1
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Spencer RKW, Smirnova YG, Soleimani A, Müller M. Transient pores in hemifusion diaphragms. Biophys J 2024; 123:2455-2475. [PMID: 38867448 PMCID: PMC11365115 DOI: 10.1016/j.bpj.2024.06.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2024] [Revised: 05/07/2024] [Accepted: 06/07/2024] [Indexed: 06/14/2024] Open
Abstract
Exchange of material across two membranes, as in the case of synaptic neurotransmitter release from a vesicle, involves the formation and poration of a hemifusion diaphragm (HD). The nontrivial geometry of the HD leads to environment-dependent control, regarding the stability and dynamics of the pores required for this kind of exocytosis. This work combines particle simulations, field-based calculations, and phenomenological modeling to explore the factors influencing the stability, dynamics, and possible control mechanisms of pores in HDs. We find that pores preferentially form at the HD rim, and that their stability is sensitive to a number of factors, including the three line tensions, membrane tension, HD size, and the ability of lipids to "flip-flop" across leaflets. Along with a detailed analysis of these factors, we discuss ways that vesicles or cells may use them to open and close pores and thereby quickly and efficiently transport material.
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Affiliation(s)
- Russell K W Spencer
- Institute for Theoretical Physics, Georg-August University, Göttingen, Germany.
| | - Yuliya G Smirnova
- Institute for Theoretical Physics, Georg-August University, Göttingen, Germany; Technische Universität Dortmund, Dortmund, Germany
| | - Alireza Soleimani
- Institute for Theoretical Physics, Georg-August University, Göttingen, Germany
| | - Marcus Müller
- Institute for Theoretical Physics, Georg-August University, Göttingen, Germany.
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2
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Siegel F, Schmidt H, Juneja M, Smith J, Herrmann P, Kobelt D, Sharma K, Fichtner I, Walther W, Dittmar G, Volkmer R, Rathjen FG, Schlag PM, Stein U. GIPC1 regulates MACC1-driven metastasis. Front Oncol 2023; 13:1280977. [PMID: 38144523 PMCID: PMC10748395 DOI: 10.3389/fonc.2023.1280977] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Accepted: 11/14/2023] [Indexed: 12/26/2023] Open
Abstract
Background Identification of cancer metastasis-relevant molecular networks is desired to provide the basis for understanding and developing intervention strategies. Here we address the role of GIPC1 in the process of MACC1-driven metastasis. MACC1 is a prognostic indicator for patient metastasis formation and metastasis-free survival. MACC1 controls gene transcription, promotes motility, invasion and proliferation of colon cancer cells in vitro, and causes tumor growth and metastasis in mice. Methods By using yeast-two-hybrid assay, mass spectrometry, co-immunoprecipitation and peptide array we analyzed GIPC1 protein binding partners, by using the MACC1 gene promoter and chromatin immunoprecipitation and electrophoretic mobility shift assay we probed for GIPC1 as transcription factor. We employed GIPC1/MACC1-manipulated cell lines for in vitro and in vivo analyses, and we probed the GIPC1/MACC1 impact using human primary colorectal cancer (CRC) tissue. Results We identified MACC1 and its paralogue SH3BP4 as protein binding partners of the protein GIPC1, and we also demonstrated the binding of GIPC1 as transcription factor to the MACC1 promoter (TSS to -60 bp). GIPC1 knockdown reduced endogenous, but not CMV promoter-driven MACC1 expression, and diminished MACC1-induced cell migration and invasion. GIPC1 suppression reduced tumor growth and metastasis in mice intrasplenically transplanted with MACC1-overexpressing CRC cells. In human primary CRC specimens, GIPC1 correlates with MACC1 expression and is of prognostic value for metastasis formation and metastasis-free survival. Combination of MACC1 and GIPC1 expression improved patient survival prognosis, whereas SH3BP4 expression did not show any prognostic value. Conclusions We identified an important, dual function of GIPC1 - as protein interaction partner and as transcription factor of MACC1 - for tumor progression and cancer metastasis.
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Affiliation(s)
- Franziska Siegel
- Department Translational Oncology of Solid Tumors, Experimental and Clinical Research Institute, Charité Universitätsmedizin Berlin, and Max-Delbrück-Center for Molecular Medicine, Berlin, Germany
| | - Hannes Schmidt
- Department Developmental Neurobiology, Max-Delbrück-Center for Molecular Medicine, Berlin, Germany
| | - Manisha Juneja
- Department Translational Oncology of Solid Tumors, Experimental and Clinical Research Institute, Charité Universitätsmedizin Berlin, and Max-Delbrück-Center for Molecular Medicine, Berlin, Germany
| | - Janice Smith
- Department Translational Oncology of Solid Tumors, Experimental and Clinical Research Institute, Charité Universitätsmedizin Berlin, and Max-Delbrück-Center for Molecular Medicine, Berlin, Germany
| | - Pia Herrmann
- Department Translational Oncology of Solid Tumors, Experimental and Clinical Research Institute, Charité Universitätsmedizin Berlin, and Max-Delbrück-Center for Molecular Medicine, Berlin, Germany
| | - Dennis Kobelt
- Department Translational Oncology of Solid Tumors, Experimental and Clinical Research Institute, Charité Universitätsmedizin Berlin, and Max-Delbrück-Center for Molecular Medicine, Berlin, Germany
- German Cancer Consortium, Heidelberg, Germany
| | - Kamal Sharma
- Department Developmental Neurobiology, Max-Delbrück-Center for Molecular Medicine, Berlin, Germany
| | - Iduna Fichtner
- Experimental Pharmacology and Oncology, GmbH, Berlin, Germany
| | - Wolfgang Walther
- Department Translational Oncology of Solid Tumors, Experimental and Clinical Research Institute, Charité Universitätsmedizin Berlin, and Max-Delbrück-Center for Molecular Medicine, Berlin, Germany
| | - Gunnar Dittmar
- Department Mass Spectrometry, Max-Delbrück-Center for Molecular Medicine, Berlin, Germany
| | - Rudolf Volkmer
- Institute for Medicinal Immunology, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Fritz G. Rathjen
- Department Developmental Neurobiology, Max-Delbrück-Center for Molecular Medicine, Berlin, Germany
| | | | - Ulrike Stein
- Department Translational Oncology of Solid Tumors, Experimental and Clinical Research Institute, Charité Universitätsmedizin Berlin, and Max-Delbrück-Center for Molecular Medicine, Berlin, Germany
- German Cancer Consortium, Heidelberg, Germany
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3
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Szewczyk-Roszczenko OK, Roszczenko P, Shmakova A, Finiuk N, Holota S, Lesyk R, Bielawska A, Vassetzky Y, Bielawski K. The Chemical Inhibitors of Endocytosis: From Mechanisms to Potential Clinical Applications. Cells 2023; 12:2312. [PMID: 37759535 PMCID: PMC10527932 DOI: 10.3390/cells12182312] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Accepted: 09/07/2023] [Indexed: 09/29/2023] Open
Abstract
Endocytosis is one of the major ways cells communicate with their environment. This process is frequently hijacked by pathogens. Endocytosis also participates in the oncogenic transformation. Here, we review the approaches to inhibit endocytosis, discuss chemical inhibitors of this process, and discuss potential clinical applications of the endocytosis inhibitors.
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Affiliation(s)
| | - Piotr Roszczenko
- Department of Biotechnology, Medical University of Bialystok, Kilinskiego 1, 15-089 Bialystok, Poland; (P.R.); (A.B.)
| | - Anna Shmakova
- CNRS, UMR 9018, Institut Gustave Roussy, Université Paris-Saclay, 94800 Villejuif, France;
| | - Nataliya Finiuk
- Department of Regulation of Cell Proliferation and Apoptosis, Institute of Cell Biology of National Academy of Sciences of Ukraine, Drahomanov 14/16, 79005 Lviv, Ukraine;
| | - Serhii Holota
- Department of Pharmaceutical, Organic and Bioorganic Chemistry, Danylo Halytsky Lviv National Medical University, Pekarska 69, 79010 Lviv, Ukraine; (S.H.); (R.L.)
| | - Roman Lesyk
- Department of Pharmaceutical, Organic and Bioorganic Chemistry, Danylo Halytsky Lviv National Medical University, Pekarska 69, 79010 Lviv, Ukraine; (S.H.); (R.L.)
| | - Anna Bielawska
- Department of Biotechnology, Medical University of Bialystok, Kilinskiego 1, 15-089 Bialystok, Poland; (P.R.); (A.B.)
| | - Yegor Vassetzky
- CNRS, UMR 9018, Institut Gustave Roussy, Université Paris-Saclay, 94800 Villejuif, France;
| | - Krzysztof Bielawski
- Department of Synthesis and Technology of Drugs, Medical University of Bialystok, Kilinskiego 1, 15-089 Bialystok, Poland;
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4
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Wang X, Li Y, Liu A, Padilla R, Lee DM, Kim D, Mettlen M, Chen Z, Schmid SL, Danuser G. Endocytosis gated by emergent properties of membrane-clathrin interactions. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.02.551737. [PMID: 37577632 PMCID: PMC10418234 DOI: 10.1101/2023.08.02.551737] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/15/2023]
Abstract
Clathrin-mediated endocytosis (CME), the major cellular entry pathway, starts when clathrin assembles on the plasma membrane into clathrin-coated pits (CCPs). Two populations of CCPs are detected within the same cell: 'productive' CCPs that invaginate and pinch off, forming clathrin-coated vesicles (CCVs) [1, 2], and 'abortive' CCPs [3, 4, 5] that prematurely disassemble. The mechanisms of gating between these two populations and their relations to the functions of dozens of early-acting endocytic accessory proteins (EAPs) [5, 6, 7, 8, 9] have remained elusive. Here, we use experimentally-guided modeling to integrate the clathrin machinery and membrane mechanics in a single dynamical system. We show that the split between the two populations is an emergent property of this system, in which a switch between an Open state and a Closed state follows from the competition between the chemical energy of the clathrin basket and the mechanical energy of membrane bending. In silico experiments revealed an abrupt transition between the two states that acutely depends on the strength of the clathrin basket. This critical strength is lowered by membrane-bending EAPs [10, 11, 12]. Thus, CME is poised to be shifted between abortive and productive events by small changes in membrane curvature and/or coat stability. This model clarifies the workings of a putative endocytic checkpoint whose existence was previously proposed based on statistical analyses of the lifetime distributions of CCPs [4, 13]. Overall, a mechanistic framework is established to elucidate the diverse and redundant functions of EAPs in regulating CME progression.
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5
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Biasetti L, Rey S, Fowler M, Ratnayaka A, Fennell K, Smith C, Marshall K, Hall C, Vargas-Caballero M, Serpell L, Staras K. Elevated amyloid beta disrupts the nanoscale organization and function of synaptic vesicle pools in hippocampal neurons. Cereb Cortex 2023; 33:1263-1276. [PMID: 35368053 PMCID: PMC9930632 DOI: 10.1093/cercor/bhac134] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 02/02/2022] [Accepted: 03/07/2022] [Indexed: 11/14/2022] Open
Abstract
Alzheimer's disease is linked to increased levels of amyloid beta (Aβ) in the brain, but the mechanisms underlying neuronal dysfunction and neurodegeneration remain enigmatic. Here, we investigate whether organizational characteristics of functional presynaptic vesicle pools, key determinants of information transmission in the central nervous system, are targets for elevated Aβ. Using an optical readout method in cultured hippocampal neurons, we show that acute Aβ42 treatment significantly enlarges the fraction of functional vesicles at individual terminals. We observe the same effect in a chronically elevated Aβ transgenic model (APPSw,Ind) using an ultrastructure-function approach that provides detailed information on nanoscale vesicle pool positioning. Strikingly, elevated Aβ is correlated with excessive accumulation of recycled vesicles near putative endocytic sites, which is consistent with deficits in vesicle retrieval pathways. Using the glutamate reporter, iGluSnFR, we show that there are parallel functional consequences, where ongoing information signaling capacity is constrained. Treatment with levetiracetam, an antiepileptic that dampens synaptic hyperactivity, partially rescues these transmission defects. Our findings implicate organizational and dynamic features of functional vesicle pools as targets in Aβ-driven synaptic impairment, suggesting that interventions to relieve the overloading of vesicle retrieval pathways might have promising therapeutic value.
