL, UK
| | - Pengyi Yang
- Computational Systems Biology, University of Sydney, Westmead, 2145 NSW, Australia; Charles Perkins Centre, School of Mathematics and Statistics, University of Sydney, Sydney, NSW 2006, Australia; School of Medical Sciences, Faculty of Medicine and Health, University of Sydney, NSW 2006, Australia
| | - Mark E Graham
- Synapse Proteomics, University of Sydney, Westmead, 2145 NSW, Australia; School of Medical Sciences, Faculty of Medicine and Health, University of Sydney, NSW 2006, Australia
| | - Anai Gonzalez-Cordero
- Stem Cell Medicine and Stem Cell and Organoid Facility, University of Sydney, Westmead, 2145 NSW, Australia; School of Medical Sciences, Faculty of Medicine and Health, University of Sydney, NSW 2006, Australia.
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8
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Almazi JG, Alomari M, Belov L, Best OG, Shen Y, Graham ME, Mulligan SP, Christopherson RI. Fludarabine nucleoside induces major changes in the p53 interactome in human B-lymphoid cancer cell lines. Nucleosides Nucleotides Nucleic Acids 2021; 41:314-320. [PMID: 34886743 DOI: 10.1080/15257770.2021.2013500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2021] [Revised: 11/09/2021] [Accepted: 11/27/2021] [Indexed: 06/13/2023]
Abstract
Triple combination FCR (fludarabine, cyclophosphamide and rituximab) is often used as front-line treatment for chronic lymphocytic leukemia (CLL) and non-Hodgkin's lymphoma. Results from our laboratory indicate that 2-FaraAMP (fludarabine) has multiple mechanisms of cytotoxicity that include accumulation of isoforms and phosphorylated derivatives of p53, and induction of the unfolded protein response (UPR). Using protein pull-downs with Dynabeads coated with p53 antibody, we have found that 2-FaraA (fludarabine nucleoside) induces major changes in the p53 interactome in human Raji lymphoma and IM9 multiple myeloma cells. These changes are likely driven by DNA strand breaks induced by 2-FaraA that activate protein kinases such as ATM, ATR and Chk1.
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Affiliation(s)
- Juhura G Almazi
- School of Life and Environmental Sciences, University of Sydney, Sydney, NSW, Australia
- Respiratory Technology, The Woolcock Institute of Medical Research, University of Sydney, Sydney, NSW, Australia
| | - Munther Alomari
- School of Life and Environmental Sciences, University of Sydney, Sydney, NSW, Australia
- Department of Stem Cell Biology, Institute for Research and Medical Consultations, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia
| | - Larissa Belov
- School of Life and Environmental Sciences, University of Sydney, Sydney, NSW, Australia
| | - O Giles Best
- Hematology, Kolling Institute for Medical Research, Royal North Shore Hospital, St. Leonards, NSW, Australia
| | - Yandong Shen
- School of Life and Environmental Sciences, University of Sydney, Sydney, NSW, Australia
| | - Mark E Graham
- Children's Medical Research Institute, University of Sydney, Westmead, NSW, Australia
| | - Stephen P Mulligan
- School of Life and Environmental Sciences, University of Sydney, Sydney, NSW, Australia
- Hematology, Kolling Institute for Medical Research, Royal North Shore Hospital, St. Leonards, NSW, Australia
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9
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Fan X, Masamsetti VP, Sun JQ, Engholm-Keller K, Osteil P, Studdert J, Graham ME, Fossat N, Tam PP. TWIST1 and chromatin regulatory proteins interact to guide neural crest cell differentiation. eLife 2021; 10:62873. [PMID: 33554859 PMCID: PMC7968925 DOI: 10.7554/elife.62873] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Accepted: 02/05/2021] [Indexed: 12/11/2022] Open
Abstract
Protein interaction is critical molecular regulatory activity underlining cellular functions and precise cell fate choices. Using TWIST1 BioID-proximity-labeling and network propagation analyses, we discovered and characterized a TWIST-chromatin regulatory module (TWIST1-CRM) in the neural crest cells (NCC). Combinatorial perturbation of core members of TWIST1-CRM: TWIST1, CHD7, CHD8, and WHSC1 in cell models and mouse embryos revealed that loss of the function of the regulatory module resulted in abnormal differentiation of NCCs and compromised craniofacial tissue patterning. Following NCC delamination, low level of TWIST1-CRM activity is instrumental to stabilize the early NCC signatures and migratory potential by repressing the neural stem cell programs. High level of TWIST1 module activity at later phases commits the cells to the ectomesenchyme. Our study further revealed the functional interdependency of TWIST1 and potential neurocristopathy factors in NCC development. Shaping the head and face during development relies on a complex ballet of molecular signals that orchestrates the movement and specialization of various groups of cells. In animals with a backbone for example, neural crest cells (NCCs for short) can march long distances from the developing spine to become some of the tissues that form the skull and cartilage but also the pigment cells and nervous system. NCCs mature into specific cell types thanks to a complex array of factors which trigger a precise sequence of binary fate decisions at the right time and place. Amongst these factors, the protein TWIST1 can set up a cascade of genetic events that control how NCCs will ultimately form tissues in the head. To do so, the TWIST1 protein interacts with many other molecular actors, many of which are still unknown. To find some of these partners, Fan et al. studied TWIST1 in the NCCs of mice and cells grown in the lab. The experiments showed that TWIST1 interacted with CHD7, CHD8 and WHSC1, three proteins that help to switch genes on and off, and which contribute to NCCs moving across the head during development. Further work by Fan et al. then revealed that together, these molecular actors are critical for NCCs to form cells that will form facial bones and cartilage, as opposed to becoming neurons. This result helps to show that there is a trade-off between NCCs forming the face or being part of the nervous system. One in three babies born with a birth defect shows anomalies of the head and face: understanding the exact mechanisms by which NCCs contribute to these structures may help to better predict risks for parents, or to develop new approaches for treatment.
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Affiliation(s)
- Xiaochen Fan
- Embryology Unit, Children's Medical Research Institute, The University of Sydney, Sydney, Australia.,The University of Sydney, School of Medical Sciences, Faculty of Medicine and Health, Sydney, Australia
| | - V Pragathi Masamsetti
- Embryology Unit, Children's Medical Research Institute, The University of Sydney, Sydney, Australia
| | - Jane Qj Sun
- Embryology Unit, Children's Medical Research Institute, The University of Sydney, Sydney, Australia
| | - Kasper Engholm-Keller
- Synapse Proteomics Group, Children's Medical Research Institute, The University of Sydney, Sydney, Australia
| | - Pierre Osteil
- Embryology Unit, Children's Medical Research Institute, The University of Sydney, Sydney, Australia
| | - Joshua Studdert
- Embryology Unit, Children's Medical Research Institute, The University of Sydney, Sydney, Australia
| | - Mark E Graham
- Synapse Proteomics Group, Children's Medical Research Institute, The University of Sydney, Sydney, Australia
| | - Nicolas Fossat
- Embryology Unit, Children's Medical Research Institute, The University of Sydney, Sydney, Australia.,The University of Sydney, School of Medical Sciences, Faculty of Medicine and Health, Sydney, Australia
| | - Patrick Pl Tam
- Embryology Unit, Children's Medical Research Institute, The University of Sydney, Sydney, Australia.,The University of Sydney, School of Medical Sciences, Faculty of Medicine and Health, Sydney, Australia
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10
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Ruiter M, Houy S, Engholm-Keller K, Graham ME, Sørensen JB. SNAP-25 phosphorylation at Ser187 is not involved in Ca 2+ or phorbolester-dependent potentiation of synaptic release. Mol Cell Neurosci 2019; 102:103452. [PMID: 31794878 DOI: 10.1016/j.mcn.2019.103452] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Revised: 10/13/2019] [Accepted: 11/29/2019] [Indexed: 11/25/2022] Open
Abstract
SNAP-25, one of the three SNARE-proteins responsible for synaptic release, can be phosphorylated by Protein Kinase C on Ser-187, close to the fusion pore. In neuroendocrine cells, this phosphorylation event potentiates vesicle recruitment into releasable pools, whereas the consequences of phosphorylation for synaptic release remain unclear. We mutated Ser-187 and expressed two mutants (S187C and S187E) in the context of the SNAP-25B-isoform in SNAP-25 knockout glutamatergic autaptic neurons. Whole-cell patch clamp recordings were performed to assess the effect of Ser-187 phosphorylation on synaptic transmission. Blocking phosphorylation by expressing the S187C mutant did not affect synapse density, basic evoked or spontaneous neurotransmission, the readily-releasable pool size or its Ca2+-independent or Ca2+-dependent replenishment. Furthermore, it did not affect the response to phorbol esters, which activate PKC. Expressing S187C in the context of the SNAP-25A isoform also did not affect synaptic transmission. Strikingly, the - potentially phosphomimetic - mutant S187E reduced spontaneous release and release probability, with the largest effect seen in the SNAP-25B isoform, showing that a negative charge in this position is detrimental for neurotransmission, in agreement with electrostatic fusion triggering. During the course of our experiments, we found that higher SNAP-25B expression levels led to decreased paired pulse potentiation, probably due to higher release probabilities. Under these conditions, the potentiation of evoked EPSCs by phorbol esters was followed by a persistent down-regulation, probably due to a ceiling effect. In conclusion, our results indicate that phosphorylation of Ser-187 in SNAP-25 is not involved in modulation of synaptic release by Ca2+ or phorbol esters.
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Affiliation(s)
- Marvin Ruiter
- Department of Neuroscience, University of Copenhagen, Blegdamsvej 3C, 2200 Copenhagen N, Denmark
| | - Sébastien Houy
- Department of Neuroscience, University of Copenhagen, Blegdamsvej 3C, 2200 Copenhagen N, Denmark
| | - Kasper Engholm-Keller
- Synapse Proteomics Group, Children's Medical Research Institute, The University of Sydney, 214 Hawkesbury Road, Westmead NSW 2145, New South Wales, Australia; Department of Biochemistry and Molecular Biology, University of Southern Denmark, Campusvej 55, 5230 Odense M, Denmark
| | - Mark E Graham
- Synapse Proteomics Group, Children's Medical Research Institute, The University of Sydney, 214 Hawkesbury Road, Westmead NSW 2145, New South Wales, Australia
| | - Jakob B Sørensen
- Department of Neuroscience, University of Copenhagen, Blegdamsvej 3C, 2200 Copenhagen N, Denmark.
