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Tsemperouli M, Cheppali SK, Molina FR, Chetrit D, Landajuela A, Toomre D, Karatekin E. Vesicle docking and fusion pore modulation by the neuronal calcium sensor Synaptotagmin-1. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.09.12.612660. [PMID: 39314345 PMCID: PMC11419119 DOI: 10.1101/2024.09.12.612660] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 09/25/2024]
Abstract
Synaptotagmin-1 (Syt1) is a major calcium sensor for rapid neurotransmitter release in neurons and hormone release in many neuroendocrine cells. It possesses two tandem cytosolic C2 domains that bind calcium, negatively charged phospholipids, and the neuronal SNARE complex. Calcium binding to Syt1 triggers exocytosis, but how this occurs is not well understood. Syt1 has additional roles in docking dense core vesicles (DCV) and synaptic vesicles (SV) to the plasma membrane (PM) and in regulating fusion pore dynamics. Thus, Syt1 perturbations could affect release through vesicle docking, fusion triggering, fusion pore regulation, or a combination of these. Here, using a human neuroendocrine cell line, we show that neutralization of highly conserved polybasic patches in either C2 domain of Syt1 impairs both DCV docking and efficient release of serotonin from DCVs. Interestingly, the same mutations resulted in larger fusion pores and faster release of serotonin during individual fusion events. Thus, Syt1's roles in vesicle docking, fusion triggering, and fusion pore control may be functionally related.
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Affiliation(s)
- Maria Tsemperouli
- Cellular and Molecular Physiology, School of Medicine, Yale University, New Haven, CT
- Nanobiology Institute, Yale University, West Haven, CT
| | - Sudheer Kumar Cheppali
- Cellular and Molecular Physiology, School of Medicine, Yale University, New Haven, CT
- Nanobiology Institute, Yale University, West Haven, CT
| | - Felix Rivera Molina
- Cell Biology, School of Medicine, Yale University
- CINEMA Lab, School of Medicine, Yale University
| | - David Chetrit
- Cellular and Molecular Physiology, School of Medicine, Yale University, New Haven, CT
- Nanobiology Institute, Yale University, West Haven, CT
| | - Ane Landajuela
- Cellular and Molecular Physiology, School of Medicine, Yale University, New Haven, CT
- Nanobiology Institute, Yale University, West Haven, CT
| | - Derek Toomre
- Cell Biology, School of Medicine, Yale University
- CINEMA Lab, School of Medicine, Yale University
| | - Erdem Karatekin
- Cellular and Molecular Physiology, School of Medicine, Yale University, New Haven, CT
- Nanobiology Institute, Yale University, West Haven, CT
- Molecular Biophysics and Biochemistry, Yale University, New Haven, CT
- Saints-Pères Paris Institute for the Neurosciences (SPPIN), Université de Paris, Centre National de la Recherche Scientifique (CNRS) UMR 8003, Paris, France
- Wu Tsai Institute, Yale University
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2
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Xu W, Ma X, Wang Q, Ye J, Wang N, Ye Z, Chen T. GCN5L1 regulates pulmonary surfactant production by modulating lamellar body biogenesis and trafficking in mouse alveolar epithelial cells. Cell Mol Biol Lett 2023; 28:90. [PMID: 37936104 PMCID: PMC10631113 DOI: 10.1186/s11658-023-00506-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Accepted: 10/25/2023] [Indexed: 11/09/2023] Open
Abstract
BACKGROUND The pulmonary surfactant that lines the air-liquid surface within alveoli is a protein-lipid mixture essential for gas exchange. Surfactant lipids and proteins are synthesized and stored in the lamellar body (LB) before being secreted from alveolar type II (AT2) cells. The molecular and cellular mechanisms that regulate these processes are incompletely understood. We previously identified an essential role of general control of amino acid synthesis 5 like 1 (GCN5L1) and the biogenesis of lysosome-related organelle complex 1 subunit 1 (BLOS1) in surfactant system development in zebrafish. Here, we explored the role of GCN5L1 in pulmonary surfactant regulation. METHOD GCN5L1 knockout cell lines were generated with the CRISPR/Cas9 system. Cell viability was analyzed by MTT assay. Released surfactant proteins were measured by ELISA. Released surfactant lipids were measured based on coupled enzymatic reactions. Gene overexpression was mediated through lentivirus. The RNA levels were detected through RNA-sequencing (RNA-seq) and quantitative reverse transcription (qRT)- polymerase chain reaction (PCR). The protein levels were detected through western blotting. The cellular localization was analyzed by immunofluorescence. Morphology of the lamellar body was analyzed through transmission electron microscopy (TEM), Lysotracker staining, and BODIPY phosphatidylcholine labeling. RESULTS Knocking out GCN5L1 in MLE-12 significantly decreased the release of surfactant proteins and lipids. We detected the downregulation of some surfactant-related genes and misregulation of the ROS-Erk-Foxo1-Cebpα axis in mutant cells. Modulating the activity of the axis or reconstructing the mitochondrial expression of GCN5L1 could partially restore the expression of these surfactant-related genes. We further showed that MLE-12 cells contained many LB-like organelles that were lipid enriched and positive for multiple LB markers. These organelles were smaller in size and accumulated in the absence of GCN5L1, indicating both biogenesis and trafficking defects. Accumulated endogenous surfactant protein (SP)-B or exogenously expressed SP-B/SP-C in adenosine triphosphate-binding cassette transporterA3 (ABCA3)-positive organelles was detected in mutant cells. GCN5L1 localized to the mitochondria and LBs. Reconstruction of mitochondrial GCN5L1 expression rescued the organelle morphology but failed to restore the trafficking defect and surfactant release, indicating specific roles associated with different subcellular localizations. CONCLUSIONS In summary, our study identified GCN5L1 as a new regulator of pulmonary surfactant that plays a role in the biogenesis and positioning/trafficking of surfactant-containing LBs.
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Affiliation(s)
- Wenqin Xu
- Central Laboratory, Yijishan Hospital of Wannan Medical College, Wuhu, China
- Anhui Province Key Laboratory of Non-Coding RNA Basic and Clinical Transformation, Wannan Medical College, Wuhu, China
- Clinical Research Center for Critical Respiratory Medicine of Anhui Province, Wannan Medical College, Wuhu, China
| | - Xiaocui Ma
- Henan Clinical Research Center of Childhood Diseases, Children's Hospital Affiliated to Zhengzhou University, Zhengzhou, China
| | - Qing Wang
- Central Laboratory, Yijishan Hospital of Wannan Medical College, Wuhu, China
- Anhui Province Key Laboratory of Non-Coding RNA Basic and Clinical Transformation, Wannan Medical College, Wuhu, China
- Clinical Research Center for Critical Respiratory Medicine of Anhui Province, Wannan Medical College, Wuhu, China
| | - Jingjing Ye
- Central Laboratory, Yijishan Hospital of Wannan Medical College, Wuhu, China
- Anhui Province Key Laboratory of Non-Coding RNA Basic and Clinical Transformation, Wannan Medical College, Wuhu, China
- Clinical Research Center for Critical Respiratory Medicine of Anhui Province, Wannan Medical College, Wuhu, China
| | - Nengqian Wang
- Department of Pediatrics, Yijishan Hospital of Wannan Medical College, Wuhu, China
| | - Zhenzhen Ye
- Department of Pediatrics, Yijishan Hospital of Wannan Medical College, Wuhu, China
| | - Tianbing Chen
- Central Laboratory, Yijishan Hospital of Wannan Medical College, Wuhu, China.
- Anhui Province Key Laboratory of Non-Coding RNA Basic and Clinical Transformation, Wannan Medical College, Wuhu, China.
- Clinical Research Center for Critical Respiratory Medicine of Anhui Province, Wannan Medical College, Wuhu, China.
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3
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Chang HF, Schirra C, Pattu V, Krause E, Becherer U. Lytic granule exocytosis at immune synapses: lessons from neuronal synapses. Front Immunol 2023; 14:1177670. [PMID: 37275872 PMCID: PMC10233144 DOI: 10.3389/fimmu.2023.1177670] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Accepted: 05/09/2023] [Indexed: 06/07/2023] Open
Abstract
Regulated exocytosis is a central mechanism of cellular communication. It is not only the basis for neurotransmission and hormone release, but also plays an important role in the immune system for the release of cytokines and cytotoxic molecules. In cytotoxic T lymphocytes (CTLs), the formation of the immunological synapse is required for the delivery of the cytotoxic substances such as granzymes and perforin, which are stored in lytic granules and released via exocytosis. The molecular mechanisms of their fusion with the plasma membrane are only partially understood. In this review, we discuss the molecular players involved in the regulated exocytosis of CTL, highlighting the parallels and differences to neuronal synaptic transmission. Additionally, we examine the strengths and weaknesses of both systems to study exocytosis.
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4
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Lee YH, Suh BK, Lee U, Ryu SH, Shin SR, Chang S, Park SK, Chung KC. DYRK3 phosphorylates SNAPIN to regulate axonal retrograde transport and neurotransmitter release. Cell Death Dis 2022; 8:503. [PMID: 36585413 PMCID: PMC9803678 DOI: 10.1038/s41420-022-01290-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Revised: 12/19/2022] [Accepted: 12/21/2022] [Indexed: 12/31/2022]
Abstract
Among the five members of the dual-specificity tyrosine-phosphorylation-regulated kinase (DYRK) family, the cellular functions of DYRK3 have not been fully elucidated. Some studies have indicated limited physiological roles and substrates of DYRK3, including promotion of glioblastoma, requirement in influenza virus replication, and coupling of stress granule condensation with mammalian target of rapamycin complex 1 signaling. Here, we demonstrate that serum deprivation causes a decrease in intracellular DYRK3 levels via the proteolytic autophagy pathway, as well as the suppression of DYRK3 gene expression. To further demonstrate how DYRK3 affects cell viability, especially in neurons, we used a yeast two-hybrid assay and identified multiple DYRK3-binding proteins, including SNAPIN, a SNARE-associated protein implicated in synaptic transmission. We also found that DYRK3 directly phosphorylates SNAPIN at the threonine (Thr) 14 residue, increasing the interaction of SNAPIN with other proteins such as dynein and synaptotagmin-1. In central nervous system neurons, SNAPIN is associated with and mediate the retrograde axonal transport of diverse cellular products from the distal axon terminal to the soma and the synaptic release of neurotransmitters, respectively. Moreover, phosphorylation of SNAPIN at Thr-14 was found to positively modulate mitochondrial retrograde transport in mouse cortical neurons and the recycling pool size of synaptic vesicles, contributing to neuronal viability. In conclusion, the present study demonstrates that DYRK3 phosphorylates SNAPIN, positively regulating the dynein-mediated retrograde transport of mitochondria and SNARE complex-mediated exocytosis of synaptic vesicles within the neurons. This finding further suggests that DYRK3 affects cell viability and provides a novel neuroprotective mechanism.