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Affiliation(s)
- Luca Biasetti
- Sussex Neuroscience, School of Life Sciences, University of Sussex, Brighton, BN1 9QG, United Kingdom
| | - Stephanie Rey
- Sussex Neuroscience, School of Life Sciences, University of Sussex, Brighton, BN1 9QG, United Kingdom
- National Physical Laboratory, Middlesex, TW11 0LW, United Kingdom
| | - Milena Fowler
- Sussex Neuroscience, School of Life Sciences, University of Sussex, Brighton, BN1 9QG, United Kingdom
| | - Arjuna Ratnayaka
- Sussex Neuroscience, School of Life Sciences, University of Sussex, Brighton, BN1 9QG, United Kingdom
- Faculty of Medicine, University of Southampton, SO17 1BJ, United Kingdom
| | - Kate Fennell
- Sussex Neuroscience, School of Life Sciences, University of Sussex, Brighton, BN1 9QG, United Kingdom
| | - Catherine Smith
- Sussex Neuroscience, School of Life Sciences, University of Sussex, Brighton, BN1 9QG, United Kingdom
| | - Karen Marshall
- Sussex Neuroscience, School of Life Sciences, University of Sussex, Brighton, BN1 9QG, United Kingdom
| | - Catherine Hall
- Sussex Neuroscience, School of Psychology, University of Sussex, Brighton, BN1 9QH, United Kingdom
| | - Mariana Vargas-Caballero
- School of Biological Sciences, University of Southampton, Highfield Campus, Southampton SO17 1BJ, United Kingdom
| | - Louise Serpell
- Sussex Neuroscience, School of Life Sciences, University of Sussex, Brighton, BN1 9QG, United Kingdom
| | - Kevin Staras
- Sussex Neuroscience, School of Life Sciences, University of Sussex, Brighton, BN1 9QG, United Kingdom
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6
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Wu X, Qiu H, Zhang M. Interactions between Membraneless Condensates and Membranous Organelles at the Presynapse: A Phase Separation View of Synaptic Vesicle Cycle. J Mol Biol 2023; 435:167629. [PMID: 35595170 DOI: 10.1016/j.jmb.2022.167629] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Revised: 05/03/2022] [Accepted: 05/04/2022] [Indexed: 02/04/2023]
Abstract
Action potential-induced neurotransmitter release in presynaptic boutons involves coordinated actions of a large list of proteins that are associated directly or indirectly with membrane structures including synaptic vesicles and plasma membranes. These proteins are often highly abundant in different synaptic bouton sub-compartments, and they rarely act alone. Instead, these proteins interact with each other forming intricate and distinct molecular complexes. Many of these complexes form condensed clusters on membrane surfaces. This review summarizes findings in recent years showing that many of presynaptic protein complex assemblies are formed via phase separation. These protein condensates extensively interact with lipid membranes via distinct modes, forming various mesoscale structures by different mode of organizations between membraneless condensates and membranous organelles. We discuss that such mesoscale interactions could have deep implications on mobilization, exocytosis, and retrieval of synaptic vesicles.
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Affiliation(s)
- Xiandeng Wu
- Division of Life Science, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Hua Qiu
- Division of Life Science, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Mingjie Zhang
- Greater Bay Biomedical Innocenter, Shenzhen Bay Laboratory, Shenzhen 518036, China; School of Life Sciences, Southern University of Science and Technology, Shenzhen 518055, China.
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7
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Liang Y, Xu H, Cheng T, Fu Y, Huang H, Qian W, Wang J, Zhou Y, Qian P, Yin Y, Xu P, Zou W, Chen B. Gene activation guided by nascent RNA-bound transcription factors. Nat Commun 2022; 13:7329. [PMID: 36443367 PMCID: PMC9705438 DOI: 10.1038/s41467-022-35041-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Accepted: 11/16/2022] [Indexed: 11/29/2022] Open
Abstract
Technologies for gene activation are valuable tools for the study of gene functions and have a wide range of potential applications in bioengineering and medicine. In contrast to existing methods based on recruiting transcriptional modulators via DNA-binding proteins, we developed a strategy termed Narta (nascent RNA-guided transcriptional activation) to achieve gene activation by recruiting artificial transcription factors (aTFs) to transcription sites through nascent RNAs of the target gene. Using Narta, we demonstrate robust activation of a broad range of exogenous and endogenous genes in various cell types, including zebrafish embryos, mouse and human cells. Importantly, the activation is reversible, tunable and specific. Moreover, Narta provides better activation potency of some expressed genes than CRISPRa and, when used in combination with CRISPRa, has an enhancing effect on gene activation. Quantitative imaging illustrated that nascent RNA-directed aTFs could induce the high-density assembly of coactivators at transcription sites, which may explain the larger transcriptional burst size induced by Narta. Overall, our work expands the gene activation toolbox for biomedical research.
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Affiliation(s)
- Ying Liang
- grid.13402.340000 0004 1759 700XDepartment of Cell Biology and Bone Marrow Transplantation Center of the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China ,grid.13402.340000 0004 1759 700XLiangzhu Laboratory, Zhejiang University Medical Center, Hangzhou, China
| | - Haiyue Xu
- grid.13402.340000 0004 1759 700XDepartment of Cell Biology and Bone Marrow Transplantation Center of the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China ,grid.13402.340000 0004 1759 700XLiangzhu Laboratory, Zhejiang University Medical Center, Hangzhou, China
| | - Tao Cheng
- grid.13402.340000 0004 1759 700XWomen’s Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Yujuan Fu
- grid.13402.340000 0004 1759 700XDepartment of Cell Biology and Bone Marrow Transplantation Center of the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Hanwei Huang
- grid.13402.340000 0004 1759 700XDepartment of Cell Biology and Bone Marrow Transplantation Center of the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Wenchang Qian
- grid.13402.340000 0004 1759 700XCenter of Stem Cell and Regenerative Medicine, Zhejiang University School of Medicine, Hangzhou, China
| | - Junyan Wang
- grid.13402.340000 0004 1759 700XDepartment of Cell Biology and Bone Marrow Transplantation Center of the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Yuenan Zhou
- grid.13402.340000 0004 1759 700XDepartment of Cell Biology, Zhejiang University School of Medicine, Hangzhou, China
| | - Pengxu Qian
- grid.13402.340000 0004 1759 700XCenter of Stem Cell and Regenerative Medicine, Zhejiang University School of Medicine, Hangzhou, China
| | - Yafei Yin
- grid.13402.340000 0004 1759 700XDepartment of Cell Biology, Zhejiang University School of Medicine, Hangzhou, China
| | - Pengfei Xu
- grid.13402.340000 0004 1759 700XWomen’s Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Wei Zou
- grid.13402.340000 0004 1759 700XThe Fourth Affiliated Hospital, Zhejiang University School of Medicine, Yiwu, China ,grid.13402.340000 0004 1759 700XInsititute of Translational Medicine, Zhejiang University, Hangzhou, China
| | - Baohui Chen
- grid.13402.340000 0004 1759 700XDepartment of Cell Biology and Bone Marrow Transplantation Center of the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China ,grid.13402.340000 0004 1759 700XLiangzhu Laboratory, Zhejiang University Medical Center, Hangzhou, China ,grid.13402.340000 0004 1759 700XInstitute of Hematology, Zhejiang University & Zhejiang Engineering Laboratory for Stem Cell and Immunotherapy, Hangzhou, China ,grid.13402.340000 0004 1759 700XZhejiang Provincial Key Laboratory of Genetic & Developmental Disorders, Hangzhou, China
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8
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Hoshino F, Sakane F. The SAC1 phosphatase domain of synaptojanin-1 is activated by interacting with polyunsaturated fatty acid-containing phosphatidic acids. FEBS Lett 2021; 595:2479-2492. [PMID: 34387861 DOI: 10.1002/1873-3468.14177] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Revised: 08/10/2021] [Accepted: 08/10/2021] [Indexed: 11/07/2022]
Abstract
Although there are many phosphatidic acid (PA) molecular species based on its fatty acyl compositions, their interacting partners have been poorly investigated. Here, we identified synaptojanin-1 (SYNJ1), Parkinson's disease-related protein that is essential for regulating clathrin-mediated synaptic vesicle endocytosis via dually dephosphorylating D5 and D4 position phosphates from phosphatidylinositol (PI) (4,5)-bisphosphate, as a 1-stearoyl-2-docosahexaenoyl (18:0/22:6)-PA-binding protein. SYNJ1 failed to substantially associate with other acidic phospholipids. Although SYNJ1 interacted with 18:0/20:4-PA in addition to 18:0/22:6-PA, the association of the enzyme with 16:0/16:0-, 16:0/18:1-, 18:0/18:0-, or 18:1/18:1-PA was not considerable. 18:0/20:4- and 18:0/22:6-PAs bound to SYNJ1 via its SAC1 domain, which preferentially hydrolyses D4 position phosphate. Moreover, 18:0/20:4- and 18:0/22:6-PA selectively enhanced the D4-phosphatase activity, but not the D5-phosphatase activity, of SYNJ1.
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Affiliation(s)
- Fumi Hoshino
- Department of Chemistry, Graduate School of Science, Chiba University, Japan
| | - Fumio Sakane
- Department of Chemistry, Graduate School of Science, Chiba University, Japan
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9
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Robbins M, Clayton E, Kaminski Schierle GS. Synaptic tau: A pathological or physiological phenomenon? Acta Neuropathol Commun 2021; 9:149. [PMID: 34503576 PMCID: PMC8428049 DOI: 10.1186/s40478-021-01246-y] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Accepted: 08/12/2021] [Indexed: 12/17/2022] Open
Abstract
In this review, we discuss the synaptic aspects of Tau pathology occurring during Alzheimer's disease (AD) and how this may relate to memory impairment, a major hallmark of AD. Whilst the clinical diagnosis of AD patients is a loss of working memory and long-term declarative memory, the histological diagnosis is the presence of neurofibrillary tangles of hyperphosphorylated Tau and Amyloid-beta plaques. Tau pathology spreads through synaptically connected neurons to impair synaptic function preceding the formation of neurofibrillary tangles, synaptic loss, axonal retraction and cell death. Alongside synaptic pathology, recent data suggest that Tau has physiological roles in the pre- or post- synaptic compartments. Thus, we have seen a shift in the research focus from Tau as a microtubule-stabilising protein in axons, to Tau as a synaptic protein with roles in accelerating spine formation, dendritic elongation, and in synaptic plasticity coordinating memory pathways. We collate here the myriad of emerging interactions and physiological roles of synaptic Tau, and discuss the current evidence that synaptic Tau contributes to pathology in AD.
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10
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Clathrin: the molecular shape shifter. Biochem J 2021; 478:3099-3123. [PMID: 34436540 DOI: 10.1042/bcj20200740] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Revised: 07/19/2021] [Accepted: 08/04/2021] [Indexed: 12/11/2022]
Abstract
Clathrin is best known for its contribution to clathrin-mediated endocytosis yet it also participates to a diverse range of cellular functions. Key to this is clathrin's ability to assemble into polyhedral lattices that include curved football or basket shapes, flat lattices or even tubular structures. In this review, we discuss clathrin structure and coated vesicle formation, how clathrin is utilised within different cellular processes including synaptic vesicle recycling, hormone desensitisation, spermiogenesis, cell migration and mitosis, and how clathrin's remarkable 'shapeshifting' ability to form diverse lattice structures might contribute to its multiple cellular functions.
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11
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Wu M, Wu X. A kinetic view of clathrin assembly and endocytic cargo sorting. Curr Opin Cell Biol 2021; 71:130-138. [PMID: 33865229 DOI: 10.1016/j.ceb.2021.02.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2020] [Revised: 02/10/2021] [Accepted: 02/12/2021] [Indexed: 01/30/2023]
Abstract
Specificity and sensitivity in biochemical reactions can be achieved through regulation of equilibrium binding affinity or through proofreading mechanisms that allow for the dissociation of unwanted intermediates. In this essay, we aim to provide our perspectives on how the concept of kinetic proofreading might apply in the context of cargo sorting in clathrin-mediated endocytosis.
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Affiliation(s)
- Min Wu
- Department of Cell Biology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT, 06520-8002, USA.
| | - Xudong Wu
- Howard Hughes Medical Institute and Department of Cell Biology, Harvard Medical School, 240 Longwood Avenue, Boston, MA, 02115, USA
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12
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Yılmaz D, Culha M. Investigation of the pathway dependent endocytosis of gold nanoparticles by surface-enhanced Raman scattering. Talanta 2021; 225:122071. [PMID: 33592789 DOI: 10.1016/j.talanta.2020.122071] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 12/15/2020] [Accepted: 12/27/2020] [Indexed: 01/02/2023]
Abstract
Endocytosis is a critical mechanism providing not only internalization of biomacromolecular structures but also communication with the environment where cells reside. Due to being the first step at the interaction interface, the route of cellular uptake has a major role governing the intracellular destinations and behaviors of molecular and non-molecular species including nanoparticles. To this end, various methods employing variety of techniques are investigated. In this study, surface-enhanced Raman spectroscopy (SERS) based approach for the investigation of endocytosis of gold nanoparticles (AuNPs) is reported. Internalization pathways of AuNPs were examined by flow cytometry via specific inhibitors for each endocytosis pathway type using three model cell lines Beas-2b, A549 and PNT1A. Macropinocytosis was blocked by cytochalasin D (CytoD), clathrin mediated endocytosis (CME) by sucrose (Scr), and caveolae mediated endocytosis (CE) by filipin (Fil). The results showed that cell type dependent AuNPs internalization affects not only the response of the cells to the inhibitors but also the obtained SERS spectra. SERS spectra of PNT1A cells treated with inhibitors was influenced most. The inhibition of each endocytosis pathway significantly affected the SERS spectral pattern and the spectral changes in different endocytosis pathways were clearly discriminated from each other. This means that SERS can significantly contribute to the investigation of different endosomal pathways from single living cells without any disruption of the cells or labeling.
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Affiliation(s)
- Deniz Yılmaz
- Yeditepe University, Faculty of Engineering, Department of Genetics and Bioengineering, 34755, Istanbul, Turkey
| | - Mustafa Culha
- Yeditepe University, Faculty of Engineering, Department of Genetics and Bioengineering, 34755, Istanbul, Turkey; Oregon Health and Science University, The Knight Cancer Research Institute, Cancer Early Detection Advanced Research (CEDAR) Center, Portland, OR 97239 USA; Sabanci University Nanotechnology Research and Application Center (SUNUM), Tuzla, Istanbul, 34956 Turkey.
