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Lin C, Merley A, Jaminet SS. TM4SF1 is a molecular facilitator that distributes cargo proteins intracellularly in endothelial cells in support of blood vessel formation. J Cell Commun Signal 2024; 18:e12031. [PMID: 38946725 PMCID: PMC11208120 DOI: 10.1002/ccs3.12031] [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: 03/06/2024] [Revised: 04/08/2024] [Accepted: 04/15/2024] [Indexed: 07/02/2024] Open
Abstract
Transmembrane-4 L-six family member-1 (TM4SF1) is an atypical tetraspanin that is highly and selectively expressed in proliferating endothelial cells and plays an essential role in blood vessel development. TM4SF1 forms clusters on the cell surface called TMED (TM4SF1-enriched microdomains) and recruits other proteins that internalize along with TM4SF1 via microtubules to intracellular locations including the nucleus. We report here that tumor growth and wound healing are inhibited in Tm4sf1-heterozygous mice. Investigating the mechanisms of TM4SF1 activity, we show that 12 out of 18 signaling molecules examined are recruited to TMED on the surface of cultured human umbilical vein endothelial cells (HUVEC) and internalize along with TMED; notable among them are PLCγ and HDAC6. When TM4SF1 is knocked down in HUVEC, microtubules are heavily acetylated despite normal levels of HDAC6 protein, and, despite normal levels of VEGFR2, are unable to proliferate. Together, our studies indicate that pathological angiogenesis is inhibited when levels of TM4SF1 are reduced as in Tm4sf1-heterozygous mice; a likely mechanism is that TM4SF1 regulates the intracellular distribution of signaling molecules necessary for endothelial cell proliferation and migration.
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Affiliation(s)
- Chi‐Iou Lin
- Center for Vascular Biology Research and Department of PathologyBeth Israel Deaconess Medical Center and Harvard Medical SchoolBostonMassachusettsUSA
- Department of AnesthesiologyRiverview HospitalNoblesvilleIndianaUSA
| | - Anne Merley
- Center for Vascular Biology Research and Department of PathologyBeth Israel Deaconess Medical Center and Harvard Medical SchoolBostonMassachusettsUSA
- Center for Animal Resources and EducationBrown UniversityProvidenceRhode IslandUSA
| | - Shou‐Ching S. Jaminet
- Center for Vascular Biology Research and Department of PathologyBeth Israel Deaconess Medical Center and Harvard Medical SchoolBostonMassachusettsUSA
- Biology DepartmentAngiex Inc.CambridgeMassachusettsUSA
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2
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Masjedi MNK, Sadroddiny E, Ai J, Balalaie S, Asgari Y. Targeted expression of a designed fusion protein containing BMP2 into the lumen of exosomes. Biochim Biophys Acta Gen Subj 2024; 1868:130505. [PMID: 37925035 DOI: 10.1016/j.bbagen.2023.130505] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2023] [Revised: 10/07/2023] [Accepted: 10/28/2023] [Indexed: 11/06/2023]
Abstract
BACKGROUND Exosomes are 30-150 nm membrane vesicles, originating from the endocytic pathway. By acting as natural carriers of biomolecules, they can transfer various materials to recipient cells. Therefore, discovering novel strategies for cargo packaging into exosomes is crucial. METHODS The fusion constructs, consisting of protein of interest (BMP2) along with the targeting motif, linkers, tracking proteins, and enzyme cleavage sites, were computationally designed. Following the homology modeling, the best structure was selected and subjected to molecular dynamics (MD) simulation and docking analyses. The fusion protein gene was expressed in the HEK-293LTV cell line. The high-efficiency transfected and transduced cells were screened and their exosomes were isolated. Finally, cell and exosome lysates were evaluated for expression of the fusion protein. RESULTS A total of 12 constructs with lengths ranging from 483 to 496 were designed. The top three templates, 1REW, 2H5Q, and 2MOF were screened. MD simulation and docking analyses of the structures revealed their stability and functionality. In the protein expression analyses, three bands at sizes of approximately 60, 25, and 12.5 kDa were observed, consistent with the sizes of the complete fusion protein, dimeric, and monomeric BMP2 protein. The presence of a 12.5 kDa band at exosome lysate analysis might suggest that it was loaded and cleaved inside exosomes. CONCLUSION In summary, these findings revealed that the proposed idea for cargo sorting within the exosome lumen through incorporating an appropriate cleavage site was effective, thus providing further insight into the potential of exosomes as nano-shuttles bearing therapeutic biomolecules.
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Affiliation(s)
- Maryam Noei-Khesht Masjedi
- Department of Medical Biotechnology, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Esmaeil Sadroddiny
- Department of Tissue Engineering, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran, Iran.
| | - Jafar Ai
- Department of Tissue Engineering, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Saeed Balalaie
- Peptide Chemistry Research Center, K. N. Toosi University of Technology, Tehran, Iran; Medical Biology Research Center, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Yazdan Asgari
- Department of Medical Biotechnology, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran, Iran
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3
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Pérez MJ, Carden TR, Dos Santos Claro PA, Silberstein S, Páez PM, Cheli VT, Correale J, Pasquini JM. Transferrin Enhances Neuronal Differentiation. ASN Neuro 2023; 15:17590914231170703. [PMID: 37093743 PMCID: PMC10134178 DOI: 10.1177/17590914231170703] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/25/2023] Open
Abstract
Although transferrin (Tf) is a glycoprotein best known for its role in iron delivery, iron-independent functions have also been reported. Here, we assessed apoTf (aTf) treatment effects on Neuro-2a (N2a) cells, a mouse neuroblastoma cell line which, once differentiated, shares many properties with neurons, including process outgrowth, expression of selective neuronal markers, and electrical activity. We first examined the binding of Tf to its receptor (TfR) in our model and verified that, like neurons, N2a cells can internalize Tf from the culture medium. Next, studies on neuronal developmental parameters showed that Tf increases N2a survival through a decrease in apoptosis. Additionally, Tf accelerated the morphological development of N2a cells by promoting neurite outgrowth. These pro-differentiating effects were also observed in primary cultures of mouse cortical neurons treated with aTf, as neurons matured at a higher rate than controls and showed a decrease in the expression of early neuronal markers. Further experiments in iron-enriched and iron-deficient media showed that Tf preserved its pro-differentiation properties in N2a cells, with results hinting at a modulatory role for iron. Moreover, N2a-microglia co-cultures revealed an increase in IL-10 upon aTf treatment, which may be thought to favor N2a differentiation. Taken together, these findings suggest that Tf reduces cell death and favors the neuronal differentiation process, thus making Tf a promising candidate to be used in regenerative strategies for neurodegenerative diseases.
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Affiliation(s)
- María Julia Pérez
- Departamento de Química Biológica, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires, Argentina
- Instituto de Química y Fisicoquímica Biológicas (IQUIFIB), Universidad de Buenos Aires-CONICET, Buenos Aires, Argentina
| | - Tomas Roberto Carden
- Departamento de Química Biológica, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires, Argentina
- Instituto de Química y Fisicoquímica Biológicas (IQUIFIB), Universidad de Buenos Aires-CONICET, Buenos Aires, Argentina
| | - Paula Ayelen Dos Santos Claro
- Instituto de Investigación en Biomedicina de Buenos Aires (IBIoBA), CONICET-Partner Institute of The Max Plank Society, Buenos Aires, Argentina
| | - Susana Silberstein
- Instituto de Investigación en Biomedicina de Buenos Aires (IBIoBA), CONICET-Partner Institute of The Max Plank Society, Buenos Aires, Argentina
| | - Pablo Martin Páez
- Department of Pharmacology and Toxicology, Jacobs School of Medicine and Biomedical Sciences, Institute for Myelin and Glia Exploration, State University of New York at Buffalo, Buffalo, New York, USA
| | - Veronica Teresita Cheli
- Department of Pharmacology and Toxicology, Jacobs School of Medicine and Biomedical Sciences, Institute for Myelin and Glia Exploration, State University of New York at Buffalo, Buffalo, New York, USA
| | - Jorge Correale
- Instituto de Química y Fisicoquímica Biológicas (IQUIFIB), Universidad de Buenos Aires-CONICET, Buenos Aires, Argentina
- Departamento de Neurología, Fleni, Buenos Aires, Argentina
| | - Juana M Pasquini
- Departamento de Química Biológica, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires, Argentina
- Instituto de Química y Fisicoquímica Biológicas (IQUIFIB), Universidad de Buenos Aires-CONICET, Buenos Aires, Argentina
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4
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Current Methods to Unravel the Functional Properties of Lysosomal Ion Channels and Transporters. Cells 2022; 11:cells11060921. [PMID: 35326372 PMCID: PMC8946281 DOI: 10.3390/cells11060921] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Revised: 03/04/2022] [Accepted: 03/05/2022] [Indexed: 02/07/2023] Open
Abstract
A distinct set of channels and transporters regulates the ion fluxes across the lysosomal membrane. Malfunctioning of these transport proteins and the resulting ionic imbalance is involved in various human diseases, such as lysosomal storage disorders, cancer, as well as metabolic and neurodegenerative diseases. As a consequence, these proteins have stimulated strong interest for their suitability as possible drug targets. A detailed functional characterization of many lysosomal channels and transporters is lacking, mainly due to technical difficulties in applying the standard patch-clamp technique to these small intracellular compartments. In this review, we focus on current methods used to unravel the functional properties of lysosomal ion channels and transporters, stressing their advantages and disadvantages and evaluating their fields of applicability.
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5
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Sathler MF, Khatri L, Roberts JP, Schmidt IG, Zaytseva A, Kubrusly RCC, Ziff EB, Kim S. Phosphorylation of AMPA receptor subunit GluA1 regulates clathrin-mediated receptor internalization. J Cell Sci 2021; 134:272078. [PMID: 34369573 DOI: 10.1242/jcs.257972] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Accepted: 07/29/2021] [Indexed: 11/20/2022] Open
Abstract
Synaptic strength is altered during synaptic plasticity by controlling the number of AMPA receptors (AMPARs) at excitatory synapses. During long-term potentiation and synaptic up-scaling, AMPARs are accumulated at synapses to increase synaptic strength. Neuronal activity leads to phosphorylation of AMPAR subunit GluA1 and subsequent elevation of GluA1 surface expression, either by an increase in receptor forward trafficking to the synaptic membrane or a decrease in receptor internalization. However, the molecular pathways underlying GluA1 phosphorylation-induced elevation of surface AMPAR expression are not completely understood. Here, we employ fluorescence recovery after photobleaching (FRAP) to reveal that phosphorylation of GluA1 Serine 845 (S845) predominantly plays a role in receptor internalization than forward trafficking during synaptic plasticity. Notably, internalization of AMPARs depends upon the clathrin adaptor, AP2, which recruits cargo proteins into endocytic clathrin coated pits. In fact, we further reveal that an increase in GluA1 S845 phosphorylation by two distinct forms of synaptic plasticity diminishes the binding of the AP2 adaptor, reducing internalization, and resulting in elevation of GluA1 surface expression. We thus demonstrate a mechanism of GluA1 phosphorylation-regulated clathrin-mediated internalization of AMPARs.
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Affiliation(s)
- Matheus F Sathler
- Department of Biochemistry and Molecular Pharmacology, NYU Grossman School of Medicine, 540 First Avenue, New York, NY 10016, USA.,Department of Biomedical Sciences, 1617 Campus Delivery, Colorado State University, Fort Collins, CO, 80525, USA.,Neuroscience Program, Department of Physiology and Pharmacology, Rua São João Batista, 187, sala 428, Fluminense Federal University, Niterói, RJ, 24020-005, Brazil
| | - Latika Khatri
- Department of Biochemistry and Molecular Pharmacology, NYU Grossman School of Medicine, 540 First Avenue, New York, NY 10016, USA
| | | | | | | | - Regina C C Kubrusly
- Neuroscience Program, Department of Physiology and Pharmacology, Rua São João Batista, 187, sala 428, Fluminense Federal University, Niterói, RJ, 24020-005, Brazil
| | - Edward B Ziff
- Department of Biochemistry and Molecular Pharmacology, NYU Grossman School of Medicine, 540 First Avenue, New York, NY 10016, USA
| | - Seonil Kim
- Department of Biomedical Sciences, 1617 Campus Delivery, Colorado State University, Fort Collins, CO, 80525, USA.,Molecular, Cellular and Integrative Neurosciences Program
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6
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Harper CB, Blumrich EM, Cousin MA. Synaptophysin controls synaptobrevin-II retrieval via a cryptic C-terminal interaction site. J Biol Chem 2021; 296:100266. [PMID: 33769286 PMCID: PMC7948965 DOI: 10.1016/j.jbc.2021.100266] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Revised: 01/03/2021] [Accepted: 01/06/2021] [Indexed: 12/22/2022] Open
Abstract
The accurate retrieval of synaptic vesicle (SV) proteins during endocytosis is essential for the maintenance of neurotransmission. Synaptophysin (Syp) and synaptobrevin-II (SybII) are the most abundant proteins on SVs. Neurons lacking Syp display defects in the activity-dependent retrieval of SybII and a general slowing of SV endocytosis. To determine the role of the cytoplasmic C terminus of Syp in the control of these two events, we performed molecular replacement studies in primary cultures of Syp knockout neurons using genetically encoded reporters of SV cargo trafficking at physiological temperatures. Under these conditions, we discovered, 1) no slowing in SV endocytosis in Syp knockout neurons, and 2) a continued defect in SybII retrieval in knockout neurons expressing a form of Syp lacking its C terminus. Sequential truncations of the Syp C-terminus revealed a cryptic interaction site for the SNARE motif of SybII that was concealed in the full-length form. This suggests that a conformational change within the Syp C terminus is key to permitting SybII binding and thus its accurate retrieval. Furthermore, this study reveals that the sole presynaptic role of Syp is the control of SybII retrieval, since no defect in SV endocytosis kinetics was observed at physiological temperatures.