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11
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Graham ME, Loveridge KM, Pollard SH, Moore KR, Skirko JR. Infant Midnasal Stenosis: Reliability of Nasal Metrics. AJNR Am J Neuroradiol 2019; 40:562-567. [PMID: 30765383 DOI: 10.3174/ajnr.a5980] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Accepted: 01/14/2019] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Midnasal stenosis is a poorly defined entity that may be a component of other conditions of nasal obstruction contributing to respiratory distress in infants. We sought to establish whether midnasal vault narrowing is a component of well-defined syndromes of nasal narrowing, such as bilateral choanal atresia and pyriform aperture stenosis, and to characterize the nasal anatomy of patients with syndromic craniosynostosis. MATERIALS AND METHODS A convenience sample of patients with pyriform aperture stenosis, bilateral choanal atresia, and Apert and Crouzon syndromes with maxillofacial CT scans was identified. Patients with Pierre Robin Sequence were used as controls. Nasal measurements were performed at the pyriform aperture, choana, and defined midnasal points on axial and coronal CT scans. Intra- and interrater reliability was quantified with the intraclass correlation coefficient. T tests with Bonferroni adjustment were used to assess differences from controls. RESULTS The study included 50 patients: Eleven had pyriform aperture stenosis, 10 had Apert and Crouzon syndromes, 9 had choanal atresia, and 20 were controls. Measurements in patients with pyriform aperture stenosis and Apert and Crouzon syndromes were narrower than those of controls at all measured points (P < .001). Measurements in patients with choanal atresia were only narrow in the posterior half of the nose (P < .001). The intra- and interrater reliability of midnasal and pyriform measurements was very good to excellent (intraclass correlation coefficient > 0.87). The choanal measurement was good (intraclass correlation coefficient = 0.76-0.77). CONCLUSIONS Pyriform aperture stenosis, Apert and Crouzon patients were narrower at all measured points compared to controls. Bilateral choanal atresia patients were only narrower in the posterior half of the nose. More research is needed to evaluate the clinical implications of these radiographic findings.
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Affiliation(s)
- M E Graham
- From the Department of Otolaryngology-Head and Neck Surgery, and Schulich School of Medicine and Dentistry (M.E.G.), Western University, London, Ontario, Canada.,London Health Sciences Center (M.E.G.), London, Ontario, Canada
| | - K M Loveridge
- Division of Pediatric Otolaryngology-Head and Neck Surgery (K.M.L., S.H.P., J.R.S.), University of Utah and Primary Children's Hospital, Salt Lake City, Utah
| | - S H Pollard
- Division of Pediatric Otolaryngology-Head and Neck Surgery (K.M.L., S.H.P., J.R.S.), University of Utah and Primary Children's Hospital, Salt Lake City, Utah
| | - K R Moore
- Department of Medical Imaging (K.R.M.), Primary Children's Hospital, Salt Lake City, Utah
| | - J R Skirko
- Division of Pediatric Otolaryngology-Head and Neck Surgery (K.M.L., S.H.P., J.R.S.), University of Utah and Primary Children's Hospital, Salt Lake City, Utah
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12
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Abstract
ATM (ataxia-telangiectasia mutated) protein kinase is a key regulator of cellular responses to DNA damage and oxidative stress. DNA damage triggers complex cascade of signaling events leading to numerous posttranslational modification on multitude of proteins. Understanding the regulation of ATM kinase is therefore critical not only for understanding the human genetic disorder ataxia-telangiectasia and potential treatment strategies, but essential for deciphering physiological responses of cells to stress. These responses play an important role in carcinogenesis, neurodegeneration, and aging. We focus here on the identification of DNA damage inducible ATM phosphorylation sites to understand the importance of autophosphorylation in the mechanism of ATM kinase activation. We demonstrate the utility of using immunoprecipitated ATM in quantitative LC-MS/MS workflow with stable isotope dimethyl labeling of ATM peptides for identification of phosphorylation sites.
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Affiliation(s)
- Mark E Graham
- Children's Medical Research Institute, University of Sydney, Westmead, NSW, 2145, Australia
| | - Martin F Lavin
- University of Queensland Centre for Clinical Research (UQCCR), University of Queensland, Building 71/918, Royal Brisbane & Women's Hospital Campus, Herston, Brisbane, QLD4029, Australia
| | - Sergei V Kozlov
- University of Queensland Centre for Clinical Research (UQCCR), University of Queensland, Building 71/918, Royal Brisbane & Women's Hospital Campus, Herston, Brisbane, QLD4029, Australia.
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13
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Kozlov SV, Waardenberg AJ, Engholm-Keller K, Arthur JW, Graham ME, Lavin M. Reactive Oxygen Species (ROS)-Activated ATM-Dependent Phosphorylation of Cytoplasmic Substrates Identified by Large-Scale Phosphoproteomics Screen. Mol Cell Proteomics 2016; 15:1032-47. [PMID: 26699800 PMCID: PMC4813686 DOI: 10.1074/mcp.m115.055723] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Revised: 12/08/2015] [Indexed: 01/06/2023] Open
Abstract
Ataxia-telangiectasia, mutated (ATM) protein plays a central role in phosphorylating a network of proteins in response to DNA damage. These proteins function in signaling pathways designed to maintain the stability of the genome and minimize the risk of disease by controlling cell cycle checkpoints, initiating DNA repair, and regulating gene expression. ATM kinase can be activated by a variety of stimuli, including oxidative stress. Here, we confirmed activation of cytoplasmic ATM by autophosphorylation at multiple sites. Then we employed a global quantitative phosphoproteomics approach to identify cytoplasmic proteins altered in their phosphorylation state in control and ataxia-telangiectasia (A-T) cells in response to oxidative damage. We demonstrated that ATM was activated by oxidative damage in the cytoplasm as well as in the nucleus and identified a total of 9,833 phosphorylation sites, including 6,686 high-confidence sites mapping to 2,536 unique proteins. A total of 62 differentially phosphorylated peptides were identified; of these, 43 were phosphorylated in control but not in A-T cells, and 19 varied in their level of phosphorylation. Motif enrichment analysis of phosphopeptides revealed that consensus ATM serine glutamine sites were overrepresented. When considering phosphorylation events, only observed in control cells (not observed in A-T cells), with predicted ATM sites phosphoSerine/phosphoThreonine glutamine, we narrowed this list to 11 candidate ATM-dependent cytoplasmic proteins. Two of these 11 were previously described as ATM substrates (HMGA1 and UIMCI/RAP80), another five were identified in a whole cell extract phosphoproteomic screens, and the remaining four proteins had not been identified previously in DNA damage response screens. We validated the phosphorylation of three of these proteins (oxidative stress responsive 1 (OSR1), HDGF, and ccdc82) as ATM dependent after H2O2 exposure, and another protein (S100A11) demonstrated ATM-dependence for translocation from the cytoplasm to the nucleus. These data provide new insights into the activation of ATM by oxidative stress through identification of novel substrates for ATM in the cytoplasm.
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Affiliation(s)
- Sergei V Kozlov
- From the ‡University of Queensland Centre for Clinical Research, University of Queensland, Royal Brisbane & Women's Hospital Campus, Herston, Brisbane, QLD 4029 Australia
| | - Ashley J Waardenberg
- §Bioinformatics Unit, Children's Medical Research Institute, University of Sydney, 214 Hawkesbury Road, Westmead, NSW, 2145, Australia
| | - Kasper Engholm-Keller
- ¶Synapse Proteomics Group, Children's Medical Research Institute, University of Sydney, 214 Hawkesbury Road, Westmead, NSW, 2145, Australia; ‖Department of Biochemistry and Molecular Biology, University of Southern Denmark, DK-5230 Odense M, Denmark
| | - Jonathan W Arthur
- §Bioinformatics Unit, Children's Medical Research Institute, University of Sydney, 214 Hawkesbury Road, Westmead, NSW, 2145, Australia
| | - Mark E Graham
- ¶Synapse Proteomics Group, Children's Medical Research Institute, University of Sydney, 214 Hawkesbury Road, Westmead, NSW, 2145, Australia
| | - Martin Lavin
- From the ‡University of Queensland Centre for Clinical Research, University of Queensland, Royal Brisbane & Women's Hospital Campus, Herston, Brisbane, QLD 4029 Australia;
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14
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Wang X, Knapp P, Vaynman S, Graham ME, Cao J, Ulmer MP. Experimental study and analytical model of deformation of magnetostrictive films as applied to mirrors for x-ray space telescopes. Appl Opt 2014; 53:6256-6267. [PMID: 25322105 DOI: 10.1364/ao.53.006256] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2014] [Accepted: 08/16/2014] [Indexed: 06/04/2023]
Abstract
The desire for continuously gaining new knowledge in astronomy has pushed the frontier of engineering methods to deliver lighter, thinner, higher quality mirrors at an affordable cost for use in an x-ray observatory. To address these needs, we have been investigating the application of magnetic smart materials (MSMs) deposited as a thin film on mirror substrates. MSMs have some interesting properties that make the application of MSMs to mirror substrates a promising solution for making the next generation of x-ray telescopes. Due to the ability to hold a shape with an impressed permanent magnetic field, MSMs have the potential to be the method used to make light weight, affordable x-ray telescope mirrors. This paper presents the experimental setup for measuring the deformation of the magnetostrictive bimorph specimens under an applied magnetic field, and the analytical and numerical analysis of the deformation. As a first step in the development of tools to predict deflections, we deposited Terfenol-D on the glass substrates. We then made measurements that were compared with the results from the analytical and numerical analysis. The surface profiles of thin-film specimens were measured under an external magnetic field with white light interferometry (WLI). The analytical model provides good predictions of film deformation behavior under various magnetic field strengths. This work establishes a solid foundation for further research to analyze the full three-dimensional deformation behavior of magnetostrictive thin films.