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Affiliation(s)
- Ye Hyung Lee
- grid.15444.300000 0004 0470 5454Department of Systems Biology, College of Life Science and Biotechnology, Yonsei University, Seoul, Korea
| | - Bo Kyoung Suh
- grid.49100.3c0000 0001 0742 4007Department of Life Sciences, Pohang University of Science and Technology, Pohang-si, Gyeongsangbuk-do Korea
| | - Unghwi Lee
- grid.31501.360000 0004 0470 5905Department of Physiology and Biomedical Sciences, Seoul National University College of Medicine, Seoul, Korea
| | - Seung Hyun Ryu
- grid.31501.360000 0004 0470 5905Department of Physiology and Biomedical Sciences, Seoul National University College of Medicine, Seoul, Korea
| | - Sung Ryong Shin
- grid.49100.3c0000 0001 0742 4007Department of Life Sciences, Pohang University of Science and Technology, Pohang-si, Gyeongsangbuk-do Korea
| | - Sunghoe Chang
- grid.31501.360000 0004 0470 5905Department of Physiology and Biomedical Sciences, Seoul National University College of Medicine, Seoul, Korea
| | - Sang Ki Park
- grid.49100.3c0000 0001 0742 4007Department of Life Sciences, Pohang University of Science and Technology, Pohang-si, Gyeongsangbuk-do Korea
| | - Kwang Chul Chung
- grid.15444.300000 0004 0470 5454Department of Systems Biology, College of Life Science and Biotechnology, Yonsei University, Seoul, Korea
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5
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Bell CJ, Gupta N, Tremblay KD, Mager J. Borcs6 is required for endo-lysosomal degradation during early development. Mol Reprod Dev 2022; 89:337-350. [PMID: 35726782 PMCID: PMC9391301 DOI: 10.1002/mrd.23626] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Revised: 06/07/2022] [Accepted: 06/10/2022] [Indexed: 11/10/2022]
Abstract
Early development and differentiation require precise control of cellular functions. Lysosomal degradation is a critical component of normal cellular homeostasis, allowing for degradation of signaling molecules, proteins, and other macromolecules for cellular remodeling and signaling. Little is known about the role of lysosomal function in mammalian embryos before gastrulation. Borcs6 is a protein involved in lysosomal trafficking as well as endo-lysosomal and autophagosome fusion. Here, we show that Borcs6 is necessary for efficient endo-lysosomal degradation in the early embryo. Although embryos lacking Borcs6 are developmentally comparable to control littermates at E5.5, they are characterized by large cells containing increased levels of late endosomes and abnormal nuclei. Furthermore, these embryos display a skewed ratio of extraembryonic and embryonic cell lineages, are delayed by E6.5, and do not undergo normal gastrulation. These results demonstrate the essential functions of lysosomal positioning and fusion with endosomes during early embryonic development and indicate that the early lethality of BORCS6 mutant embryos is primarily due to defects in the HOPS-related function of BORC rather than lysosomal positioning.
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Affiliation(s)
- Charlotte J Bell
- Department of Veterinary and Animal Sciences, University of Massachusetts, Amherst, Massachusetts, USA
| | - Neha Gupta
- Department of Veterinary and Animal Sciences, University of Massachusetts, Amherst, Massachusetts, USA
| | - Kimberly D Tremblay
- Department of Veterinary and Animal Sciences, University of Massachusetts, Amherst, Massachusetts, USA
| | - Jesse Mager
- Department of Veterinary and Animal Sciences, University of Massachusetts, Amherst, Massachusetts, USA
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6
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Li W, Hao CJ, Hao ZH, Ma J, Wang QC, Yuan YF, Gong JJ, Chen YY, Yu JY, Wei AH. New insights into the pathogenesis of Hermansky-Pudlak syndrome. Pigment Cell Melanoma Res 2022; 35:290-302. [PMID: 35129281 DOI: 10.1111/pcmr.13030] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Revised: 02/02/2022] [Accepted: 02/03/2022] [Indexed: 12/14/2022]
Abstract
Hermansky-Pudlak syndrome (HPS) is characterized by defects of multiple tissue-specific lysosome-related organelles (LROs), typically manifesting with oculocutaneous albinism or ocular albinism, bleeding tendency, and in some cases with pulmonary fibrosis, inflammatory bowel disease or immunodeficiency, neuropsychological disorders. Eleven HPS subtypes in humans and at least 15 subtypes in mice have been molecularly identified. Current understanding of the underlying mechanisms of HPS is focusing on the defective biogenesis of LROs. Compelling evidences have shown that HPS protein-associated complexes (HPACs) function in cargo transport, cargo recycling, and cargo removal to maintain LRO homeostasis. Further investigation on the molecular and cellular mechanism of LRO biogenesis and secretion will be helpful for better understanding of its pathogenesis and for the precise intervention of HPS.
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Affiliation(s)
- Wei Li
- Beijing Key Laboratory for Genetics of Birth Defects, Beijing Pediatric Research Institute, Beijing Children's Hospital, Capital Medical University, Center of Rare Diseases, National Center for Children's Health, Beijing, China.,MOE Key Laboratory of Major Diseases in Children, Capital Medical University, Beijing, China
| | - Chan-Juan Hao
- Beijing Key Laboratory for Genetics of Birth Defects, Beijing Pediatric Research Institute, Beijing Children's Hospital, Capital Medical University, Center of Rare Diseases, National Center for Children's Health, Beijing, China.,MOE Key Laboratory of Major Diseases in Children, Capital Medical University, Beijing, China
| | - Zhen-Hua Hao
- Beijing Key Laboratory for Genetics of Birth Defects, Beijing Pediatric Research Institute, Beijing Children's Hospital, Capital Medical University, Center of Rare Diseases, National Center for Children's Health, Beijing, China.,MOE Key Laboratory of Major Diseases in Children, Capital Medical University, Beijing, China
| | - Jing Ma
- Beijing Key Laboratory for Genetics of Birth Defects, Beijing Pediatric Research Institute, Beijing Children's Hospital, Capital Medical University, Center of Rare Diseases, National Center for Children's Health, Beijing, China.,MOE Key Laboratory of Major Diseases in Children, Capital Medical University, Beijing, China
| | - Qiao-Chu Wang
- Beijing Key Laboratory for Genetics of Birth Defects, Beijing Pediatric Research Institute, Beijing Children's Hospital, Capital Medical University, Center of Rare Diseases, National Center for Children's Health, Beijing, China.,MOE Key Laboratory of Major Diseases in Children, Capital Medical University, Beijing, China
| | - Ye-Feng Yuan
- Beijing Key Laboratory for Genetics of Birth Defects, Beijing Pediatric Research Institute, Beijing Children's Hospital, Capital Medical University, Center of Rare Diseases, National Center for Children's Health, Beijing, China.,MOE Key Laboratory of Major Diseases in Children, Capital Medical University, Beijing, China
| | - Juan-Juan Gong
- Beijing Key Laboratory for Genetics of Birth Defects, Beijing Pediatric Research Institute, Beijing Children's Hospital, Capital Medical University, Center of Rare Diseases, National Center for Children's Health, Beijing, China.,MOE Key Laboratory of Major Diseases in Children, Capital Medical University, Beijing, China
| | - Yuan-Ying Chen
- Beijing Key Laboratory for Genetics of Birth Defects, Beijing Pediatric Research Institute, Beijing Children's Hospital, Capital Medical University, Center of Rare Diseases, National Center for Children's Health, Beijing, China.,MOE Key Laboratory of Major Diseases in Children, Capital Medical University, Beijing, China
| | - Jia-Ying Yu
- Beijing Key Laboratory for Genetics of Birth Defects, Beijing Pediatric Research Institute, Beijing Children's Hospital, Capital Medical University, Center of Rare Diseases, National Center for Children's Health, Beijing, China.,MOE Key Laboratory of Major Diseases in Children, Capital Medical University, Beijing, China
| | - Ai-Hua Wei
- Department of Dermatology, Tongren Hospital, Capital Medical University, Beijing, China
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7
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Jeong S, Rhee JS, Lee JH. Snapin Specifically Up-Regulates Ca v1.3 Ca 2+ Channel Variant with a Long Carboxyl Terminus. Int J Mol Sci 2021; 22:ijms222011268. [PMID: 34681928 PMCID: PMC8537452 DOI: 10.3390/ijms222011268] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Revised: 10/14/2021] [Accepted: 10/15/2021] [Indexed: 11/16/2022] Open
Abstract
Ca2+ entry through Cav1.3 Ca2+ channels plays essential roles in diverse physiological events. We employed yeast-two-hybrid (Y2H) assays to mine novel proteins interacting with Cav1.3 and found Snapin2, a synaptic protein, as a partner interacting with the long carboxyl terminus (CTL) of rat Cav1.3L variant. Co-expression of Snapin with Cav1.3L/Cavβ3/α2δ2 subunits increased the peak current density or amplitude by about 2-fold in HEK-293 cells and Xenopus oocytes, without affecting voltage-dependent gating properties and calcium-dependent inactivation. However, the Snapin up-regulation effect was not found for rat Cav1.3S containing a short CT (CTS) in which a Snapin interaction site in the CTL was deficient. Luminometry and electrophysiology studies uncovered that Snapin co-expression did not alter the membrane expression of HA tagged Cav1.3L but increased the slope of tail current amplitudes plotted against ON-gating currents, indicating that Snapin increases the opening probability of Cav1.3L. Taken together, our results strongly suggest that Snapin directly interacts with the CTL of Cav1.3L, leading to up-regulation of Cav1.3L channel activity via facilitating channel opening probability.