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Affiliation(s)
- Callista B Harper
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, Scotland, EH8 9XD, UK; Muir Maxwell Epilepsy Centre, University of Edinburgh, Edinburgh, Scotland, EH8 9XD, UK
| | - Eva-Maria Blumrich
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, Scotland, EH8 9XD, UK; Muir Maxwell Epilepsy Centre, University of Edinburgh, Edinburgh, Scotland, EH8 9XD, UK
| | - Michael A Cousin
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, Scotland, EH8 9XD, UK; Muir Maxwell Epilepsy Centre, University of Edinburgh, Edinburgh, Scotland, EH8 9XD, UK; Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh, Scotland, EH8 9XD, UK.
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7
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Mino RE, Chen Z, Mettlen M, Schmid SL. An internally eGFP-tagged α-adaptin is a fully functional and improved fiduciary marker for clathrin-coated pit dynamics. Traffic 2020; 21:603-616. [PMID: 32657003 PMCID: PMC7495412 DOI: 10.1111/tra.12755] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 07/05/2020] [Accepted: 07/06/2020] [Indexed: 12/18/2022]
Abstract
Clathrin mediated endocytosis (CME) has been extensively studied in living cells by quantitative total internal reflection fluorescence microscopy (TIRFM). Fluorescent protein fusions to subunits of the major coat proteins, clathrin light chains or the heterotetrameric adaptor protein (AP2) complexes, have been used as fiduciary markers of clathrin coated pits (CCPs). However, the functionality of these fusion proteins has not been rigorously compared. Here, we generated stable cells lines overexpressing mRuby‐CLCa and/or μ2‐eGFP, σ2‐eGFP, two markers currently in use, or a novel marker generated by inserting eGFP into the unstructured hinge region of the α subunit (α‐eGFP). Using biochemical and TIRFM‐based assays, we compared the functionality of the AP2 markers. All of the eGFP‐tagged subunits were efficiently incorporated into AP2 and displayed greater accuracy in image‐based CCP analyses than mRuby‐CLCa. However, overexpression of either μ2‐eGFP or σ2‐eGFP impaired transferrin receptor uptake. In addition, μ2‐eGFP reduced the rates of CCP initiation and σ2‐eGFP perturbed AP2 incorporation into CCPs and CCP maturation. In contrast, CME and CCP dynamics were unperturbed in cells overexpressing α‐eGFP. Moreover, α‐eGFP was a more sensitive and accurate marker of CCP dynamics than mRuby‐CLCa. Thus, our work establishes α‐eGFP as a robust, fully functional marker for CME.
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Affiliation(s)
- Rosa E Mino
- Department of Cell Biology, UT Southwestern Medical Center, Dallas, Texas, USA
| | - Zhiming Chen
- Department of Cell Biology, UT Southwestern Medical Center, Dallas, Texas, USA
| | - Marcel Mettlen
- Department of Cell Biology, UT Southwestern Medical Center, Dallas, Texas, USA
| | - Sandra L Schmid
- Department of Cell Biology, UT Southwestern Medical Center, Dallas, Texas, USA
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8
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An Epilepsy-Associated SV2A Mutation Disrupts Synaptotagmin-1 Expression and Activity-Dependent Trafficking. J Neurosci 2020; 40:4586-4595. [PMID: 32341095 DOI: 10.1523/jneurosci.0210-20.2020] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Revised: 03/05/2020] [Accepted: 03/27/2020] [Indexed: 01/28/2023] Open
Abstract
The epilepsy-linked gene SV2A, has a number of potential roles in the synaptic vesicle (SV) life cycle. However, how loss of SV2A function translates into presynaptic dysfunction and ultimately seizure activity is still undetermined. In this study, we examined whether the first SV2A mutation identified in human disease (R383Q) could provide information regarding which SV2A-dependent events are critical in the translation to epilepsy. We utilized a molecular replacement strategy in which exogenous SV2A was expressed in mouse neuronal cultures of either sex, which had been depleted of endogenous SV2A to mimic the homozygous human condition. We found that the R383Q mutation resulted in a mislocalization of SV2A from SVs to the plasma membrane, but had no effect on its activity-dependent trafficking. This SV2A mutant displayed reduced mobility when stranded on the plasma membrane and reduced binding to its interaction partner synaptotagmin-1 (Syt1). Furthermore, the R383Q mutant failed to rescue reduced expression and dysfunctional activity-dependent trafficking of Syt1 in the absence of endogenous SV2A. This suggests that the inability to control Syt1 expression and trafficking at the presynapse may be key in the transition from loss of SV2A function to seizure activity.SIGNIFICANCE STATEMENT SV2A is a synaptic vesicle (SV) protein, the absence or dysfunction of which is linked to epilepsy. However, the series of molecular events that result in this neurological disorder is still undetermined. We demonstrate here that the first human mutation in SV2A identified in an individual with epilepsy displays reduced binding to synaptotagmin-1 (Syt1), an SV protein essential for synchronous neurotransmitter release. Furthermore, this mutant cannot correct alterations in both Syt1 expression and trafficking when expressed in the absence of endogenous SV2A (to mimic the homozygous human condition). This suggests that the inability to control Syt1 expression and trafficking may be key in the transition from loss of SV2A function to seizure activity.
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9
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Kokotos AC, Harper CB, Marland JRK, Smillie KJ, Cousin MA, Gordon SL. Synaptophysin sustains presynaptic performance by preserving vesicular synaptobrevin-II levels. J Neurochem 2019; 151:28-37. [PMID: 31216055 PMCID: PMC6851701 DOI: 10.1111/jnc.14797] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Revised: 05/24/2019] [Accepted: 06/01/2019] [Indexed: 01/01/2023]
Abstract
The two most abundant molecules on synaptic vesicles (SVs) are synaptophysin and synaptobrevin‐II (sybII). SybII is essential for SV fusion, whereas synaptophysin is proposed to control the trafficking of sybII after SV fusion and its retrieval during endocytosis. Despite controlling key aspects of sybII packaging into SVs, the absence of synaptophysin results in negligible effects on neurotransmission. We hypothesised that this apparent absence of effect may be because of the abundance of sybII on SVs, with the impact of inefficient sybII retrieval only revealed during periods of repeated SV turnover. To test this hypothesis, we subjected primary cultures of synaptophysin knockout neurons to repeated trains of neuronal activity, while monitoring SV fusion events and levels of vesicular sybII. We identified a significant decrease in both the number of SV fusion events (monitored using the genetically encoded reporter vesicular glutamate transporter‐pHluorin) and vesicular sybII levels (via both immunofluorescence and Western blotting) using this protocol. This revealed that synaptophysin is essential to sustain both parameters during periods of repetitive SV turnover. This was confirmed by the rescue of presynaptic performance by the expression of exogenous synaptophysin. Importantly, the expression of exogenous sybII also fully restored SV fusion events in synaptophysin knockout neurons. The ability of additional copies of sybII to fully rescue presynaptic performance in these knockout neurons suggests that the principal role of synaptophysin is to mediate the efficient retrieval of sybII to sustain neurotransmitter release. ![]()
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Affiliation(s)
- Alexandros C Kokotos
- Centre for Discovery Brain Sciences, Hugh Robson Building, University of Edinburgh, George Square, Edinburgh, Scotland, UK, EH8 9XD.,Muir Maxwell Epilepsy Centre, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh, Scotland, UK, EH8 9XD
| | - Callista B Harper
- Centre for Discovery Brain Sciences, Hugh Robson Building, University of Edinburgh, George Square, Edinburgh, Scotland, UK, EH8 9XD.,Muir Maxwell Epilepsy Centre, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh, Scotland, UK, EH8 9XD.,Simons Initiative for the Developing Brain, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh, Scotland, UK, EH8 9XD
| | - Jamie R K Marland
- Centre for Discovery Brain Sciences, Hugh Robson Building, University of Edinburgh, George Square, Edinburgh, Scotland, UK, EH8 9XD
| | - Karen J Smillie
- Centre for Discovery Brain Sciences, Hugh Robson Building, University of Edinburgh, George Square, Edinburgh, Scotland, UK, EH8 9XD.,Muir Maxwell Epilepsy Centre, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh, Scotland, UK, EH8 9XD
| | - Michael A Cousin
- Centre for Discovery Brain Sciences, Hugh Robson Building, University of Edinburgh, George Square, Edinburgh, Scotland, UK, EH8 9XD.,Muir Maxwell Epilepsy Centre, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh, Scotland, UK, EH8 9XD.,Simons Initiative for the Developing Brain, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh, Scotland, UK, EH8 9XD
| | - Sarah L Gordon
- The Florey Institute of Neuroscience and Mental Health, and Melbourne Dementia Research Centre, The Florey Institute for Neuroscience and Mental Health, The University of Melbourne, Victoria, Australia
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10
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Sullivan R, Légaré C, Lamontagne‐Proulx J, Breton S, Soulet D. Revisiting structure/functions of the human epididymis. Andrology 2019; 7:748-757. [DOI: 10.1111/andr.12633] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Revised: 02/07/2019] [Accepted: 03/29/2019] [Indexed: 01/20/2023]
Affiliation(s)
- R. Sullivan
- Department Obstetrics, Gynecology and Reproduction Faculty Medicine Université Laval Quebec QC Canada
- Reproduction, Mother and Youth Health Division Centre de recherche du CHU de Québec‐Université Laval Quebec QC Canada
| | - C. Légaré
- Department Obstetrics, Gynecology and Reproduction Faculty Medicine Université Laval Quebec QC Canada
- Reproduction, Mother and Youth Health Division Centre de recherche du CHU de Québec‐Université Laval Quebec QC Canada
| | - J. Lamontagne‐Proulx
- Faculty Pharmacy Université Laval Quebec QC Canada
- Neurosciences Division Centre de recherche du CHU de Québec‐Université Laval Quebec QC Canada
| | - S. Breton
- Massachusetts General Hospital Harvard Medical School Boston MA USA
| | - D. Soulet
- Faculty Pharmacy Université Laval Quebec QC Canada
- Neurosciences Division Centre de recherche du CHU de Québec‐Université Laval Quebec QC Canada
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11
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Talbot EL, Kotar J, Di Michele L, Cicuta P. Directed tubule growth from giant unilamellar vesicles in a thermal gradient. SOFT MATTER 2019; 15:1676-1683. [PMID: 30681117 DOI: 10.1039/c8sm01892h] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
We demonstrate experimental control over tubule growth in giant unilamellar vesicles with liquid-liquid phase coexistence, using a thermal gradient to redistribute lipid phase domains on the membrane. As studied previously, the domains of the less abundant phase always partition towards hotter temperatures, depleting the cold side of the vesicle of domains. We couple this mechanism of domain migration with the inclusion of negative-curvature lipids within the membrane, resulting in control of tubule growth direction towards the high temperature. Control of composition determines the interior/exterior growth of tubules, whereas the thermal gradient regulates the length of the tubule relative to the vesicle radius. Maintaining lipid membranes under non-equilibrium conditions, such as thermal gradients, allows the creation of thermally-oriented protrusions, which could be a key step towards developing functional materials or artificial tissues. Interconnected vesicle compartments or ejected daughter vesicles as transport intermediaries towards hot/cold are just two possibilities.
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Affiliation(s)
- Emma L Talbot
- Department of Physics, Cavendish Laboratory, University of Cambridge, JJ Thomson Avenue, Cambridge, CB3 0HE, UK.
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12
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Hanley JG. The Regulation of AMPA Receptor Endocytosis by Dynamic Protein-Protein Interactions. Front Cell Neurosci 2018; 12:362. [PMID: 30364226 PMCID: PMC6193100 DOI: 10.3389/fncel.2018.00362] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Accepted: 09/25/2018] [Indexed: 11/13/2022] Open
Abstract
The precise regulation of AMPA receptor (AMPAR) trafficking in neurons is crucial for excitatory neurotransmission, synaptic plasticity and the consequent formation and modification of neural circuits during brain development and learning. Clathrin-mediated endocytosis (CME) is an essential trafficking event for the activity-dependent removal of AMPARs from the neuronal plasma membrane, resulting in a reduction in synaptic strength known as long-term depression (LTD). The regulated AMPAR endocytosis that underlies LTD is caused by specific modes of synaptic activity, most notably stimulation of NMDA receptors (NMDARs) and metabotropic glutamate receptors (mGluRs). Numerous proteins associate with AMPAR subunits, directly or indirectly, to control their trafficking, and therefore the regulation of these protein-protein interactions in response to NMDAR or mGluR signaling is a critical feature of synaptic plasticity. This article reviews the protein-protein interactions that are dynamically regulated during synaptic plasticity to modulate AMPAR endocytosis, focussing on AMPAR binding proteins and proteins that bind the core endocytic machinery. In addition, the mechanisms for the regulation of protein-protein interactions are considered, as well as the functional consequences of these dynamic interactions on AMPAR endocytosis.