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15
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Moshkanbaryans L, Chan LS, Graham ME. The Biochemical Properties and Functions of CALM and AP180 in Clathrin Mediated Endocytosis. Membranes (Basel) 2014; 4:388-413. [PMID: 25090048 PMCID: PMC4194041 DOI: 10.3390/membranes4030388] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/05/2014] [Revised: 07/03/2014] [Accepted: 07/22/2014] [Indexed: 01/26/2023]
Abstract
Clathrin-mediated endocytosis (CME) is a fundamental process for the regulated internalization of transmembrane cargo and ligands via the formation of vesicles using a clathrin coat. A vesicle coat is initially created at the plasma membrane by clathrin assembly into a lattice, while a specific cargo sorting process selects and concentrates proteins for inclusion in the new vesicle. Vesicles formed via CME traffic to different parts of the cell and fuse with target membranes to deliver cargo. Both clathrin assembly and cargo sorting functions are features of the two gene family consisting of assembly protein 180 kDa (AP180) and clathrin assembly lymphoid myeloid leukemia protein (CALM). In this review, we compare the primary structure and domain organization of CALM and AP180 and relate these properties to known functions and roles in CME and disease.
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Affiliation(s)
- Lia Moshkanbaryans
- Children's Medical Research Institute, The University of Sydney, 214 Hawkesbury Road, Westmead, NSW 2145, Australia.
| | - Ling-Shan Chan
- Children's Medical Research Institute, The University of Sydney, 214 Hawkesbury Road, Westmead, NSW 2145, Australia.
| | - Mark E Graham
- Children's Medical Research Institute, The University of Sydney, 214 Hawkesbury Road, Westmead, NSW 2145, Australia.
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16
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Parker BL, Thaysen-Andersen M, Solis N, Scott NE, Larsen MR, Graham ME, Packer NH, Cordwell SJ. Site-Specific Glycan-Peptide Analysis for Determination of N-Glycoproteome Heterogeneity. J Proteome Res 2013; 12:5791-800. [DOI: 10.1021/pr400783j] [Citation(s) in RCA: 140] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- Benjamin L. Parker
- Discipline
of Pathology, School of Medical Sciences, The University of Sydney, Sydney 2006, Australia
| | - Morten Thaysen-Andersen
- Department
of Chemistry and Biomolecular Sciences, Macquarie University, North Ryde 2106, Australia
| | - Nestor Solis
- School
of Molecular Bioscience, The University of Sydney, Sydney 2006, Australia
| | - Nichollas E. Scott
- School
of Molecular Bioscience, The University of Sydney, Sydney 2006, Australia
| | - Martin R. Larsen
- Department of Biochemistry
and Molecular Biology, The University of Southern Denmark, DK-5230, Denmark
| | - Mark E. Graham
- Cell Signalling Unit, Children’s Medical Research Institute, Westmead 2145, Australia
| | - Nicolle H. Packer
- Department
of Chemistry and Biomolecular Sciences, Macquarie University, North Ryde 2106, Australia
| | - Stuart J. Cordwell
- Discipline
of Pathology, School of Medical Sciences, The University of Sydney, Sydney 2006, Australia
- School
of Molecular Bioscience, The University of Sydney, Sydney 2006, Australia
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17
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Palmisano G, Parker BL, Engholm-Keller K, Lendal SE, Kulej K, Schulz M, Schwämmle V, Graham ME, Saxtorph H, Cordwell SJ, Larsen MR. A novel method for the simultaneous enrichment, identification, and quantification of phosphopeptides and sialylated glycopeptides applied to a temporal profile of mouse brain development. Mol Cell Proteomics 2012; 11:1191-202. [PMID: 22843994 DOI: 10.1074/mcp.m112.017509] [Citation(s) in RCA: 107] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We describe a method that combines an optimized titanium dioxide protocol and hydrophilic interaction liquid chromatography to simultaneously enrich, identify and quantify phosphopeptides and formerly N-linked sialylated glycopeptides to monitor changes associated with cell signaling during mouse brain development. We initially applied the method to enriched membrane fractions from HeLa cells, which allowed the identification of 4468 unique phosphopeptides and 1809 formerly N-linked sialylated glycopeptides. We subsequently combined the method with isobaric tagging for relative quantification to compare changes in phosphopeptide and formerly N-linked sialylated glycopeptide abundance in the developing mouse brain. A total of 7682 unique phosphopeptide sequences and 3246 unique formerly sialylated glycopeptides were identified. Moreover 669 phosphopeptides and 300 formerly N-sialylated glycopeptides differentially regulated during mouse brain development were detected. This strategy allowed us to reveal extensive changes in post-translational modifications from postnatal mice from day 0 until maturity at day 80. The results of this study confirm the role of sialylation in organ development and provide the first extensive global view of dynamic changes between N-linked sialylation and phosphorylation.
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Affiliation(s)
- Giuseppe Palmisano
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, and Biomedical Laboratory, Odense University Hospital, Campusvej 55, 5230 Odense M, Denmark
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18
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Bolderson E, Savage KI, Mahen R, Pisupati V, Graham ME, Richard DJ, Robinson PJ, Venkitaraman AR, Khanna KK. Kruppel-associated Box (KRAB)-associated co-repressor (KAP-1) Ser-473 phosphorylation regulates heterochromatin protein 1β (HP1-β) mobilization and DNA repair in heterochromatin. J Biol Chem 2012; 287:28122-31. [PMID: 22715096 DOI: 10.1074/jbc.m112.368381] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
The DNA damage response encompasses a complex series of signaling pathways that function to regulate and facilitate the repair of damaged DNA. Recent studies have shown that the repair of transcriptionally inactive chromatin, named heterochromatin, is dependent upon the phosphorylation of the co-repressor, Krüppel-associated box (KRAB) domain-associated protein (KAP-1), by the ataxia telangiectasia-mutated (ATM) kinase. Co-repressors, such as KAP-1, function to regulate the rigid structure of heterochromatin by recruiting histone-modifying enzymes, such HDAC1/2, SETDB1, and nucleosome-remodeling complexes such as CHD3. Here, we have characterized a phosphorylation site in the HP1-binding domain of KAP-1, Ser-473, which is phosphorylated by the cell cycle checkpoint kinase Chk2. Expression of a nonphosphorylatable S473A mutant conferred cellular sensitivity to DNA-damaging agents and led to defective repair of DNA double-strand breaks in heterochromatin. In addition, cells expressing S473A also displayed defective mobilization of the HP1-β chromodomain protein. The DNA repair defect observed in cells expressing S473A was alleviated by depletion of HP1-β, suggesting that phosphorylation of KAP-1 on Ser-473 promotes the mobilization of HP1-β from heterochromatin and subsequent DNA repair. These results suggest a novel mechanism of KAP-1-mediated chromatin restructuring via Chk2-regulated HP1-β exchange from heterochromatin, promoting DNA repair.
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Affiliation(s)
- Emma Bolderson
- Signal Transduction Laboratory, Queensland Institute of Medical Research, Brisbane, Queensland 4029, Australia
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19
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Abstract
Congenital indifference to pain (CIP) is a rare condition characterised by painless injuries beginning in early life, with normal sensory exam findings. Young people with inexplicable, painless chronic wounds may present to the plastic surgeon for surgical management. Given the young age of onset and high likelihood of postoperative failure, alternative options for closure of non-healing wounds should be considered. We present the case of a 17-year-old boy with congenital indifference to pain and successful management of his longstanding plantar ulcer.
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Affiliation(s)
- A Simpson
- Faculty of Medicine, Dalhousie University, Novia Scotia, Canada
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Graham ME, Stone RS, Robinson PJ, Payne RJ. Synthesis and protein binding studies of a peptide fragment of clathrin assembly protein AP180 bearing an O-linked β-N-acetylglucosaminyl-6-phosphate modification. Org Biomol Chem 2012; 10:2545-51. [DOI: 10.1039/c2ob07139h] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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21
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Chircop M, Sarcevic B, Larsen MR, Malladi CS, Chau N, Zavortink M, Smith CM, Quan A, Anggono V, Hains PG, Graham ME, Robinson PJ. Phosphorylation of dynamin II at serine-764 is associated with cytokinesis. Biochimica et Biophysica Acta (BBA) - Molecular Cell Research 2011; 1813:1689-99. [DOI: 10.1016/j.bbamcr.2010.12.018] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2010] [Revised: 11/30/2010] [Accepted: 12/21/2010] [Indexed: 10/18/2022]
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22
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Xue J, Graham ME, Novelle AE, Sue N, Gray N, McNiven MA, Smillie KJ, Cousin MA, Robinson PJ. Calcineurin selectively docks with the dynamin Ixb splice variant to regulate activity-dependent bulk endocytosis. J Biol Chem 2011; 286:30295-30303. [PMID: 21730063 DOI: 10.1074/jbc.m111.273110] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Depolarization of nerve terminals stimulates rapid dephosphorylation of two isoforms of dynamin I (dynI), mediated by the calcium-dependent phosphatase calcineurin (CaN). Dephosphorylation at the major phosphorylation sites Ser-774/778 promotes a dynI-syndapin I interaction for a specific mode of synaptic vesicle endocytosis called activity-dependent bulk endocytosis (ADBE). DynI has two main splice variants at its extreme C terminus, long or short (dynIxa and dynIxb) varying only by 20 (xa) or 7 (xb) residues. Recombinant GST fusion proteins of dynIxa and dynIxb proline-rich domains (PRDs) were used to pull down interacting proteins from rat brain nerve terminals. Both bound equally to syndapin, but dynIxb PRD exclusively bound to the catalytic subunit of CaNA, which recruited CaNB. Binding of CaN was increased in the presence of calcium and was accompanied by further recruitment of calmodulin. Point mutations showed that the entire C terminus of dynIxb is a CaN docking site related to a conserved CaN docking motif (PXIXI(T/S)). This sequence is unique to dynIxb among all other dynamin variants or genes. Peptide mimetics of the dynIxb tail blocked CaN binding in vitro and selectively inhibited depolarization-evoked dynI dephosphorylation in nerve terminals but not of other dephosphins. Therefore, docking to dynIxb is required for the regulation of both dynI splice variants, yet it does not regulate the phosphorylation cycle of other dephosphins. The peptide blocked ADBE, but not clathrin-mediated endocytosis of synaptic vesicles. Our results indicate that Ca(2+) influx regulates assembly of a fully active CaN-calmodulin complex selectively on the tail of dynIxb and that the complex is recruited to sites of ADBE in nerve terminals.