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Affiliation(s)
- Sua Jeong
- Department of Life Science, Sogang University, 35 Baekbeom-ro, Mapo-gu, Seoul 04107, Korea;
| | - Jeong-Seop Rhee
- Synaptic Physiology Group, Department of Molecular Neurobiology, Max Planck Institute for Experimental Medicine, Hermann-Rein-Str. 3, 37075 Göttingen, Germany;
| | - Jung-Ha Lee
- Department of Life Science, Sogang University, 35 Baekbeom-ro, Mapo-gu, Seoul 04107, Korea;
- Correspondence: ; Tel.: +82-2-705-8791; Fax: +82-3-704-3601
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8
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A Novel Likely Pathogenic Variant in the BLOC1S5 Gene Associated with Hermansky-Pudlak Syndrome Type 11 and an Overview of Human BLOC-1 Deficiencies. Cells 2021; 10:cells10102630. [PMID: 34685610 PMCID: PMC8533863 DOI: 10.3390/cells10102630] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 09/10/2021] [Accepted: 09/26/2021] [Indexed: 01/18/2023] Open
Abstract
Hermansky-Pudlak syndrome (HPS) is a heterogeneous disorder combining oculocutaneous albinism (OCA) and a platelet function disorder of varying severity as its most prominent features. The genes associated with HPS encode for different BLOC- (biogenesis of lysosome-related organelles complex) complexes and for the AP-3 (adaptor protein-3) complex, respectively. These proteins are involved in maturation, trafficking, and the function of lysosome-related organelles (LROs) such as melanosomes and platelet δ-granules. Some patients with different types of HPS can develop additional complications and symptoms like pulmonary fibrosis, granulomatous colitis, and immunodeficiency. A new type of HPS has recently been identified associated with genetic alterations in the BLOC1S5 gene, which encodes the subunit Muted of the BLOC-1 complex. Our aim was to unravel the genetic defect in two siblings with a suspected HPS diagnosis (because of OCA and bleeding symptoms) using next generation sequencing (NGS). Platelet functional analysis revealed reduced platelet aggregation after stimulation with ADP and a severe secretion defect in platelet δ-granules. NGS identified a novel homozygous essential splice site variant in the BLOC1S5 gene present in both affected siblings who are descendants of a consanguine marriage. The patients exhibited no additional symptoms. Our study confirms that pathogenic variants of BLOC1S5 cause the recently described HPS type 11.
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9
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Schnöder L, Tomic I, Schwindt L, Helm D, Rettel M, Schulz-Schaeffer W, Krause E, Rettig J, Fassbender K, Liu Y. P38α-MAPK phosphorylates Snapin and reduces Snapin-mediated BACE1 transportation in APP-transgenic mice. FASEB J 2021; 35:e21691. [PMID: 34118085 DOI: 10.1096/fj.202100017r] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 04/18/2021] [Accepted: 05/07/2021] [Indexed: 11/11/2022]
Abstract
Amyloid β peptide (Aβ) is the major pathogenic molecule in Alzheimer's disease (AD). BACE1 enzyme is essential for the generation of Aβ. Deficiency of p38α-MAPK in neurons increases lysosomal degradation of BACE1 and decreases Aβ deposition in the brain of APP-transgenic mice. However, the mechanisms mediating effects of p38α-MAPK are largely unknown. In this study, we used APP-transgenic mice and cultured neurons and observed that deletion of p38α-MAPK specifically in neurons decreased phosphorylation of Snapin at serine, increased retrograde transportation of BACE1 in axons and reduced BACE1 at synaptic terminals, which suggests that p38α-MAPK deficiency promotes axonal transportation of BACE1 from its predominant locations, axonal terminals, to lysosomes in the cell body. In vitro kinase assay revealed that p38α-MAPK directly phosphorylates Snapin. By further performing mass spectrometry analysis and site-directed mutagenic experiments in SH-SY5Y cell lines, we identified serine residue 112 as a p38α-MAPK-phosphorylating site on Snapin. Replacement of serine 112 with alanine did abolish p38α-MAPK knockdown-induced reduction of BACE1 activity and protein level, and transportation to lysosomes in SH-SY5Y cells. Taken together, our study suggests that activation of p38α-MAPK phosphorylates Snapin and inhibits the retrograde transportation of BACE1 in axons, which might exaggerate amyloid pathology in AD brain.
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Affiliation(s)
- Laura Schnöder
- Department of Neurology, Saarland University, Homburg/Saar, Germany.,German Institute for Dementia Prevention (DIDP), Saarland University, Homburg/Saar, Germany
| | - Inge Tomic
- Department of Neurology, Saarland University, Homburg/Saar, Germany.,German Institute for Dementia Prevention (DIDP), Saarland University, Homburg/Saar, Germany
| | - Laura Schwindt
- Department of Neurology, Saarland University, Homburg/Saar, Germany.,German Institute for Dementia Prevention (DIDP), Saarland University, Homburg/Saar, Germany
| | - Dominic Helm
- European Molecular Biology Laboratory, Proteomics Core Facility, Heidelberg, Germany
| | - Mandy Rettel
- European Molecular Biology Laboratory, Proteomics Core Facility, Heidelberg, Germany
| | | | - Elmar Krause
- Cellular Neurophysiology, Center for Integrative Physiology and Molecular Medicine (CIPMM), Saarland University, Homburg, Germany
| | - Jens Rettig
- Cellular Neurophysiology, Center for Integrative Physiology and Molecular Medicine (CIPMM), Saarland University, Homburg, Germany
| | - Klaus Fassbender
- Department of Neurology, Saarland University, Homburg/Saar, Germany.,German Institute for Dementia Prevention (DIDP), Saarland University, Homburg/Saar, Germany
| | - Yang Liu
- Department of Neurology, Saarland University, Homburg/Saar, Germany.,German Institute for Dementia Prevention (DIDP), Saarland University, Homburg/Saar, Germany
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10
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Harper CB, Smillie KJ. Current molecular approaches to investigate pre-synaptic dysfunction. J Neurochem 2021; 157:107-129. [PMID: 33544872 DOI: 10.1111/jnc.15316] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Revised: 01/29/2021] [Accepted: 02/01/2021] [Indexed: 12/19/2022]
Abstract
Over the course of the last few decades it has become clear that many neurodevelopmental and neurodegenerative disorders have a synaptic defect, which contributes to pathogenicity. A rise in new techniques, and in particular '-omics'-based methods providing large datasets, has led to an increase in potential proteins and pathways implicated in synaptic function and related disorders. Additionally, advancements in imaging techniques have led to the recent discovery of alternative modes of synaptic vesicle recycling. This has resulted in a lack of clarity over the precise role of different pathways in maintaining synaptic function and whether these new pathways are dysfunctional in neurodevelopmental and neurodegenerative disorders. A greater understanding of the molecular detail of pre-synaptic function in health and disease is key to targeting new proteins and pathways for novel treatments and the variety of new techniques currently available provides an ideal opportunity to investigate these functions. This review focuses on techniques to interrogate pre-synaptic function, concentrating mainly on synaptic vesicle recycling. It further examines techniques to determine the underlying molecular mechanism of pre-synaptic dysfunction and discusses methods to identify molecular targets, along with protein-protein interactions and cellular localization. In combination, these techniques will provide an expanding and more complete picture of pre-synaptic function. With the application of recent technological advances, we are able to resolve events with higher spatial and temporal resolution, leading research towards a greater understanding of dysfunction at the presynapse and the role it plays in pathogenicity.
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Affiliation(s)
- Callista B Harper
- Centre for Discovery Brain Sciences, University of Edinburgh, Scotland, UK
| | - Karen J Smillie
- Centre for Discovery Brain Sciences, University of Edinburgh, Scotland, UK
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11
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Eggert S, Gruebl T, Rajender R, Rupp C, Sander B, Heesch A, Zimmermann M, Hoepfner S, Zentgraf H, Kins S. The Rab5 activator RME-6 is required for amyloid precursor protein endocytosis depending on the YTSI motif. Cell Mol Life Sci 2020; 77:5223-5242. [PMID: 32065241 PMCID: PMC7671991 DOI: 10.1007/s00018-020-03467-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Revised: 12/20/2019] [Accepted: 01/14/2020] [Indexed: 12/13/2022]
Abstract
Endocytosis of the amyloid precursor protein (APP) is critical for generation of β-amyloid, aggregating in Alzheimer's disease. APP endocytosis depending on the intracellular NPTY motif is well investigated, whereas involvement of the YTSI (also termed BaSS) motif remains controversial. Here, we show that APP lacking the YTSI motif (ΔYTSI) displays reduced localization to early endosomes and decreased internalization rates, similar to APP ΔNPTY. Additionally, we show that the YTSI-binding protein, PAT1a interacts with the Rab5 activator RME-6, as shown by several independent assays. Interestingly, knockdown of RME-6 decreased APP endocytosis, whereas overexpression increased the same. Similarly, APP ΔNPTY endocytosis was affected by PAT1a and RME-6 overexpression, whereas APP ΔYTSI internalization remained unchanged. Moreover, we could show that RME-6 mediated increase of APP endocytosis can be diminished upon knocking down PAT1a. Together, our data identify RME-6 as a novel player in APP endocytosis, involving the YTSI-binding protein PAT1a.
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Affiliation(s)
- Simone Eggert
- Department of Human Biology and Human Genetics, Technical University of Kaiserslautern, Erwin-Schrödinger-Str. 13, 67663, Kaiserslautern, Germany
| | - Tomas Gruebl
- Department of Human Biology and Human Genetics, Technical University of Kaiserslautern, Erwin-Schrödinger-Str. 13, 67663, Kaiserslautern, Germany
| | - Ritu Rajender
- Department of Human Biology and Human Genetics, Technical University of Kaiserslautern, Erwin-Schrödinger-Str. 13, 67663, Kaiserslautern, Germany
| | - Carsten Rupp
- Department of Human Biology and Human Genetics, Technical University of Kaiserslautern, Erwin-Schrödinger-Str. 13, 67663, Kaiserslautern, Germany
| | - Bianca Sander
- Department of Human Biology and Human Genetics, Technical University of Kaiserslautern, Erwin-Schrödinger-Str. 13, 67663, Kaiserslautern, Germany
| | - Amelie Heesch
- Department of Human Biology and Human Genetics, Technical University of Kaiserslautern, Erwin-Schrödinger-Str. 13, 67663, Kaiserslautern, Germany
| | - Marius Zimmermann
- Department of Human Biology and Human Genetics, Technical University of Kaiserslautern, Erwin-Schrödinger-Str. 13, 67663, Kaiserslautern, Germany
| | - Sebastian Hoepfner
- MPI of Molecular Cell Biology and Genetics, Dresden, Germany
- Bird & Bird LLM, Munich, Germany
| | | | - Stefan Kins
- Department of Human Biology and Human Genetics, Technical University of Kaiserslautern, Erwin-Schrödinger-Str. 13, 67663, Kaiserslautern, Germany.