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13
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Tarasenko D, Meinecke M. Protein-dependent membrane remodeling in mitochondrial morphology and clathrin-mediated endocytosis. EUROPEAN BIOPHYSICS JOURNAL : EBJ 2021; 50:295-306. [PMID: 33527201 PMCID: PMC8071792 DOI: 10.1007/s00249-021-01501-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 01/04/2021] [Accepted: 01/13/2021] [Indexed: 11/30/2022]
Abstract
Cellular membranes can adopt a plethora of complex and beautiful shapes, most of which are believed to have evolved for a particular physiological reason. The closely entangled relationship between membrane morphology and cellular physiology is strikingly seen in membrane trafficking pathways. During clathrin-mediated endocytosis, for example, over the course of a minute, a patch of the more or less flat plasma membrane is remodeled into a highly curved clathrin-coated vesicle. Such vesicles are internalized by the cell to degrade or recycle plasma membrane receptors or to take up extracellular ligands. Other, steadier, membrane morphologies can be observed in organellar membranes like the endoplasmic reticulum or mitochondria. In the case of mitochondria, which are double membrane-bound, ubiquitous organelles of eukaryotic cells, especially the mitochondrial inner membrane displays an intricated ultrastructure. It is highly folded and consequently has a much larger surface than the mitochondrial outer membrane. It can adopt different shapes in response to cellular demands and changes of the inner membrane morphology often accompany severe diseases, including neurodegenerative- and metabolic diseases and cancer. In recent years, progress was made in the identification of molecules that are important for the aforementioned membrane remodeling events. In this review, we will sum up recent results and discuss the main players of membrane remodeling processes that lead to the mitochondrial inner membrane ultrastructure and in clathrin-mediated endocytosis. We will compare differences and similarities between the molecular mechanisms that peripheral and integral membrane proteins use to deform membranes.
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Affiliation(s)
- Daryna Tarasenko
- Department of Cellular Biochemistry, University Medical Center Göttingen, Humboldtallee 23, 37073, Göttingen, Germany
| | - Michael Meinecke
- Department of Cellular Biochemistry, University Medical Center Göttingen, Humboldtallee 23, 37073, Göttingen, Germany.
- Göttinger Zentrum für Molekulare Biowissenschaften - GZMB, 37077, Göttingen, Germany.
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14
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Kroppen B, Teske N, Yambire KF, Denkert N, Mukherjee I, Tarasenko D, Jaipuria G, Zweckstetter M, Milosevic I, Steinem C, Meinecke M. Cooperativity of membrane-protein and protein-protein interactions control membrane remodeling by epsin 1 and affects clathrin-mediated endocytosis. Cell Mol Life Sci 2020; 78:2355-2370. [PMID: 32997199 PMCID: PMC7966211 DOI: 10.1007/s00018-020-03647-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Revised: 08/11/2020] [Accepted: 09/12/2020] [Indexed: 01/01/2023]
Abstract
Membrane remodeling is a critical process for many membrane trafficking events, including clathrin-mediated endocytosis. Several molecular mechanisms for protein-induced membrane curvature have been described in some detail. Contrary, the effect that the physico-chemical properties of the membrane have on these processes is far less well understood. Here, we show that the membrane binding and curvature-inducing ENTH domain of epsin1 is regulated by phosphatidylserine (PS). ENTH binds to membranes in a PI(4,5)P2-dependent manner but only induces curvature in the presence of PS. On PS-containing membranes, the ENTH domain forms rigid homo-oligomers and assembles into clusters. Membrane binding and membrane remodeling can be separated by structure-to-function mutants. Such oligomerization mutants bind to membranes but do not show membrane remodeling activity. In vivo, they are not able to rescue defects in epidermal growth factor receptor (EGFR) endocytosis in epsin knock-down cells. Together, these data show that the membrane lipid composition is important for the regulation of protein-dependent membrane deformation during clathrin-mediated endocytosis.
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Affiliation(s)
- Benjamin Kroppen
- Department of Cellular Biochemistry, University Medical Center Göttingen, Humboldtallee 23, 37073, Göttingen, Germany
| | - Nelli Teske
- Institute for Organic and Biomolecular Chemistry, University of Göttingen, Tammannstr. 2, 37077, Göttingen, Germany
| | - King F Yambire
- European Neuroscience Institute, Göttingen - A Joint Initiative of the University Medical Center Göttingen and the Max-Planck-Society, Grisebachstr. 5, 37077, Göttingen, Germany
| | - Niels Denkert
- Department of Cellular Biochemistry, University Medical Center Göttingen, Humboldtallee 23, 37073, Göttingen, Germany
| | - Indrani Mukherjee
- Department of Cellular Biochemistry, University Medical Center Göttingen, Humboldtallee 23, 37073, Göttingen, Germany
| | - Daryna Tarasenko
- Department of Cellular Biochemistry, University Medical Center Göttingen, Humboldtallee 23, 37073, Göttingen, Germany
| | - Garima Jaipuria
- German Center for Neurodegenerative Diseases (DZNE), Von-Siebold-Str. 3a, 37075, Göttingen, Germany
| | - Markus Zweckstetter
- German Center for Neurodegenerative Diseases (DZNE), Von-Siebold-Str. 3a, 37075, Göttingen, Germany
- Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077, Göttingen, Germany
| | - Ira Milosevic
- European Neuroscience Institute, Göttingen - A Joint Initiative of the University Medical Center Göttingen and the Max-Planck-Society, Grisebachstr. 5, 37077, Göttingen, Germany
- Wellcome Centre for Human Genetics, Nuffield Department of Medicine, NIHR Oxford Biomedical Research Centre, University of Oxford, Oxford, OX3 7BN, UK
| | - Claudia Steinem
- Institute for Organic and Biomolecular Chemistry, University of Göttingen, Tammannstr. 2, 37077, Göttingen, Germany.
- Göttinger Zentrum für Molekulare Biowissenschaften - GZMB, 37077, Göttingen, Germany.
- Max Planck Institute for Dynamics and Self-Organization, Am Faßberg 17, 37077, Göttingen, Germany.
| | - Michael Meinecke
- Department of Cellular Biochemistry, University Medical Center Göttingen, Humboldtallee 23, 37073, Göttingen, Germany.
- Göttinger Zentrum für Molekulare Biowissenschaften - GZMB, 37077, Göttingen, Germany.
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15
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The Mechanistic Role of Bridging Integrator 1 (BIN1) in Alzheimer's Disease. Cell Mol Neurobiol 2020; 41:1431-1440. [PMID: 32719966 DOI: 10.1007/s10571-020-00926-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Accepted: 07/17/2020] [Indexed: 01/18/2023]
Abstract
Alzheimer's disease (AD) is the leading cause of dementia. The majority of AD cases are late-onset, multifactorial cases. Genome-wide association studies have identified more than 30 loci associated with sporadic AD (SAD), one of which is Bridging integrator 1 (BIN1). For the past few years, there has been a consensus that BIN1 is second only to APOE as the strongest genetic risk factor for SAD. Therefore, many researchers have put great effort into studying the mechanism by which BIN1 might be involved in the pathogenetic process of AD. To date, plenty of evidence has shown that BIN1 may participate in several pathways in AD, including tau and amyloid pathology. In addition, BIN1 has been indicated to take part in other relevant pathways such as inflammation, apoptosis, and calcium homeostasis. In this review, we systemically summarize the research progress on how BIN1 participates in the development of AD, with the expectation of providing promising perspectives for future research.
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16
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Pourhaghighi R, Ash PEA, Phanse S, Goebels F, Hu LZM, Chen S, Zhang Y, Wierbowski SD, Boudeau S, Moutaoufik MT, Malty RH, Malolepsza E, Tsafou K, Nathan A, Cromar G, Guo H, Abdullatif AA, Apicco DJ, Becker LA, Gitler AD, Pulst SM, Youssef A, Hekman R, Havugimana PC, White CA, Blum BC, Ratti A, Bryant CD, Parkinson J, Lage K, Babu M, Yu H, Bader GD, Wolozin B, Emili A. BraInMap Elucidates the Macromolecular Connectivity Landscape of Mammalian Brain. Cell Syst 2020; 10:333-350.e14. [PMID: 32325033 PMCID: PMC7938770 DOI: 10.1016/j.cels.2020.03.003] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Revised: 11/25/2019] [Accepted: 03/20/2020] [Indexed: 12/12/2022]
Abstract
Connectivity webs mediate the unique biology of the mammalian brain. Yet, while cell circuit maps are increasingly available, knowledge of their underlying molecular networks remains limited. Here, we applied multi-dimensional biochemical fractionation with mass spectrometry and machine learning to survey endogenous macromolecules across the adult mouse brain. We defined a global "interactome" comprising over one thousand multi-protein complexes. These include hundreds of brain-selective assemblies that have distinct physical and functional attributes, show regional and cell-type specificity, and have links to core neurological processes and disorders. Using reciprocal pull-downs and a transgenic model, we validated a putative 28-member RNA-binding protein complex associated with amyotrophic lateral sclerosis, suggesting a coordinated function in alternative splicing in disease progression. This brain interaction map (BraInMap) resource facilitates mechanistic exploration of the unique molecular machinery driving core cellular processes of the central nervous system. It is publicly available and can be explored here https://www.bu.edu/dbin/cnsb/mousebrain/.
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Affiliation(s)
- Reza Pourhaghighi
- Donnelly Center for Cellular and Biomolecular Research, University of Toronto, Toronto, ON, Canada
| | - Peter E A Ash
- Department of Pharmacology and Experimental Therapeutics, Boston University School of Medicine, Boston, MA, USA
| | - Sadhna Phanse
- Donnelly Center for Cellular and Biomolecular Research, University of Toronto, Toronto, ON, Canada; Department of Biochemistry, University of Regina, Regina, SK, Canada; Center for Network Systems Biology, Boston University, Boston, MA, USA
| | - Florian Goebels
- Donnelly Center for Cellular and Biomolecular Research, University of Toronto, Toronto, ON, Canada
| | - Lucas Z M Hu
- Donnelly Center for Cellular and Biomolecular Research, University of Toronto, Toronto, ON, Canada
| | - Siwei Chen
- Department of Biological Statistics and Computational Biology, Cornell University, Ithaca, NY, USA
| | - Yingying Zhang
- Department of Biological Statistics and Computational Biology, Cornell University, Ithaca, NY, USA
| | - Shayne D Wierbowski
- Department of Biological Statistics and Computational Biology, Cornell University, Ithaca, NY, USA
| | - Samantha Boudeau
- Department of Pharmacology and Experimental Therapeutics, Boston University School of Medicine, Boston, MA, USA
| | | | - Ramy H Malty
- Department of Biochemistry, University of Regina, Regina, SK, Canada
| | - Edyta Malolepsza
- Department of Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA; Broad Institute of Massachusetts Institute of Technology and Harvard University, Boston, MA, USA
| | - Kalliopi Tsafou
- Department of Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA; Broad Institute of Massachusetts Institute of Technology and Harvard University, Boston, MA, USA
| | - Aparna Nathan
- Department of Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA; Broad Institute of Massachusetts Institute of Technology and Harvard University, Boston, MA, USA
| | - Graham Cromar
- Program in Molecular Medicine, Hospital for Sick Children and University of Toronto, Toronto, ON, Canada
| | - Hongbo Guo
- Donnelly Center for Cellular and Biomolecular Research, University of Toronto, Toronto, ON, Canada
| | - Ali Al Abdullatif
- Department of Pharmacology and Experimental Therapeutics, Boston University School of Medicine, Boston, MA, USA
| | - Daniel J Apicco
- Department of Pharmacology and Experimental Therapeutics, Boston University School of Medicine, Boston, MA, USA
| | - Lindsay A Becker
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
| | - Aaron D Gitler
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
| | - Stefan M Pulst
- Department of Neurology, University of Utah, Salt Lake City, UT, USA
| | - Ahmed Youssef
- Program in Bioinformatics, Boston University, Boston, MA, USA; Center for Network Systems Biology, Boston University, Boston, MA, USA; Department of Biochemistry, Boston University School of Medicine, Boston University, Boston, MA, USA
| | - Ryan Hekman
- Center for Network Systems Biology, Boston University, Boston, MA, USA; Department of Biochemistry, Boston University School of Medicine, Boston University, Boston, MA, USA
| | - Pierre C Havugimana
- Center for Network Systems Biology, Boston University, Boston, MA, USA; Department of Biochemistry, Boston University School of Medicine, Boston University, Boston, MA, USA; Departments of Biochemistry and Biology, Boston University, Boston, MA, USA
| | - Carl A White
- Center for Network Systems Biology, Boston University, Boston, MA, USA; Department of Biochemistry, Boston University School of Medicine, Boston University, Boston, MA, USA
| | - Benjamin C Blum
- Center for Network Systems Biology, Boston University, Boston, MA, USA; Department of Biochemistry, Boston University School of Medicine, Boston University, Boston, MA, USA
| | - Antonia Ratti
- Department of Neurology and Laboratory of Neuroscience, IRCCS, Milan, Italy
| | - Camron D Bryant
- Department of Pharmacology and Experimental Therapeutics, Boston University School of Medicine, Boston, MA, USA
| | - John Parkinson
- Program in Molecular Medicine, Hospital for Sick Children and University of Toronto, Toronto, ON, Canada
| | - Kasper Lage
- Department of Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA; Broad Institute of Massachusetts Institute of Technology and Harvard University, Boston, MA, USA
| | - Mohan Babu
- Department of Biochemistry, University of Regina, Regina, SK, Canada
| | - Haiyuan Yu
- Department of Biological Statistics and Computational Biology, Cornell University, Ithaca, NY, USA
| | - Gary D Bader
- Donnelly Center for Cellular and Biomolecular Research, University of Toronto, Toronto, ON, Canada
| | - Benjamin Wolozin
- Department of Pharmacology and Experimental Therapeutics, Boston University School of Medicine, Boston, MA, USA; Department of Neurology, Boston University School of Medicine, Boston, MA, USA; Program in Neuroscience, Boston University, Boston, MA, USA.
| | - Andrew Emili
- Donnelly Center for Cellular and Biomolecular Research, University of Toronto, Toronto, ON, Canada; Program in Bioinformatics, Boston University, Boston, MA, USA; Center for Network Systems Biology, Boston University, Boston, MA, USA; Department of Biochemistry, Boston University School of Medicine, Boston University, Boston, MA, USA; Departments of Biochemistry and Biology, Boston University, Boston, MA, USA.