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Affiliation(s)
- Jing Xue
- Cell Signalling Unit, Children's Medical Research Institute, University of Sydney, Locked Bag 23, Wentworthville 2145, New South Wales, Australia
| | - Mark E Graham
- Cell Signalling Unit, Children's Medical Research Institute, University of Sydney, Locked Bag 23, Wentworthville 2145, New South Wales, Australia
| | - Aimee E Novelle
- Cell Signalling Unit, Children's Medical Research Institute, University of Sydney, Locked Bag 23, Wentworthville 2145, New South Wales, Australia
| | - Nancy Sue
- Cell Signalling Unit, Children's Medical Research Institute, University of Sydney, Locked Bag 23, Wentworthville 2145, New South Wales, Australia
| | - Noah Gray
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, Minnesota 55905
| | - Mark A McNiven
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, Minnesota 55905
| | - Karen J Smillie
- Membrane Biology Group, Centre for Integrative Physiology, University of Edinburgh, George Square, Edinburgh EH8 9XD, United Kingdom
| | - Michael A Cousin
- Membrane Biology Group, Centre for Integrative Physiology, University of Edinburgh, George Square, Edinburgh EH8 9XD, United Kingdom
| | - Phillip J Robinson
- Cell Signalling Unit, Children's Medical Research Institute, University of Sydney, Locked Bag 23, Wentworthville 2145, New South Wales, Australia.
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Graham ME, Thaysen-Andersen M, Bache N, Craft GE, Larsen MR, Packer NH, Robinson PJ. A novel post-translational modification in nerve terminals: O-linked N-acetylglucosamine phosphorylation. J Proteome Res 2011; 10:2725-33. [PMID: 21500857 DOI: 10.1021/pr1011153] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Protein phosphorylation and glycosylation are the most common post-translational modifications observed in biology, frequently on the same protein. Assembly protein AP180 is a synapse-specific phosphoprotein and O-linked beta-N-acetylglucosamine (O-GlcNAc) modified glycoprotein. AP180 is involved in the assembly of clathrin coated vesicles in synaptic vesicle endocytosis. Unlike other types of O-glycosylation, O-GlcNAc is nucleocytoplasmic and reversible. It was thought to be a terminal modification, that is, the O-GlcNAc was not found to be additionally modified in any way. We now show that AP180 purified from rat brain contains a phosphorylated O-GlcNAc (O-GlcNAc-P) within a highly conserved sequence. O-GlcNAc or O-GlcNAc-P, but not phosphorylation alone, was found at Thr-310. Analysis of synthetic GlcNAc-6-P produced identical fragmentation products to GlcNAc-P from AP180. Direct O-linkage of GlcNAc-P to a Thr residue was confirmed by electron transfer dissociation MS. A second AP180 tryptic peptide was also glycosyl phosphorylated, but the site of modification was not assigned. Sequence similarities suggest there may be a common motif within AP180 involving glycosyl phosphorylation and dual flanking phosphorylation sites within 4 amino acid residues. This novel type of protein glycosyl phosphorylation adds a new signaling mechanism to the regulation of neurotransmission and more complexity to the study of O-GlcNAc modification.
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Affiliation(s)
- Mark E Graham
- Cell Signalling Unit, Children's Medical Research Institute, The University of Sydney, Westmead, Australia.
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Kozlov SV, Graham ME, Jakob B, Tobias F, Kijas AW, Tanuji M, Chen P, Robinson PJ, Taucher-Scholz G, Suzuki K, So S, Chen D, Lavin MF. Autophosphorylation and ATM activation: additional sites add to the complexity. J Biol Chem 2011; 286:9107-19. [PMID: 21149446 PMCID: PMC3059052 DOI: 10.1074/jbc.m110.204065] [Citation(s) in RCA: 141] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2010] [Indexed: 12/18/2022] Open
Abstract
The recognition and signaling of DNA double strand breaks involves the participation of multiple proteins, including the protein kinase ATM (mutated in ataxia-telangiectasia). ATM kinase is activated in the vicinity of the break and is recruited to the break site by the Mre11-Rad50-Nbs1 complex, where it is fully activated. In human cells, the activation process involves autophosphorylation on three sites (Ser(367), Ser(1893), and Ser(1981)) and acetylation on Lys(3016). We now describe the identification of a new ATM phosphorylation site, Thr(P)(1885) and an additional autophosphorylation site, Ser(P)(2996), that is highly DNA damage-inducible. We also confirm that human and murine ATM share five identical phosphorylation sites. We targeted the ATM phosphorylation sites, Ser(367) and Ser(2996), for further study by generating phosphospecific antibodies against these sites and demonstrated that phosphorylation of both was rapidly induced by radiation. These phosphorylations were abolished by a specific inhibitor of ATM and were dependent on ATM and the Mre11-Rad50-Nbs1 complex. As found for Ser(P)(1981), ATM phosphorylated at Ser(367) and Ser(2996) localized to sites of DNA damage induced by radiation, but ATM recruitment was not dependent on phosphorylation at these sites. Phosphorylation at Ser(367) and Ser(2996) was functionally important because mutant forms of ATM were defective in correcting the S phase checkpoint defect and restoring radioresistance in ataxia-telangiectasia cells. These data provide further support for the importance of autophosphorylation in the activation and function of ATM in vivo.
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Affiliation(s)
- Sergei V. Kozlov
- From Radiation Biology and Oncology, Queensland Institute of Medical Research, Brisbane, Queensland 4029, Australia
| | - Mark E. Graham
- the Children's Medical Research Institute, University of Sydney, Westmead, New South Wales 2145, Australia
| | - Burkhard Jakob
- GSI Helmholtzzentrum für Schwerionenforschung GmbH, Biophysik, Planckstrasse 1, D-64291 Darmstadt, Germany
| | - Frank Tobias
- GSI Helmholtzzentrum für Schwerionenforschung GmbH, Biophysik, Planckstrasse 1, D-64291 Darmstadt, Germany
| | - Amanda W. Kijas
- From Radiation Biology and Oncology, Queensland Institute of Medical Research, Brisbane, Queensland 4029, Australia
| | - Marcel Tanuji
- From Radiation Biology and Oncology, Queensland Institute of Medical Research, Brisbane, Queensland 4029, Australia
| | - Philip Chen
- From Radiation Biology and Oncology, Queensland Institute of Medical Research, Brisbane, Queensland 4029, Australia
| | - Phillip J. Robinson
- the Children's Medical Research Institute, University of Sydney, Westmead, New South Wales 2145, Australia
| | - Gisela Taucher-Scholz
- GSI Helmholtzzentrum für Schwerionenforschung GmbH, Biophysik, Planckstrasse 1, D-64291 Darmstadt, Germany
| | - Keiji Suzuki
- the Department of Molecular Medicine, Nagasaki University Graduate School of Biomedical Sciences, 1-12-4 Sakamoto, Nagasaki 852-8523, Japan
| | - Sairai So
- the University of Texas Southwestern Medical Center, Dallas, Texas 75390, and
| | - David Chen
- the University of Texas Southwestern Medical Center, Dallas, Texas 75390, and
| | - Martin F. Lavin
- From Radiation Biology and Oncology, Queensland Institute of Medical Research, Brisbane, Queensland 4029, Australia
- the University of Queensland Centre for Clinical Research, Brisbane, Queensland 4029, Australia
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Chan LS, Hansra G, Robinson PJ, Graham ME. Differential phosphorylation of dynamin I isoforms in subcellular compartments demonstrates the hidden complexity of phosphoproteomes. J Proteome Res 2010; 9:4028-37. [PMID: 20560669 DOI: 10.1021/pr100223n] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Large-scale comparative phosphoproteomics studies have frequently been done on whole cells or organs by conventional bottom-up mass spectrometry approaches, that is, at the phosphopeptide level. Using this approach, there is no way to know which protein isoforms the phosphopeptide signal originated from. Also, as a consequence of the scale of these studies, important information on the localization of phosphorylation sites in subcellular compartments is not surveyed. As a case study, we investigated whether the isoforms of dynamin I (dynI), at the whole brain and subcellular level, had differential phosphorylation. We first established that the dynI isoforms xa, xb, and xd were expressed in nerve terminals. Our investigation revealed that dynI xa was constitutively phosphorylated to a higher extent than the other isoforms despite identical sequences in the phosphorylated subdomains. DynI xa had a 10-fold higher stoichiometry of diphosphorylation at Ser-774 and Ser-778 than dynI xb and xd combined. Diphosphorylation was 2-fold enriched in nerve terminals relative to whole brain and was preferentially targeted for stimulus-dependent dephosphorylation. Phospho-Ser-851 and Ser-857 were depleted from nerve terminals. Our data reveals major differential phosphorylation of dynI phosphosites in different variants and in different neuronal compartments that would be completely imperceptible to a large-scale phosphoproteomics approach.