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Affiliation(s)
- Jonathan G Hanley
- Centre for Synaptic Plasticity and School of Biochemistry, University of Bristol, Bristol, United Kingdom
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13
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Haucke V, Kozlov MM. Membrane remodeling in clathrin-mediated endocytosis. J Cell Sci 2018; 131:131/17/jcs216812. [PMID: 30177505 DOI: 10.1242/jcs.216812] [Citation(s) in RCA: 76] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Clathrin-mediated endocytosis is an essential cellular mechanism by which all eukaryotic cells regulate their plasma membrane composition to control processes ranging from cell signaling to adhesion, migration and morphogenesis. The formation of endocytic vesicles and tubules involves extensive protein-mediated remodeling of the plasma membrane that is organized in space and time by protein-protein and protein-phospholipid interactions. Recent studies combining high-resolution imaging with genetic manipulations of the endocytic machinery and with theoretical approaches have led to novel multifaceted phenomenological data of the temporal and spatial organization of the endocytic reaction. This gave rise to various - often conflicting - models as to how endocytic proteins and their association with lipids regulate the endocytic protein choreography to reshape the plasma membrane. In this Review, we discuss these findings in light of the hypothesis that endocytic membrane remodeling may be determined by an interplay between protein-protein interactions, the ability of proteins to generate and sense membrane curvature, and the ability of lipids to stabilize and reinforce the generated membrane shape through adopting their lateral distribution to the local membrane curvature.
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Affiliation(s)
- Volker Haucke
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Robert-Rössle-Straße 10, 13125 Berlin, Germany .,Freie Universität Berlin, Department of Biology, Chemistry, Pharmacy, Takustrasse 3, 14195 Berlin, Germany
| | - Michael M Kozlov
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
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14
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Purification of Clathrin-Coated Vesicles from Adult Rat Brain. Methods Mol Biol 2018. [PMID: 30129005 DOI: 10.1007/978-1-4939-8719-1_1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
Here, we describe a purification protocol for isolating clathrin-coated vesicles (CCVs) from adult rat brain by using differential centrifugation coupled with Ficoll-sucrose and D2O-sucrose density gradient centrifugation and an additional linear sucrose step gradient at the end to separate CCVs from contaminating membranes present in the crude microsomal fraction.
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15
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Minetti G, Achilli C, Perotti C, Ciana A. Continuous Change in Membrane and Membrane-Skeleton Organization During Development From Proerythroblast to Senescent Red Blood Cell. Front Physiol 2018; 9:286. [PMID: 29632498 PMCID: PMC5879444 DOI: 10.3389/fphys.2018.00286] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Accepted: 03/12/2018] [Indexed: 12/11/2022] Open
Abstract
Within the context of erythropoiesis and the possibility of producing artificial red blood cells (RBCs) in vitro, a most critical step is the final differentiation of enucleated erythroblasts, or reticulocytes, to a fully mature biconcave discocyte, the RBC. Reviewed here is the current knowledge about this fundamental maturational process. By combining literature data with our own experimental evidence we propose that the early phase in the maturation of reticulocytes to RBCs is driven by a membrane raft-based mechanism for the sorting of disposable membrane proteins, mostly the no longer needed transferrin receptor (TfR), to the multivesicular endosome (MVE) as cargo of intraluminal vesicles that are subsequently exocytosed as exosomes, consistently with the seminal and original observation of Johnstone and collaborators of more than 30 years ago (Pan BT, Johnstone RM. Cell. 1983;33:967-978). According to a strikingly selective sorting process, the TfR becomes cargo destined to exocytosis while other molecules, including the most abundant RBC transmembrane protein, band 3, are completely retained in the cell membrane. It is also proposed that while this process could be operating in the early maturational steps in the bone marrow, additional mechanism(s) must be at play for the final removal of the excess reticulocyte membrane that is observed to occur in the circulation. This processing will most likely require the intervention of the spleen, whose function is also necessary for the continuous remodeling of the RBC membrane all along this cell's circulatory life.
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Affiliation(s)
- Giampaolo Minetti
- Laboratori di Biochimica, Dipartimento di Biologia e Biotecnologie, Università degli Studi di Pavia, Pavia, Italy
| | - Cesare Achilli
- Laboratori di Biochimica, Dipartimento di Biologia e Biotecnologie, Università degli Studi di Pavia, Pavia, Italy
| | - Cesare Perotti
- Servizio Immunoematologia e Medicina Trasfusionale, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy
| | - Annarita Ciana
- Laboratori di Biochimica, Dipartimento di Biologia e Biotecnologie, Università degli Studi di Pavia, Pavia, Italy
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16
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Dannhauser PN, Camus SM, Sakamoto K, Sadacca LA, Torres JA, Camus MD, Briant K, Vassilopoulos S, Rothnie A, Smith CJ, Brodsky FM. CHC22 and CHC17 clathrins have distinct biochemical properties and display differential regulation and function. J Biol Chem 2017; 292:20834-20844. [PMID: 29097553 PMCID: PMC5743061 DOI: 10.1074/jbc.m117.816256] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Revised: 10/30/2017] [Indexed: 11/06/2022] Open
Abstract
Clathrins are cytoplasmic proteins that play essential roles in endocytosis and other membrane traffic pathways. Upon recruitment to intracellular membranes, the canonical clathrin triskelion assembles into a polyhedral protein coat that facilitates vesicle formation and captures cargo molecules for transport. The triskelion is formed by trimerization of three clathrin heavy-chain subunits. Most vertebrates have two isoforms of clathrin heavy chains, CHC17 and CHC22, generating two clathrins with distinct cellular functions. CHC17 forms vesicles at the plasma membrane for receptor-mediated endocytosis and at the trans-Golgi network for organelle biogenesis. CHC22 plays a key role in intracellular targeting of the insulin-regulated glucose transporter 4 (GLUT4), accumulates at the site of GLUT4 sequestration during insulin resistance, and has also been implicated in neuronal development. Here, we demonstrate that CHC22 and CHC17 share morphological features, in that CHC22 forms a triskelion and latticed vesicle coats. However, cellular CHC22-coated vesicles were distinct from those formed by CHC17. The CHC22 coat was more stable to pH change and was not removed by the enzyme complex that disassembles the CHC17 coat. Moreover, the two clathrins were differentially recruited to membranes by adaptors, and CHC22 did not support vesicle formation or transferrin endocytosis at the plasma membrane in the presence or absence of CHC17. Our findings provide biochemical evidence for separate regulation and distinct functional niches for CHC17 and CHC22 in human cells. Furthermore, the greater stability of the CHC22 coat relative to the CHC17 coat may be relevant to its excessive accumulation with GLUT4 during insulin resistance.
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Affiliation(s)
- Philip N Dannhauser
- From the Division of Biosciences, University College London, London WC1E 6BT, United Kingdom.,the Institute of Cell Biology/Electron Microscopy, Centre of Anatomy, Hanover Medical School, 30625 Hanover, Germany
| | - Stéphane M Camus
- From the Division of Biosciences, University College London, London WC1E 6BT, United Kingdom.,the Departments of Bioengineering and Therapeutic Sciences, Pharmaceutical Chemistry, Microbiology and Immunology and The G.W. Hooper Foundation, University of California at San Francisco, San Francisco, California 94143
| | - Kazuho Sakamoto
- the Departments of Bioengineering and Therapeutic Sciences, Pharmaceutical Chemistry, Microbiology and Immunology and The G.W. Hooper Foundation, University of California at San Francisco, San Francisco, California 94143.,the Department of Pharmacology, Fukushima Medical University School of Medicine, Fukushima, Fukushima 960-1295, Japan
| | - L Amanda Sadacca
- From the Division of Biosciences, University College London, London WC1E 6BT, United Kingdom
| | - Jorge A Torres
- the Departments of Bioengineering and Therapeutic Sciences, Pharmaceutical Chemistry, Microbiology and Immunology and The G.W. Hooper Foundation, University of California at San Francisco, San Francisco, California 94143
| | - Marine D Camus
- From the Division of Biosciences, University College London, London WC1E 6BT, United Kingdom.,the Departments of Bioengineering and Therapeutic Sciences, Pharmaceutical Chemistry, Microbiology and Immunology and The G.W. Hooper Foundation, University of California at San Francisco, San Francisco, California 94143
| | - Kit Briant
- From the Division of Biosciences, University College London, London WC1E 6BT, United Kingdom
| | - Stéphane Vassilopoulos
- the Departments of Bioengineering and Therapeutic Sciences, Pharmaceutical Chemistry, Microbiology and Immunology and The G.W. Hooper Foundation, University of California at San Francisco, San Francisco, California 94143.,the Institut de Myologie, Paris F-75013, France
| | - Alice Rothnie
- Life & Health Sciences, Aston University, Aston Triangle, Birmingham B4 7ET, United Kingdom, and
| | - Corinne J Smith
- the Department of Biological Sciences, Warwick University, Coventry CV4 7AL, United Kingdom
| | - Frances M Brodsky
- From the Division of Biosciences, University College London, London WC1E 6BT, United Kingdom, .,the Departments of Bioengineering and Therapeutic Sciences, Pharmaceutical Chemistry, Microbiology and Immunology and The G.W. Hooper Foundation, University of California at San Francisco, San Francisco, California 94143
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17
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Archuleta TL, Frazier MN, Monken AE, Kendall AK, Harp J, McCoy AJ, Creanza N, Jackson LP. Structure and evolution of ENTH and VHS/ENTH-like domains in tepsin. Traffic 2017; 18:590-603. [PMID: 28691777 PMCID: PMC5567745 DOI: 10.1111/tra.12499] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Revised: 07/02/2017] [Accepted: 07/06/2017] [Indexed: 12/28/2022]
Abstract
Tepsin is currently the only accessory trafficking protein identified in adaptor-related protein 4 (AP4)-coated vesicles originating at the trans-Golgi network (TGN). The molecular basis for interactions between AP4 subunits and motifs in the tepsin C-terminus have been characterized, but the biological role of tepsin remains unknown. We determined X-ray crystal structures of the tepsin epsin N-terminal homology (ENTH) and VHS/ENTH-like domains. Our data reveal unexpected structural features that suggest key functional differences between these and similar domains in other trafficking proteins. The tepsin ENTH domain lacks helix0, helix8 and a lipid binding pocket found in epsin1/2/3. These results explain why tepsin requires AP4 for its membrane recruitment and further suggest ENTH domains cannot be defined solely as lipid binding modules. The VHS domain lacks helix8 and thus contains fewer helices than other VHS domains. Structural data explain biochemical and biophysical evidence that tepsin VHS does not mediate known VHS functions, including recognition of dileucine-based cargo motifs or ubiquitin. Structural comparisons indicate the domains are very similar to each other, and phylogenetic analysis reveals their evolutionary pattern within the domain superfamily. Phylogenetics and comparative genomics further show tepsin within a monophyletic clade that diverged away from epsins early in evolutionary history (~1500 million years ago). Together, these data provide the first detailed molecular view of tepsin and suggest tepsin structure and function diverged away from other epsins. More broadly, these data highlight the challenges inherent in classifying and understanding protein function based only on sequence and structure.