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17
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Moldovean SN, Chiş V. Molecular Dynamics Simulations Applied to Structural and Dynamical Transitions of the Huntingtin Protein: A Review. ACS Chem Neurosci 2020; 11:105-120. [PMID: 31841621 DOI: 10.1021/acschemneuro.9b00561] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Over the recent years, Huntington's disease (HD) has become widely discussed in the scientific literature especially because at the mutant level there are several contradictions regarding the aggregation mechanism. The specific role of the physiological huntingtin protein remains unknown, due to the lack of characterization of its entire crystallographic structure, making the experimental and theoretical research even harder when taking into consideration its involvement in multiple biological functions and its high affinity for different interacting partners. Different types of models, containing fewer (not more than 35 Qs) polyglutamine residues for the WT structure and above 35 Qs for the mutants, were subjected to classical or advanced MD simulations to establish the proteins' structural stability by evaluating their conformational changes. Outside the polyQ tract, there are two other regions of interest (the N17 domain and the polyP rich domain) considered to be essential for the aggregation kinetics at the mutant level. The polymerization process is considered to be dependent on the polyQ length. As the polyQ tract's dimension increases, the structures present more β-sheet conformations. Contrarily, it is also considered that the aggregation stability is not necessarily dependent on the number of Qs, while the initial stage of the aggregation seed might play the decisive role. A general assumption regarding the polyP domain is that it might preserve the polyQ structures soluble by acting as an antagonist for β-sheet formation.
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Affiliation(s)
| | - Vasile Chiş
- Babeş-Bolyai University, Faculty of Physics, Kogălniceanu 1, RO-400084 Cluj-Napoca, Romania
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18
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Zhang XM, François U, Silm K, Angelo MF, Fernandez-Busch MV, Maged M, Martin C, Bernard V, Cordelières FP, Deshors M, Pons S, Maskos U, Bemelmans AP, Wojcik SM, El Mestikawy S, Humeau Y, Herzog E. A proline-rich motif on VGLUT1 reduces synaptic vesicle super-pool and spontaneous release frequency. eLife 2019; 8:50401. [PMID: 31663854 PMCID: PMC6861006 DOI: 10.7554/elife.50401] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Accepted: 10/27/2019] [Indexed: 12/29/2022] Open
Abstract
Glutamate secretion at excitatory synapses is tightly regulated to allow for the precise tuning of synaptic strength. Vesicular Glutamate Transporters (VGLUT) accumulate glutamate into synaptic vesicles (SV) and thereby regulate quantal size. Further, the number of release sites and the release probability of SVs maybe regulated by the organization of active-zone proteins and SV clusters. In the present work, we uncover a mechanism mediating an increased SV clustering through the interaction of VGLUT1 second proline-rich domain, endophilinA1 and intersectin1. This strengthening of SV clusters results in a combined reduction of axonal SV super-pool size and miniature excitatory events frequency. Our findings support a model in which clustered vesicles are held together through multiple weak interactions between Src homology three and proline-rich domains of synaptic proteins. In mammals, VGLUT1 gained a proline-rich sequence that recruits endophilinA1 and turns the transporter into a regulator of SV organization and spontaneous release.
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Affiliation(s)
- Xiao Min Zhang
- Interdisciplinary Institute for Neuroscience, Université de Bordeaux, Bordeaux, France.,Interdisciplinary Institute for Neuroscience CNRS UMR 5297, Bordeaux, France.,Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Urielle François
- Interdisciplinary Institute for Neuroscience, Université de Bordeaux, Bordeaux, France.,Interdisciplinary Institute for Neuroscience CNRS UMR 5297, Bordeaux, France
| | - Kätlin Silm
- Neuroscience Paris Seine NPS, Université Pierre et Marie Curie INSERM U1130 CNRS UMR8246, Paris, France
| | - Maria Florencia Angelo
- Interdisciplinary Institute for Neuroscience, Université de Bordeaux, Bordeaux, France.,Interdisciplinary Institute for Neuroscience CNRS UMR 5297, Bordeaux, France
| | - Maria Victoria Fernandez-Busch
- Interdisciplinary Institute for Neuroscience, Université de Bordeaux, Bordeaux, France.,Interdisciplinary Institute for Neuroscience CNRS UMR 5297, Bordeaux, France
| | - Mona Maged
- Interdisciplinary Institute for Neuroscience, Université de Bordeaux, Bordeaux, France.,Interdisciplinary Institute for Neuroscience CNRS UMR 5297, Bordeaux, France
| | - Christelle Martin
- Interdisciplinary Institute for Neuroscience, Université de Bordeaux, Bordeaux, France.,Interdisciplinary Institute for Neuroscience CNRS UMR 5297, Bordeaux, France
| | - Véronique Bernard
- Neuroscience Paris Seine NPS, Université Pierre et Marie Curie INSERM U1130 CNRS UMR8246, Paris, France
| | - Fabrice P Cordelières
- Bordeaux Imaging Center, Université de Bordeaux, CNRS UMS 3420, INSERM US4, Bordeaux, France
| | - Melissa Deshors
- Interdisciplinary Institute for Neuroscience, Université de Bordeaux, Bordeaux, France.,Interdisciplinary Institute for Neuroscience CNRS UMR 5297, Bordeaux, France
| | - Stéphanie Pons
- Institut Pasteur, CNRS UMR 3571, Unité NISC, Paris, France
| | - Uwe Maskos
- Institut Pasteur, CNRS UMR 3571, Unité NISC, Paris, France
| | - Alexis Pierre Bemelmans
- Commissariat à l'Energie Atomique et aux Energies Alternatives (CEA), Direction de laRecherche Fondamentale (DRF), Institut de Biologie François Jacob (IBFJ), MolecularImaging Research Center (MIRCen), Fontenay-aux-Roses, France
| | - Sonja M Wojcik
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Salah El Mestikawy
- Neuroscience Paris Seine NPS, Université Pierre et Marie Curie INSERM U1130 CNRS UMR8246, Paris, France.,Department of Psychiatry, Douglas Mental Health University Institute, McGill University, Montreal, Canada
| | - Yann Humeau
- Interdisciplinary Institute for Neuroscience, Université de Bordeaux, Bordeaux, France.,Interdisciplinary Institute for Neuroscience CNRS UMR 5297, Bordeaux, France
| | - Etienne Herzog
- Interdisciplinary Institute for Neuroscience, Université de Bordeaux, Bordeaux, France.,Interdisciplinary Institute for Neuroscience CNRS UMR 5297, Bordeaux, France
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19
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Varga K, Jiang ZJ, Gong LW. Phosphatidylserine is critical for vesicle fission during clathrin-mediated endocytosis. J Neurochem 2019; 152:48-60. [PMID: 31587282 DOI: 10.1111/jnc.14886] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Revised: 09/25/2019] [Accepted: 10/01/2019] [Indexed: 12/11/2022]
Abstract
Phosphatidylserine (PS), a negatively charged phospholipid present predominantly at the inner leaflet of the plasma membrane, has been widely implicated in many cellular processes including membrane trafficking. Along this line, PS has been demonstrated to be important for endocytosis, however, the involved mechanisms remain uncertain. By monitoring clathrin-mediated endocytosis (CME) of single vesicles in mouse chromaffin cells using cell-attached capacitance measurements that offer millisecond time resolution, we demonstrate in the present study that the fission-pore duration is reduced by PS addition, indicating a stimulatory role of PS in regulating the dynamics of vesicle fission during CME. Furthermore, our results show that the PS-mediated effect on the fission-pore duration is Ca2+ -dependent and abolished in the absence of synaptotagmin 1 (Syt1), implying that Syt1 is necessary for the stimulatory role of PS in vesicle fission during CME. Consistently, a Syt1 mutant with a defective PS-Syt1 interaction increases the fission-pore duration. Taken together, our study suggests that PS-Syt1 interaction may be critical in regulating fission dynamics during CME.
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Affiliation(s)
- Kelly Varga
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, Illinois, USA.,Department of Biological Sciences, University of North Texas at Dallas, Dallas, Texas, USA
| | - Zhong-Jiao Jiang
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Liang-Wei Gong
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, Illinois, USA
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20
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Rópolo AS, Feliziani C, Touz MC. Unusual proteins in Giardia duodenalis and their role in survival. ADVANCES IN PARASITOLOGY 2019; 106:1-50. [PMID: 31630755 DOI: 10.1016/bs.apar.2019.07.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The capacity of the parasite Giardia duodenalis to perform complex functions with minimal amounts of proteins and organelles has attracted increasing numbers of scientists worldwide, trying to explain how this parasite adapts to internal and external changes to survive. One explanation could be that G. duodenalis evolved from a structurally complex ancestor by reductive evolution, resulting in adaptation to its parasitic lifestyle. Reductive evolution involves the loss of genes, organelles, and functions that commonly occur in many parasites, by which the host renders some structures and functions redundant. However, there is increasing data that Giardia possesses proteins able to perform more than one function. During recent decades, the concept of moonlighting was described for multitasking proteins, which involves only proteins with an extra independent function(s). In this chapter, we provide an overview of unusual proteins in Giardia that present multifunctional properties depending on the location and/or parasite requirement. We also discuss experimental evidence that may allow some giardial proteins to be classified as moonlighting proteins by examining the properties of moonlighting proteins in general. Up to date, Giardia does not seem to require the numerous redundant proteins present in other organisms to accomplish its normal functions, and thus this parasite may be an appropriate model for understanding different aspects of moonlighting proteins, which may be helpful in the design of drug targets.
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Affiliation(s)
- Andrea S Rópolo
- Instituto de Investigación Médica Mercedes y Martín Ferreyra, INIMEC-CONICET-Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Constanza Feliziani
- Instituto de Investigación Médica Mercedes y Martín Ferreyra, INIMEC-CONICET-Universidad Nacional de Córdoba, Córdoba, Argentina
| | - María C Touz
- Instituto de Investigación Médica Mercedes y Martín Ferreyra, INIMEC-CONICET-Universidad Nacional de Córdoba, Córdoba, Argentina.
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21
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Chen Y, Yong J, Martínez-Sánchez A, Yang Y, Wu Y, De Camilli P, Fernández-Busnadiego R, Wu M. Dynamic instability of clathrin assembly provides proofreading control for endocytosis. J Cell Biol 2019; 218:3200-3211. [PMID: 31451612 PMCID: PMC6781453 DOI: 10.1083/jcb.201804136] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Revised: 06/03/2019] [Accepted: 08/01/2019] [Indexed: 12/18/2022] Open
Abstract
Chen et al. reconstitute endocytosis in a cell-free system and show that cargo sorting requires the dynamic dissociation of clathrin during the growth phase of the clathrin-coated pit formation. Clathrin-mediated endocytosis depends on the formation of functional clathrin-coated pits that recruit cargos and mediate the uptake of those cargos into the cell. However, it remains unclear whether the cargos in the growing clathrin-coated pits are actively monitored by the coat assembly machinery. Using a cell-free reconstitution system, we report that clathrin coat formation and cargo sorting can be uncoupled, indicating that a checkpoint is required for functional cargo incorporation. We demonstrate that the ATPase Hsc70 and a dynamic exchange of clathrin during assembly are required for this checkpoint. In the absence of Hsc70 function, clathrin assembles into pits but fails to enrich cargo. Using single-molecule imaging, we further show that uncoating takes place throughout the lifetime of the growing clathrin-coated pits. Our results suggest that the dynamic exchange of clathrin, at the cost of the reduced overall assembly rates, primarily serves as a proofreading mechanism for quality control of endocytosis.
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Affiliation(s)
- Yan Chen
- Centre for Bioimaging Sciences, Department of Biological Sciences, National University of Singapore, Singapore
| | - Jeffery Yong
- Centre for Bioimaging Sciences, Department of Biological Sciences, National University of Singapore, Singapore
| | | | - Yang Yang
- Centre for Bioimaging Sciences, Department of Biological Sciences, National University of Singapore, Singapore
| | - Yumei Wu
- Howard Hughes Medical Institute, Department of Cell Biology and Department of Neuroscience, Program in Cellular Neuroscience, Neurodegeneration and Repair, Yale University School of Medicine, New Haven, CT
| | - Pietro De Camilli
- Howard Hughes Medical Institute, Department of Cell Biology and Department of Neuroscience, Program in Cellular Neuroscience, Neurodegeneration and Repair, Yale University School of Medicine, New Haven, CT
| | - Rubén Fernández-Busnadiego
- Max Planck Institute for Biochemistry, Martinsried, Germany.,Department of Neuropathology, University Medical Center, Georg-August University Göttingen, Göttingen, Germany
| | - Min Wu
- Centre for Bioimaging Sciences, Department of Biological Sciences, National University of Singapore, Singapore .,Mechanobiology Institute, National University of Singapore, Singapore
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22
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Cao J, Zhong MB, Toro CA, Zhang L, Cai D. Endo-lysosomal pathway and ubiquitin-proteasome system dysfunction in Alzheimer's disease pathogenesis. Neurosci Lett 2019; 703:68-78. [PMID: 30890471 PMCID: PMC6760990 DOI: 10.1016/j.neulet.2019.03.016] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Revised: 02/19/2019] [Accepted: 03/11/2019] [Indexed: 01/04/2023]
Abstract
Several lines of evidence have shown that defects in the endo-lysosomal autophagy degradation pathway and the ubiquitin-proteasome system play a role in Alzheimer's Disease (AD) pathogenesis and pathophysiology. Early pathological changes, such as marked enlargement of endosomal compartments, gradual accumulation of autophagic vacuoles (AVs) and lysosome dyshomeostasis, are well-recognized in AD. In addition to these pathological indicators, many genetic variants of key regulators in the endo-lysosomal autophagy networks and the ubiquitin-proteasome system have been found to be associated with AD. Furthermore, altered expression levels of key proteins in these pathways have been found in AD human brain tissues, primary cells and AD mouse models. In this review, we discuss potential disease mechanisms underlying the dysregulation of protein homeostasis governing systems. While the importance of two major protein degradation pathways in AD pathogenesis has been highlighted, targeted therapy at key components of these pathways has great potential in developing novel therapeutic interventions for AD. Future investigations are needed to define molecular mechanisms by which these complex regulatory systems become malfunctional at specific stages of AD development and progression, which will facilitate future development of novel therapeutic interventions. It is also critical to investigate all key components of the protein degradation pathways, both upstream and downstream, to improve our abilities to manipulate transport pathways with higher efficacy and less side effects.