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Affiliation(s)
- Ling-Shan Chan
- Cell Signalling Unit, Children's Medical Research Institute, The University of Sydney, Westmead, Australia
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Baker MA, Smith ND, Hetherington L, Taubman K, Graham ME, Robinson PJ, Aitken RJ. Label-Free Quantitation of Phosphopeptide Changes During Rat Sperm Capacitation. J Proteome Res 2010; 9:718-29. [DOI: 10.1021/pr900513d] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Mark A. Baker
- The ARC Centre of Excellence in Biotechnology and Development, Priority Research Centre in Reproductive Science, School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW, 2308, Australia, and Cell Signaling Unit, Childrens’ Medical Research Institute, The University of Sydney, Westmead, NSW, 2145, Australia
| | - Nathan D. Smith
- The ARC Centre of Excellence in Biotechnology and Development, Priority Research Centre in Reproductive Science, School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW, 2308, Australia, and Cell Signaling Unit, Childrens’ Medical Research Institute, The University of Sydney, Westmead, NSW, 2145, Australia
| | - Louise Hetherington
- The ARC Centre of Excellence in Biotechnology and Development, Priority Research Centre in Reproductive Science, School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW, 2308, Australia, and Cell Signaling Unit, Childrens’ Medical Research Institute, The University of Sydney, Westmead, NSW, 2145, Australia
| | - Kristy Taubman
- The ARC Centre of Excellence in Biotechnology and Development, Priority Research Centre in Reproductive Science, School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW, 2308, Australia, and Cell Signaling Unit, Childrens’ Medical Research Institute, The University of Sydney, Westmead, NSW, 2145, Australia
| | - Mark E. Graham
- The ARC Centre of Excellence in Biotechnology and Development, Priority Research Centre in Reproductive Science, School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW, 2308, Australia, and Cell Signaling Unit, Childrens’ Medical Research Institute, The University of Sydney, Westmead, NSW, 2145, Australia
| | - Phillip J. Robinson
- The ARC Centre of Excellence in Biotechnology and Development, Priority Research Centre in Reproductive Science, School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW, 2308, Australia, and Cell Signaling Unit, Childrens’ Medical Research Institute, The University of Sydney, Westmead, NSW, 2145, Australia
| | - R. John Aitken
- The ARC Centre of Excellence in Biotechnology and Development, Priority Research Centre in Reproductive Science, School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW, 2308, Australia, and Cell Signaling Unit, Childrens’ Medical Research Institute, The University of Sydney, Westmead, NSW, 2145, Australia
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Chircop M, Oakes V, Graham ME, Ma MPC, Smith CM, Robinson PJ, Khanna KK. The actin-binding and bundling protein, EPLIN, is required for cytokinesis. Cell Cycle 2009; 8:757-64. [PMID: 19221476 DOI: 10.4161/cc.8.5.7878] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Cytokinesis involves two phases: (1) membrane ingression followed by (2) membrane abscission. The ingression phase generates a cleavage furrow and this requires co-operative function of the actin-myosin II contractile ring and septin filaments. We demonstrate that the actin-binding protein, EPLIN, locates to the cleavage furrow during cytokinesis and this is possibly via association with the contractile ring components, myosin II and the septin, Sept2. Depletion of EPLIN results in formation of multinucleated cells and this is associated with inefficient accumulation of active myosin II (MRLC(S19)) and Sept2 and their regulatory small GTPases, RhoA and Cdc42, respectively, to the cleavage furrow during the final stages of cytokinesis. We suggest that EPLIN may function during cytokinesis to maintain local accumulation of key cytokinesis proteins at the furrow.
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Affiliation(s)
- Megan Chircop
- Queensland Institute of Medical Research, Post Office Royal Brisbane Hospital, Brisbane, Queensland, Australia.
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Craft GE, Graham ME, Bache N, Larsen MR, Robinson PJ. The in vivo phosphorylation sites in multiple isoforms of amphiphysin I from rat brain nerve terminals. Mol Cell Proteomics 2008; 7:1146-61. [PMID: 18344231 DOI: 10.1074/mcp.m700351-mcp200] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Amphiphysin I (amphI) is dephosphorylated by calcineurin during nerve terminal depolarization and synaptic vesicle endocytosis (SVE). Some amphI phosphorylation sites (phosphosites) have been identified with in vitro studies or phosphoproteomics screens. We used a multifaceted strategy including 32P tracking to identify all in vivo amphI phosphosites and determine their relative abundance and potential relevance to SVE. AmphI was extracted from 32P-labeled synaptosomes, phosphopeptides were isolated from proteolytic digests using TiO2 chromatography, and mass spectrometry revealed 13 sites: serines 250, 252, 262, 268, 272, 276, 285, 293, 496, 514, 539, and 626 and Thr-310. These were distributed into two clusters around the proline-rich domain and the C-terminal Src homology 3 domain. Hierarchical phosphorylation of Ser-262 preceded phosphorylation of Ser-268, -272, -276, and -285. Off-line HPLC separation and two-dimensional tryptic mapping of 32P-labeled amphI revealed that Thr-310, Ser-293, Ser-285, Ser-272, Ser-276, and Ser-268 contained the highest 32P incorporation and were the most stimulus-sensitive. Individually Thr-310 and Ser-293 were the most abundant phosphosites, incorporating 16 and 23% of the 32P. The multiple phosphopeptides containing Ser-268, Ser-276, Ser-272, and Ser-285 had 27% of the 32P. Evidence for a role for at least one proline-directed protein kinase and one non-proline-directed kinase was obtained. Four phosphosites predicted for non-proline-directed kinases, Ser-626, -250, -252, and -539, contained low amounts of 32P and were not depolarization-responsive. At least one alternatively spliced amphI isoform was identified in synaptosomes as being constitutively phosphorylated because it did not incorporate 32P during the 1-h labeling period. Multiple phosphosites from amphI-co-migrating synaptosomal proteins were also identified, including SGIP (Src homology 3 domain growth factor receptor-bound 2 (Grb2)-like (endophilin)-interacting protein 1), AAK1, eps15R, MAP6, alpha/beta-adducin, and HCN1. The results reveal two sets of amphI phosphosites that are either dynamically turning over or constitutively phosphorylated in nerve terminals and improve understanding of the role of individual amphI sites or phosphosite clusters in synaptic SVE.
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Affiliation(s)
- George E Craft
- Cell Signalling Unit, Children's Medical Research Institute, The University of Sydney, Locked Bag 23, Wentworthville, New South Wales 2145, Australia
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Abstract
Telomeric DNA can assemble into a nonlinear, higher-order conformation known as a G-quadruplex. Here, we demonstrate by electrospray ionization mass spectrometry that the two repeat telomeric sequence d(TGGGGTTGGGGT) from Tetrahymena thermophila gives rise to a novel parallel four-stranded G-quadruplex in the presence of sodium. The G-quadruplex directly interacts with the catalytic subunit of Tetrahymena telomerase (TERT) with micromolar affinity, and the presence of telomerase RNA is not obligatory for this interaction. Both N- and C-terminal halves of TERT bind the G-quadruplex independently. This G-quadruplex is a robust substrate for both recombinant and cell extract-derived telomerase in vitro. Furthermore, the G-quadruplex weakens the affinity of wild-type telomerase for the incoming nucleotide (dTTP) and likely perturbs the nucleotide binding pocket of the enzyme. In agreement with this, a lysine to alanine substitution at amino acid 538 (K538A) within motif 1 of TERT dramatically reduces the ability of telomerase to extend G-quadruplex but not linear DNA. The K538A mutant retains binding affinity for the quadruplex. This suggests that telomerase undergoes changes in conformation in its active site to specifically accommodate binding and subsequent extension of G-quadruplex DNA. We propose that telomerase recognizes G-quadruplex DNA as a substrate that is distinct from linear DNA.
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Affiliation(s)
- Liana Oganesian
- Children's Medical Research Institute, 214 Hawkesbury Road, Westmead NSW 2145, Australia and University of Sydney, NSW 2006, Australia
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Graham ME, Kilby DM, Firth SM, Robinson PJ, Baxter RC. The in vivo phosphorylation and glycosylation of human insulin-like growth factor-binding protein-5. Mol Cell Proteomics 2007; 6:1392-405. [PMID: 17496250 DOI: 10.1074/mcp.m700027-mcp200] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Mass spectrometry is often used to determine post-translational modifications by analysis of tryptic digests of proteins. Here we demonstrate that the analysis of tryptic peptides together with analysis of the full-length protein provided optimal characterization of insulin-like growth factor-binding protein-5 (IGFBP-5) phosphorylation and glycosylation. IGFBP-5 binds insulin-like growth factors with high affinity and has important roles in cell survival, differentiation, and apoptosis. Until now, the primary structure of IGFBP-5 has been incompletely defined. We analyzed human IGFBP-5 from T47D cells by mass spectrometry to determine all of the in vivo post-translational modifications. In full-length IGFBP-5, 31% of the protein was unmodified, 37% was monophosphorylated, and 4% was diphosphorylated with no other modification. The remaining 27% was glycosylated, more than half of which was also monophosphorylated. The major phosphorylation site was Ser(96) in the central domain, and a minor phosphorylation site was Ser(248) near the C terminus. Neither site was phosphorylated in vitro by casein kinase 2, ruling it out as the in vivo kinase. An in vivo phosphorylation site was also found in IGFBP-2 at an analogous position, Ser(106). IGFBP-5 was heterogeneously O-glycosylated mainly by sialylated core 1 type glycans. The most abundant structure contained N-acetylhexosamine, hexose, and two N-acetylneuraminic acid carbohydrates. A small amount of sialylated core 2 type glycan was also present. Phosphorylation and O-glycosylation both affected IGFBP-5 binding to heparin but not insulin-like growth factor binding or ternary complex formation with the acid-labile subunit. The results reveal the first description of the in vivo phosphorylation of IGFBP-5 and its glycan composition.
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Affiliation(s)
- Mark E Graham
- Cell Signalling Unit, Children's Medical Research Institute, Locked Bag 23, Wentworthville, New South Wales 2145, Australia
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31
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Abstract
Telomerase is a ribonucleoprotein enzyme complex that adds 5'-TTAGGG-3' repeats onto the ends of human chromosomes, providing a telomere maintenance mechanism for approximately 90% of human cancers. We have purified human telomerase approximately 10(8)-fold, with the final elution dependent on the enzyme's ability to catalyze nucleotide addition onto a DNA oligonucleotide of telomeric sequence, thereby providing specificity for catalytically active telomerase. Mass spectrometric sequencing of the protein components and molecular size determination indicated an enzyme composition of two molecules each of telomerase reverse transcriptase, telomerase RNA, and dyskerin.