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Affiliation(s)
- Tara L. Archuleta
- Department of Biological Sciences, Vanderbilt University, Nashville,
TN, USA
- Center for Structural Biology, Vanderbilt University, Nashville, TN,
USA
| | - Meredith N. Frazier
- Department of Biological Sciences, Vanderbilt University, Nashville,
TN, USA
- Center for Structural Biology, Vanderbilt University, Nashville, TN,
USA
| | - Anderson E. Monken
- Department of Biological Sciences, Vanderbilt University, Nashville,
TN, USA
- Center for Structural Biology, Vanderbilt University, Nashville, TN,
USA
| | - Amy K. Kendall
- Department of Biological Sciences, Vanderbilt University, Nashville,
TN, USA
- Center for Structural Biology, Vanderbilt University, Nashville, TN,
USA
| | - Joel Harp
- Center for Structural Biology, Vanderbilt University, Nashville, TN,
USA
| | - Airlie J. McCoy
- Cambridge Institute for Medical Research, Department of Clinical
Biochemistry, University of Cambridge, Hills Road, Cambridge, United Kingdom
| | - Nicole Creanza
- Department of Biological Sciences, Vanderbilt University, Nashville,
TN, USA
| | - Lauren P. Jackson
- Department of Biological Sciences, Vanderbilt University, Nashville,
TN, USA
- Center for Structural Biology, Vanderbilt University, Nashville, TN,
USA
- Department of Biochemistry, Vanderbilt University, Nashville, TN,
USA
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18
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Fiuza M, Rostosky CM, Parkinson GT, Bygrave AM, Halemani N, Baptista M, Milosevic I, Hanley JG. PICK1 regulates AMPA receptor endocytosis via direct interactions with AP2 α-appendage and dynamin. J Cell Biol 2017; 216:3323-3338. [PMID: 28855251 PMCID: PMC5626541 DOI: 10.1083/jcb.201701034] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Revised: 06/09/2017] [Accepted: 07/18/2017] [Indexed: 01/01/2023] Open
Abstract
Clathrin-mediated endocytosis (CME) is used to internalize a diverse range of cargo proteins from the cell surface, often in response to specific signals. In neurons, the rapid endocytosis of GluA2-containing AMPA receptors (AMPARs) in response to NMDA receptor (NMDAR) stimulation causes a reduction in synaptic strength and is the central mechanism for long-term depression, which underlies certain forms of learning. The mechanisms that link NMDAR activation to CME of AMPARs remain elusive. PICK1 is a BAR domain protein required for NMDAR-dependent reductions in surface GluA2; however, the molecular mechanisms involved are unclear. In this study, we show that PICK1 makes direct, NMDAR-dependent interactions with the core endocytic proteins AP2 and dynamin. PICK1-AP2 interactions are required for clustering AMPARs at endocytic zones in dendrites in response to NMDAR stimulation and for consequent AMPAR internalization. We further show that PICK1 stimulates dynamin polymerization. We propose that PICK1 is a cargo-specific endocytic accessory protein required for efficient, activity-dependent AMPAR endocytosis.
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Affiliation(s)
- Maria Fiuza
- Centre for Synaptic Plasticity and School of Biochemistry, University of Bristol, Bristol, England, UK
| | - Christine M Rostosky
- European Neuroscience Institute, University Medical Center Göttingen, Göttingen, Germany
| | - Gabrielle T Parkinson
- Centre for Synaptic Plasticity and School of Biochemistry, University of Bristol, Bristol, England, UK
| | - Alexei M Bygrave
- Centre for Synaptic Plasticity and School of Biochemistry, University of Bristol, Bristol, England, UK
| | - Nagaraj Halemani
- Centre for Synaptic Plasticity and School of Biochemistry, University of Bristol, Bristol, England, UK
| | - Marcio Baptista
- Centre for Synaptic Plasticity and School of Biochemistry, University of Bristol, Bristol, England, UK
| | - Ira Milosevic
- European Neuroscience Institute, University Medical Center Göttingen, Göttingen, Germany
| | - Jonathan G Hanley
- Centre for Synaptic Plasticity and School of Biochemistry, University of Bristol, Bristol, England, UK
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19
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Cousin MA. Integration of Synaptic Vesicle Cargo Retrieval with Endocytosis at Central Nerve Terminals. Front Cell Neurosci 2017; 11:234. [PMID: 28824381 PMCID: PMC5541026 DOI: 10.3389/fncel.2017.00234] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Accepted: 07/25/2017] [Indexed: 12/12/2022] Open
Abstract
Central nerve terminals contain a limited number of synaptic vesicles (SVs) which mediate the essential process of neurotransmitter release during their activity-dependent fusion. The rapid and accurate formation of new SVs with the appropriate cargo is essential to maintain neurotransmission in mammalian brain. Generating SVs containing the correct SV cargo with the appropriate stoichiometry is a significant challenge, especially when multiple modes of endocytosis exist in central nerve terminals, which occur at different locations within the nerve terminals. These endocytosis modes include ultrafast endocytosis, clathrin-mediated endocytosis (CME) and activity-dependent bulk endocytosis (ADBE) which are triggered by specific patterns of neuronal activity. This review article will assess the evidence for the role of classical adaptor protein complexes in SV retrieval, discuss the role of monomeric adaptors and how interactions between specific SV cargoes can facilitate retrieval. In addition it will consider the evidence for preassembled plasma membrane cargo complexes and their role in facilitating these endocytosis modes. Finally it will present a unifying model for cargo retrieval at the presynapse, which integrates endocytosis modes in time and space.
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Affiliation(s)
- Michael A Cousin
- Centre for Integrative Physiology, University of EdinburghEdinburgh, United Kingdom
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20
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Gleason RJ, Vora M, Li Y, Kane NS, Liao K, Padgett RW. C. elegans SMA-10 regulates BMP receptor trafficking. PLoS One 2017; 12:e0180681. [PMID: 28704415 PMCID: PMC5509155 DOI: 10.1371/journal.pone.0180681] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Accepted: 06/19/2017] [Indexed: 11/18/2022] Open
Abstract
Signal transduction of the conserved transforming growth factor-β (TGFβ) family signaling pathway functions through two distinct serine/threonine transmembrane receptors, the type I and type II receptors. Endocytosis orchestrates the assembly of signaling complexes by coordinating the entry of receptors with their downstream signaling mediators. Recently, we showed that the C. elegans type I bone morphogenetic protein (BMP) receptor SMA-6, part of the TGFβ family, is recycled through the retromer complex while the type II receptor, DAF-4 is recycled in a retromer-independent, ARF-6 dependent manner. From genetic screens in C. elegans aimed at identifying new modifiers of BMP signaling, we reported on SMA-10, a conserved LRIG (leucine-rich and immunoglobulin-like domains) transmembrane protein. It is a positive regulator of BMP signaling that binds to the SMA-6 receptor. Here we show that the loss of sma-10 leads to aberrant endocytic trafficking of SMA-6, resulting in its accumulation in distinct intracellular endosomes including the early endosome, multivesicular bodies (MVB), and the late endosome with a reduction in signaling strength. Our studies show that trafficking defects caused by the loss of sma-10 are not universal, but affect only a limited set of receptors. Likewise, in Drosophila, we find that the fly homolog of sma-10, lambik (lbk), reduces signaling strength of the BMP pathway, consistent with its function in C. elegans and suggesting evolutionary conservation of function. Loss of sma-10 results in reduced ubiquitination of the type I receptor SMA-6, suggesting a possible mechanism for its regulation of BMP signaling.
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Affiliation(s)
- Ryan J. Gleason
- Waksman Institute, Department of Molecular Biology and Biochemistry, Cancer Institute of New Jersey, Rutgers University, Piscataway, New Jersey, United States of America
| | - Mehul Vora
- Waksman Institute, Department of Molecular Biology and Biochemistry, Cancer Institute of New Jersey, Rutgers University, Piscataway, New Jersey, United States of America
| | - Ying Li
- Waksman Institute, Department of Molecular Biology and Biochemistry, Cancer Institute of New Jersey, Rutgers University, Piscataway, New Jersey, United States of America
| | - Nanci S. Kane
- Waksman Institute, Department of Molecular Biology and Biochemistry, Cancer Institute of New Jersey, Rutgers University, Piscataway, New Jersey, United States of America
| | - Kelvin Liao
- Waksman Institute, Department of Molecular Biology and Biochemistry, Cancer Institute of New Jersey, Rutgers University, Piscataway, New Jersey, United States of America
| | - Richard W. Padgett
- Waksman Institute, Department of Molecular Biology and Biochemistry, Cancer Institute of New Jersey, Rutgers University, Piscataway, New Jersey, United States of America
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21
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Inhibition of endocytic pathways impacts cytomegalovirus maturation. Sci Rep 2017; 7:46069. [PMID: 28406138 PMCID: PMC5390266 DOI: 10.1038/srep46069] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Accepted: 03/08/2017] [Indexed: 12/18/2022] Open
Abstract
Endocytic processes are critical for cellular entry of several viruses; however, the role of endocytosis in cellular trafficking of viruses beyond virus entry is only partially understood. Here, we utilized two laboratory strains (AD169 and Towne) of human cytomegalovirus (HCMV), which are known to use cell membrane fusion rather than endocytosis to enter fibroblasts, in order to study a post-entry role of endocytosis in HCMV life cycle. Upon pharmacological inhibition of dynamin-2 or clathrin terminal domain (TD) ligand association, these strains entered the cells successfully based on the expression of immediate early viral protein. However, both the inhibitors significantly reduced the growth rates and final virus yields of viruses without inhibiting the expression of early to late viral proteins. Clathrin accumulated in the cytoplasmic virus assembly compartment (vAC) of infected cells co-localizing with virus tegument protein pp150 and the formation of vAC was compromised upon endocytic inhibition. Transmission electron micrographs (TEM) of infected cells treated with endocytosis inhibitors showed intact nuclear stages of nucleocapsid assembly but the cytoplasmic virus maturation was greatly compromised. Thus, the data presented here implicate endocytic pathways in HCMV maturation and egress.
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22
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Brüser L, Bogdan S. Adherens Junctions on the Move-Membrane Trafficking of E-Cadherin. Cold Spring Harb Perspect Biol 2017; 9:cshperspect.a029140. [PMID: 28096264 DOI: 10.1101/cshperspect.a029140] [Citation(s) in RCA: 70] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Cadherin-based adherens junctions are conserved structures that mediate epithelial cell-cell adhesion in invertebrates and vertebrates. Despite their pivotal function in epithelial integrity, adherens junctions show a remarkable plasticity that is a prerequisite for tissue architecture and morphogenesis. Epithelial cadherin (E-cadherin) is continuously turned over and undergoes cycles of endocytosis, sorting and recycling back to the plasma membrane. Mammalian cell culture and genetically tractable model systems such as Drosophila have revealed conserved, but also distinct, mechanisms in the regulation of E-cadherin membrane trafficking. Here, we discuss our current knowledge about molecules and mechanisms controlling endocytosis, sorting and recycling of E-cadherin during junctional remodeling.
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Affiliation(s)
- Lena Brüser
- Institut für Neurobiologie, Universität Münster, Badestraße 9, 48149 Münster, Germany
| | - Sven Bogdan
- Institut für Neurobiologie, Universität Münster, Badestraße 9, 48149 Münster, Germany.,Institut für Physiologie und Pathophysiologie, Abteilung Molekulare Zellphysiologie, Phillips-Universität Marburg, Emil-Mannkopff-Straße 2, 35037 Marburg, Germany
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23
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Zhou C, Ma K, Gao R, Mu C, Chen L, Liu Q, Luo Q, Feng D, Zhu Y, Chen Q. Regulation of mATG9 trafficking by Src- and ULK1-mediated phosphorylation in basal and starvation-induced autophagy. Cell Res 2017; 27:184-201. [PMID: 27934868 PMCID: PMC5339848 DOI: 10.1038/cr.2016.146] [Citation(s) in RCA: 136] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2016] [Revised: 10/13/2016] [Accepted: 10/27/2016] [Indexed: 01/04/2023] Open
Abstract
Autophagy requires diverse membrane sources and involves membrane trafficking of mATG9, the only membrane protein in the ATG family. However, the molecular regulation of mATG9 trafficking for autophagy initiation remains unclear. Here we identified two conserved classic adaptor protein sorting signals within the cytosolic N-terminus of mATG9, which mediate trafficking of mATG9 from the plasma membrane and trans-Golgi network (TGN) via interaction with the AP1/2 complex. Src phosphorylates mATG9 at Tyr8 to maintain its endocytic and constitutive trafficking in unstressed conditions. In response to starvation, phosphorylation of mATG9 at Tyr8 by Src and at Ser14 by ULK1 functionally cooperate to promote interactions between mATG9 and the AP1/2 complex, leading to redistribution of mATG9 from the plasma membrane and juxta-nuclear region to the peripheral pool for autophagy initiation. Our findings uncover novel mechanisms of mATG9 trafficking and suggest a coordination of basal and stress-induced autophagy.