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12
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Domingues HS, Urbanski MM, Macedo-Ribeiro S, Almaktari A, Irfan A, Hernandez Y, Wang H, Relvas JB, Rubinstein B, Melendez-Vasquez CV, Pinto IM. Pushing myelination - developmental regulation of myosin expression drives oligodendrocyte morphological differentiation. J Cell Sci 2020; 133:jcs232264. [PMID: 32620697 PMCID: PMC7426197 DOI: 10.1242/jcs.232264] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Accepted: 06/24/2020] [Indexed: 01/26/2023] Open
Abstract
Oligodendrocytes are the central nervous system myelin-forming cells providing axonal electrical insulation and higher-order neuronal circuitry. The mechanical forces driving the differentiation of oligodendrocyte precursor cells into myelinating oligodendrocytes are largely unknown, but likely require the spatiotemporal regulation of the architecture and dynamics of the actin and actomyosin cytoskeletons. In this study, we analyzed the expression pattern of myosin motors during oligodendrocyte development. We report that oligodendrocyte differentiation is regulated by the synchronized expression and non-uniform distribution of several members of the myosin network, particularly non-muscle myosins 2B and 2C, which potentially operate as nanomechanical modulators of cell tension and myelin membrane expansion at different cell stages.This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Helena Sofia Domingues
- International Iberian Nanotechnology Laboratory (INL), 4715-330 Braga, Portugal
- Instituto de Investigação e Inovação em Saúde (I3S), Universidade do Porto, 4200-135 Porto, Portugal
- Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, 4200-135 Porto, Portugal
| | - Mateusz M Urbanski
- Department of Biological Sciences, Hunter College City University of New York, New York, NY 10065, USA
| | - Sandra Macedo-Ribeiro
- Instituto de Investigação e Inovação em Saúde (I3S), Universidade do Porto, 4200-135 Porto, Portugal
- Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, 4200-135 Porto, Portugal
| | - Amr Almaktari
- Department of Biological Sciences, Hunter College City University of New York, New York, NY 10065, USA
| | - Azka Irfan
- Department of Biological Sciences, Hunter College City University of New York, New York, NY 10065, USA
| | - Yamely Hernandez
- Department of Biological Sciences, Hunter College City University of New York, New York, NY 10065, USA
| | - Haibo Wang
- Department of Biological Sciences, Hunter College City University of New York, New York, NY 10065, USA
| | - João Bettencourt Relvas
- Instituto de Investigação e Inovação em Saúde (I3S), Universidade do Porto, 4200-135 Porto, Portugal
- Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, 4200-135 Porto, Portugal
| | - Boris Rubinstein
- Stowers Institute for Medical Research, Kansas City, MO 64110, USA
| | - Carmen V Melendez-Vasquez
- Department of Biological Sciences, Hunter College City University of New York, New York, NY 10065, USA
- The Graduate Center, City University of New York (CUNY), New York, NY 10016, USA
| | - Inês Mendes Pinto
- International Iberian Nanotechnology Laboratory (INL), 4715-330 Braga, Portugal
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13
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Bowman SL, Bi-Karchin J, Le L, Marks MS. The road to lysosome-related organelles: Insights from Hermansky-Pudlak syndrome and other rare diseases. Traffic 2020; 20:404-435. [PMID: 30945407 DOI: 10.1111/tra.12646] [Citation(s) in RCA: 120] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Revised: 04/02/2019] [Accepted: 04/02/2019] [Indexed: 12/11/2022]
Abstract
Lysosome-related organelles (LROs) comprise a diverse group of cell type-specific, membrane-bound subcellular organelles that derive at least in part from the endolysosomal system but that have unique contents, morphologies and functions to support specific physiological roles. They include: melanosomes that provide pigment to our eyes and skin; alpha and dense granules in platelets, and lytic granules in cytotoxic T cells and natural killer cells, which release effectors to regulate hemostasis and immunity; and distinct classes of lamellar bodies in lung epithelial cells and keratinocytes that support lung plasticity and skin lubrication. The formation, maturation and/or secretion of subsets of LROs are dysfunctional or entirely absent in a number of hereditary syndromic disorders, including in particular the Hermansky-Pudlak syndromes. This review provides a comprehensive overview of LROs in humans and model organisms and presents our current understanding of how the products of genes that are defective in heritable diseases impact their formation, motility and ultimate secretion.
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Affiliation(s)
- Shanna L Bowman
- Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia Research Institute, Philadelphia, Pennsylvania.,Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.,Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Jing Bi-Karchin
- Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia Research Institute, Philadelphia, Pennsylvania.,Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.,Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Linh Le
- Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia Research Institute, Philadelphia, Pennsylvania.,Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.,Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.,Cell and Molecular Biology Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Michael S Marks
- Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia Research Institute, Philadelphia, Pennsylvania.,Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.,Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
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14
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Huizing M, Malicdan MCV, Wang JA, Pri-Chen H, Hess RA, Fischer R, O'Brien KJ, Merideth MA, Gahl WA, Gochuico BR. Hermansky-Pudlak syndrome: Mutation update. Hum Mutat 2020; 41:543-580. [PMID: 31898847 DOI: 10.1002/humu.23968] [Citation(s) in RCA: 62] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Revised: 12/06/2019] [Accepted: 12/26/2019] [Indexed: 12/14/2022]
Abstract
Hermansky-Pudlak syndrome (HPS) is a group of 10 autosomal recessive multisystem disorders, each defined by the deficiency of a specific gene. HPS-associated genes encode components of four ubiquitously expressed protein complexes: Adaptor protein-3 (AP-3) and biogenesis of lysosome-related organelles complex-1 (BLOC-1) through -3. All individuals with HPS exhibit albinism and a bleeding diathesis; additional features occur depending on the defective protein complex. Pulmonary fibrosis is associated with AP-3 and BLOC-3 deficiency, immunodeficiency with AP-3 defects, and gastrointestinal symptoms are more prevalent and severe in BLOC-3 deficiency. Therefore, identification of the HPS subtype is valuable for prognosis, clinical management, and treatment options. The prevalence of HPS is estimated at 1-9 per 1,000,000. Here we summarize 264 reported and novel variants in 10 HPS genes and estimate that ~333 Puerto Rican HPS subjects and ~385 with other ethnicities are reported to date. We provide pathogenicity predictions for missense and splice site variants and list variants with high minor allele frequencies. Current cellular and clinical aspects of HPS are also summarized. This review can serve as a manifest for molecular diagnostics and genetic counseling aspects of HPS.
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Affiliation(s)
- Marjan Huizing
- Human Biochemical Genetics Section, Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland
| | - May C V Malicdan
- Human Biochemical Genetics Section, Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland
| | - Jennifer A Wang
- Human Biochemical Genetics Section, Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland
| | - Hadass Pri-Chen
- Human Biochemical Genetics Section, Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland.,Metabolic Disease Unit, Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel Hashomer and Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Richard A Hess
- Human Biochemical Genetics Section, Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland
| | - Roxanne Fischer
- Human Biochemical Genetics Section, Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland
| | - Kevin J O'Brien
- Office of the Clinical Director, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland
| | - Melissa A Merideth
- Office of the Clinical Director, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland
| | - William A Gahl
- Human Biochemical Genetics Section, Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland
| | - Bernadette R Gochuico
- Human Biochemical Genetics Section, Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland
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15
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Abstract
Recent evidence from genetics, animal model systems and biochemical studies suggests that defects in membrane trafficking play an important part in the pathophysiology of Parkinson’s disease (PD). Mutations in leucine-rich repeat kinase 2 (LRRK2) constitute the most frequent genetic cause of both familial and sporadic PD, and LRRK2 has been suggested as a druggable target for PD. Although the precise physiological function of LRRK2 remains largely unknown, mounting evidence suggests that LRRK2 controls membrane trafficking by interacting with key regulators of the endosomal-lysosomal pathway and synaptic recycling. In this review, we discuss the genetic, biochemical and functional links between LRRK2 and membrane trafficking. Understanding the mechanism by which LRRK2 influences such processes may contribute to the development of disease-modifying therapies for PD.
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Affiliation(s)
- Eun-Mi Hur
- Department of Neuroscience, College of Veterinary Medicine, Research Institute for Veterinary Science, and BK21 PLUS Program for Creative Veterinary Science Research, Seoul National University, Seoul 08826, Korea
| | - Eun-Hae Jang
- Department of Neuroscience, College of Veterinary Medicine, Research Institute for Veterinary Science, and BK21 PLUS Program for Creative Veterinary Science Research, Seoul National University, Seoul 08826, Korea
- Division of Bio-Medical Science & Technology, KIST School, Korea University of Science and Technology, Seoul 02792, Korea
| | - Ga Ram Jeong
- Department of Neuroscience, Kyung Hee University, Seoul 02447, Korea
| | - Byoung Dae Lee
- Department of Neuroscience, Kyung Hee University, Seoul 02447, Korea
- Department of Physiology, Kyung Hee University School of Medicine, Seoul 02447, Korea
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16
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Snouwaert JN, Church RJ, Jania L, Nguyen M, Wheeler ML, Saintsing A, Mieczkowski P, Manuel de Villena FP, Armao D, Moy SS, Lorenzo DN, Koller BH. A Mutation in the Borcs7 Subunit of the Lysosome Regulatory BORC Complex Results in Motor Deficits and Dystrophic Axonopathy in Mice. Cell Rep 2018; 24:1254-1265. [PMID: 30067980 DOI: 10.1016/j.celrep.2018.06.118] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Revised: 05/06/2018] [Accepted: 06/28/2018] [Indexed: 12/13/2022] Open
Abstract
Lysosomes play a critical role in maintenance of the integrity of neuronal function, and mutations in genes that contribute to lysosome formation, transport, and activity are associated with neurodegenerative disorders. Recently, the multisubunit complex, BLOC-one-related complex (BORC), has been shown to be involved in positioning lysosomes within the cytoplasm, although the consequences of altered BORC function in adult animals have not been established. We show that a spontaneous truncation mutation in the mouse Borcs7 gene, identified through whole-genome sequencing followed by genetic complementation, results in progressive axonal dystrophy with dramatic impairment of motor function. Furthermore, mice homozygous for deletion of the entire Borcs7 coding sequence die shortly after birth, and neurons cultured from these animals show impaired centrifugal transport of lysosomes. This identifies BORCS7 as a central factor in axonal transport of lysosomes and a possible target for improving disease-related disturbances in this important function.