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Affiliation(s)
- Scott B Cohen
- Cancer Research Unit, Children's Medical Research Institute, 214 Hawkesbury Road, Westmead NSW 2145, Australia
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Abstract
Dynamin I (dynI) is phosphorylated in synaptosomes at Ser(774) and Ser(778) by cyclin-dependent kinase 5 to regulate recruitment of syndapin I for synaptic vesicle endocytosis, and in PC12 cells on Ser(857). Hierarchical phosphorylation of Ser(774) precedes phosphorylation of Ser(778). In contrast, Thr(780) phosphorylation by cdk5 has been reported as the sole site (Tomizawa, K., Sunada, S., Lu, Y. F., Oda, Y., Kinuta, M., Ohshima, T., Saito, T., Wei, F. Y., Matsushita, M., Li, S. T., Tsutsui, K., Hisanaga, S. I., Mikoshiba, K., Takei, K., and Matsui, H. (2003) J. Cell Biol. 163, 813-824). To resolve the discrepancy and to better understand the biological roles of dynI phosphorylation, we undertook a systematic identification of all phosphorylation sites in rat brain nerve terminal dynI. Using phosphoamino acid analysis, exclusively phospho-serine residues were found. Thr(780) phosphorylation was not detectable. Mutation of Ser(774), Ser(778), and Thr(780) confirmed that Thr(780) phosphorylation is restricted to in vitro conditions. Mass spectrometry of (32)P-labeled phosphopeptides separated by two-dimensional mapping revealed seven in vivo phosphorylation sites: Ser(774), Ser(778), Ser(822), Ser(851), Ser(857), Ser(512), and Ser(347). Quantification of (32)P radiation in each phosphopeptide showed that Ser(774) and Ser(778) were the major sites (up to 69% of the total), followed by Ser(851) and Ser(857) (12%), and Ser(853) (2%). Phosphorylation of Ser(851) and Ser(857) was restricted to the long tail splice variant dynIxa and was not hierarchical. Co-purified, (32)P-labeled dynIII was phosphorylated at Ser(759), Ser(763), and Ser(853). Ser(853) is homologous to Ser(851) in dynIxa. The results identify all major and several minor phosphorylation sites in dynI and provide the first measure of their relative abundance and relative responses to depolarization. The multiple phospho-sites suggest subtle regulation of synaptic vesicle endocytosis by new protein kinases and new protein-protein interactions. The homologous dynI and dynIII phosphorylation indicates a high mechanistic similarity. The results suggest a unique role for the long splice variants of dynI and dynIII in nerve terminals.
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Affiliation(s)
- Mark E Graham
- Cell Signaling Unit, Children's Medical Research Institute, Locked Bag 23, Wentworthville, New South Wales 2145, Australia
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33
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Kozlov SV, Graham ME, Peng C, Chen P, Robinson PJ, Lavin MF. Involvement of novel autophosphorylation sites in ATM activation. EMBO J 2006; 25:3504-14. [PMID: 16858402 PMCID: PMC1538573 DOI: 10.1038/sj.emboj.7601231] [Citation(s) in RCA: 213] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2005] [Accepted: 06/20/2006] [Indexed: 12/31/2022] Open
Abstract
ATM kinase plays a central role in signaling DNA double-strand breaks to cell cycle checkpoints and to the DNA repair machinery. Although the exact mechanism of ATM activation remains unknown, efficient activation requires the Mre11 complex, autophosphorylation on S1981 and the involvement of protein phosphatases and acetylases. We report here the identification of several additional phosphorylation sites on ATM in response to DNA damage, including autophosphorylation on pS367 and pS1893. ATM autophosphorylates all these sites in vitro in response to DNA damage. Antibodies against phosphoserine 1893 revealed rapid and persistent phosphorylation at this site after in vivo activation of ATM kinase by ionizing radiation, paralleling that observed for S1981 phosphorylation. Phosphorylation was dependent on functional ATM and on the Mre11 complex. All three autophosphorylation sites are physiologically important parts of the DNA damage response, as phosphorylation site mutants (S367A, S1893A and S1981A) were each defective in ATM signaling in vivo and each failed to correct radiosensitivity, genome instability and cell cycle checkpoint defects in ataxia-telangiectasia cells. We conclude that there are at least three functionally important radiation-induced autophosphorylation events in ATM.
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Affiliation(s)
- Sergei V Kozlov
- The Queensland Institute of Medical Research, Post Office Royal Brisbane Hospital, Herston, Brisbane, Queensland, Australia
| | - Mark E Graham
- Cell Signalling Unit, Children's Medical Research Institute, Westmead, New South Wales, Australia
| | - Cheng Peng
- The Queensland Institute of Medical Research, Post Office Royal Brisbane Hospital, Herston, Brisbane, Queensland, Australia
| | - Philip Chen
- The Queensland Institute of Medical Research, Post Office Royal Brisbane Hospital, Herston, Brisbane, Queensland, Australia
| | - Phillip J Robinson
- Cell Signalling Unit, Children's Medical Research Institute, Westmead, New South Wales, Australia
| | - Martin F Lavin
- The Queensland Institute of Medical Research, Post Office Royal Brisbane Hospital, Herston, Brisbane, Queensland, Australia
- Central Clinical Division, University of Queensland, PO Royal Brisbane Hospital, Herston, Queensland, Australia
- The Queensland Cancer Fund Research Unit, The Queensland Institute of Medical Research, Post Office Royal Brisbane Hospital, Herston, Brisbane, Queensland 4029, Australia. Tel.: +61 7 3362 0335; Fax: +61 7 3362 0106; E-mail:
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Anggono V, Smillie KJ, Graham ME, Valova VA, Cousin MA, Robinson PJ. Syndapin I is the phosphorylation-regulated dynamin I partner in synaptic vesicle endocytosis. Nat Neurosci 2006; 9:752-60. [PMID: 16648848 PMCID: PMC2082060 DOI: 10.1038/nn1695] [Citation(s) in RCA: 176] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2006] [Accepted: 04/10/2006] [Indexed: 01/12/2023]
Abstract
Dynamin I is dephosphorylated at Ser-774 and Ser-778 during synaptic vesicle endocytosis (SVE) in nerve terminals. Phosphorylation was proposed to regulate the assembly of an endocytic protein complex with amphiphysin or endophilin. Instead, we found it recruits syndapin I for SVE and does not control amphiphysin or endophilin binding in rat synaptosomes. After depolarization, syndapin showed a calcineurin-mediated interaction with dynamin. A peptide mimicking the phosphorylation sites disrupted the dynamin-syndapin complex, not the dynamin-endophilin complex, arrested SVE and produced glutamate release fatigue after repetitive stimulation. Pseudophosphorylation of Ser-774 or Ser-778 inhibited syndapin binding without affecting amphiphysin recruitment. Site mutagenesis to alanine arrested SVE in cultured neurons. The effects of the sites were additive for syndapin I binding and SVE. Thus syndapin I is a central component of the endocytic protein complex for SVE via stimulus-dependent recruitment to dynamin I and has a key role in synaptic transmission.
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Affiliation(s)
- Victor Anggono
- Cell Signalling Unit, Children's Medical Research Institute, Locked Bag 23, Wentworthville, NSW 2145, Australia
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Abstract
PKC (protein kinase C) has been known for many years to modulate regulated exocytosis in a wide variety of cell types. In neurons and neuroendocrine cells, PKC regulates several different stages of the exocytotic process, suggesting that these multiple actions of PKC are mediated by phosphorylation of distinct protein targets. In recent years, a variety of exocytotic proteins have been identified as PKC substrates, the best characterized of which are SNAP-25 (25 kDa synaptosome-associated protein) and Munc18. In the present study, we review recent evidence suggesting that site-specific phosphorylation of SNAP-25 and Munc18 by PKC regulates distinct stages of exocytosis.
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Affiliation(s)
- A Morgan
- The Physiological Laboratory, School of Biomedical Sciences, University of Liverpool, Liverpool, UK.
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Hill T, Odell LR, Edwards JK, Graham ME, McGeachie AB, Rusak J, Quan A, Abagyan R, Scott JL, Robinson PJ, McCluskey A. Small molecule inhibitors of dynamin I GTPase activity: development of dimeric tyrphostins. J Med Chem 2006; 48:7781-8. [PMID: 16302817 DOI: 10.1021/jm040208l] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Dynamin I is a GTPase enzyme required for endocytosis and is an excellent target for the design of potential endocytosis inhibitors. Screening of a library of tyrphostins, in our laboratory, against the GTPase activity of dynamin I gave rise to a microM potent lead, 2-cyano-3-(3,4-dihydroxyphenyl)thioacrylamide (1, IC50 70 microM). Our initial investigations suggested that only the dimeric form of 1 displayed dynamin I GTPase inhibitory activity. Subsequent synthetic iterations were based on dimeric analogues and afforded a number of small molecules, low microM potent, inhibitors of dynamin I GTPase, in particular, symmetrical analogues with a minimum of two free phenolic -OHs: catechol-acrylamide (9) (IC50= 5.1 +/- 0.6 microM), its 3,4,5-trihydroxy congener (10) (IC50= 1.7 +/- 0.2 microM), and the corresponding 3-methyl ether (11) (IC50= 9 +/- 3 microM). Increasing the length of the central alkyl spacer from ethyl to propyl (22-24) afforded essentially identical activity with IC50's of 1.7 +/- 0.2, 1.7 +/- 0.2, and 5 +/- 1 microM, respectively. No decrease in activity was noted until the introduction of a hexyl spacer. Our studies highlight the requirement for two free amido NHs with neither the mono-N-methyl (86) nor the bis-N-methyl (87) analogues inhibiting dynamin I GTPase. A similar effect was noted for the removal of the nitrile moieties. However, modest potency was observed with the corresponding ester analogues of 9-11: ethyl ester (90), propyl ester (91), and butyl ester (92), with IC50's of 42 +/- 3, 38 +/- 2, and 61 +/- 2 microM, respectively. Our studies reveal the most potent and promising dynamin I GTPase inhibitor in this series as (22), which is also known as BisT.