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Affiliation(s)
- Changqian Zhou
- State Key Laboratory of Medicinal Chemical Biology, Tianjin Key Laboratory of Protein Sciences, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Kaili Ma
- State Key Laboratory of Medicinal Chemical Biology, Tianjin Key Laboratory of Protein Sciences, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Ruize Gao
- State Key Laboratory of Medicinal Chemical Biology, Tianjin Key Laboratory of Protein Sciences, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Chenglong Mu
- State Key Laboratory of Medicinal Chemical Biology, Tianjin Key Laboratory of Protein Sciences, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Linbo Chen
- State Key Laboratory of Medicinal Chemical Biology, Tianjin Key Laboratory of Protein Sciences, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Qiangqiang Liu
- State Key Laboratory of Medicinal Chemical Biology, Tianjin Key Laboratory of Protein Sciences, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Qian Luo
- State Key Laboratory of Medicinal Chemical Biology, Tianjin Key Laboratory of Protein Sciences, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Du Feng
- Guangdong Key Laboratory of Age-related Cardiac-cerebral Vascular Disease, Department of Neurology, Institute of Neurology, The Affiliated Hospital of Guangdong Medical University, Guangdong Medical University, Zhanjiang, Guangdong 524001, China
| | - Yushan Zhu
- State Key Laboratory of Medicinal Chemical Biology, Tianjin Key Laboratory of Protein Sciences, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Quan Chen
- State Key Laboratory of Medicinal Chemical Biology, Tianjin Key Laboratory of Protein Sciences, College of Life Sciences, Nankai University, Tianjin 300071, China
- State Key Laboratory of Membrane Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
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24
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Blume LC, Leone-Kabler S, Luessen DJ, Marrs GS, Lyons E, Bass CE, Chen R, Selley DE, Howlett AC. Cannabinoid receptor interacting protein suppresses agonist-driven CB 1 receptor internalization and regulates receptor replenishment in an agonist-biased manner. J Neurochem 2016; 139:396-407. [PMID: 27513693 DOI: 10.1111/jnc.13767] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Revised: 07/09/2016] [Accepted: 08/03/2016] [Indexed: 01/30/2023]
Abstract
Cannabinoid receptor interacting protein 1a (CRIP1a) is a CB1 receptor (CB1 R) distal C-terminus-associated protein that modulates CB1 R signaling via G proteins, and CB1 R down-regulation but not desensitization (Blume et al. [2015] Cell Signal., 27, 716-726; Smith et al. [2015] Mol. Pharmacol., 87, 747-765). In this study, we determined the involvement of CRIP1a in CB1 R plasma membrane trafficking. To follow the effects of agonists and antagonists on cell surface CB1 Rs, we utilized the genetically homogeneous cloned neuronal cell line N18TG2, which endogenously expresses both CB1 R and CRIP1a, and exhibits a well-characterized endocannabinoid signaling system. We developed stable CRIP1a-over-expressing and CRIP1a-siRNA-silenced knockdown clones to investigate gene dose effects of CRIP1a on CB1 R plasma membrane expression. Results indicate that CP55940 or WIN55212-2 (10 nM, 5 min) reduced cell surface CB1 R by a dynamin- and clathrin-dependent process, and this was attenuated by CRIP1a over-expression. CP55940-mediated cell surface CB1 R loss was followed by a cycloheximide-sensitive recovery of surface receptors (30-120 min), suggesting the requirement for new protein synthesis. In contrast, WIN55212-2-mediated cell surface CB1 Rs recovered only in CRIP1a knockdown cells. Changes in CRIP1a expression levels did not affect a transient rimonabant (10 nM)-mediated increase in cell surface CB1 Rs, which is postulated to be as a result of rimonabant effects on 'non-agonist-driven' internalization. These studies demonstrate a novel role for CRIP1a in agonist-driven CB1 R cell surface regulation postulated to occur by two mechanisms: 1) attenuating internalization that is agonist-mediated, but not that in the absence of exogenous agonists, and 2) biased agonist-dependent trafficking of de novo synthesized receptor to the cell surface.
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Affiliation(s)
- Lawrence C Blume
- Department of Physiology and Pharmacology, Wake Forest University Health Sciences, Winston-Salem, North Carolina, USA
| | - Sandra Leone-Kabler
- Department of Physiology and Pharmacology, Wake Forest University Health Sciences, Winston-Salem, North Carolina, USA
| | - Deborah J Luessen
- Department of Physiology and Pharmacology, Wake Forest University Health Sciences, Winston-Salem, North Carolina, USA
| | - Glen S Marrs
- Department of Biology, Wake Forest University, Winston-Salem, North Carolina, USA.,Center for Molecular Signaling, Wake Forest University, Winston-Salem, North Carolina, USA
| | - Erica Lyons
- Department of Physiology and Pharmacology, Wake Forest University Health Sciences, Winston-Salem, North Carolina, USA
| | - Caroline E Bass
- Department of Physiology and Pharmacology, Wake Forest University Health Sciences, Winston-Salem, North Carolina, USA
| | - Rong Chen
- Department of Physiology and Pharmacology, Wake Forest University Health Sciences, Winston-Salem, North Carolina, USA.,Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Dana E Selley
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Allyn C Howlett
- Department of Physiology and Pharmacology, Wake Forest University Health Sciences, Winston-Salem, North Carolina, USA. .,Center for Molecular Signaling, Wake Forest University, Winston-Salem, North Carolina, USA.
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25
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Chamberland JP, Antonow LT, Dias Santos M, Ritter B. NECAP2 controls clathrin coat recruitment to early endosomes for fast endocytic recycling. J Cell Sci 2016; 129:2625-37. [PMID: 27206861 DOI: 10.1242/jcs.173708] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Accepted: 05/19/2016] [Indexed: 01/04/2023] Open
Abstract
Endocytic recycling returns receptors to the plasma membrane following internalization and is essential to maintain receptor levels on the cell surface, re-sensitize cells to extracellular ligands and for continued nutrient uptake. Yet, the protein machineries and mechanisms that drive endocytic recycling remain ill-defined. Here, we establish that NECAP2 regulates the endocytic recycling of EGFR and transferrin receptor. Our analysis of the recycling dynamics revealed that NECAP2 functions in the fast recycling pathway that directly returns cargo from early endosomes to the cell surface. In contrast, NECAP2 does not regulate the clathrin-mediated endocytosis of these cargos, the degradation of EGFR or the recycling of transferrin along the slow, Rab11-dependent recycling pathway. We show that protein knockdown of NECAP2 leads to enlarged early endosomes and causes the loss of the clathrin adapter AP-1 from the organelle. Through structure-function analysis, we define the protein-binding interfaces in NECAP2 that are crucial for AP-1 recruitment to early endosomes. Together, our data identify NECAP2 as a pathway-specific regulator of clathrin coat formation on early endosomes for fast endocytic recycling.
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Affiliation(s)
- John P Chamberland
- Boston University School of Medicine, Biochemistry Department, Boston, MA 02118, USA
| | - Lauren T Antonow
- Boston University School of Medicine, Biochemistry Department, Boston, MA 02118, USA
| | - Michel Dias Santos
- Boston University School of Medicine, Biochemistry Department, Boston, MA 02118, USA
| | - Brigitte Ritter
- Boston University School of Medicine, Biochemistry Department, Boston, MA 02118, USA
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Paez Valencia J, Goodman K, Otegui MS. Endocytosis and Endosomal Trafficking in Plants. ANNUAL REVIEW OF PLANT BIOLOGY 2016; 67:309-35. [PMID: 27128466 DOI: 10.1146/annurev-arplant-043015-112242] [Citation(s) in RCA: 152] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Endocytosis and endosomal trafficking are essential processes in cells that control the dynamics and turnover of plasma membrane proteins, such as receptors, transporters, and cell wall biosynthetic enzymes. Plasma membrane proteins (cargo) are internalized by endocytosis through clathrin-dependent or clathrin-independent mechanism and delivered to early endosomes. From the endosomes, cargo proteins are recycled back to the plasma membrane via different pathways, which rely on small GTPases and the retromer complex. Proteins that are targeted for degradation through ubiquitination are sorted into endosomal vesicles by the ESCRT (endosomal sorting complex required for transport) machinery for degradation in the vacuole. Endocytic and endosomal trafficking regulates many cellular, developmental, and physiological processes, including cellular polarization, hormone transport, metal ion homeostasis, cytokinesis, pathogen responses, and development. In this review, we discuss the mechanisms that mediate the recognition and sorting of endocytic and endosomal cargos, the vesiculation processes that mediate their trafficking, and their connection to cellular and physiological responses in plants.
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Affiliation(s)
- Julio Paez Valencia
- Department of Botany
- R.M. Bock Laboratories of Cell and Molecular Biology, and
| | - Kaija Goodman
- Department of Botany
- R.M. Bock Laboratories of Cell and Molecular Biology, and
| | - Marisa S Otegui
- Department of Botany
- R.M. Bock Laboratories of Cell and Molecular Biology, and
- Department of Genetics, University of Wisconsin-Madison, Madison, Wisconsin 53706; , ,
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27
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Nicholson-Fish JC, Smillie KJ, Cousin MA. Monitoring activity-dependent bulk endocytosis with the genetically-encoded reporter VAMP4-pHluorin. J Neurosci Methods 2016; 266:1-10. [PMID: 27015791 PMCID: PMC4881416 DOI: 10.1016/j.jneumeth.2016.03.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Revised: 03/11/2016] [Accepted: 03/13/2016] [Indexed: 11/19/2022]
Abstract
BACKGROUND Activity-dependent bulk endocytosis (ADBE) is the dominant mode of synaptic vesicle (SV) endocytosis during intense neuronal activity, implicating it as a major contributor to presynaptic plasticity under these stimulation conditions. However methods to monitor this endocytosis mode have been limited to either morphological or optical observation of the uptake of large fluid phase markers. NEW METHOD We present here a method to monitor ADBE using the genetically-encoded reporter VAMP4-pHluorin in primary neuronal cultures. RESULTS Individual nerve terminals expressing VAMP4-pHluorin display either an increase or decrease in fluorescence after stimulation terminates. The decrease in fluorescence reflects the slow acidification of large bulk endosomes to which VAMP4-pHluorin is selectively recruited. Use of VAMP4-pHluorin during sequential high frequency stimuli revealed that all nerve terminals perform ADBE, but not all do so in response to a single stimulus. VAMP4-pHluorin also displays a rapid activity-dependent decrease in fluorescence during high frequency stimulation, a response which is particularly prominent when expressed in hippocampal neurons. The molecular mechanism responsible for this decrease is still unclear, but is not due to loss of VAMP4-pHluorin from the nerve terminal. COMPARISON WITH EXISTING METHODS This method allows the selective reporting of ADBE for the first time, when compared to previous approaches using markers of fluid phase uptake. CONCLUSIONS The development of VAMP4-pHluorin as a selective genetically-encoded reporter of ADBE increases the palette of approaches used to monitor this endocytosis mode both in vitro and in vivo.
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Affiliation(s)
- Jessica C Nicholson-Fish
- Centre for Integrative Physiology, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh EH8 9XD, Scotland, United Kingdom.
| | - Karen J Smillie
- Centre for Integrative Physiology, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh EH8 9XD, Scotland, United Kingdom.
| | - Michael A Cousin
- Centre for Integrative Physiology, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh EH8 9XD, Scotland, United Kingdom.
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28
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Derganc J, Čopič A. Membrane bending by protein crowding is affected by protein lateral confinement. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2016; 1858:1152-9. [PMID: 26969088 DOI: 10.1016/j.bbamem.2016.03.009] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Revised: 02/24/2016] [Accepted: 03/01/2016] [Indexed: 02/02/2023]
Abstract
Crowding of asymmetrically-distributed membrane proteins has been recently recognized as an important factor in remodeling of biological membranes, for example during transport vesicle formation. In this paper, we theoretically analyze the effect of protein crowding on membrane bending and examine its dependence on protein size, shape, transmembrane asymmetry and lateral confinement. We consider three scenarios of protein lateral organization, which are highly relevant for cellular membranes in general: freely diffusing membrane proteins without lateral confinement, the presence of a diffusion barrier and interactions with a vesicular coat. We show that protein crowding affects vesicle formation even if the proteins are distributed symmetrically across the membrane and that this effect depends significantly on lateral confinement. The largest crowding effect is predicted for the proteins that are confined to the forming vesicle by a diffusion barrier. We calculate the bending properties of a crowded membrane and find that its spontaneous curvature depends primarily on the degree of transmembrane asymmetry, and its effective bending modulus on the type of lateral confinement. Using the example of COPII vesicle formation from the endoplasmic reticulum, we analyze the energetic cost of vesicle formation. The results provide a novel insight into the effects of lateral and transmembrane organization of membrane proteins, and can guide data interpretation and future experimental approaches.
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Affiliation(s)
- Jure Derganc
- Institute of Biophysics, Faculty of Medicine, University of Ljubljana, 1000 Ljubljana, Slovenia.
| | - Alenka Čopič
- Institut Jacques Monod, CNRS, UMR 7592, University Paris Diderot, Sorbonne Paris Cité, F-75013 Paris, France.
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29
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Gordon SL, Cousin MA. The iTRAPs: Guardians of Synaptic Vesicle Cargo Retrieval During Endocytosis. Front Synaptic Neurosci 2016; 8:1. [PMID: 26903854 PMCID: PMC4746236 DOI: 10.3389/fnsyn.2016.00001] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Accepted: 01/25/2016] [Indexed: 11/30/2022] Open
Abstract
The reformation of synaptic vesicles (SVs) during endocytosis is essential for the maintenance of neurotransmission in central nerve terminals. Newly formed SVs must be generated with the correct protein cargo in the correct stoichiometry to be functional for exocytosis. Classical clathrin adaptor protein complexes play a key role in sorting and clustering synaptic vesicle cargo in this regard. However it is becoming increasingly apparent that additional “fail-safe” mechanisms exist to ensure the accurate retrieval of essential cargo molecules. For example, the monomeric adaptor proteins AP180/CALM and stonin-2 are required for the efficient retrieval of synaptobrevin II (sybII) and synaptotagmin-1 respectively. Furthermore, recent studies have revealed that sybII and synaptotagmin-1 interact with other SV cargoes to ensure a high fidelity of retrieval. These cargoes are synaptophysin (for sybII) and SV2A (for synaptotagmin-1). In this review, we summarize current knowledge regarding the retrieval mechanisms for both sybII and synaptotagmin-1 during endocytosis. We also define and set criteria for a new functional group of SV molecules that facilitate the retrieval of their interaction partners. We have termed these molecules intrinsic trafficking partners (iTRAPs) and we discuss how the function of this group impacts on presynaptic performance in both health and disease.