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Affiliation(s)
- John N Snouwaert
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Rachel J Church
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Leigh Jania
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - MyTrang Nguyen
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Matthew L Wheeler
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Andrew Saintsing
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Piotr Mieczkowski
- High Throughput Sequencing Facility, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Fernando Pardo Manuel de Villena
- Department of Genetics and Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Diane Armao
- Department of Radiology, UNC Healthcare System, Chapel Hill, NC 27599, USA; Department of Pathology and Laboratory Medicine, University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA; Department of Physician Assistant Studies, Elon University, Elon, NC 27244, USA
| | - Sheryl S Moy
- Department of Psychiatry and Carolina Institute for Developmental Disorders, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Damaris N Lorenzo
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Beverly H Koller
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
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17
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Botulinum Toxin for Central Neuropathic Pain. Toxins (Basel) 2018; 10:toxins10060224. [PMID: 29857568 PMCID: PMC6024683 DOI: 10.3390/toxins10060224] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Revised: 05/26/2018] [Accepted: 05/28/2018] [Indexed: 11/17/2022] Open
Abstract
Botulinum toxin (BTX) is widely used to treat muscle spasticity by acting on motor neurons. Recently, studies of the effects of BTX on sensory nerves have been reported and several studies have been conducted to evaluate its effects on peripheral and central neuropathic pain. Central neuropathic pain includes spinal cord injury-related neuropathic pain, post-stroke shoulder pain, multiple sclerosis-related pain, and complex regional pain syndrome. This article reviews the mechanism of central neuropathic pain and assesses the effect of BTX on central neuropathic pain.
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18
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Structural and Functional Characterization of the Interaction of Snapin with the Dopamine Transporter: Differential Modulation of Psychostimulant Actions. Neuropsychopharmacology 2018; 43:1041-1051. [PMID: 28905875 PMCID: PMC5854797 DOI: 10.1038/npp.2017.217] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Revised: 09/06/2017] [Accepted: 09/08/2017] [Indexed: 12/12/2022]
Abstract
The importance of dopamine (DA) neurotransmission is emphasized by its direct implication in several neurological and psychiatric disorders. The DA transporter (DAT), target of psychostimulant drugs, is the key protein that regulates spatial and temporal activity of DA in the synaptic cleft via the rapid reuptake of DA into the presynaptic terminal. There is strong evidence suggesting that DAT-interacting proteins may have a role in its function and regulation. Performing a two-hybrid screening, we identified snapin, a SNARE-associated protein implicated in synaptic transmission, as a new binding partner of the carboxyl terminal of DAT. Our data show that snapin is a direct partner and regulator of DAT. First, we determined the domains required for this interaction in both proteins and characterized the DAT-snapin interface by generating a 3D model. Using different approaches, we demonstrated that (i) snapin is expressed in vivo in dopaminergic neurons along with DAT; (ii) both proteins colocalize in cultured cells and brain and, (iii) DAT and snapin are present in the same protein complex. Moreover, by functional studies we showed that snapin produces a significant decrease in DAT uptake activity. Finally, snapin downregulation in mice produces an increase in DAT levels and transport activity, hence increasing DA concentration and locomotor response to amphetamine. In conclusion, snapin/DAT interaction represents a direct link between exocytotic and reuptake mechanisms and is a potential target for DA transmission modulation.
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19
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Development of the Swimbladder Surfactant System and Biogenesis of Lysosome-Related Organelles Is Regulated by BLOS1 in Zebrafish. Genetics 2018; 208:1131-1146. [PMID: 29339408 DOI: 10.1534/genetics.117.300621] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Accepted: 01/08/2018] [Indexed: 01/02/2023] Open
Abstract
Hermansky-Pudlak syndrome (HPS) is a human autosomal recessive disorder that is characterized by oculocutaneous albinism and a deficiency of the platelet storage pool resulting from defective biogenesis of lysosome-related organelles (LROs). To date, 10 HPS genes have been identified, three of which belong to the octamer complex BLOC-1 (biogenesis of lysosome-related organelles complex 1). One subunit of the BLOC-1 complex, BLOS1, also participates in the BLOC-1-related complex (BORC). Due to lethality at the early embryo stage in BLOS1 knockout mice, the function of BLOS1 in the above two complexes and whether it has a novel function are unclear. Here, we generated three zebrafish mutant lines with a BLOC-1 deficiency, in which melanin and silver pigment formation was attenuated as a result of mutation of bloc1s1, bloc1s2, and dtnbp1a, suggesting that they function in the same complex. In addition, mutations of bloc1s1 and bloc1s2 caused an accumulation of clusters of lysosomal vesicles at the posterior part of the tectum, representing a BORC-specific function in zebrafish. Moreover, bloc1s1 is highly expressed in the swimbladder during postembryonic stages and is required for positively regulating the expression of the genes, which is known to govern surfactant production and lung development in mammals. Our study identified BLOS1 as a crucial regulator of the surfactant system. Thus, the zebrafish swimbladder might be an easy system to screen and study genetic modifiers that control surfactant production and homeostasis.
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20
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Abstract
Three neurodegenerative diseases [Amyotrophic Lateral Sclerosis (ALS), Parkinson's disease (PD) and Alzheimer's disease (AD)] have many characteristics like pathological mechanisms and genes. In this sense some researchers postulate that these diseases share the same alterations and that one alteration in a specific protein triggers one of these diseases. Analyses of gene expression may shed more light on how to discover pathways, pathologic mechanisms associated with the disease, biomarkers and potential therapeutic targets. In this review, we analyze four microarrays related to three neurodegenerative diseases. We will systematically examine seven genes (CHN1, MDH1, PCP4, RTN1, SLC14A1, SNAP25 and VSNL1) that are altered in the three neurodegenerative diseases. A network was built and used to identify pathways, miRNA and drugs associated with ALS, AD and PD using Cytoscape software an interaction network based on the protein interactions of these genes. The most important affected pathway is PI3K-Akt signalling. Thirteen microRNAs (miRNA-19B1, miRNA-107, miRNA-124-1, miRNA-124-2, miRNA-9-2, miRNA-29A, miRNA-9-3, miRNA-328, miRNA-19B2, miRNA-29B2, miRNA-124-3, miRNA-15A and miRNA-9-1) and four drugs (Estradiol, Acetaminophen, Resveratrol and Progesterone) for new possible treatments were identified.
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Affiliation(s)
| | - Marcelo Alarcón
- Department of Clinical Biochemistry and Immunohematology, Faculty of Health Sciences, Universidad de Talca, Talca 3460000, Chile; Interdisciplinary Excellence Research Program on Healthy Aging (PIEI-ES), Universidad de Talca, Talca 3460000, Chile.
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21
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Kononenko NL, Claßen GA, Kuijpers M, Puchkov D, Maritzen T, Tempes A, Malik AR, Skalecka A, Bera S, Jaworski J, Haucke V. Retrograde transport of TrkB-containing autophagosomes via the adaptor AP-2 mediates neuronal complexity and prevents neurodegeneration. Nat Commun 2017; 8:14819. [PMID: 28387218 PMCID: PMC5385568 DOI: 10.1038/ncomms14819] [Citation(s) in RCA: 102] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Accepted: 02/06/2017] [Indexed: 12/29/2022] Open
Abstract
Autophagosomes primarily mediate turnover of cytoplasmic proteins or organelles to provide nutrients and eliminate damaged proteins. In neurons, autophagosomes form in distal axons and are trafficked retrogradely to fuse with lysosomes in the soma. Although defective neuronal autophagy is associated with neurodegeneration, the function of neuronal autophagosomes remains incompletely understood. We show that in neurons, autophagosomes promote neuronal complexity and prevent neurodegeneration in vivo via retrograde transport of brain-derived neurotrophic factor (BDNF)-activated TrkB receptors. p150Glued/dynactin-dependent transport of TrkB-containing autophagosomes requires their association with the endocytic adaptor AP-2, an essential protein complex previously thought to function exclusively in clathrin-mediated endocytosis. These data highlight a novel non-canonical function of AP-2 in retrograde transport of BDNF/TrkB-containing autophagosomes in neurons and reveal a causative link between autophagy and BDNF/TrkB signalling. The endocytic adaptor protein complex AP-2 is mostly known for its role in endocytosis and in synaptic vesicle reformation. Here the authors show that AP-2 also mediates retrograde transport of TrkB-containing autophagosomes in neurons; this process promotes neuronal complexity and prevents the degeneration of cortical and thalamic neurons.
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Affiliation(s)
- Natalia L Kononenko
- Leibniz-Institut für Molekulare Pharmakologie, 13125 Berlin, Germany.,NeuroCure Cluster of Excellence, Charité Universitätsmedizin Berlin, 10117 Berlin, Germany.,CECAD Research Center, University of Cologne, 50931 Cologne, Germany
| | - Gala A Claßen
- Leibniz-Institut für Molekulare Pharmakologie, 13125 Berlin, Germany
| | - Marijn Kuijpers
- Leibniz-Institut für Molekulare Pharmakologie, 13125 Berlin, Germany
| | - Dmytro Puchkov
- Leibniz-Institut für Molekulare Pharmakologie, 13125 Berlin, Germany
| | - Tanja Maritzen
- Leibniz-Institut für Molekulare Pharmakologie, 13125 Berlin, Germany
| | - Aleksandra Tempes
- Laboratory of Molecular and Cellular Neurobiology, International Institute of Molecular and Cell Biology, 02-109 Warsaw, Poland
| | - Anna R Malik
- Laboratory of Molecular and Cellular Neurobiology, International Institute of Molecular and Cell Biology, 02-109 Warsaw, Poland
| | - Agnieszka Skalecka
- Laboratory of Molecular and Cellular Neurobiology, International Institute of Molecular and Cell Biology, 02-109 Warsaw, Poland
| | - Sujoy Bera
- CECAD Research Center, University of Cologne, 50931 Cologne, Germany
| | - Jacek Jaworski
- Laboratory of Molecular and Cellular Neurobiology, International Institute of Molecular and Cell Biology, 02-109 Warsaw, Poland
| | - Volker Haucke
- Leibniz-Institut für Molekulare Pharmakologie, 13125 Berlin, Germany.,NeuroCure Cluster of Excellence, Charité Universitätsmedizin Berlin, 10117 Berlin, Germany.,Freie Universität Berlin, Faculty of Biology, Chemistry and Pharmacy, 14195 Berlin, Germany
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22
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The BLOC-1 Subunit Pallidin Facilitates Activity-Dependent Synaptic Vesicle Recycling. eNeuro 2017; 4:eN-NWR-0335-16. [PMID: 28317021 PMCID: PMC5356223 DOI: 10.1523/eneuro.0335-16.2017] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Revised: 01/06/2017] [Accepted: 01/24/2017] [Indexed: 02/02/2023] Open
Abstract
Membrane trafficking pathways must be exquisitely coordinated at synaptic terminals to maintain functionality, particularly during conditions of high activity. We have generated null mutations in the Drosophila homolog of pallidin, a central subunit of the biogenesis of lysosome-related organelles complex-1 (BLOC-1), to determine its role in synaptic development and physiology. We find that Pallidin localizes to presynaptic microtubules and cytoskeletal structures, and that the stability of Pallidin protein is highly dependent on the BLOC-1 components Dysbindin and Blos1. We demonstrate that the rapidly recycling vesicle pool is not sustained during high synaptic activity in pallidin mutants, leading to accelerated rundown and slowed recovery. Following intense activity, we observe a loss of early endosomes and a concomitant increase in tubular endosomal structures in synapses without Pallidin. Together, our data reveal that Pallidin subserves a key role in promoting efficient synaptic vesicle recycling and re-formation through early endosomes during sustained activity.