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Affiliation(s)
- Timothy Hill
- Discipline of Chemistry, Chemistry Building, School of Environmental and Life Sciences, The University of Newcastle, Callaghan, NSW 2308, Australia
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37
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Fabbro M, Zhou BB, Takahashi M, Sarcevic B, Lal P, Graham ME, Gabrielli BG, Robinson PJ, Nigg EA, Ono Y, Khanna KK. Cdk1/Erk2- and Plk1-dependent phosphorylation of a centrosome protein, Cep55, is required for its recruitment to midbody and cytokinesis. Dev Cell 2005; 9:477-88. [PMID: 16198290 DOI: 10.1016/j.devcel.2005.09.003] [Citation(s) in RCA: 242] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2005] [Revised: 08/15/2005] [Accepted: 09/01/2005] [Indexed: 11/30/2022]
Abstract
Centrosomes in mammalian cells have recently been implicated in cytokinesis; however, their role in this process is poorly defined. Here, we describe a human coiled-coil protein, Cep55 (centrosome protein 55 kDa), that localizes to the mother centriole during interphase. Despite its association with gamma-TuRC anchoring proteins CG-NAP and Kendrin, Cep55 is not required for microtubule nucleation. Upon mitotic entry, centrosome dissociation of Cep55 is triggered by Erk2/Cdk1-dependent phosphorylation at S425 and S428. Furthermore, Cep55 locates to the midbody and plays a role in cytokinesis, as its depletion by siRNA results in failure of this process. S425/428 phosphorylation is required for interaction with Plk1, enabling phosphorylation of Cep55 at S436. Cells expressing phosphorylation-deficient mutant forms of Cep55 undergo cytokinesis failure. These results highlight the centrosome as a site to organize phosphorylation of Cep55, enabling it to relocate to the midbody to function in mitotic exit and cytokinesis.
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Affiliation(s)
- Megan Fabbro
- Queensland Institute of Medical Research, P.O. Royal Brisbane Hospital, Brisbane, Queensland 4029, Australia
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38
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Abstract
The rate-limiting enzyme in catecholamine synthesis is tyrosine hydroxylase. It is phosphorylated at serine (Ser) residues Ser8, Ser19, Ser31 and Ser40 in vitro, in situ and in vivo. A range of protein kinases and protein phosphatases are able to phosphorylate or dephosphorylate these sites in vitro. Some of these enzymes are able to regulate tyrosine hydroxylase phosphorylation in situ and in vivo but the identity of the kinases and phosphatases is incomplete, especially for physiologically relevant stimuli. The stoichiometry of tyrosine hydroxylase phosphorylation in situ and in vivo is low. The phosphorylation of tyrosine hydroxylase at Ser40 increases the enzyme's activity in vitro, in situ and in vivo. Phosphorylation at Ser31 also increases the activity but to a much lesser extent than for Ser40 phosphorylation. The phosphorylation of tyrosine hydroxylase at Ser19 or Ser8 has no direct effect on tyrosine hydroxylase activity. Hierarchical phosphorylation of tyrosine hydroxylase occurs both in vitro and in situ, whereby the phosphorylation at Ser19 increases the rate of Ser40 phosphorylation leading to an increase in enzyme activity. Hierarchical phosphorylation depends on the state of the substrate providing a novel form of control of tyrosine hydroxylase activation.
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Affiliation(s)
- Peter R Dunkley
- School of Biomedical Sciences, The University of Newcastle, Callaghan, New South Wales, Australia.
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39
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Larsen MR, Graham ME, Robinson PJ, Roepstorff P. Improved detection of hydrophilic phosphopeptides using graphite powder microcolumns and mass spectrometry: evidence for in vivo doubly phosphorylated dynamin I and dynamin III. Mol Cell Proteomics 2004; 3:456-65. [PMID: 14762214 DOI: 10.1074/mcp.m300105-mcp200] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
A common strategy in proteomics to improve the number and quality of peptides detected by mass spectrometry (MS) is to desalt and concentrate proteolytic digests using reversed phase (RP) chromatography prior to analysis. However, this does not allow for detection of small or hydrophilic peptides, or peptides altered in hydrophilicity such as phosphopeptides. We used microcolumns to compare the ability of RP resin or graphite powder to retain phosphopeptides. A number of standard phosphopeptides and a biologically relevant phosphoprotein, dynamin I, were analyzed. MS revealed that some phosphopeptides did not bind the RP resin but were retained efficiently on the graphite. Those that did bind the RP resin often produced much stronger signals from the graphite powder. In particular, the method revealed a doubly phosphorylated peptide in a tryptic digest of dynamin I purified from rat brain nerve terminals. The detection of this peptide was greatly enhanced by graphite micropurification. Sequencing by tandem MS confirmed the presence of phosphate at both Ser-774 and Ser-778, while a singly phosphorylated peptide was predominantly phosphorylated only on Ser-774. The method further revealed a singly and doubly phosphorylated peptide in dynamin III, analogous to the dynamin I sequence. A pair of dynamin III phosphorylation sites were found at Ser-759 and Ser-763 by tandem MS. The results directly define the in vivo phosphorylation sites in dynamins I and III for the first time. The findings indicate a large improvement in the detection of small amounts of phosphopeptides by MS and the approach has major implications for both small- and large-scale projects in phosphoproteomics.
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Affiliation(s)
- Martin R Larsen
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, DK-5230 Odense, Denmark.
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40
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Linn JG, Neff JA, Theriot R, Harris JL, Interrante J, Graham ME. Reaching impaired populations with HIV prevention programs: a clinical trial for homeless mentally ill African-American men. Cell Mol Biol (Noisy-le-grand) 2003; 49:1167-75. [PMID: 14682400] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/27/2023]
Abstract
This study tested an intervention to reduce sexual risk behaviors in a high risk impaired population: homeless African-American, Caucasian and Hispanic men with mental illness. In a comparison group clinical trial, men were assigned to an experimental cognitive-behavioral or a control intervention and followed up over 16 months. Men were recruited from a psychiatric program in two shelters for homeless men in Nashville, Tennessee. An ethnically mixed cohort of subjects (54% African-American, 42% Caucasian and 4% Hispanic) were included in the study. Most had a chronic psychiatric disorder and a co-morbid substance abuse disorder. The 257 participants who were sexually active (130 experimental, 127 control) prior to the trial were the main target of the intervention. An experimental intervention (SexG), adapted from Susser and Associates (51), comprised 6 group sessions. The control intervention was a 6-session HIV educational program. Sexual risk behavior was the primary outcome. The experimental and control groups were compared with respect to the mean score on a sexual risk index. Complete follow-up data were obtained on 257 men (100%) for the initial six-month follow-up. These individuals have been followed for the remainder of the 16-month follow-up. This intervention, (SexG), successfully reduced sexual risk behaviors of homeless mentally ill African-American, Caucasian and Hispanic men. Similar approaches may be effective in other impaired high-risk populations.
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Affiliation(s)
- J G Linn
- School of Nursing and Center for Health Research, Tennessee State University, Box 9580, Nashville, TN 37209, USA.
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41
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Tan TC, Valova VA, Malladi CS, Graham ME, Berven LA, Jupp OJ, Hansra G, McClure SJ, Sarcevic B, Boadle RA, Larsen MR, Cousin MA, Robinson PJ. Cdk5 is essential for synaptic vesicle endocytosis. Nat Cell Biol 2003; 5:701-10. [PMID: 12855954 DOI: 10.1038/ncb1020] [Citation(s) in RCA: 259] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2002] [Accepted: 06/20/2003] [Indexed: 11/09/2022]
Abstract
Synaptic vesicle endocytosis (SVE) is triggered by calcineurin-mediated dephosphorylation of the dephosphin proteins. SVE is maintained by the subsequent rephosphorylation of the dephosphins by unidentified protein kinases. Here, we show that cyclin-dependent kinase 5 (Cdk5) phosphorylates dynamin I on Ser 774 and Ser 778 in vitro, which are identical to its endogenous phosphorylation sites in vivo. Cdk5 antagonists and expression of dominant-negative Cdk5 block phosphorylation of dynamin I, but not of amphiphysin or AP180, in nerve terminals and inhibit SVE. Thus Cdk5 has an essential role in SVE and is the first dephosphin kinase identified in nerve terminals.
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Affiliation(s)
- Timothy C Tan
- Cell Signalling Unit, Children's Medical Research Institute, Locked Bag 23, Wentworthville, NSW 2145, Australia
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42
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Pearson H, Graham ME, Burgoyne RD. Relationship Between Intracellular Free Calcium Concentration and NMDA-induced Cerebellar Granule Cell Survival In Vitro. Eur J Neurosci 2002; 4:1369-75. [PMID: 12106400 DOI: 10.1111/j.1460-9568.1992.tb00162.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The survival of cerebellar granule cells in culture is stimulated by activation of the N-methyl-d-aspartate (NMDA) class of glutamate receptors. Activation of these receptors at the key period for cell survival in vitro (3 days; 3DIV) resulted in a sustained elevation of intracellular free calcium concentration [Ca2+]i over the same concentration range of NMDA that led to granule cell survival. Agents that release Ca2+ from intracellular stores led to only small, transient elevations of [Ca2+]i and were unable to stimulate granule cell survival. Addition of the Ca2+ ionophore ionomycin to granule cell cultures at 3DIV resulted in increased granule cell number at 7DIV. The ability of ionomycin to stimulate granule cell survival was related to the [Ca2+]i elicited, indicating that a rise in [Ca2+]i is sufficient to activate the processes leading to granule cell survival and that the extent of the elevation in [Ca2+]i is crucially important in determining granule cell fate.