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Affiliation(s)
- Sarah L Gordon
- Florey Institute of Neuroscience and Mental Health, The University of Melbourne Parkville, VIC, Australia
| | - Michael A Cousin
- Centre for Integrative Physiology, University of Edinburgh Edinburgh, UK
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30
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Pillay S, Meyer NL, Puschnik AS, Davulcu O, Diep J, Ishikawa Y, Jae LT, Wosen JE, Nagamine CM, Chapman MS, Carette JE. An essential receptor for adeno-associated virus infection. Nature 2016; 530:108-12. [PMID: 26814968 PMCID: PMC4962915 DOI: 10.1038/nature16465] [Citation(s) in RCA: 302] [Impact Index Per Article: 37.8] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Accepted: 11/18/2015] [Indexed: 01/20/2023]
Affiliation(s)
- S Pillay
- Department of Microbiology and Immunology, Stanford University School of Medicine, 299 Campus Drive, Stanford, California 94305, USA
| | - N L Meyer
- Department of Biochemistry and Molecular Biology, School of Medicine, Oregon Health &Science University, 3181 Sam Jackson Park Road, Portland, Oregon 97239-3098, USA
| | - A S Puschnik
- Department of Microbiology and Immunology, Stanford University School of Medicine, 299 Campus Drive, Stanford, California 94305, USA
| | - O Davulcu
- Department of Biochemistry and Molecular Biology, School of Medicine, Oregon Health &Science University, 3181 Sam Jackson Park Road, Portland, Oregon 97239-3098, USA
| | - J Diep
- Department of Microbiology and Immunology, Stanford University School of Medicine, 299 Campus Drive, Stanford, California 94305, USA
| | - Y Ishikawa
- Department of Biochemistry and Molecular Biology, School of Medicine, Oregon Health &Science University, 3181 Sam Jackson Park Road, Portland, Oregon 97239-3098, USA.,Shriners Hospital for Children, 3101 Sam Jackson Park Road, Portland, Oregon 97239, USA
| | - L T Jae
- Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX, Amsterdam, Netherlands
| | - J E Wosen
- Department of Microbiology and Immunology, Stanford University School of Medicine, 299 Campus Drive, Stanford, California 94305, USA
| | - C M Nagamine
- Department of Comparative Medicine, Stanford University School of Medicine, 287 Campus Drive, Stanford, California 94305, USA
| | - M S Chapman
- Department of Biochemistry and Molecular Biology, School of Medicine, Oregon Health &Science University, 3181 Sam Jackson Park Road, Portland, Oregon 97239-3098, USA
| | - J E Carette
- Department of Microbiology and Immunology, Stanford University School of Medicine, 299 Campus Drive, Stanford, California 94305, USA
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31
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Tang BL. Rab, Arf, and Arl-Regulated Membrane Traffic in Cortical Neuron Migration. J Cell Physiol 2015; 231:1417-23. [DOI: 10.1002/jcp.25261] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Accepted: 11/18/2015] [Indexed: 12/13/2022]
Affiliation(s)
- Bor Luen Tang
- Department of Biochemistry; Yong Loo Lin School of Medicine; National University of Singapore; Singapore
- NUS Graduate School for Integrative Sciences and Engineering; National University of Singapore; Singapore
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32
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Xu Y, Wang T. CULD is required for rhodopsin and TRPL channel endocytic trafficking and survival of photoreceptor cells. J Cell Sci 2015; 129:394-405. [PMID: 26598556 PMCID: PMC4732287 DOI: 10.1242/jcs.178764] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Accepted: 11/18/2015] [Indexed: 01/19/2023] Open
Abstract
Endocytosis of G-protein-coupled receptors (GPCRs) and associated channels contributes to desensitization and adaptation of a variety of signaling cascades. In Drosophila melanogaster, the main light-sensing rhodopsin (Rh1; encoded by ninaE) and the downstream ion channel, transient receptor potential like (TRPL), are endocytosed in response to light, but the mechanism is unclear. By using an RNA-Sequencing (RNA-Seq) approach, we discovered a protein we named CULD, a photoreceptor-cell enriched CUB- and LDLa-domain transmembrane protein, that is required for endocytic trafficking of Rh1 and TRPL. CULD localized to endocytic Rh1-positive or TRPL-positive vesicles. Mutations in culd resulted in the accumulation of Rh1 and TRPL within endocytic vesicles, and disrupted the regular turnover of endocytic Rh1 and TRPL. In addition, loss of CULD induced light- and age-dependent retinal degeneration, and reduced levels of Rh1, but not of TRPL, suppressed retinal degeneration in culd-null mutant flies. Our data demonstrate that CULD plays an important role in the endocytic turnover of Rh1 and TRPL, and suggest that CULD-dependent rhodopsin endocytic trafficking is required for maintaining photoreceptor integrity.
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Affiliation(s)
- Ying Xu
- School of Life Sciences, Beijing Normal University, Beijing, China, 100875 National Institute of Biological Sciences, Beijing, China, 102206
| | - Tao Wang
- National Institute of Biological Sciences, Beijing, China, 102206
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33
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Nicholson-Fish JC, Kokotos AC, Gillingwater TH, Smillie KJ, Cousin MA. VAMP4 Is an Essential Cargo Molecule for Activity-Dependent Bulk Endocytosis. Neuron 2015; 88:973-984. [PMID: 26607000 PMCID: PMC4678114 DOI: 10.1016/j.neuron.2015.10.043] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Revised: 09/22/2015] [Accepted: 10/15/2015] [Indexed: 11/23/2022]
Abstract
The accurate formation of synaptic vesicles (SVs) and incorporation of their protein cargo during endocytosis is critical for the maintenance of neurotransmission. During intense neuronal activity, a transient and acute accumulation of SV cargo occurs at the plasma membrane. Activity-dependent bulk endocytosis (ADBE) is the dominant SV endocytosis mode under these conditions; however, it is currently unknown how ADBE mediates cargo retrieval. We examined the retrieval of different SV cargo molecules during intense stimulation using a series of genetically encoded pH-sensitive reporters in neuronal cultures. The retrieval of only one reporter, VAMP4-pHluorin, was perturbed by inhibiting ADBE. This selective recovery was confirmed by the enrichment of endogenous VAMP4 in purified bulk endosomes formed by ADBE. VAMP4 was also essential for ADBE, with a cytoplasmic di-leucine motif being critical for this role. Therefore, VAMP4 is the first identified ADBE cargo and is essential for this endocytosis mode to proceed. VAMP4 is the first identified ADBE cargo VAMP4 is essential for ADBE Most synaptic vesicle cargoes are not selectively recovered by ADBE
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Affiliation(s)
- Jessica C Nicholson-Fish
- Centre for Integrative Physiology, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh EH8 9XD, Scotland
| | - Alexandros C Kokotos
- Centre for Integrative Physiology, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh EH8 9XD, Scotland
| | - Thomas H Gillingwater
- Centre for Integrative Physiology, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh EH8 9XD, Scotland
| | - Karen J Smillie
- Centre for Integrative Physiology, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh EH8 9XD, Scotland.
| | - Michael A Cousin
- Centre for Integrative Physiology, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh EH8 9XD, Scotland.
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34
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Sciuto TE, Merley A, Lin CI, Richardson D, Liu Y, Li D, Dvorak AM, Dvorak HF, Jaminet SCS. Intracellular distribution of TM4SF1 and internalization of TM4SF1-antibody complex in vascular endothelial cells. Biochem Biophys Res Commun 2015; 465:338-43. [PMID: 26241677 DOI: 10.1016/j.bbrc.2015.07.142] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2015] [Accepted: 07/29/2015] [Indexed: 10/23/2022]
Abstract
Transmembrane-4 L-six family member-1 (TM4SF1) is a small plasma membrane-associated glycoprotein that is highly and selectively expressed on the plasma membranes of tumor cells, cultured endothelial cells, and, in vivo, on tumor-associated endothelium. Immunofluorescence microscopy also demonstrated TM4SF1 in cytoplasm and, tentatively, within nuclei. With monoclonal antibody 8G4, and the finer resolution afforded by immuno-nanogold transmission electron microscopy, we now demonstrate TM4SF1 in uncoated cytoplasmic vesicles, nuclear pores and nucleoplasm. Because of its prominent surface location on tumor cells and tumor-associated endothelium, TM4SF1 has potential as a dual therapeutic target using an antibody drug conjugate (ADC) approach. For ADC to be successful, antibodies reacting with cell surface antigens must be internalized for delivery of associated toxins to intracellular targets. We now report that 8G4 is efficiently taken up into cultured endothelial cells by uncoated vesicles in a dynamin-dependent, clathrin-independent manner. It is then transported along microtubules through the cytoplasm and passes through nuclear pores into the nucleus. These findings validate TM4SF1 as an attractive candidate for cancer therapy with antibody-bound toxins that have the capacity to react with either cytoplasmic or nuclear targets in tumor cells or tumor-associated vascular endothelium.
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Affiliation(s)
- Tracey E Sciuto
- Center for Vascular Biology Research and Department of Pathology, Beth Israel Deaconess Medical Center and Harvard Medical School, USA
| | - Anne Merley
- Center for Vascular Biology Research and Department of Pathology, Beth Israel Deaconess Medical Center and Harvard Medical School, USA
| | - Chi-Iou Lin
- Center for Vascular Biology Research and Department of Pathology, Beth Israel Deaconess Medical Center and Harvard Medical School, USA
| | | | - Yu Liu
- Department of Pharmacology, Shanxi Medical University, Xinjiannanlu 56, Shanxi Province, Taiyuan 030001, China
| | - Dan Li
- Center for Vascular Biology Research and Department of Pathology, Beth Israel Deaconess Medical Center and Harvard Medical School, USA
| | - Ann M Dvorak
- Center for Vascular Biology Research and Department of Pathology, Beth Israel Deaconess Medical Center and Harvard Medical School, USA
| | - Harold F Dvorak
- Center for Vascular Biology Research and Department of Pathology, Beth Israel Deaconess Medical Center and Harvard Medical School, USA.
| | - Shou-Ching S Jaminet
- Center for Vascular Biology Research and Department of Pathology, Beth Israel Deaconess Medical Center and Harvard Medical School, USA.
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35
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Endocytosis and Trafficking of Natriuretic Peptide Receptor-A: Potential Role of Short Sequence Motifs. MEMBRANES 2015; 5:253-87. [PMID: 26151885 PMCID: PMC4584282 DOI: 10.3390/membranes5030253] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/18/2015] [Revised: 06/25/2015] [Accepted: 06/25/2015] [Indexed: 12/19/2022]
Abstract
The targeted endocytosis and redistribution of transmembrane receptors among membrane-bound subcellular organelles are vital for their correct signaling and physiological functions. Membrane receptors committed for internalization and trafficking pathways are sorted into coated vesicles. Cardiac hormones, atrial and brain natriuretic peptides (ANP and BNP) bind to guanylyl cyclase/natriuretic peptide receptor-A (GC-A/NPRA) and elicit the generation of intracellular second messenger cyclic guanosine 3',5'-monophosphate (cGMP), which lowers blood pressure and incidence of heart failure. After ligand binding, the receptor is rapidly internalized, sequestrated, and redistributed into intracellular locations. Thus, NPRA is considered a dynamic cellular macromolecule that traverses different subcellular locations through its lifetime. The utilization of pharmacologic and molecular perturbants has helped in delineating the pathways of endocytosis, trafficking, down-regulation, and degradation of membrane receptors in intact cells. This review describes the investigation of the mechanisms of internalization, trafficking, and redistribution of NPRA compared with other cell surface receptors from the plasma membrane into the cell interior. The roles of different short-signal peptide sequence motifs in the internalization and trafficking of other membrane receptors have been briefly reviewed and their potential significance in the internalization and trafficking of NPRA is discussed.
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36
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Manna PT, Gadelha C, Puttick AE, Field MC. ENTH and ANTH domain proteins participate in AP2-independent clathrin-mediated endocytosis. J Cell Sci 2015; 128:2130-42. [PMID: 25908855 PMCID: PMC4450294 DOI: 10.1242/jcs.167726] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Accepted: 04/13/2015] [Indexed: 01/17/2023] Open
Abstract
Clathrin-mediated endocytosis (CME) is a major route of entry into eukaryotic cells. A core of evolutionarily ancient genes encodes many components of this system but much of our mechanistic understanding of CME is derived from a phylogenetically narrow sampling of a few model organisms. In the parasite Trypanosoma brucei, which is distantly related to the better characterised animals and fungi, exceptionally fast endocytic turnover aids its evasion of the host immune system. Although clathrin is absolutely essential for this process, the adaptor protein complex 2 (AP2) has been secondarily lost, suggesting mechanistic divergence. Here, we characterise two phosphoinositide-binding monomeric clathrin adaptors, T. brucei (Tb)EpsinR and TbCALM, which in trypanosomes are represented by single genes, unlike the expansions present in animals and fungi. Depletion of these gene products reveals essential, but partially redundant, activities in CME. Ultrastructural analysis of TbCALM and TbEpsinR double-knockdown cells demonstrated severe defects to clathrin-coated pit formation and morphology associated with a dramatic inhibition of endocytosis. Depletion of TbCALM alone, however, produced a distinct lysosomal segregation phenotype, indicating an additional non-redundant role for this protein. Therefore, TbEpsinR and TbCALM represent ancient phosphoinositide-binding proteins with distinct and vital roles in AP2-independent endocytosis.