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23
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Regulation of Synaptic Amyloid-β Generation through BACE1 Retrograde Transport in a Mouse Model of Alzheimer's Disease. J Neurosci 2017; 37:2639-2655. [PMID: 28159908 DOI: 10.1523/jneurosci.2851-16.2017] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2016] [Revised: 01/02/2017] [Accepted: 01/09/2017] [Indexed: 12/20/2022] Open
Abstract
Amyloid-β (Aβ) peptides play a key role in synaptic damage and memory deficits in the early pathogenesis of Alzheimer's disease (AD). Abnormal accumulation of Aβ at nerve terminals leads to synaptic pathology and ultimately to neurodegeneration. β-site amyloid precursor protein (APP) cleaving enzyme 1 (BACE1) is the major neuronal β-secretase for Aβ generation. However, the mechanisms regulating BACE1 distribution in axons and β cleavage of APP at synapses remain largely unknown. Here, we reveal that dynein-Snapin-mediated retrograde transport regulates BACE1 trafficking in axons and APP processing at presynaptic terminals. BACE1 is predominantly accumulated within late endosomes at the synapses of AD-related mutant human APP (hAPP) transgenic (Tg) mice and patient brains. Defective retrograde transport by genetic ablation of snapin in mice recapitulates late endocytic retention of BACE1 and increased APP processing at presynaptic sites. Conversely, overexpressing Snapin facilitates BACE1 trafficking and reduces synaptic BACE1 accumulation by enhancing the removal of BACE1 from distal AD axons and presynaptic terminals. Moreover, elevated Snapin expression via stereotactic hippocampal injections of adeno-associated virus particles in mutant hAPP Tg mouse brains decreases synaptic Aβ levels and ameliorates synapse loss, thus rescuing cognitive impairments associated with hAPP mice. Altogether, our study provides new mechanistic insights into the complex regulation of BACE1 trafficking and presynaptic localization through Snapin-mediated dynein-driven retrograde axonal transport, thereby suggesting a potential approach of modulating Aβ levels and attenuating synaptic deficits in AD.SIGNIFICANCE STATEMENT β-Site amyloid precursor protein (APP) cleaving enzyme 1 (BACE1) trafficking and synaptic localization significantly influence its β secretase activity and amyloid-β (Aβ) production. In AD brains, BACE1 is accumulated within dystrophic neurites, which is thought to augment Aβ-induced synaptotoxicity by Aβ overproduction. However, it remains largely unknown whether axonal transport regulates synaptic APP processing. Here, we demonstrate that Snapin-mediated retrograde transport plays a critical role in removing BACE1 from presynaptic terminals toward the soma, thus reducing synaptic Aβ production. Adeno-associated virus-mediated Snapin overexpression in the hippocampus of mutant hAPP mice significantly decreases synaptic Aβ levels, attenuates synapse loss, and thus rescues cognitive deficits. Our study uncovers a new pathway that controls synaptic APP processing by enhancing axonal BACE1 trafficking, thereby advancing our fundamental knowledge critical for ameliorating Aβ-linked synaptic pathology.
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Tammineni P, Ye X, Feng T, Aikal D, Cai Q. Impaired retrograde transport of axonal autophagosomes contributes to autophagic stress in Alzheimer's disease neurons. eLife 2017; 6. [PMID: 28085665 PMCID: PMC5235353 DOI: 10.7554/elife.21776] [Citation(s) in RCA: 112] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Accepted: 12/22/2016] [Indexed: 12/20/2022] Open
Abstract
Neurons face unique challenges of transporting nascent autophagic vacuoles (AVs) from distal axons toward the soma, where mature lysosomes are mainly located. Autophagy defects have been linked to Alzheimer’s disease (AD). However, the mechanisms underlying altered autophagy remain unknown. Here, we demonstrate that defective retrograde transport contributes to autophagic stress in AD axons. Amphisomes predominantly accumulate at axonal terminals of mutant hAPP mice and AD patient brains. Amyloid-β (Aβ) oligomers associate with AVs in AD axons and interact with dynein motors. This interaction impairs dynein recruitment to amphisomes through competitive interruption of dynein-Snapin motor-adaptor coupling, thus immobilizing them in distal axons. Consistently, deletion of Snapin in mice causes AD-like axonal autophagic stress, whereas overexpressing Snapin in hAPP neurons reduces autophagic accumulation at presynaptic terminals by enhancing AV retrograde transport. Altogether, our study provides new mechanistic insight into AD-associated autophagic stress, thus establishing a foundation for ameliorating axonal pathology in AD. DOI:http://dx.doi.org/10.7554/eLife.21776.001 Alzheimer’s disease is the result of protein fragments called amyloid-β peptides accumulating in the brain and forming clumps. These protein “aggregates” disrupt cellular activities and cause serious problems. To combat this process, healthy cells use a process called autophagy to destroy aggregated proteins. The aggregates are first loaded into structures called autophagosomes that then fuse with cell compartments called lysosomes, which contain enzymes that can break down the proteins. Brain cells called neurons have an unusual shape with branch-like structures and a long projection called an axon that all form off the main cell body. Autophagosomes predominantly form in the axons and need to move toward the cell body where the lysosomes are found. A motor protein called dynein drives the movement of autophagosomes by interacting with an adaptor protein known as Snapin on the surface of these structures. Autophagosomes tend to accumulate within the neurons of individuals with Alzheimer’s disease, but it is not known why. Cai et al. examined the ability of autophagosomes to move to the cell body of neurons from a mouse model of Alzheimer’s disease in which human amyloid-β peptides accumulate in the brain, and in the brains of human patients with Alzheimer’s disease. The experiments show that autophagosomes predominantly accumulate in the axons and at the ends of axons during Alzheimer’s disease. Amyloid-β aggregates associate with autophagosomes in the axons and interact with dynein motors. This disrupts the interaction between dynein and Snapin and impairs dynein binding to the autophagosomes, trapping the autophagosomes in the axons. Increasing the production of Snapin proteins inside the mouse neurons enhances dynein binding to autophagosomes and thus helps these structures move to the cell body. The next step is to investigate whether increasing the ability of autophagosomes to move to the cell body reduces the symptoms of Alzheimer’s disease in the mutant mice. This will help to build a foundation for the future development of new strategies to treat Alzheimer’s disease and other neurodegenerative disorders that are caused by protein aggregates. DOI:http://dx.doi.org/10.7554/eLife.21776.002
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Affiliation(s)
- Prasad Tammineni
- Department of Cell Biology and Neuroscience, Rutgers, The State University of New Jersey, Piscataway, United States
| | - Xuan Ye
- Department of Cell Biology and Neuroscience, Rutgers, The State University of New Jersey, Piscataway, United States
| | - Tuancheng Feng
- Department of Cell Biology and Neuroscience, Rutgers, The State University of New Jersey, Piscataway, United States
| | - Daniyal Aikal
- Department of Cell Biology and Neuroscience, Rutgers, The State University of New Jersey, Piscataway, United States
| | - Qian Cai
- Department of Cell Biology and Neuroscience, Rutgers, The State University of New Jersey, Piscataway, United States
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Zhou W, He Q, Zhang C, He X, Cui Z, Liu F, Li W. BLOS2 negatively regulates Notch signaling during neural and hematopoietic stem and progenitor cell development. eLife 2016; 5. [PMID: 27719760 PMCID: PMC5094856 DOI: 10.7554/elife.18108] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Accepted: 10/04/2016] [Indexed: 12/28/2022] Open
Abstract
Notch signaling plays a crucial role in controling the proliferation and differentiation of stem and progenitor cells during embryogenesis or organogenesis, but its regulation is incompletely understood. BLOS2, encoded by the Bloc1s2 gene, is a shared subunit of two lysosomal trafficking complexes, biogenesis of lysosome-related organelles complex-1 (BLOC-1) and BLOC-1-related complex (BORC). Bloc1s2-/- mice were embryonic lethal and exhibited defects in cortical development and hematopoiesis. Loss of BLOS2 resulted in elevated Notch signaling, which consequently increased the proliferation of neural progenitor cells and inhibited neuronal differentiation in cortices. Likewise, ablation of bloc1s2 in zebrafish or mice led to increased hematopoietic stem and progenitor cell production in the aorta-gonad-mesonephros region. BLOS2 physically interacted with Notch1 in endo-lysosomal trafficking of Notch1. Our findings suggest that BLOS2 is a novel negative player in regulating Notch signaling through lysosomal trafficking to control multiple stem and progenitor cell homeostasis in vertebrates.