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Affiliation(s)
- Jiqing Cao
- Research and Development, James J Peters VA Medical Center, Bronx, NY 10468, United States; Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, United States; The Central Hospital of The Hua Zhong University of Science and Technology, Wuhan, China.
| | - Margaret B Zhong
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, United States; Barnard College of Columbia University, New York, NY 10027, United States.
| | - Carlos A Toro
- Research and Development, James J Peters VA Medical Center, Bronx, NY 10468, United States; National Center for the Medical Consequences of Spinal Cord Injury, James J Peters VA Medical Center, Bronx, NY 10468, United States; Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029, United States.
| | - Larry Zhang
- Research and Development, James J Peters VA Medical Center, Bronx, NY 10468, United States; Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, United States.
| | - Dongming Cai
- Research and Development, James J Peters VA Medical Center, Bronx, NY 10468, United States; Neurology Section, James J Peters VA Medical Center, Bronx, NY 10468, United States; Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, United States; The Central Hospital of The Hua Zhong University of Science and Technology, Wuhan, China.
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23
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Epsins Regulate Mouse Embryonic Stem Cell Exit from Pluripotency and Neural Commitment by Controlling Notch Activation. Stem Cells Int 2019; 2019:4084351. [PMID: 30930949 PMCID: PMC6410434 DOI: 10.1155/2019/4084351] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Revised: 10/29/2018] [Accepted: 11/19/2018] [Indexed: 01/09/2023] Open
Abstract
Epsins are part of the internalization machinery pivotal to control clathrin-mediated endocytosis. Here, we report that epsin family members are expressed in mouse embryonic stem cells (mESCs) and that epsin1/2 knockdown alters both mESC exits from pluripotency and their differentiation. Furthermore, we show that epsin1/2 knockdown compromises the correct polarization and division of mESC-derived neural progenitors and their conversion into expandable radial glia-like neural stem cells. Finally, we provide evidence that Notch signaling is impaired following epsin1/2 knockdown and that experimental restoration of Notch signaling rescues the epsin-mediated phenotypes. We conclude that epsins contribute to control mESC exit from pluripotency and allow their neural differentiation by appropriate modulation of Notch signaling.
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24
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Piccini A, Castroflorio E, Valente P, Guarnieri FC, Aprile D, Michetti C, Bramini M, Giansante G, Pinto B, Savardi A, Cesca F, Bachi A, Cattaneo A, Wren JD, Fassio A, Valtorta F, Benfenati F, Giovedì S. APache Is an AP2-Interacting Protein Involved in Synaptic Vesicle Trafficking and Neuronal Development. Cell Rep 2018; 21:3596-3611. [PMID: 29262337 DOI: 10.1016/j.celrep.2017.11.073] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Revised: 10/23/2017] [Accepted: 11/20/2017] [Indexed: 11/25/2022] Open
Abstract
Synaptic transmission is critically dependent on synaptic vesicle (SV) recycling. Although the precise mechanisms of SV retrieval are still debated, it is widely accepted that a fundamental role is played by clathrin-mediated endocytosis, a form of endocytosis that capitalizes on the clathrin/adaptor protein complex 2 (AP2) coat and several accessory factors. Here, we show that the previously uncharacterized protein KIAA1107, predicted by bioinformatics analysis to be involved in the SV cycle, is an AP2-interacting clathrin-endocytosis protein (APache). We found that APache is highly enriched in the CNS and is associated with clathrin-coated vesicles via interaction with AP2. APache-silenced neurons exhibit a severe impairment of maturation at early developmental stages, reduced SV density, enlarged endosome-like structures, and defects in synaptic transmission, consistent with an impaired clathrin/AP2-mediated SV recycling. Our data implicate APache as an actor in the complex regulation of SV trafficking, neuronal development, and synaptic plasticity.
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Affiliation(s)
- Alessandra Piccini
- Department of Experimental Medicine, University of Genova, 16132 Genova, Italy
| | - Enrico Castroflorio
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, 16132 Genova, Italy
| | - Pierluigi Valente
- Department of Experimental Medicine, University of Genova, 16132 Genova, Italy
| | - Fabrizia C Guarnieri
- San Raffaele Scientific Institute and Vita Salute University, 20132 Milano, Italy
| | - Davide Aprile
- Department of Experimental Medicine, University of Genova, 16132 Genova, Italy
| | - Caterina Michetti
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, 16132 Genova, Italy
| | - Mattia Bramini
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, 16132 Genova, Italy
| | - Giorgia Giansante
- Department of Experimental Medicine, University of Genova, 16132 Genova, Italy
| | - Bruno Pinto
- Local Micro-environment and Brain Development Laboratory, Istituto Italiano di Tecnologia, 16163 Genova, Italy; Bio@SNS, Scuola Normale Superiore, 56126 Pisa, Italy
| | - Annalisa Savardi
- Department of Experimental Medicine, University of Genova, 16132 Genova, Italy; Local Micro-environment and Brain Development Laboratory, Istituto Italiano di Tecnologia, 16163 Genova, Italy
| | - Fabrizia Cesca
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, 16132 Genova, Italy
| | - Angela Bachi
- IFOM, FIRC Institute of Molecular Oncology, 20132 Milano, Italy
| | - Angela Cattaneo
- IFOM, FIRC Institute of Molecular Oncology, 20132 Milano, Italy
| | - Jonathan D Wren
- Department of Arthritis and Clinical Immunology, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104-5005, USA
| | - Anna Fassio
- Department of Experimental Medicine, University of Genova, 16132 Genova, Italy; Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, 16132 Genova, Italy
| | - Flavia Valtorta
- San Raffaele Scientific Institute and Vita Salute University, 20132 Milano, Italy
| | - Fabio Benfenati
- Department of Experimental Medicine, University of Genova, 16132 Genova, Italy; Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, 16132 Genova, Italy.
| | - Silvia Giovedì
- Department of Experimental Medicine, University of Genova, 16132 Genova, Italy.
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25
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Abstract
Synapse is the basic structural and functional component for neural communication in the brain. The presynaptic terminal is the structural and functionally essential area that initiates communication and maintains the continuous functional neural information flow. It contains synaptic vesicles (SV) filled with neurotransmitters, an active zone for release, and numerous proteins for SV fusion and retrieval. The structural and functional synaptic plasticity is a representative characteristic; however, it is highly vulnerable to various pathological conditions. In fact, synaptic alteration is thought to be central to neural disease processes. In particular, the alteration of the structural and functional phenotype of the presynaptic terminal is a highly significant evidence for neural diseases. In this review, we specifically describe structural and functional alteration of nerve terminals in several neurodegenerative diseases, including Alzheimer’s disease (AD), Parkinson’s disease (PD), Amyotrophic lateral sclerosis (ALS), and Huntington’s disease (HD).
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Affiliation(s)
- Jae Ryul Bae
- Department of Biomedical Science, Graduate School, Kyung Hee University, Seoul 02447, Korea
| | - Sung Hyun Kim
- Department of Physiology, School of Medicine, Kyung Hee University, Seoul 02447, Korea
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26
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Manni MM, Tiberti ML, Pagnotta S, Barelli H, Gautier R, Antonny B. Acyl chain asymmetry and polyunsaturation of brain phospholipids facilitate membrane vesiculation without leakage. eLife 2018. [PMID: 29543154 PMCID: PMC5903860 DOI: 10.7554/elife.34394] [Citation(s) in RCA: 94] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Phospholipid membranes form cellular barriers but need to be flexible enough to divide by fission. Phospholipids generally contain a saturated fatty acid (FA) at position sn1 whereas the sn2-FA is saturated, monounsaturated or polyunsaturated. Our understanding of the impact of phospholipid unsaturation on membrane flexibility and fission is fragmentary. Here, we provide a comprehensive view of the effects of the FA profile of phospholipids on membrane vesiculation by dynamin and endophilin. Coupled to simulations, this analysis indicates that: (i) phospholipids with two polyunsaturated FAs make membranes prone to vesiculation but highly permeable; (ii) asymmetric sn1-saturated-sn2-polyunsaturated phospholipids provide a tradeoff between efficient membrane vesiculation and low membrane permeability; (iii) When incorporated into phospholipids, docosahexaenoic acid (DHA; omega-3) makes membranes more deformable than arachidonic acid (omega-6). These results suggest an explanation for the abundance of sn1-saturated-sn2-DHA phospholipids in synaptic membranes and for the importance of the omega-6/omega-3 ratio on neuronal functions. Surrounding each living cell is a membrane that is mainly made of fat molecules called phospholipids. Similar membranes also surround many of the structures inside cells. It is important for life that these membranes are impermeable to many molecules; for example, they do not allow ions to cross them freely. The membranes also need to be flexible and allow cells to form different shapes. Flexible membranes also allow cells to move molecules around and to divide to produce new cells. Each phospholipid includes two long chains of atoms called fatty acids. There are many fatty acids but they are typically grouped into saturated and unsaturated based on their chemical structures. The omega-3 and omega-6 fats are both groups of unsaturated fatty acids that are found in brain cells. Many phospholipids in cell membranes contain one saturated and one unsaturated fatty acid but it is not clear why. By studying fat molecules in the laboratory and combining this with simulations, Manni et al. have now examined the effects of fatty acids on membranes. The investigation showed that phospholipids with both saturated and unsaturated fatty acids strike a balance between impermeable and flexible membranes. More unsaturated fatty acids make more flexible membranes but they are too permeable to be used in cells. The experiments also revealed that omega-3 unsaturated fats aid flexibility more than omega-6. This finding may help to explain why the relative amounts of omega-3 and -6 are so important in the membranes of brain cells. The connection between the fats we eat and the fatty acids in our cells is complex. Yet, findings like these serve to remind us that we need a balanced diet of different fats to keep all our cells healthy.
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Affiliation(s)
- Marco M Manni
- Institut de Pharmacologie Moléculaire et Cellulaire, Université Côte d'Azur et CNRS, Valbonne, France.,Instituto Biofisika (UPV/EHU, CSIC), Leioa, Spain
| | - Marion L Tiberti
- Institut de Pharmacologie Moléculaire et Cellulaire, Université Côte d'Azur et CNRS, Valbonne, France
| | - Sophie Pagnotta
- Centre Commun de Microscopie Appliquée, Université Côte d'Azur, Nice, France
| | - Hélène Barelli
- Institut de Pharmacologie Moléculaire et Cellulaire, Université Côte d'Azur et CNRS, Valbonne, France
| | - Romain Gautier
- Institut de Pharmacologie Moléculaire et Cellulaire, Université Côte d'Azur et CNRS, Valbonne, France
| | - Bruno Antonny
- Institut de Pharmacologie Moléculaire et Cellulaire, Université Côte d'Azur et CNRS, Valbonne, France
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27
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Hypoxia-inducible factor prolyl hydroxylase 2 (PHD2) is a direct regulator of epidermal growth factor receptor (EGFR) signaling in breast cancer. Oncotarget 2018; 8:9885-9898. [PMID: 28038470 PMCID: PMC5354778 DOI: 10.18632/oncotarget.14241] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Accepted: 12/02/2016] [Indexed: 01/09/2023] Open
Abstract
Clinical studies in breast cancer suggest important associations between intratumoral hypoxia, the upregulation of epidermal growth factor receptor (EGFR or HER1), hypoxia-inducible factor 1α (HIF-1α), and reduced patient survival. However, direct molecular links between EGFR and the hypoxia signaling system are not yet established. Since the oxygen sensor hypoxia-inducible factor prolyl hydroxylase 2 (PHD2) is considered to be the main HIF-1α regulator, we hypothesized that PHD2 and EGFR may be interconnected at the molecular level. By analyzing samples from 313 breast cancer patients, we found that EGFR is a first clinicopathological parameter positively correlating with PHD2. Mechanistically, we identified PHD2 as a direct binding partner of EGFR and show that PHD2 regulates EGFR stability as well as its subsequent signaling in breast carcinoma cells. Overall, we introduce for the first time the direct crosstalk between the oxygen sensor PHD2 and EGFR-mediated tumorigenesis in breast cancer.