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Affiliation(s)
- Paul T Manna
- Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QP, UK
| | - Catarina Gadelha
- School of Life Sciences, University of Nottingham, Queen's Medical Centre, Nottingham NG7 2UH, UK
| | - Amy E Puttick
- Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QP, UK
| | - Mark C Field
- Division of Biological Chemistry and Drug Discovery, University of Dundee, Dundee DD1 5EH, UK
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37
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Daniel JA, Chau N, Abdel-Hamid MK, Hu L, von Kleist L, Whiting A, Krishnan S, Maamary P, Joseph SR, Simpson F, Haucke V, McCluskey A, Robinson PJ. Phenothiazine-derived antipsychotic drugs inhibit dynamin and clathrin-mediated endocytosis. Traffic 2015; 16:635-54. [PMID: 25693808 DOI: 10.1111/tra.12272] [Citation(s) in RCA: 100] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2014] [Revised: 01/13/2015] [Accepted: 02/10/2015] [Indexed: 12/22/2022]
Abstract
Chlorpromazine is a phenothiazine-derived antipsychotic drug (APD) that inhibits clathrin-mediated endocytosis (CME) in cells by an unknown mechanism. We examined whether its action and that of other APDs might be mediated by the GTPase activity of dynamin. Eight of eight phenothiazine-derived APDs inhibited dynamin I (dynI) in the 2-12 µm range, the most potent being trifluoperazine (IC50 2.6 ± 0.7 µm). They also inhibited dynamin II (dynII) at similar concentrations. Typical and atypical APDs not based on the phenothiazine scaffold were 8- to 10-fold less potent (haloperidol and clozapine) or were inactive (droperidol, olanzapine and risperidone). Kinetic analysis showed that phenothiazine-derived APDs were lipid competitive, while haloperidol was uncompetitive with lipid. Accordingly, phenothiazine-derived APDs inhibited dynI GTPase activity stimulated by lipids but not by various SH3 domains. All dynamin-active APDs also inhibited transferrin (Tfn) CME in cells at related potencies. Structure-activity relationships (SAR) revealed dynamin inhibition to be conferred by a substituent group containing a terminal tertiary amino group at the N2 position. Chlorpromazine was previously proposed to target AP-2 recruitment in the formation of clathrin-coated vesicles (CCV). However, neither chlorpromazine nor thioridazine affected AP-2 interaction with amphiphysin or clathrin. Super-resolution microscopy revealed that chlorpromazine blocks neither clathrin recruitment by AP-2, nor AP-2 recruitment, showing that CME inhibition occurs downstream of CCV formation. Overall, potent dynamin inhibition is a shared characteristic of phenothiazine-derived APDs, but not other typical or atypical APDs, and the data indicate that dynamin is their likely in-cell target in endocytosis.
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Affiliation(s)
- James A Daniel
- Cell Signalling Unit, Children's Medical Research Institute, The University of Sydney, Sydney, NSW, 2145, Australia.,Present address: Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, Hermann-Rein-Str. 3, 37075 Göttingen, Germany
| | - Ngoc Chau
- Cell Signalling Unit, Children's Medical Research Institute, The University of Sydney, Sydney, NSW, 2145, Australia
| | - Mohammed K Abdel-Hamid
- Centre for Chemical Biology, Chemistry, The University of Newcastle, Callaghan, NSW, 2308, Australia
| | - Lingbo Hu
- Epithelial Cancer Group, The University of Queensland Diamantina Institute, Translational Research Institute, University of Queensland, Woolloongabba, QLD, 4102, Australia
| | - Lisa von Kleist
- Leibniz Institut für Molekulare Pharmakologie & Freie Universität Berlin, 13125, Berlin, Germany
| | - Ainslie Whiting
- Cell Signalling Unit, Children's Medical Research Institute, The University of Sydney, Sydney, NSW, 2145, Australia
| | - Sai Krishnan
- Cell Signalling Unit, Children's Medical Research Institute, The University of Sydney, Sydney, NSW, 2145, Australia
| | - Peter Maamary
- Cell Signalling Unit, Children's Medical Research Institute, The University of Sydney, Sydney, NSW, 2145, Australia
| | - Shannon R Joseph
- Epithelial Cancer Group, The University of Queensland Diamantina Institute, Translational Research Institute, University of Queensland, Woolloongabba, QLD, 4102, Australia
| | - Fiona Simpson
- Epithelial Cancer Group, The University of Queensland Diamantina Institute, Translational Research Institute, University of Queensland, Woolloongabba, QLD, 4102, Australia
| | - Volker Haucke
- Leibniz Institut für Molekulare Pharmakologie & Freie Universität Berlin, 13125, Berlin, Germany
| | - Adam McCluskey
- Centre for Chemical Biology, Chemistry, The University of Newcastle, Callaghan, NSW, 2308, Australia
| | - Phillip J Robinson
- Cell Signalling Unit, Children's Medical Research Institute, The University of Sydney, Sydney, NSW, 2145, Australia
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38
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Paczkowski JE, Richardson BC, Fromme JC. Cargo adaptors: structures illuminate mechanisms regulating vesicle biogenesis. Trends Cell Biol 2015; 25:408-16. [PMID: 25795254 DOI: 10.1016/j.tcb.2015.02.005] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2014] [Revised: 02/11/2015] [Accepted: 02/19/2015] [Indexed: 12/29/2022]
Abstract
Cargo adaptors sort transmembrane protein cargos into nascent vesicles by binding directly to their cytosolic domains. Recent studies have revealed previously unappreciated roles for cargo adaptors and regulatory mechanisms governing their function. The adaptor protein (AP)-1 and AP-2 clathrin adaptors switch between open and closed conformations that ensure they function at the right place at the right time. The exomer cargo adaptor has a direct role in remodeling the membrane for vesicle fission. Several different cargo adaptors functioning in distinct trafficking pathways at the Golgi are similarly regulated through bivalent binding to the ADP-ribosylation factor 1 (Arf1) GTPase, potentially enabling regulation by a threshold concentration of Arf1. Taken together, these studies highlight that cargo adaptors do more than just adapt cargos.
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Affiliation(s)
- Jon E Paczkowski
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853, USA
| | - Brian C Richardson
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853, USA
| | - J Christopher Fromme
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853, USA.
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Whitt MA, Cox ME, Kansal R, Cox JV. Kinetically Distinct Sorting Pathways through the Golgi Exhibit Different Requirements for Arf1. Traffic 2015; 16:267-83. [DOI: 10.1111/tra.12248] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2014] [Revised: 11/26/2014] [Accepted: 11/26/2014] [Indexed: 01/10/2023]
Affiliation(s)
- Michael A. Whitt
- Department of Microbiology, Immunology, and Biochemistry; University of Tennessee Health Science Center; Memphis TN 38163 USA
| | - Michelle E. Cox
- Department of Microbiology, Immunology, and Biochemistry; University of Tennessee Health Science Center; Memphis TN 38163 USA
| | - Rita Kansal
- Department of Microbiology, Immunology, and Biochemistry; University of Tennessee Health Science Center; Memphis TN 38163 USA
| | - John V. Cox
- Department of Microbiology, Immunology, and Biochemistry; University of Tennessee Health Science Center; Memphis TN 38163 USA
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40
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Karamanos Y, Gosselet F, Dehouck MP, Cecchelli R. Blood–Brain Barrier Proteomics: Towards the Understanding of Neurodegenerative Diseases. Arch Med Res 2014; 45:730-7. [DOI: 10.1016/j.arcmed.2014.11.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2014] [Accepted: 11/12/2014] [Indexed: 11/15/2022]
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Umasankar PK, Ma L, Thieman JR, Jha A, Doray B, Watkins SC, Traub LM. A clathrin coat assembly role for the muniscin protein central linker revealed by TALEN-mediated gene editing. eLife 2014; 3. [PMID: 25303365 PMCID: PMC4215538 DOI: 10.7554/elife.04137] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2014] [Accepted: 10/08/2014] [Indexed: 12/12/2022] Open
Abstract
Clathrin-mediated endocytosis is an evolutionarily ancient membrane transport system regulating cellular receptivity and responsiveness. Plasmalemma clathrin-coated structures range from unitary domed assemblies to expansive planar constructions with internal or flanking invaginated buds. Precisely how these morphologically-distinct coats are formed, and whether all are functionally equivalent for selective cargo internalization is still disputed. We have disrupted the genes encoding a set of early arriving clathrin-coat constituents, FCHO1 and FCHO2, in HeLa cells. Endocytic coats do not disappear in this genetic background; rather clustered planar lattices predominate and endocytosis slows, but does not cease. The central linker of FCHO proteins acts as an allosteric regulator of the prime endocytic adaptor, AP-2. By loading AP-2 onto the plasma membrane, FCHO proteins provide a parallel pathway for AP-2 activation and clathrin-coat fabrication. Further, the steady-state morphology of clathrin-coated structures appears to be a manifestation of the availability of the muniscin linker during lattice polymerization. DOI:http://dx.doi.org/10.7554/eLife.04137.001 Cells can take proteins and other molecules that are either embedded in, or attached to, their surface membrane and move them inside via a process called endocytosis. This process often involves a protein called clathrin working together with numerous other proteins. Early on, a complex of four proteins, called the adaptor protein-2 complex, interacts with both the ‘cargo’ molecules that are to be taken into the cell, and the cell membrane. Clathrin molecules then assemble into an ordered lattice-like coat, on top of the adaptor protein complex layer. This deforms a small patch of the cell membrane and curves it inwards. The clathrin molecules coat this pocket as it grows in size, until it engulfs the cargo. The pocket quickly pinches off from the membrane to form a bubble-like structure called a vesicle, which is brought into the cell. A family of proteins termed Muniscins were thought to be involved in the early stages of endocytosis and have to arrive at the membrane before the adaptor protein-2 complex and clathrin. But experiments to test this idea—that reduced, or ‘knocked-down’, the production of Muniscins—had given conflicting results. As such, it remained unclear how the small patches of membrane carrying cargo molecules are marked as being destined to become clathrin-coated vesicles. Now Umasankar et al. have studied the role that these proteins play in the early stages of endocytosis in human cells grown in a laboratory. A gene-editing approach was used to precisely disrupt a gene that codes for a Muniscin protein called FCHO2. Umasankar et al. observed that these ‘edited’ cells formed clathrin coats that were more irregular compared with those that form in normal cells. Nevertheless, clathrin-mediated vesicles still formed when this protein was absent, though the process of endocytosis was slower. Similar results were seen when Umasankar et al. used the same approach to disrupt the gene for a related protein called FCHO1 in the same cells. A short fragment of the Muniscin proteins, called the linker, was shown to bind to, and activate, the adaptor protein-2 complex. The linker then recruits this complex to the specific regions of the cell membrane where clathrin-coated vesicles will form. Several dozen other proteins also accumulate where clathrin pockets form; as such, one of the next challenges will be to investigate if this mechanism of locally activating the cargo-gathering machinery is common in living cells. DOI:http://dx.doi.org/10.7554/eLife.04137.002
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Affiliation(s)
| | - Li Ma
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, United States
| | - James R Thieman
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, United States
| | - Anupma Jha
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, United States
| | - Balraj Doray
- Department of Medicine, Washington University School of Medicine, St. Louis, United States
| | - Simon C Watkins
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, United States
| | - Linton M Traub
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, United States
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Moshkanbaryans L, Chan LS, Graham ME. The Biochemical Properties and Functions of CALM and AP180 in Clathrin Mediated Endocytosis. MEMBRANES 2014; 4:388-413. [PMID: 25090048 PMCID: PMC4194041 DOI: 10.3390/membranes4030388] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/05/2014] [Revised: 07/03/2014] [Accepted: 07/22/2014] [Indexed: 01/26/2023]
Abstract
Clathrin-mediated endocytosis (CME) is a fundamental process for the regulated internalization of transmembrane cargo and ligands via the formation of vesicles using a clathrin coat. A vesicle coat is initially created at the plasma membrane by clathrin assembly into a lattice, while a specific cargo sorting process selects and concentrates proteins for inclusion in the new vesicle. Vesicles formed via CME traffic to different parts of the cell and fuse with target membranes to deliver cargo. Both clathrin assembly and cargo sorting functions are features of the two gene family consisting of assembly protein 180 kDa (AP180) and clathrin assembly lymphoid myeloid leukemia protein (CALM). In this review, we compare the primary structure and domain organization of CALM and AP180 and relate these properties to known functions and roles in CME and disease.