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Affiliation(s)
- Wenwen Zhou
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Qiuping He
- University of Chinese Academy of Sciences, Beijing, China.,State Key Laboratory of Membrane Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Chunxia Zhang
- University of Chinese Academy of Sciences, Beijing, China.,State Key Laboratory of Membrane Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Xin He
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Zongbin Cui
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Beijing, China
| | - Feng Liu
- University of Chinese Academy of Sciences, Beijing, China.,State Key Laboratory of Membrane Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Wei Li
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China.,Center for Medical Genetics, Beijing Children's Hospital, Capital Medical University, Beijing, China.,Center of Alzheimer's Disease, Beijing Institute for Brain Disorders, Beijing, China.,MOE Key Laboratory of Major Diseases in Children, Beijing, China.,Beijing Pediatric Research Institute, Beijing, China
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Somanath S, Partridge CJ, Marshall C, Rowe T, Turner MD. Snapin mediates insulin secretory granule docking, but not trans-SNARE complex formation. Biochem Biophys Res Commun 2016; 473:403-7. [DOI: 10.1016/j.bbrc.2016.02.123] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Accepted: 02/29/2016] [Indexed: 10/22/2022]
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Pu J, Schindler C, Jia R, Jarnik M, Backlund P, Bonifacino JS. BORC, a multisubunit complex that regulates lysosome positioning. Dev Cell 2015; 33:176-88. [PMID: 25898167 DOI: 10.1016/j.devcel.2015.02.011] [Citation(s) in RCA: 252] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2014] [Revised: 01/14/2015] [Accepted: 02/11/2015] [Indexed: 01/10/2023]
Abstract
The positioning of lysosomes within the cytoplasm is emerging as a critical determinant of many lysosomal functions. Here we report the identification of a multisubunit complex named BORC that regulates lysosome positioning. BORC comprises eight subunits, some of which are shared with the BLOC-1 complex involved in the biogenesis of lysosome-related organelles, and the others of which are products of previously uncharacterized open reading frames. BORC associates peripherally with the lysosomal membrane, where it functions to recruit the small GTPase Arl8. This initiates a chain of interactions that promotes the kinesin-dependent movement of lysosomes toward the plus ends of microtubules in the peripheral cytoplasm. Interference with BORC or other components of this pathway results in collapse of the lysosomal population into the pericentriolar region. In turn, this causes reduced cell spreading and migration, highlighting the importance of BORC-dependent centrifugal transport for non-degradative functions of lysosomes.
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Affiliation(s)
- Jing Pu
- Cell Biology and Metabolism Program, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Christina Schindler
- Cell Biology and Metabolism Program, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Rui Jia
- Cell Biology and Metabolism Program, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Michal Jarnik
- Cell Biology and Metabolism Program, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Peter Backlund
- Biomedical Mass Spectrometry Facility, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Juan S Bonifacino
- Cell Biology and Metabolism Program, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA.
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Di Giovanni J, Sheng ZH. Regulation of synaptic activity by snapin-mediated endolysosomal transport and sorting. EMBO J 2015; 34:2059-77. [PMID: 26108535 DOI: 10.15252/embj.201591125] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2015] [Accepted: 05/29/2015] [Indexed: 11/09/2022] Open
Abstract
Recycling synaptic vesicles (SVs) transit through early endosomal sorting stations, which raises a fundamental question: are SVs sorted toward endolysosomal pathways? Here, we used snapin mutants as tools to assess how endolysosomal sorting and trafficking impact presynaptic activity in wild-type and snapin(-/-) neurons. Snapin acts as a dynein adaptor that mediates the retrograde transport of late endosomes (LEs) and interacts with dysbindin, a subunit of the endosomal sorting complex BLOC-1. Expressing dynein-binding defective snapin mutants induced SV accumulation at presynaptic terminals, mimicking the snapin(-/-) phenotype. Conversely, over-expressing snapin reduced SV pool size by enhancing SV trafficking to the endolysosomal pathway. Using a SV-targeted Ca(2+) sensor, we demonstrate that snapin-dysbindin interaction regulates SV positional priming through BLOC-1/AP-3-dependent sorting. Our study reveals a bipartite regulation of presynaptic activity by endolysosomal trafficking and sorting: LE transport regulates SV pool size, and BLOC-1/AP-3-dependent sorting fine-tunes the Ca(2+) sensitivity of SV release. Therefore, our study provides new mechanistic insights into the maintenance and regulation of SV pool size and synchronized SV fusion through snapin-mediated LE trafficking and endosomal sorting.
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Affiliation(s)
- Jerome Di Giovanni
- Synaptic Functions Section, The Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
| | - Zu-Hang Sheng
- Synaptic Functions Section, The Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
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29
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Hao Z, Wei L, Feng Y, Chen X, Du W, Ma J, Zhou Z, Chen L, Li W. Impaired maturation of large dense core vesicles in muted-deficient adrenal chromaffin cells. J Cell Sci 2015; 128:1365-74. [DOI: 10.1242/jcs.161414] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
The large dense-core vesicle (LDCV), a type of lysosome-related organelle, is involved in the secretion of hormones and neuropeptides in specialized secretory cells. The granin family is a driving force in LDCV biogenesis, but the machinery for granin sorting to this biogenesis pathway is largely unknown. The mu mutant mouse, which carries a spontaneous null mutation on the Muted gene (also known as Bloc1s5) that encodes a subunit of lysosome-related organelles complex-1 (BLOC-1), is a mouse model of Hermansky-Pudlak syndrome. We here found that LDCVs were enlarged in mu adrenal chromaffin cells. Chromogranin A (CgA) was increased in mu adrenals and muted-knockdown cells. The increased CgA in mu mice was likely due to the failure of its sorting-out, which impairs LDCV maturation and docking. In mu chromaffin cells, the size of readily releasable pool and the vesicle release frequency were reduced. Our studies suggest that the muted protein is involved in the sorting-out of CgA during the biogenesis of LDCVs.
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30
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Abstract
Protein Interacting with C Kinase 1 (PICK1) is a Bin/Amphiphysin/Rvs (BAR) domain protein involved in AMPA receptor trafficking. Here, we identify a selective role for PICK1 in the biogenesis of large, dense core vesicles (LDCVs) in mouse chromaffin cells. PICK1 colocalized with syntaxin-6, a marker for immature granules. In chromaffin cells isolated from a PICK1 knockout (KO) mouse the amount of exocytosis was reduced, while release kinetics and Ca(2+) sensitivity were unaffected. Vesicle-fusion events had a reduced frequency and released lower amounts of transmitter per vesicle (i.e., reduced quantal size). This was paralleled by a reduction in the mean single-vesicle capacitance, estimated by averaging time-locked capacitance traces. EM confirmed that LDCVs were fewer and of markedly reduced size in the PICK1 KO, demonstrating that all phenotypes can be explained by reductions in vesicle number and size, whereas the fusion competence of generated vesicles was unaffected by the absence of PICK1. Viral rescue experiments demonstrated that long-term re-expression of PICK1 is necessary to restore normal vesicular content and secretion, while short-term overexpression is ineffective, consistent with an upstream role for PICK1. Disrupting lipid binding of the BAR domain (2K-E mutation) or of the PDZ domain (CC-GG mutation) was sufficient to reproduce the secretion phenotype of the null mutant. The same mutations are known to eliminate PICK1 function in receptor trafficking, indicating that the multiple functions of PICK1 involve a conserved mechanism. Summarized, our findings demonstrate that PICK1 functions in vesicle biogenesis and is necessary to maintain normal vesicle numbers and size.
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Zhang A, He X, Zhang L, Yang L, Woodman P, Li W. Biogenesis of lysosome-related organelles complex-1 subunit 1 (BLOS1) interacts with sorting nexin 2 and the endosomal sorting complex required for transport-I (ESCRT-I) component TSG101 to mediate the sorting of epidermal growth factor receptor into endosomal compartments. J Biol Chem 2014; 289:29180-94. [PMID: 25183008 DOI: 10.1074/jbc.m114.576561] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Biogenesis of lysosome-related organelles complex-1 (BLOC-1) is a component of the molecular machinery required for the biogenesis of specialized organelles and lysosomal targeting of cargoes via the endosomal to lysosomal trafficking pathway. BLOS1, one subunit of BLOC-1, is implicated in lysosomal trafficking of membrane proteins. We found that the degradation and trafficking of epidermal growth factor receptor (EGFR) were delayed in BLOS1 knockdown cells, which were rescued through BLOS1 overexpression. A key feature to the delayed EGFR degradation is the accumulation of endolysosomes in BLOS1 knockdown cells or BLOS1 knock-out mouse embryonic fibroblasts. BLOS1 interacted with SNX2 (a retromer subunit) and TSG101 (an endosomal sorting complex required for transport subunit-I) to mediate EGFR lysosomal trafficking. These results suggest that coordination of the endolysosomal trafficking proteins is important for proper targeting of EGFR to lysosomes.
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Affiliation(s)
- Aili Zhang
- From the State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China, the University of Chinese Academy of Sciences, Beijing 100039, China, and
| | - Xin He
- From the State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Ling Zhang
- the Faculty of Life Sciences, University of Manchester, Manchester M13 9PT, United Kingdom
| | - Lin Yang
- From the State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Philip Woodman
- the Faculty of Life Sciences, University of Manchester, Manchester M13 9PT, United Kingdom
| | - Wei Li
- From the State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China,
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32
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Walter AM, Kurps J, de Wit H, Schöning S, Toft-Bertelsen TL, Lauks J, Ziomkiewicz I, Weiss AN, Schulz A, Fischer von Mollard G, Verhage M, Sørensen JB. The SNARE protein vti1a functions in dense-core vesicle biogenesis. EMBO J 2014; 33:1681-97. [PMID: 24902738 DOI: 10.15252/embj.201387549] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
The SNARE protein vti1a is proposed to drive fusion of intracellular organelles, but recent data also implicated vti1a in exocytosis. Here we show that vti1a is absent from mature secretory vesicles in adrenal chromaffin cells, but localizes to a compartment near the trans-Golgi network, partially overlapping with syntaxin-6. Exocytosis is impaired in vti1a null cells, partly due to fewer Ca(2+)-channels at the plasma membrane, partly due to fewer vesicles of reduced size and synaptobrevin-2 content. In contrast, release kinetics and Ca(2+)-sensitivity remain unchanged, indicating that the final fusion reaction leading to transmitter release is unperturbed. Additional deletion of the closest related SNARE, vti1b, does not exacerbate the vti1a phenotype, and vti1b null cells show no secretion defects, indicating that vti1b does not participate in exocytosis. Long-term re-expression of vti1a (days) was necessary for restoration of secretory capacity, whereas strong short-term expression (hours) was ineffective, consistent with vti1a involvement in an upstream step related to vesicle generation, rather than in fusion. We conclude that vti1a functions in vesicle generation and Ca(2+)-channel trafficking, but is dispensable for transmitter release.