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28
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Wei IH, Chen KT, Tsai MH, Wu CH, Lane HY, Huang CC. Acute Amino Acid d-Serine Administration, Similar to Ketamine, Produces Antidepressant-like Effects through Identical Mechanisms. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2017; 65:10792-10803. [PMID: 29161812 DOI: 10.1021/acs.jafc.7b04217] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
d-Serine is an amino acid and can work as an agonist at the glycine sites of N-methyl-d-aspartate receptor (NMDAR). Interestingly, both types of glutamatergic modulators, NMDAR enhancers and blockers, can improve depression through common targets, namely alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionaic acid receptors (AMPARs) and mammalian target of rapamycin (mTOR). To elucidate the cellular signaling pathway underlying this counterintuitive observation, we activated NMDARs in rats by using d-serine. Saline, ketamine (NMDAR antagonist), and desipramine (tricyclic antidepressant) were used as controls. The antidepressant-like effects of all agents were evaluated using the forced swim test. The activation of the AMPAR-mTOR signaling pathway, release of brain-derived neurotrophic factor (BDNF), and alteration of AMPAR and NMDAR trafficking in the hippocampus of rats were examined. A single high dose of d-serine exerted an antidepressant-like effect that was mediated by rapid AMPAR-induced mTOR signaling pathway and increased BDNF proteins, identical to that of ketamine. Furthermore, in addition to the increased protein kinase A phosphorylation of the AMPAR subunit GluR1 (an indicator of AMPAR insertion in neurons), treatment with individual optimal doses of d-serine and ketamine also increased adaptin β2-NMDAR association (an indicator of the intracellular endocytic machinery and subsequent internalization of NMDARs). Desipramine did not influence these processes. Our study is the first to demonstrate an association between d-serine and ketamine; following adaptative regulation of AMPAR and NMDAR may lead to common changes of them. These findings provide novel targets for safer antidepressant agents with mechanisms similar to those of ketamine.
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Affiliation(s)
| | | | | | - Ching-Hsiang Wu
- Department of Anatomy, College of Medicine, Taipei Medical University , 110 Taipei, Taiwan
| | - Hsien-Yuan Lane
- Brain Disease Research Center & Department of Psychiatry, China Medical University Hospital , 404 Taichung, Taiwan
| | - Chih-Chia Huang
- Brain Disease Research Center & Department of Psychiatry, China Medical University Hospital , 404 Taichung, Taiwan
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29
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Choudhary B, Kamak M, Ratnakaran N, Kumar J, Awasthi A, Li C, Nguyen K, Matsumoto K, Hisamoto N, Koushika SP. UNC-16/JIP3 regulates early events in synaptic vesicle protein trafficking via LRK-1/LRRK2 and AP complexes. PLoS Genet 2017; 13:e1007100. [PMID: 29145394 PMCID: PMC5716593 DOI: 10.1371/journal.pgen.1007100] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2017] [Revised: 12/05/2017] [Accepted: 11/02/2017] [Indexed: 01/02/2023] Open
Abstract
JIP3/UNC-16/dSYD is a MAPK-scaffolding protein with roles in protein trafficking. We show that it is present on the Golgi and is necessary for the polarized distribution of synaptic vesicle proteins (SVPs) and dendritic proteins in neurons. UNC-16 excludes Golgi enzymes from SVP transport carriers and facilitates inclusion of specific SVPs into the same transport carrier. The SVP trafficking roles of UNC-16 are mediated through LRK-1, whose localization to the Golgi is reduced in unc-16 animals. UNC-16, through LRK-1, also enables Golgi-localization of the μ-subunit of the AP-1 complex. AP1 regulates the size but not the composition of SVP transport carriers. Additionally, UNC-16 and LRK-1 through the AP-3 complex regulates the composition but not the size of the SVP transport carrier. These early biogenesis steps are essential for dependence on the synaptic vesicle motor, UNC-104 for axonal transport. Our results show that UNC-16 and its downstream effectors, LRK-1 and the AP complexes function at the Golgi and/or post-Golgi compartments to control early steps of SV biogenesis. The UNC-16 dependent steps of exclusion, inclusion and motor recruitment are critical for polarized distribution of neuronal cargo. Synaptic vesicles (SVs) have a defined composition and size at the synapse. The multiple synaptic vesicle proteins (SVPs) found on these vesicle membranes are synthesized at and trafficked out of the cell body in distinct transport carriers. However, we do not yet understand how different SVPs are sorted and trafficked to the synapse. We show that UNC-16/JIP3 plays a critical role, in a series of essential steps, to ensure proper membrane composition and size of the ensuing SVP carrier exiting the cell body. These processes are “exclusion” of resident Golgi enzymes followed by the “inclusion” of synaptic vesicle proteins in the same transport carrier. Regulation of composition and size seems to occur independently of each other and depends on two distinct AP complexes acting downstream to LRK-1. Our study further indicates that the composition of the transport carrier formed is important for the recruitment of motors and consequently for the polarized localization of SVPs.
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Affiliation(s)
- Bikash Choudhary
- National Centre for Biological Sciences-Tata Institute of Fundamental Research, Bangalore, Karnataka, India
| | - Madhushree Kamak
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, Maharashtra, India
| | - Neena Ratnakaran
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, Maharashtra, India
| | - Jitendra Kumar
- National Centre for Biological Sciences-Tata Institute of Fundamental Research, Bangalore, Karnataka, India
| | - Anjali Awasthi
- National Centre for Biological Sciences-Tata Institute of Fundamental Research, Bangalore, Karnataka, India
- Department of Biological Sciences, Birla Institute of Technology and Science, Pilani, Rajasthan, India
| | - Chun Li
- Group of Signaling Mechanisms, Nagoya University, Nagoya, Japan
| | - Ken Nguyen
- Center for C. elegans Anatomy, Albert Einstein College of Medicine, New York, New York, United States of America
| | | | - Naoki Hisamoto
- Group of Signaling Mechanisms, Nagoya University, Nagoya, Japan
| | - Sandhya P. Koushika
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, Maharashtra, India
- * E-mail:
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30
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Davtyan A, Simunovic M, Voth GA. The mesoscopic membrane with proteins (MesM-P) model. J Chem Phys 2017; 147:044101. [PMID: 28764362 PMCID: PMC5552407 DOI: 10.1063/1.4993514] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Accepted: 06/26/2017] [Indexed: 12/30/2022] Open
Abstract
We present the Mesoscopic Membrane with Proteins (MesM-P) model, an extension of a previously developed elastic membrane model for mesoscale simulations of lipid membranes. MesM-P employs a discrete mesoscopic quasi-particle approach to model protein-facilitated shape and topology changes of the lipid membrane on length and time scales inaccessible to all-atom and quasimolecular coarse-grained molecular dynamics simulations. We investigate the ability of MesM-P to model the behavior of large lipid vesicles as a function of bound protein density. We find four distinct mechanisms for protein aggregation on the surface of the membrane, depending on membrane stiffness and protein spontaneous curvature. We also establish a connection between MesM-P and the results of higher resolution coarse-grained molecular dynamics simulations.
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Affiliation(s)
- Aram Davtyan
- Department of Chemistry, The James Franck Institute, Institute for Biophysical Dynamics, The University of Chicago, Chicago, Illinois 60637, USA
| | - Mijo Simunovic
- Department of Chemistry, The James Franck Institute, Institute for Biophysical Dynamics, The University of Chicago, Chicago, Illinois 60637, USA
| | - Gregory A Voth
- Department of Chemistry, The James Franck Institute, Institute for Biophysical Dynamics, The University of Chicago, Chicago, Illinois 60637, USA
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31
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Vien TN, Moss SJ, Davies PA. Regulating the Efficacy of Inhibition Through Trafficking of γ-Aminobutyric Acid Type A Receptors. Anesth Analg 2017; 123:1220-1227. [PMID: 27285004 DOI: 10.1213/ane.0000000000001349] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Trafficking of anesthetic-sensitive receptors within the plasma membrane, or from one cellular component to another, occurs continuously. Changes in receptor trafficking have implications in altering anesthetic sensitivity. γ-Aminobutyric acid type A receptors (GABAARs) are anion-permeable ion channels and are the major class of receptor in the adult mammalian central nervous system that mediates inhibition. GABAergic signaling allows for precise synchronized firing of action potentials within brain circuits that is critical for cognition, behavior, and consciousness. This precision depends upon tightly controlled trafficking of GABAARs into the membrane. General anesthetics bind to and allosterically enhance GABAARs by prolonging the open state of the receptor and thereby altering neuronal and brain circuit activity. Subunit composition and GABAAR localization strongly influence anesthetic end points; therefore, changes in GABAAR trafficking could have significant consequences to anesthetic sensitivity. GABAARs are not static membrane structures but are in a constant state of flux between extrasynaptic and synaptic locations and are continually endocytosed and recycled from and to the membrane. Neuronal activity, posttranslational modifications, and some naturally occurring and synthetic compounds can influence the expression and trafficking of GABAARs. In this article, we review GABAARs, their trafficking, and how phosphorylation of GABAAR subunits can influence the surface expression and function of the receptor. Ultimately, alterations of GABAAR trafficking could modify anesthetic end points, both unintentionally through pathologic processes but potentially as a therapeutic target to adjust anesthetic-sensitive GABAARs.
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Affiliation(s)
- Thuy N Vien
- From the *Department of Neuroscience, Tufts University School of Medicine, Sackler School of Graduate Biomedical Sciences, Boston, Massachusetts; and †Department of Neuroscience, Tufts University School of Medicine, Boston, Massachusetts
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32
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Jinesh GG, Kamat AM. Blebbishields and mitotic cells exhibit robust macropinocytosis. Biofactors 2017; 43:181-186. [PMID: 27671897 DOI: 10.1002/biof.1335] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Accepted: 09/07/2016] [Indexed: 01/14/2023]
Abstract
Cancer stem cells can survive and undergo transformation after apoptosis by initiating robust endocytosis. Endocytosis in-turn drives formation of serpentine filopodia, which promote construction of blebbishields from apoptotic bodies. However, the status and role of macropinocytosis in blebbishields is not known. Here, we show by scanning electron microscopy and by macropinocytosis assays that blebbishields exhibit robust macropinocytosis. Inhibiting dynamin-mediated endocytosis does not affect macropinocytosis in blebbishields or in mitotic cells. In addition, inhibiting macropinocytosis did not inhibit construction of blebbishields from apoptotic bodies. Thus, although apoptotic cancer stem cells exhibit robust macropinocytosis, macropinocytosis is not essential to generate blebbishields, although it may play other roles in blebbishield biology. © 2016 BioFactors, 43(2):181-186, 2017.
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Affiliation(s)
- Goodwin G Jinesh
- Department of Urology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Ashish M Kamat
- Department of Urology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
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33
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Gopi M, Arambakkam Janardhanam V. Asiaticoside: Attenuation of rotenone induced oxidative burden in a rat model of hemiparkinsonism by maintaining the phosphoinositide-mediated synaptic integrity. Pharmacol Biochem Behav 2017; 155:1-15. [PMID: 28238857 DOI: 10.1016/j.pbb.2017.02.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Revised: 02/14/2017] [Accepted: 02/20/2017] [Indexed: 02/06/2023]
Abstract
Asiaticoside (AS), a triterpenoid saponin isolated from the Indian medicinal herb Centella asiatica is known to exert a neuroprotective effect by attenuating the neurobehavioral, neurochemical and pathological changes in animal models. However, its potential neuroprotection in rotenone-induced hemiparkinsonism which implicates phospholipid-mediated neurotransmission remains unclear. Therefore, we have investigated the neuroprotective effects of AS in rat model of ROT-infused hemiparkinsonism with respect to phosphoinositides-assisted cytodynamics and synaptic function. Adult male Sprague-Dawley rats (250-300g) were distributed randomly into 6 groups, with 6 rats in each group: Sham control, Vehicle control (DMSO-0.1%), ROT-infused group (6μg/μl/kg), AS-treated group (50mg/kg/day), Drug (AS) control and Levodopa (l-DOPA)-treated group (6mg/kg/day). At the end of the experimental period, the rats were sacrificed after performing behavioral analyses and the striatum regions were dissected out. Phosphoinositides (PI) are involved in intrinsic membrane signals that regulate intracellular membrane trafficking vesicle and endocytosis. We have assessed mRNA and protein expressions of genes involved in PI-mediated signaling and also in synaptic function (PI3K, PDK 1, PEBP, Stx 1A and TH) in addition to the levels of neurotransmitters and the enzymatic antioxidant profile. AS caused an improved working memory and motor co-ordination in the ROT group. It alters the levels of neurotransmitters (p<0.01), the expression of mRNA and protein assessed which were significantly affected (P<0.001) by rotenone, thus exhibiting its intervention in the progression of neurodegeneration. We demonstrate that AS can mediate distinct function in PI-assisted vesicle endocytosis, cytoprotective signaling and in the synaptic function thereby mitigating the ROT-infused hemiparkinsonism, however, its specific regulatory role remains to be unraveled.
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Affiliation(s)
- Margabandhu Gopi
- Department of Biochemistry, University of Madras, Guindy Campus, Chennai 600 025, Tamilnadu, India.
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34
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Sabeva NS, Bykhovskaia M. FM1-43 Photoconversion and Electron Microscopy Analysis at the Drosophila Neuromuscular Junction. Bio Protoc 2017; 7:e2523. [PMID: 29094061 DOI: 10.21769/bioprotoc.2523] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022] Open
Abstract
We developed a protocol for photoconversion of endocytic marker FM1-43 followed by electron microscopy analysis of synaptic boutons at the Drosophila neuromuscular junction. This protocol allows detection of stained synaptic vesicle even when release rates are very low, such as during the spontaneous release mode. The preparations are loaded with the FM1-43 dye, pre-fixed, treated and illuminated to photoconvert the dye, and then processed for conventional electron microscopy. This procedure enables clear identification of stained synaptic vesicles at electron micrographs.