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Affiliation(s)
- Lia Moshkanbaryans
- Children's Medical Research Institute, The University of Sydney, 214 Hawkesbury Road, Westmead, NSW 2145, Australia.
| | - Ling-Shan Chan
- Children's Medical Research Institute, The University of Sydney, 214 Hawkesbury Road, Westmead, NSW 2145, Australia.
| | - Mark E Graham
- Children's Medical Research Institute, The University of Sydney, 214 Hawkesbury Road, Westmead, NSW 2145, Australia.
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43
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Structure and mechanism of COPI vesicle biogenesis. Curr Opin Cell Biol 2014; 29:67-73. [PMID: 24840894 DOI: 10.1016/j.ceb.2014.04.009] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2014] [Revised: 04/01/2014] [Accepted: 04/23/2014] [Indexed: 11/22/2022]
Abstract
Distinct trafficking pathways within the secretory and endocytic systems ensure prompt and precise delivery of specific cargo molecules to different cellular compartments via small vesicular (50-150nm) and tubular carriers. The COPI vesicular coat is required for retrograde trafficking from the cis-Golgi back to the ER and within the Golgi stack. Recent structural data have been obtained from X-ray crystallographic studies on COPI coat components alone and on COPI subunits in complex with either cargo motifs or Arf1, and from reconstructions of COPI coated vesicles by electron tomography. These studies provide important molecular information and indicate key differences in COPI coat assembly as compared with clathrin-based and COPII-based coats.
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Larson BT, Sochacki KA, Kindem JM, Taraska JW. Systematic spatial mapping of proteins at exocytic and endocytic structures. Mol Biol Cell 2014; 25:2084-93. [PMID: 24807904 PMCID: PMC4072581 DOI: 10.1091/mbc.e14-02-0771] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
A quantitative cellular imaging and spatial mapping system is developed and used to measure a library of 78 proteins at calcium-regulated exocytic or clathrin-coated endocytic structures. Structures and proteins are randomly distributed. A steady-state network map is provided for studying the behavior of membrane-trafficking proteins. Vesicular secretion (exocytosis) involves the release and then compensatory recycling of vesicle components through endocytosis. This fundamental cellular process is controlled by the coordinated assembly and interactions of dozens of proteins at the plasma membrane. Understanding the molecular composition of individual exocytic and endocytic structures and their organization across the plasma membrane is critical to understanding the behavior and regulation of these two cellular processes. Here we develop a high-resolution and high-throughput fluorescence imaging–based approach for the unbiased mapping of 78 proteins at single exocytic vesicles and endocytic structures in neuroendocrine PC12 cells. This analysis uses two-color single-frame images to provide a systems-level map of the steady-state distributions of proteins at individual exocytic and endocytic structures in the cell. Along with this quantitative map, we find that both calcium-regulated exocytic vesicles (dense core vesicles) and endocytic structures (clathrin-coated structures) and the proteins associated with these structures exhibit a random spatial distribution in unstimulated neuroendocrine PC12 cells. This approach is broadly applicable for quantitatively mapping the molecular composition and spatial organization of discrete cellular processes with central molecular hubs.
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Affiliation(s)
- Ben T Larson
- Laboratory of Molecular Biophysics, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892
| | - Kem A Sochacki
- Laboratory of Molecular Biophysics, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892
| | - Jonathan M Kindem
- Laboratory of Molecular Biophysics, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892
| | - Justin W Taraska
- Laboratory of Molecular Biophysics, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892
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Takeda M, Yamagami K, Tanaka K. Role of phosphatidylserine in phospholipid flippase-mediated vesicle transport in Saccharomyces cerevisiae. EUKARYOTIC CELL 2014; 13:363-75. [PMID: 24390140 PMCID: PMC3957583 DOI: 10.1128/ec.00279-13] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2013] [Accepted: 12/26/2013] [Indexed: 02/07/2023]
Abstract
Phospholipid flippases translocate phospholipids from the exoplasmic to the cytoplasmic leaflet of cell membranes to generate and maintain phospholipid asymmetry. The genome of budding yeast encodes four heteromeric flippases (Drs2p, Dnf1p, Dnf2p, and Dnf3p), which associate with the Cdc50 family noncatalytic subunit, and one monomeric flippase Neo1p. Flippases have been implicated in the formation of transport vesicles, but the underlying mechanisms are largely unknown. We show here that overexpression of the phosphatidylserine synthase gene CHO1 suppresses defects in the endocytic recycling pathway in flippase mutants. This suppression seems to be mediated by increased cellular phosphatidylserine. Two models can be envisioned for the suppression mechanism: (i) phosphatidylserine in the cytoplasmic leaflet recruits proteins for vesicle formation with its negative charge, and (ii) phosphatidylserine flipping to the cytoplasmic leaflet induces membrane curvature that supports vesicle formation. In a mutant depleted for flippases, a phosphatidylserine probe GFP-Lact-C2 was still localized to endosomal membranes, suggesting that the mere presence of phosphatidylserine in the cytoplasmic leaflet is not enough for vesicle formation. The CHO1 overexpression did not suppress the growth defect in a mutant depleted or mutated for all flippases, suggesting that the suppression was dependent on flippase-mediated phospholipid flipping. Endocytic recycling was not blocked in a mutant lacking phosphatidylserine or depleted in phosphatidylethanolamine, suggesting that a specific phospholipid is not required for vesicle formation. These results suggest that flippase-dependent vesicle formation is mediated by phospholipid flipping, not by flipped phospholipids.
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Affiliation(s)
- Miyoko Takeda
- Division of Molecular Interaction, Institute for Genetic Medicine, Hokkaido University, Graduate School of Life Science, Kita-ku, Sapporo, Japan
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Gordon SL, Cousin MA. The Sybtraps: control of synaptobrevin traffic by synaptophysin, α-synuclein and AP-180. Traffic 2013; 15:245-54. [PMID: 24279465 PMCID: PMC3992847 DOI: 10.1111/tra.12140] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2013] [Revised: 11/22/2013] [Accepted: 11/26/2013] [Indexed: 01/18/2023]
Abstract
Synaptobrevin II (sybII) is a key fusogenic molecule on synaptic vesicles (SVs) therefore the active maintenance of both its conformation and location in sufficient numbers on this organelle is critical in both mediating and sustaining neurotransmitter release. Recently three proteins have been identified having key roles in the presentation, trafficking and retrieval of sybII during the fusion and endocytosis of SVs. The nerve terminal protein α-synuclein catalyses sybII entry into SNARE complexes, whereas the monomeric adaptor protein AP-180 is required for sybII retrieval during SV endocytosis. Overarching these events is the tetraspan SV protein synaptophysin, which is a major sybII interaction partner on the SV. This review will evaluate recent studies to propose working models for the control of sybII traffic by synaptophysin and other Sybtraps (sybII trafficking partners) and suggest how dysfunction in sybII traffic may contribute to human disease.
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Affiliation(s)
- Sarah L Gordon
- Membrane Biology Group, Centre for Integrative Physiology, George Square, University of Edinburgh, Scotland, EH8 9XD, UK
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Boyce AKJ, Prager RT, Wicki-Stordeur LE, Swayne LA. Pore positioning: current concepts in Pannexin channel trafficking. Channels (Austin) 2013; 8:110-7. [PMID: 24300303 DOI: 10.4161/chan.27287] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Pannexins (Panxs) are a multifaceted family of ion and metabolite channels that play key roles in a number of physiological and pathophysiological settings. These single membrane large-pore channels exhibit a variety of tissue, cell type, and subcellular distributions. The lifecycles of Panxs are complex, yet must be understood to accurately target these proteins for future therapeutic use. Here we review the basics of Panx function and localization, and then analyze the recent advances in knowledge regarding Panx trafficking. We examine several intrinsic features of Panxs including specific post-translational modifications, the divergent C-termini, and oligomerization, all of which contribute to Panx anterograde transport pathways. Further, we examine the potential influence of extrinsic factors, such as protein-protein interactions, on Panx trafficking. Finally, we highlight what is currently known with respect to Panx internalization and retrograde transport, and present new data illustrating Panx1 internalization following an activating stimulus.
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Affiliation(s)
- Andrew K J Boyce
- Division of Medical Sciences; Island Medical Program; University of Victoria; Victoria, British Columbia, Canada
| | - Ross T Prager
- Division of Medical Sciences; Island Medical Program; University of Victoria; Victoria, British Columbia, Canada
| | - Leigh E Wicki-Stordeur
- Division of Medical Sciences; Island Medical Program; University of Victoria; Victoria, British Columbia, Canada
| | - Leigh Anne Swayne
- Division of Medical Sciences; Island Medical Program; University of Victoria; Victoria, British Columbia, Canada; Department of Biology; University of Victoria; Victoria, British Columbia, Canada; Department of Biochemistry and Microbiology; University of Victoria; Victoria, British Columbia, Canada; Department of Cellular and Physiological Sciences; University of British Columbia; Vancouver, British Columbia, Canada
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Baisa GA, Mayers JR, Bednarek SY. Budding and braking news about clathrin-mediated endocytosis. CURRENT OPINION IN PLANT BIOLOGY 2013; 16:718-25. [PMID: 24139529 DOI: 10.1016/j.pbi.2013.09.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2013] [Revised: 09/20/2013] [Accepted: 09/23/2013] [Indexed: 05/07/2023]
Abstract
Clathrin-mediated endocytosis (CME) is the predominate mechanism of endocytosis in eukaryotes, but an understanding of this mechanism in plants has lagged behind yeast and mammalian systems. The generation of Arabidopsis mutant libraries, and the development of the molecular tools and equipment necessary to characterize these plant lines has led to an astonishing number of new insights into the mechanisms of membrane trafficking in plants. Over the past few years progress has been made on identifying, and in some instances confirming, the core components of CME in plants. This review focuses on the recent progress made in the understanding of the mechanism and regulation of CME in plants.
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Affiliation(s)
- Gary A Baisa
- Department of Biochemistry, University of Wisconsin-Madison, 433 Babcock Drive, Madison, WI 53706, USA
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Hanamatsu H, Fujimura-Kamada K, Yamamoto T, Furuta N, Tanaka K. Interaction of the phospholipid flippase Drs2p with the F-box protein Rcy1p plays an important role in early endosome to trans-Golgi network vesicle transport in yeast. J Biochem 2013; 155:51-62. [PMID: 24272750 DOI: 10.1093/jb/mvt094] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Phospholipid composition of biological membranes differs between the cytoplasmic and exoplasmic leaflets. The type 4 P-type ATPases are phospholipid flippases that generate such membrane phospholipid asymmetry. Drs2p, a flippase in budding yeast, is involved in the endocytic recycling pathway. Drs2p is implicated in clathrin-coated vesicle formation, but the underlying mechanisms are not clearly understood. Here we show that the carboxyl-terminal cytoplasmic region of Drs2p directly binds to Rcy1p, an F-box protein that is also required for endocytic recycling. The Drs2p-binding region was mapped to the amino acids 574-778 region of Rcy1p and a mutant Rcy1p lacking this region was defective in endocytic recycling of a v-SNARE Snc1p. We isolated Drs2p point mutants that reduced the interaction with Rcy1p. The mutation sites were clustered within a small region (a.a. 1260-1268) of Drs2p. Although these point mutants did not exhibit clear phenotypes, combination of them resulted in cold-sensitive growth, defects in endocytic recycling of Snc1p and defective localization of Rcy1p to endosomal membranes like the drs2 null mutant. These results suggest that the interaction of Drs2p with Rcy1p plays an important role for Drs2p function in the endocytic recycling pathway.
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Affiliation(s)
- Hisatoshi Hanamatsu
- Division of Molecular Interaction, Institute for Genetic Medicine, Hokkaido University Graduate School of Life Science, N15 W7, Kita-ku, Sapporo 060-0815, Japan
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50
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Traub LM, Bonifacino JS. Cargo recognition in clathrin-mediated endocytosis. Cold Spring Harb Perspect Biol 2013; 5:a016790. [PMID: 24186068 DOI: 10.1101/cshperspect.a016790] [Citation(s) in RCA: 214] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The endosomal system is expansive and complex, characterized by swift morphological transitions, dynamic remodeling of membrane constituents, and intracellular positioning changes. To properly navigate this ever-altering membrane labyrinth, transmembrane protein cargoes typically require specific sorting signals that are decoded by components of protein coats. The best-characterized sorting process within the endosomal system is the rapid internalization of select transmembrane proteins within clathrin-coated vesicles. Endocytic signals consist of linear motifs, conformational determinants, or covalent modifications in the cytosolic domains of transmembrane cargo. These signals are interpreted by a diverse set of clathrin-associated sorting proteins (CLASPs) that translocate from the cytosol to the inner face of the plasma membrane. Signal recognition by CLASPs is highly cooperative, involving additional interactions with phospholipids, Arf GTPases, other CLASPs, and clathrin, and is regulated by large conformational changes and covalent modifications. Related sorting events occur at other endosomal sorting stations.
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Affiliation(s)
- Linton M Traub
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15261
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