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Affiliation(s)
- H Pearson
- The Physiological Laboratory, University of Liverpool, PO Box 147, Liverpool L69 3BX, UK
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43
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Evans GJ, Wilkinson MC, Graham ME, Turner KM, Chamberlain LH, Burgoyne RD, Morgan A. Phosphorylation of cysteine string protein by protein kinase A. Implications for the modulation of exocytosis. J Biol Chem 2001; 276:47877-85. [PMID: 11604405 DOI: 10.1074/jbc.m108186200] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Cyclic AMP-dependent protein kinase (PKA) enhances regulated exocytosis in neurons and most other secretory cells. To explore the molecular basis of this effect, known exocytotic proteins were screened for PKA substrates. Both cysteine string protein (CSP) and soluble NSF attachment protein-alpha (alpha-SNAP) were phosphorylated by PKA in vitro, but immunoprecipitation of cellular alpha-SNAP failed to detect (32)P incorporation. In contrast, endogenous CSP was phosphorylated in synaptosomes, PC12 cells, and chromaffin cells. In-gel kinase assays confirmed PKA to be a cellular CSP kinase, with phosphorylation occurring on Ser(10). PKA phosphorylation of CSP reduced its binding to syntaxin by 10-fold but had little effect on its interaction with HSC70 or G-protein subunits. Furthermore, an in vivo role for Ser(10) phosphorylation at a late stage of exocytosis is suggested by analysis of chromaffin cells transfected with wild type or non-phosphorylatable mutant CSP. We propose that PKA phosphorylation of CSP could modulate the exocytotic machinery, by selectively altering its availability for protein-protein interactions.
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Affiliation(s)
- G J Evans
- Physiological Laboratory and School of Biological Sciences, University of Liverpool, Crown Street, Liverpool L69 3BX, United Kingdom
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44
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Abstract
Considerable data support the idea that intracellular membrane fusion involves a conserved machinery containing the SNARE proteins. SNAREs assembled in vitro form a stable 4-helix bundle and it has been suggested that formation of this complex provides the driving force for bilayer fusion. We have tested this possibility in assays of exocytosis in cells expressing a botulinum neurotoxin E (BoNT/E)-resistant mutant of SNAP-25 in which additional disruptive mutations have been introduced. Single or double mutations of glutamine to glutamate or to arginine in the central zero layer residues of SNAP-25 did not impair the extent, time course or Ca2+-dependency of exocytosis in PC12 cells. Using adrenal chromaffin cells, we found that exocytosis could be reconstituted in cells transfected to express BoNT/E. A double Q→E mutation did not prevent reconstitution and the kinetics of single granule release events were indistinguishable from control cells. This shows a high level of tolerance of changes in the zero layer indicating that the conservation of these residues is not due to an essential requirement in vesicle docking or fusion and suggests that formation of a fully stable SNARE complex may not be required to drive membrane fusion.
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Affiliation(s)
- M E Graham
- The Physiological Laboratory, University of Liverpool, Crown Street, Liverpool, L69 3BX, UK
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45
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Bevilaqua LR, Graham ME, Dunkley PR, von Nagy-Felsobuki EI, Dickson PW. Phosphorylation of Ser(19) alters the conformation of tyrosine hydroxylase to increase the rate of phosphorylation of Ser(40). J Biol Chem 2001; 276:40411-6. [PMID: 11502746 DOI: 10.1074/jbc.m105280200] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The effect of phosphorylation on the shape of tyrosine hydroxylase (TH) was studied directly using gel filtration and indirectly using electrospray ionization mass spectrometry. Phosphorylation of Ser(19) and Ser(40) produced a TH molecule with a more open conformation than the non-phosphorylated form. The conformational effect of Ser(19) phosphorylation is less pronounced than that of the Ser(40) phosphorylation. The effect of Ser(19) and Ser(40) phosphorylation appears to be additive. Binding of dopamine produced a more compact form when compared with the non-dopamine-bound TH. The interdependence of Ser(19) and Ser(40) phosphorylation was probed using electrospray ionization mass spectrometry. The rate constants for the phosphorylation of Ser(19) and Ser(40) were determined by electrospray ionization mass spectrometry using a consecutive reaction model. The rate constant for the phosphorylation of Ser(40) is approximately 2- to 3-fold higher if Ser(19) is already phosphorylated. These results suggest that phosphorylation of Ser(19) alters the conformation of tyrosine hydroxylase to allow increased accessibility of Ser(40) to kinases.
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Affiliation(s)
- L R Bevilaqua
- School of Biomedical Sciences, Faculty of Medicine and Health Sciences, The University of Newcastle, Callaghan, New South Wales 2308, Australia
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46
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47
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Abstract
The study of regulated exocytosis uniquely allows the direct measurement of intracellular membrane fusion events in real time. We have exploited this to examine factors that regulate not only the extent but also the dynamics of single fusion/release events. The general strategy used has been to assess exocytosis in transiently transfected PC12 or adrenal chromaffin cells. We aimed to design mutant constructs based on in vitro biochemistry, in some cases informed by knowledge of protein structure. Using this approach we have demonstrated an inhibitory role for the putative Rab3 effector Noc2 that requires interaction with Rab3. Using carbon-fibre amperometry on adrenal chromaffin cells, we have demonstrated regulation of the kinetics of single granule release events consistent with changes in fusion pore dynamics and switches between full fusion and 'kiss-and-run' fusion. These studies have demonstrated a late role for cysteine string protein in exocytosis. In addition, they have focused attention on a key role for Munc18 in the regulation of post-fusion events that affect fusion pore dynamics.
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Affiliation(s)
- R D Burgoyne
- The Physiological Laboratory, University of Liverpool, Crown Street, Liverpool L69 3BX, UK.
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48
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Chamberlain LH, Graham ME, Kane S, Jackson JL, Maier VH, Burgoyne RD, Gould GW. The synaptic vesicle protein, cysteine-string protein, is associated with the plasma membrane in 3T3-L1 adipocytes and interacts with syntaxin 4. J Cell Sci 2001; 114:445-55. [PMID: 11148145 DOI: 10.1242/jcs.114.2.445] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Adipocytes and muscle cells play a major role in blood glucose homeostasis. This is dependent upon the expression of Glut4, an insulin-responsive facilitative glucose transporter. Glut4 is localised to specialised intracellular vesicles that fuse with the plasma membrane in response to insulin stimulation. The insulin-induced translocation of Glut4 to the cell surface is essential for the maintenance of optimal blood glucose levels, and defects in this system are associated with insulin resistance and type II diabetes. Therefore, a major focus of recent research has been to identify and characterise proteins that regulate Glut4 translocation. Cysteine-string protein (Csp) is a secretory vesicle protein that functions in presynaptic neurotransmission and also in regulated exocytosis from non-neuronal cells. We show that Csp1 is expressed in 3T3-L1 adipocytes and that cellular levels of this protein are increased following cell differentiation. Combined fractionation and immunofluorescence analyses reveal that Csp1 is not a component of intracellular Glut4-storage vesicles (GSVs), but is associated with the adipocyte plasma membrane. This association is stable, and not affected by either insulin stimulation or chemical depalmitoylation of Csp1. We also demonstrate that Csp1 interacts with the t-SNARE syntaxin 4. As syntaxin 4 is an important mediator of insulin-stimulated GSV fusion with the plasma membrane, this suggests that Csp1 may play a regulatory role in this process. Syntaxin 4 interacts specifically with Csp1, but not with Csp2. In contrast, syntaxin 1A binds to both Csp isoforms, and actually exhibits a higher affinity for the Csp2 protein. The results described raise a number of interesting questions concerning the intracellular targeting of Csp in different cell types, and suggest that the composition and synthesis of GSVs may be different from synaptic and other secretory vesicles. In addition, the interaction of Csp1 with syntaxin 4 suggests that this Csp isoform may play a role in insulin-stimulated fusion of GSVs with the plasma membrane.
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Affiliation(s)
- L H Chamberlain
- Division of Biochemistry and Molecular Biology, Davidson Building, University of Glasgow, Glasgow, G12 8QQ, UK.
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49
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Graham ME, Dickson PW, Dunkley PR, von Nagy-Felsobuki EI. Determination of phosphorylation levels of tyrosine hydroxylase by electrospray mass spectrometry. Anal Biochem 2000; 281:98-104. [PMID: 10847616 DOI: 10.1006/abio.2000.4548] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A novel approach has been developed to quantify the extent of phosphorylation of tyrosine hydroxylase (TH). The strategy consists of a chemical cleavage and characterization of the products using electrospray mass spectrometry (ESMS). The chemical cleavage involves selective hydrolysis of the aspartyl-peptide bond. Of the peptides formed, an 8-kDa NH2-terminus fragment is found to accurately duplicate the phosphorylation of TH using standard mixtures of TH-P/TH. The calibration yields a straight line with an R2 of 0.996, which is valid within the 10-90% range. The ESMS protocol has been used to determine the extent of phosphorylation of TH in the presence of CaM-PKII. The experimental conditions were designed to produce low levels of phosphorylation. Nevertheless, the ESMS analysis yielded single, double, and nonphosphorylation forms of TH. With respect to in vivo measurements, this ESMS protocol may be a generic procedure for determining the extent of phosphorylation of proteins.
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Affiliation(s)
- M E Graham
- School of Biological and Chemical Sciences, Faculty of Science and Mathematics, University of Newcastle, New South Wales, Australia
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50
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Guo Z, Achenbach JD, Madan A, Martin K, Graham ME. Integration of modeling and acoustic microscopy measurements for thin films. J Acoust Soc Am 2000; 107:2462-2471. [PMID: 10830369 DOI: 10.1121/1.428633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
A model for measuring the V(z) curve by line-focus acoustic microscopy contains the reflectance function of the specimen as a principal component. In this paper the reflectance function has been analyzed for multilayered thin films on a substrate for both fast-on-slow and slow-on-fast systems. The phase velocities of modes of surface acoustic wave propagation and their associated mode reflection coefficients can be obtained from the reflectance function. This information can be used together with estimates of the elastic constants to determine suitable frequency ranges for measuring the V(z) curve. Minimization of the difference between phase velocities obtained from measured and calculated V(z) curves is used to determine the elastic constants. Results are presented for TiN films on M2 high-speed steel substrates.
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Affiliation(s)
- Z Guo
- Center for Quality Engineering and Failure Prevention, Northwestern University, Evanston, Illinois 60208, USA
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