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Affiliation(s)
- Nadezhda S Sabeva
- Neuroscience Department, Universidad Central del Caribe, Bayamón, Puerto Rico, USA
| | - Maria Bykhovskaia
- Department of Neurology, Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, Michigan, USA
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Abstract
The ErbB receptor family, also known as the EGF receptor family or type I receptor family, includes the epidermal growth factor (EGF) receptor (EGFR) or ErbB1/Her1, ErbB2/Her2, ErbB3/Her3, and ErbB4/Her4. Among all RTKs, EGFR was the first RTK identified and the first one linked to cancer. Thus, EGFR has also been the most intensively studied among all RTKs. ErbB receptors are activated after homodimerization or heterodimerization. The ErbB family is unique among the various groups of receptor tyrosine kinases (RTKs) in that ErbB3 has impaired kinase activity, while ErbB2 does not have a direct ligand. Therefore, heterodimerization is an important mechanism that allows the activation of all ErbB receptors in response to ligand stimulation. The activated ErbB receptors bind to many signaling proteins and stimulate the activation of many signaling pathways. The specificity and potency of intracellular signaling pathways are determined by positive and negative regulators, the specific composition of activating ligand(s), receptor dimer components, and the diverse range of proteins that associate with the tyrosine phosphorylated C-terminal domain of the ErbB receptors. ErbB receptors are overexpressed or mutated in many cancers, especially in breast cancer, ovarian cancer, and non-small cell lung cancer. The overexpression and overactivation of ErbB receptors are correlated with poor prognosis, drug resistance, cancer metastasis, and lower survival rate. ErbB receptors, especially EGFR and ErbB2 have been the primary choices as targets for developing cancer therapies.
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Affiliation(s)
- Zhixiang Wang
- Signal Transduction Research Group, Department of Medical Genetics, Faculty of Medicine and Dentistry, University of Alberta, 835 MSB, 114 St NW, Edmonton, AB, Canada, T6G 2H7.
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Endosome-mediated endocytic mechanism replenishes the majority of synaptic vesicles at mature CNS synapses in an activity-dependent manner. Sci Rep 2016; 6:31807. [PMID: 27534442 PMCID: PMC4989163 DOI: 10.1038/srep31807] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Accepted: 07/26/2016] [Indexed: 11/30/2022] Open
Abstract
Whether synaptic vesicles (SVs) are recovered via endosome-mediated pathways is a matter of debate; however, recent evidence suggests that clathrin-independent bulk endocytosis (CIE) via endosomes is functional and preferentially replenishes SV pools during strong stimulation. Here, using brefeldin-A (BFA) to block CIE, we found that CIE retrieved a minority of SVs at developing CNS synapses during strong stimulation, but its contribution increased up to 61% at mature CNS synapses. Contrary to previous views, BFA not only blocked SV formation from the endosome but also blocked the endosome formation at the plasma membrane. Adaptor protein 1 and 3 (AP-1/3) have key roles in SV reformation from endosomes during CIE, and AP-1 also affects bulk endosome formation from the plasma membrane. Finally, temporary blocking of chronic or acute neuronal activity with tetrodotoxin in mature neurons redirected most SV retrieval to endosome-independent pathways. These results show that during high neuronal activity, CIE becomes the major endocytic pathway at mature CNS synapses. Moreover, mature neurons use clathrin-mediated endocytosis and the CIE pathway to different extents depending on their previous activity; this may result in activity-dependent alterations of the SV composition which ultimately influence transmitter release and contribute to synaptic plasticity.
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37
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Multiscale simulations of protein-facilitated membrane remodeling. J Struct Biol 2016; 196:57-63. [PMID: 27327264 DOI: 10.1016/j.jsb.2016.06.012] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Revised: 06/14/2016] [Accepted: 06/15/2016] [Indexed: 12/19/2022]
Abstract
Protein-facilitated shape and topology changes of cell membranes are crucial for many biological processes, such as cell division, protein trafficking, and cell signaling. However, the inherently multiscale nature of membrane remodeling presents a considerable challenge for understanding the mechanisms and physics that drive this process. To address this problem, a multiscale approach that makes use of a diverse set of computational and experimental techniques is required. The atomistic simulations provide high-resolution information on protein-membrane interactions. Experimental techniques, like electron microscopy, on the other hand, resolve high-order organization of proteins on the membrane. Coarse-grained (CG) and mesoscale computational techniques provide the intermediate link between the two scales and can give new insights into the underlying mechanisms. In this Review, we present the recent advances in multiscale computational approaches established in our group. We discuss various CG and mesoscale approaches in studying the protein-mediated large-scale membrane remodeling.
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Gopalakrishnan C, Jethi S, Kalsi N, Purohit R. Biophysical Aspect of Huntingtin Protein During polyQ: An In Silico Insight. Cell Biochem Biophys 2016; 74:129-39. [PMID: 27094178 DOI: 10.1007/s12013-016-0728-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2015] [Accepted: 03/09/2016] [Indexed: 10/21/2022]
Abstract
Huntington's disease (HD) is a neurodegenerative disorder that is caused by an abnormal elongation of the polyglutamine (polyQ) chain in the Huntington (Htt) protein. At present, the normal function of Htt of neurons as well as the mechanism by which selective neurodegeneration is caused by the expanded polyQ chain in Htt remains ambiguous. A gain of function as a result of the elongated polyQ chain can lead to abnormal interaction of the Htt protein with its interacting partners, thereby resulting in the neuropathological changes seen in the Huntington's disease. Recent research indicates protein kinase C and casein kinase substrate in neurons protein 1 (PACSIN1) as one of the interacting partners of Htt protein. It has proven experimentally that the mutant Htt and PACSIN1 formed aggregates in the cytoplasm. This aggregation is believed to be a cause for Huntington's disease. In our study, we performed in silico investigations to predict the biomolecular mechanism of Htt/PACSIN1 interaction that could be one of the major triggers of the disease. Biomolecular interaction and molecular dynamics simulation analysis were performed to understand the dynamic behavior of native and mutant structures at the atomic level. Mutant Htt showed more interaction with its biological partner than the native Htt due to its expansion of interaction surface and flexible nature of binding residues. Our investigation of native and mutant Htt clearly shows that the structural and functional consequences of the polyQ elongation cause HD. Because of the central role of the Htt-PACSIN1 complex in maintaining connections between neurons, these differences likely contribute to the mechanism responsible for HD progression.
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Affiliation(s)
- Chandrasekhar Gopalakrishnan
- Computational Biology Lab, Department of Biotechnology, School of Bio Sciences and Technology, VIT University, Vellore, 632014, Tamil Nadu, India
| | - Shraddha Jethi
- Computational Biology Lab, Department of Biotechnology, School of Bio Sciences and Technology, VIT University, Vellore, 632014, Tamil Nadu, India
| | - Namrata Kalsi
- Computational Biology Lab, Department of Biotechnology, School of Bio Sciences and Technology, VIT University, Vellore, 632014, Tamil Nadu, India
| | - Rituraj Purohit
- Division of Biotechnology, CSIR-Institute of Himalayan Bioresource Technology, Palampur, Himachal Pradesh, India.
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Lin YH, Currinn H, Pocha SM, Rothnie A, Wassmer T, Knust E. AP-2-complex-mediated endocytosis of Drosophila Crumbs regulates polarity by antagonizing Stardust. J Cell Sci 2015; 128:4538-49. [PMID: 26527400 DOI: 10.1242/jcs.174573] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Accepted: 10/26/2015] [Indexed: 12/21/2022] Open
Abstract
Maintenance of epithelial polarity depends on the correct localization and levels of polarity determinants. The evolutionarily conserved transmembrane protein Crumbs is crucial for the size and identity of the apical membrane, yet little is known about the molecular mechanisms controlling the amount of Crumbs at the surface. Here, we show that Crumbs levels on the apical membrane depend on a well-balanced state of endocytosis and stabilization. The adaptor protein 2 (AP-2) complex binds to a motif in the cytoplasmic tail of Crumbs that overlaps with the binding site of Stardust, a protein known to stabilize Crumbs on the surface. Preventing endocytosis by mutation of AP-2 causes expansion of the Crumbs-positive plasma membrane domain and polarity defects, which can be partially rescued by removing one copy of crumbs. Strikingly, knocking down both AP-2 and Stardust leads to the retention of Crumbs on the membrane. This study provides evidence for a molecular mechanism, based on stabilization and endocytosis, to adjust surface levels of Crumbs, which are essential for maintaining epithelial polarity.
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Affiliation(s)
- Ya-Huei Lin
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, Dresden 01307, Germany
| | - Heather Currinn
- School of Life and Health Sciences, Aston University, Aston Triangle, Birmingham B4 7ET, UK
| | - Shirin Meher Pocha
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, Dresden 01307, Germany
| | - Alice Rothnie
- School of Life and Health Sciences, Aston University, Aston Triangle, Birmingham B4 7ET, UK
| | - Thomas Wassmer
- School of Life and Health Sciences, Aston University, Aston Triangle, Birmingham B4 7ET, UK
| | - Elisabeth Knust
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, Dresden 01307, Germany
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Abstract
In the CNS (central nervous system), nerve cells communicate by transmitting signals from one to the next across chemical synapses. Electrical signals trigger controlled secretion of neurotransmitter by exocytosis of SV (synaptic vesicles) at the presynaptic site. Neurotransmitters diffuse across the synaptic cleft, activate receptor channels in the receiving neuron at the postsynaptic site, and thereby elicit a new electrical signal. Repetitive stimulation should result in fast depletion of fusion-competent SVs, given their limited number in the presynaptic bouton. Therefore, to support repeated rounds of release, a fast trafficking cycle is required that couples exocytosis and compensatory endocytosis. During this exo-endocytic cycle, a defined stoichiometry of SV proteins has to be preserved, that is, membrane proteins have to be sorted precisely. However, how this sorting is accomplished on a molecular level is poorly understood. In the present chapter we review recent findings regarding the molecular composition of SVs and the mechanisms that sort SV proteins during compensatory endocytosis. We identify self-assembly of SV components and individual cargo recognition by sorting adaptors as major mechanisms for maintenance of the SV protein complement.
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Verissimo F, Halavatyi A, Pepperkok R, Weiss M. A microtubule-independent role of p150glued in secretory cargo concentration at endoplasmic reticulum exit sites. J Cell Sci 2015; 128:4160-70. [PMID: 26459637 DOI: 10.1242/jcs.172395] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2015] [Accepted: 10/05/2015] [Indexed: 01/08/2023] Open
Abstract
Newly synthesized proteins are sorted into COPII-coated transport carriers at the endoplasmic reticulum (ER). Assembly of the COPII coat complex, which occurs at ER exit sites (ERES), is initiated by membrane association and GTP loading of SAR1, followed by the recruitment of the SEC23-SEC24 and SEC13-SEC31 subcomplexes. Both of these two subcomplexes stimulate GTP hydrolysis and coat disassembly. This inherent disassembly capacity of COPII complexes needs to be regulated to allow sufficient time for cargo sorting and transport carrier formation. By performing fluorescence recovery after photobleaching (FRAP) and mathematical modeling, we show that p150(glued) (also known as DCTN1), a component of the dynactin complex, stabilizes the COPII pre-budding complex on ER membranes in a microtubule-independent manner. Concentration of the secretory marker ts-O45-G at ERES is reduced in the presence of a C-terminal p150(glued) fragment that prevents binding of endogenous p150(glued) to SEC23. A similar cargo reduction is observed upon p150(glued) knockdown. Taken together, our data suggest that cargo concentration at ERES is regulated by p150(glued) to coordinate protein sorting and transport carrier formation with the subsequent long-range transport towards the Golgi complex along microtubules.
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Affiliation(s)
- Fatima Verissimo
- Cell Biology and Biophysics Unit, EMBL, Meyerhofstraße 1, Heidelberg D-69117, Germany
| | - Aliaksandr Halavatyi
- Cell Biology and Biophysics Unit, EMBL, Meyerhofstraße 1, Heidelberg D-69117, Germany
| | - Rainer Pepperkok
- Cell Biology and Biophysics Unit, EMBL, Meyerhofstraße 1, Heidelberg D-69117, Germany
| | - Matthias Weiss
- Experimental Physics I, Universitaetsstr. 30, University of Bayreuth, Bayreuth D-95440, Germany
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42
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Computational investigation of molecular mechanism and neuropathological implications in Huntington disease. Mol Cell Biochem 2015; 409:1-11. [DOI: 10.1007/s11010-015-2462-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Accepted: 05/23/2015] [Indexed: 12/31/2022]
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43
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Binding and Endocytosis of Bovine Hololactoferrin by the Parasite Entamoeba histolytica. BIOMED RESEARCH INTERNATIONAL 2015; 2015:375836. [PMID: 26090404 PMCID: PMC4450225 DOI: 10.1155/2015/375836] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/01/2014] [Revised: 09/11/2014] [Accepted: 09/16/2014] [Indexed: 11/26/2022]
Abstract
Entamoeba histolytica is a human parasite that requires iron (Fe) for its metabolic function and virulence. Bovine lactoferrin (B-Lf) and its peptides can be found in the digestive tract after dairy products are ingested. The aim of this study was to compare virulent trophozoites recently isolated from hamster liver abscesses with nonvirulent trophozoites maintained for more than 30 years in cultures in vitro regarding their interaction with iron-charged B-Lf (B-holo-Lf). We performed growth kinetics analyses of trophozoites in B-holo-Lf and throughout several consecutive transfers. The virulent parasites showed higher growth and tolerance to iron than nonvirulent parasites. Both amoeba variants specifically bound B-holo-Lf with a similar Kd. However, averages of 9.45 × 105 and 6.65 × 106 binding sites/cell were found for B-holo-Lf in nonvirulent and virulent amoebae, respectively. Virulent amoebae bound more efficiently to human and bovine holo-Lf, human holo-transferrin, and human and bovine hemoglobin than nonvirulent amoebae. Virulent amoebae showed two types of B-holo-Lf binding proteins. Although both amoebae endocytosed this glycoprotein through clathrin-coated vesicles, the virulent amoebae also endocytosed B-holo-Lf through a cholesterol-dependent mechanism. Both amoeba variants secreted cysteine proteases cleaving B-holo-Lf. These data demonstrate that the B-Lf endocytosis is more efficient in virulent amoebae.
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44
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Navarro AI, Mandyam CD. Protracted abstinence from chronic ethanol exposure alters the structure of neurons and expression of oligodendrocytes and myelin in the medial prefrontal cortex. Neuroscience 2015; 293:35-44. [PMID: 25732140 DOI: 10.1016/j.neuroscience.2015.02.043] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2014] [Revised: 02/05/2015] [Accepted: 02/21/2015] [Indexed: 10/23/2022]
Abstract
In rodents, chronic intermittent ethanol vapor exposure (CIE) produces alcohol dependence, alters the structure and activity of pyramidal neurons and decreases the number of oligodendroglial progenitors in the medial prefrontal cortex (mPFC). In this study, adult Wistar rats were exposed to seven weeks of CIE and were withdrawn from CIE for 21 days (protracted abstinence; PA). Tissue enriched in the mPFC was processed for Western blot analysis and Golgi-Cox staining to investigate the long-lasting effects of CIE on the structure of mPFC neurons and the levels of myelin-associated proteins. PA increased dendritic arborization within apical dendrites of pyramidal neurons. These changes occurred concurrently with hypophosphorylation of the N-methyl-d-aspartate (NMDA) receptor 2B (NR2B) at Tyr-1472. PA increased myelin basic protein (MBP) levels which occurred concurrently with hypophosphorylation of the premyelinating oligodendrocyte bHLH transcription factor Olig2 in the mPFC. Given that PA is associated with increased sensitivity to stress and hypothalamic-pituitary-adrenal (HPA) axis dysregulation, and stress alters oligodendrocyte expression as a function of glucocorticoid receptor (GR) activation, the levels of total GR and phosphorylated GR were also evaluated. PA produced hypophosphorylation of the GR at Ser-232 without affecting expression of total protein. These findings demonstrate persistent and compensatory effects of ethanol in the mPFC long after cessation of CIE, including enhanced myelin production and impaired GR function. Collectively, these results suggest a novel relationship between oligodendrocytes and GR in the mPFC, in which stress may alter frontal cortex function in alcohol dependent subjects by promoting hypermyelination, thereby altering the cellular composition and white matter structure in the mPFC.
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Affiliation(s)
- A I Navarro
- Committee on the Neurobiology of Addictive Disorders, The Scripps Research Institute, La Jolla, CA, USA
| | - C D Mandyam
- Committee on the Neurobiology of Addictive Disorders, The Scripps Research Institute, La Jolla, CA, USA.
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45
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Gallart-Palau X, Serra A, Qian J, Chen CP, Kalaria RN, Sze SK. Temporal lobe proteins implicated in synaptic failure exhibit differential expression and deamidation in vascular dementia. Neurochem Int 2014; 80:87-98. [PMID: 25497727 DOI: 10.1016/j.neuint.2014.12.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2014] [Revised: 11/26/2014] [Accepted: 12/02/2014] [Indexed: 12/20/2022]
Abstract
Progressive synaptic failure precedes the loss of neurons and decline in cognitive function in neurodegenerative disorders, but the specific proteins and posttranslational modifications that promote synaptic failure in vascular dementia (VaD) remain largely unknown. We therefore used an isobaric tag for relative and absolute proteomic quantitation (iTRAQ) to profile the synapse-associated proteome of post-mortem human cortex from vascular dementia patients and age-matched controls. Brain tissue from VaD patients exhibited significant down-regulation of critical synaptic proteins including clathrin (0.29; p < 1.0⋅10(-3)) and GDI1 (0.51; p = 3.0⋅10(-3)), whereas SNAP25 (1.6; p = 5.5⋅10(-3)), bassoon (1.4; p = 1.3⋅10(-3)), excitatory amino acid transporter 2 (2.6; p = 9.2⋅10(-3)) and Ca(2+)/calmodulin dependent kinase II (1.6; p = 3.0⋅10(-2)) were substantially up-regulated. Our analyses further revealed divergent patterns of protein modification in the dementia patient samples, including a specific deamidation of synapsin1 predicted to compromise protein structure. Our results reveal potential molecular targets for intervention in synaptic failure and prevention of cognitive decline in VaD.
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Affiliation(s)
| | - Aida Serra
- School of Biological Sciences, Nanyang Technological University, Singapore
| | - Jingru Qian
- School of Biological Sciences, Nanyang Technological University, Singapore
| | - Christopher P Chen
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore; Memory, Aging and Cognition Centre, National University Health System, Singapore
| | - Raj N Kalaria
- Institute for Ageing and Health, NIHR Biomedical Research Building, Newcastle University, Campus for Ageing and Vitality, Newcastle upon Tyne NE4 5PL, United Kingdom
| | - Siu Kwan Sze
- School of Biological Sciences, Nanyang Technological University, Singapore.
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46
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Abstract
Among the proteins involved in lipid membrane remodeling in intracellular traffic, dynamin has been the focus of many studies, as it was the first protein shown to be mechanistically involved in membrane fission: the reaction by which a vesicle neck can be severed to release a free vesicle. After almost 25 years of research, a wide variety of data from various techniques has been acquired on the mechanism by which dynamin breaks membranes. However, the literature may sometimes sound confusing, and the primary goal of this review will be to provide a stepping stone towards a potential consensus on how dynamin may work. I will then discuss the most recent findings in light of previous work, and the future possible lines of research in the field of dynamin.
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47
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Busch DJ, Oliphint PA, Walsh RB, Banks SML, Woods WS, George JM, Morgan JR. Acute increase of α-synuclein inhibits synaptic vesicle recycling evoked during intense stimulation. Mol Biol Cell 2014; 25:3926-41. [PMID: 25273557 PMCID: PMC4244201 DOI: 10.1091/mbc.e14-02-0708] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Parkinson's disease is associated with multiplication of the α-synuclein gene and abnormal accumulation of the protein. In animal models, α-synuclein overexpression broadly impairs synaptic vesicle trafficking. However, the exact steps of the vesicle trafficking pathway affected by excess α-synuclein and the underlying molecular mechanisms remain unknown. Therefore we acutely increased synuclein levels at a vertebrate synapse and performed a detailed ultrastructural analysis of the effects on presynaptic membranes. At stimulated synapses (20 Hz), excess synuclein caused a loss of synaptic vesicles and an expansion of the plasma membrane, indicating an impairment of vesicle recycling. The N-terminal domain (NTD) of synuclein, which folds into an α-helix, was sufficient to reproduce these effects. In contrast, α-synuclein mutants with a disrupted N-terminal α-helix (T6K and A30P) had little effect under identical conditions. Further supporting this model, another α-synuclein mutant (A53T) with a properly folded NTD phenocopied the synaptic vesicle recycling defects observed with wild type. Interestingly, the vesicle recycling defects were not observed when the stimulation frequency was reduced (5 Hz). Thus excess α-synuclein impairs synaptic vesicle recycling evoked during intense stimulation via a mechanism that requires a properly folded N-terminal α-helix.
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Affiliation(s)
- David J Busch
- Section of Molecular Cell and Developmental Biology, Department of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712
| | - Paul A Oliphint
- Section of Molecular Cell and Developmental Biology, Department of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712
| | - Rylie B Walsh
- Eugene Bell Center for Regenerative Biology and Tissue Engineering, Marine Biological Laboratory, Woods Hole, MA 02543
| | - Susan M L Banks
- Eugene Bell Center for Regenerative Biology and Tissue Engineering, Marine Biological Laboratory, Woods Hole, MA 02543
| | - Wendy S Woods
- Department of Cell and Developmental Biology, University of Illinois, Urbana, IL 61801
| | - Julia M George
- Department of Cell and Developmental Biology, University of Illinois, Urbana, IL 61801 Department of Biological and Experimental Psychology, School of Biological and Chemical Sciences, Queen Mary University of London, London E1 4NS, United Kingdom
| | - Jennifer R Morgan
- Eugene Bell Center for Regenerative Biology and Tissue Engineering, Marine Biological Laboratory, Woods Hole, MA 02543
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48
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Synaptojanin 1 mutation in Parkinson's disease brings further insight into the neuropathological mechanisms. BIOMED RESEARCH INTERNATIONAL 2014; 2014:289728. [PMID: 25302295 PMCID: PMC4181773 DOI: 10.1155/2014/289728] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/09/2014] [Accepted: 08/26/2014] [Indexed: 12/13/2022]
Abstract
Synaptojanin 1 (SYNJ1) is a phosphoinositide phosphatase highly expressed in nerve terminals. Its two phosphatase domains dephosphorylate phosphoinositides present in membranes, while its proline-rich domain directs protein-protein interactions with synaptic components, leading to efficient recycling of synaptic vesicles in neurons. Triplication of SYNJ1 in Down's syndrome is responsible for higher level of phosphoinositides, enlarged endosomes, and learning deficits. SYNJ1 downregulation in Alzheimer's disease models is protective towards amyloid-beta peptide (Aβ) toxicity. One missense mutation in one of SYNJ1 functional domains was recently incriminated in an autosomal recessive form of early-onset Parkinson's disease (PD). In the third decade of life, these patients develop progressive Parkinsonism with bradykinesia, dystonia, and variable atypical symptoms such as cognitive decline, seizures, and eyelid apraxia. The identification of this new gene, together with the fact that most of the known PD proteins play a role in synaptic vesicle recycling and lipid metabolism, points out that synaptic maintenance is a key player in PD pathological mechanisms. Studying PD genes as a network regulating synaptic activity could bring insight into understanding the neuropathological processes of PD and help identify new genes at fault in this devastating disorder.
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The regulation of synaptic vesicle recycling by cGMP-dependent protein kinase type II in cerebellar granule cells under strong and sustained stimulation. J Neurosci 2014; 34:8788-99. [PMID: 24966379 DOI: 10.1523/jneurosci.0103-14.2014] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
From the early periods of neurogenesis and migration, up until synaptogenesis, both nitric oxide (NO) and its downstream messenger, cGMP, are thought to influence the development of neurons. The NO/cGMP/cGMP-dependent protein kinase (cGK) pathway regulates the clustering and recruitment of synaptic proteins and vesicles to the synapse, adjusting the exoendocytic cycle to the intensity of activity and accelerating endocytosis following large-scale exocytosis. Here, we show that blockage of the N-methyl-D-aspartate receptor impairs the cycling of synaptic vesicles in a subset of boutons on cerebellar granule cells, an effect that was reversed by increasing cGMP. Furthermore, we demonstrate that presynaptic cGK type II (cGKII) plays a major role in this process. Using the FM1-43 dye to track vesicle recycling, we found that knockdown of cGKII and/or the application of a cGK inhibitor reduced the efficiency of synaptic vesicle recycling to a similar extent. Likewise, in cerebellar granule cells transfected with vGlut1-pHluorin to follow the exoendocytotic cycle, application of a cGK inhibitor slowed vesicle endocytosis when exocytosis was accelerated through strong and sustained stimulation. Additionally, ultrastructural analysis showed that cGKII knockdown or inhibition favored the formation of endosomal-like structures after strong and sustained stimulation. We conclude that cGKII controls the homeostatic balance of vesicle exocytosis and endocytosis in synaptic boutons of rat cerebellar granule cells.
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50
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Messa M, Fernández-Busnadiego R, Sun EW, Chen H, Czapla H, Wrasman K, Wu Y, Ko G, Ross T, Wendland B, De Camilli P. Epsin deficiency impairs endocytosis by stalling the actin-dependent invagination of endocytic clathrin-coated pits. eLife 2014; 3:e03311. [PMID: 25122462 PMCID: PMC4161027 DOI: 10.7554/elife.03311] [Citation(s) in RCA: 93] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Epsin is an evolutionarily conserved endocytic clathrin adaptor whose most critical function(s) in clathrin coat dynamics remain(s) elusive. To elucidate such function(s), we generated embryonic fibroblasts from conditional epsin triple KO mice. Triple KO cells displayed a dramatic cell division defect. Additionally, a robust impairment in clathrin-mediated endocytosis was observed, with an accumulation of early and U-shaped pits. This defect correlated with a perturbation of the coupling between the clathrin coat and the actin cytoskeleton, which we confirmed in a cell-free assay of endocytosis. Our results indicate that a key evolutionary conserved function of epsin, in addition to other roles that include, as we show here, a low affinity interaction with SNAREs, is to help generate the force that leads to invagination and then fission of clathrin-coated pits.
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Affiliation(s)
- Mirko Messa
- Program in Cellular Neuroscience, Neurodegeneration and Repair, Department of Cell Biology, Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, United States
| | - Rubén Fernández-Busnadiego
- Program in Cellular Neuroscience, Neurodegeneration and Repair, Department of Cell Biology, Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, United States
| | - Elizabeth Wen Sun
- Program in Cellular Neuroscience, Neurodegeneration and Repair, Department of Cell Biology, Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, United States
| | - Hong Chen
- Program in Cellular Neuroscience, Neurodegeneration and Repair, Department of Cell Biology, Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, United States
| | - Heather Czapla
- Program in Cellular Neuroscience, Neurodegeneration and Repair, Department of Cell Biology, Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, United States
| | - Kristie Wrasman
- Department of Biology, Johns Hopkins University, Baltimore, United States
| | - Yumei Wu
- Program in Cellular Neuroscience, Neurodegeneration and Repair, Department of Cell Biology, Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, United States
| | - Genevieve Ko
- Program in Cellular Neuroscience, Neurodegeneration and Repair, Department of Cell Biology, Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, United States
| | - Theodora Ross
- Department of Internal Medicine, UT Southwestern Medical Center, Dallas, United States
| | - Beverly Wendland
- Department of Biology, Johns Hopkins University, Baltimore, United States
| | - Pietro De Camilli
- Program in Cellular Neuroscience, Neurodegeneration and Repair, Department of Cell Biology, Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, United States
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