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Affiliation(s)
- Alexander M Walter
- Neurosecretion Group, Department of Neuroscience and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark Department of Functional Genomics and Clinical Genetics, Center for Neurogenomics and Cognitive Research, VU University Amsterdam and VU Medical Center, Amsterdam, The Netherlands
| | - Julia Kurps
- Department of Functional Genomics and Clinical Genetics, Center for Neurogenomics and Cognitive Research, VU University Amsterdam and VU Medical Center, Amsterdam, The Netherlands
| | - Heidi de Wit
- Department of Functional Genomics and Clinical Genetics, Center for Neurogenomics and Cognitive Research, VU University Amsterdam and VU Medical Center, Amsterdam, The Netherlands
| | - Susanne Schöning
- Biochemie III, Fakultät für Chemie, Universität Bielefeld, Bielefeld, Germany
| | - Trine L Toft-Bertelsen
- Neurosecretion Group, Department of Neuroscience and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Juliane Lauks
- Department of Functional Genomics and Clinical Genetics, Center for Neurogenomics and Cognitive Research, VU University Amsterdam and VU Medical Center, Amsterdam, The Netherlands
| | - Iwona Ziomkiewicz
- Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Annita N Weiss
- Department of Pharmacology, University of Michigan, Ann Arbor, MI, USA
| | - Alexander Schulz
- Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg, Denmark
| | | | - Matthijs Verhage
- Department of Functional Genomics and Clinical Genetics, Center for Neurogenomics and Cognitive Research, VU University Amsterdam and VU Medical Center, Amsterdam, The Netherlands
| | - Jakob B Sørensen
- Neurosecretion Group, Department of Neuroscience and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark Lundbeck Foundation Center for Biomembranes in Nanomedicine, University of Copenhagen, Copenhagen, Denmark
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Chlamydia psittaci inclusion membrane protein IncB associates with host protein Snapin. Int J Med Microbiol 2014; 304:542-53. [PMID: 24751478 DOI: 10.1016/j.ijmm.2014.03.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2013] [Revised: 03/21/2014] [Accepted: 03/24/2014] [Indexed: 11/23/2022] Open
Abstract
Chlamydia (C.) psittaci, the causative agent of psittacosis in birds and humans, is the most important zoonotic pathogen of the family Chlamydiaceae. During a unique developmental cycle of this obligate intracellular pathogen, the infectious elementary body gains access to the susceptible host cell, where it transforms into the replicative reticulate body. C. psittaci uses dynein motor proteins for optimal early development. Chlamydial proteins that mediate this process are unknown. Two-hybrid screening with the C. psittaci inclusion protein IncB as bait against a HeLa Yeast Two-hybrid (YTH) library revealed that the host protein Snapin interacts with IncB. Snapin is a cytoplasmic protein that plays a multivalent role in intracellular trafficking. Confocal fluorescence microscopy using an IncB-specific antibody demonstrated that IncB, Snapin, and dynein were co-localized near the inclusion of C. psittaci-infected HEp-2 cells. This co-localization was lost when Snapin was depleted by RNAi. The interaction of Snapin with both IncB and dynein has been shown in vitro and in vivo. We propose that Snapin connects chlamydial inclusions with the microtubule network by interacting with both IncB and dynein.
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Han M, Xiao X, Yang Y, Huang RY, Cao H, Zhao ZQ, Zhang YQ. SIP30 is required for neuropathic pain-evoked aversion in rats. J Neurosci 2014; 34:346-55. [PMID: 24403136 PMCID: PMC6608160 DOI: 10.1523/jneurosci.3160-13.2014] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2013] [Revised: 11/04/2013] [Accepted: 11/07/2013] [Indexed: 11/21/2022] Open
Abstract
SIP30 (SNAP25 interacting protein of 30) is a SNAP25 interaction protein of 30 kDa that functions in neurotransmitter release. Using a chronic constriction injury (CCI) model of neuropathic pain, we profiled gene expression in the rat spinal cord and brain and identified sip30, which was upregulated after CCI. Here, we show that CCI induced a bilateral increase of SIP30 in the rostral anterior cingulate cortex (rACC), a key brain region that has been implicated in pain affect. We put rats in a chamber with one half painted white (light area) and the other half painted black (dark area), and measured neuropathic pain-evoked place escape/avoidance paradigm (PEAP) to quantify the level of negative emotion evoked by painful stimuli using a Von Frey hair. Inhibition of CCI-mediated induction of SIP30 by intra-rACC injection of shRNA targeting the rat sip30 gene reduced PEAP. Interestingly, knockdown of SIP30 did not affect CCI-induced evoked pain such as heat hyperalgesia and mechanical allodynia. Neither did it affect general learning and memory. CCI-induced upregulation of SIP30 was correlated with activation of ERK, PKA, and CREB in the rACC. Intra-rACC administration of PKA or ERK inhibitors suppressed CCI-induced SIP30 upregulation and blocked the induction of PEAP. Additionally, knockdown of SIP30 suppressed the frequency of mEPSCs and increased paired-pulse ratios in rACC slices and decreased extracellular glutamate concentrations. Together, our results highlight SIP30 as a target of PKA and ERK in the rACC to mediate neuropathic pain-evoked negative emotion via modulation of glutamate release and excitatory synaptic transmission.
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Affiliation(s)
- Mei Han
- Institute of Neurobiology, Institutes of Brain Science and State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai 200032, China, and
| | - Xiao Xiao
- Institute of Neurobiology, Institutes of Brain Science and State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai 200032, China, and
| | - Yan Yang
- Institute of Neurobiology, Institutes of Brain Science and State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai 200032, China, and
| | - Ru-Yi Huang
- Department of Life Science, Fudan University, Shanghai 200433, China
| | - Hong Cao
- Institute of Neurobiology, Institutes of Brain Science and State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai 200032, China, and
| | - Zhi-Qi Zhao
- Institute of Neurobiology, Institutes of Brain Science and State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai 200032, China, and
| | - Yu-Qiu Zhang
- Institute of Neurobiology, Institutes of Brain Science and State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai 200032, China, and
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Abstract
Large dense core vesicle (LDCV) exocytosis in chromaffin cells follows a well characterized process consisting of docking, priming, and fusion. Total internal reflection fluorescence microscopy (TIRFM) studies suggest that some LDCVs, although being able to dock, are resistant to calcium-triggered release. This phenomenon termed dead-end docking has not been investigated until now. We characterized dead-end vesicles using a combination of membrane capacitance measurement and visualization of LDCVs with TIRFM. Stimulation of bovine chromaffin cells for 5 min with 6 μm free intracellular Ca2+ induced strong secretion and a large reduction of the LDCV density at the plasma membrane. Approximately 15% of the LDCVs were visible at the plasma membrane throughout experiments, indicating they were permanently docked dead-end vesicles. Overexpression of Munc18-2 or SNAP-25 reduced the fraction of dead-end vesicles. Conversely, expressing open-syntaxin increased the fraction of dead-end vesicles. These results indicate the existence of the unproductive target soluble N-ethylmaleimide-sensitive factor attachment protein receptor acceptor complex composed of 2:1 syntaxin-SNAP-25 in vivo. More importantly, they define a novel function for this acceptor complex in mediating dead-end docking.
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Snapin, positive regulator of stimulation- induced Ca²⁺ release through RyR, is necessary for HIV-1 replication in T cells. PLoS One 2013; 8:e75297. [PMID: 24130701 PMCID: PMC3794929 DOI: 10.1371/journal.pone.0075297] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2013] [Accepted: 08/13/2013] [Indexed: 11/20/2022] Open
Abstract
To identify critical host factors necessary for human immunodeficiency virus 1 (HIV-1) replication, large libraries of short-peptide-aptamers were expressed retrovirally. The target of one inhibitor peptide, Pep80, identified in this screen was determined to be Snapin, a protein associated with the soluble N-ethyl maleimide sensitive factor adaptor protein receptor (SNARE) complex that is critical for calcium-dependent exocytosis during neurotransmission. Pep80 inhibited Ca2+ release from intracellular stores and blocked downstream signaling by direct interruption of the association between Snapin and an intracellular calcium release channel, the ryanodine receptor (RyR). NFAT signaling was preferentially abolished by Pep80. Expression of Snapin overcame Pep80-mediated inhibition of Ca2+/NFAT signaling and HIV-1 replication. Furthermore, Snapin induced HIV-1 replication in primary CD4+ T cells. Thus, through its interaction with RyR, Snapin is a critical regulator of Ca2+ signaling and T cell activation. Use of the genetically selected intracellular aptamer inhibitors allowed us to define unique mechanisms important to HIV-1 replication and T cell biology.
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LRRK2 phosphorylates Snapin and inhibits interaction of Snapin with SNAP-25. Exp Mol Med 2013; 45:e36. [PMID: 23949442 PMCID: PMC3789260 DOI: 10.1038/emm.2013.68] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2012] [Revised: 05/20/2013] [Accepted: 06/10/2013] [Indexed: 01/17/2023] Open
Abstract
Leucine-rich repeat kinase 2 (LRRK2) is a gene that, upon mutation, causes autosomal-dominant familial Parkinson's disease (PD). Yeast two-hybrid screening revealed that Snapin, a SNAP-25 (synaptosomal-associated protein-25) interacting protein, interacts with LRRK2. An in vitro kinase assay exhibited that Snapin is phosphorylated by LRRK2. A glutathione-S-transferase (GST) pull-down assay showed that LRRK2 may interact with Snapin via its Ras-of-complex (ROC) and N-terminal domains, with no significant difference on interaction of Snapin with LRRK2 wild type (WT) or its pathogenic mutants. Further analysis by mutation study revealed that Threonine 117 of Snapin is one of the sites phosphorylated by LRRK2. Furthermore, a Snapin T117D phosphomimetic mutant decreased its interaction with SNAP-25 in the GST pull-down assay. SNAP-25 is a component of the SNARE (Soluble NSF Attachment protein REceptor) complex and is critical for the exocytosis of synaptic vesicles. Incubation of rat brain lysate with recombinant Snapin T117D, but not WT, protein caused decreased interaction of synaptotagmin with the SNARE complex based on a co-immunoprecipitation assay. We further found that LRRK2-dependent phosphorylation of Snapin in the hippocampal neurons resulted in a decrease in the number of readily releasable vesicles and the extent of exocytotic release. Combined, these data suggest that LRRK2 may regulate neurotransmitter release via control of Snapin function by inhibitory phosphorylation.
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Snapin accelerates exocytosis at low intracellular calcium concentration in mouse chromaffin cells. Cell Calcium 2013; 54:105-10. [DOI: 10.1016/j.ceca.2013.05.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2013] [Revised: 04/30/2013] [Accepted: 05/03/2013] [Indexed: 11/20/2022]
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Saggu S, Cannon TD, Jentsch JD, Lavin A. Potential molecular mechanisms for decreased synaptic glutamate release in dysbindin-1 mutant mice. Schizophr Res 2013; 146:254-63. [PMID: 23473812 PMCID: PMC3628687 DOI: 10.1016/j.schres.2013.01.037] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2012] [Revised: 01/28/2013] [Accepted: 01/30/2013] [Indexed: 01/14/2023]
Abstract
Behavioral genetic studies of humans have associated variation in the DTNBP1 gene with schizophrenia and its cognitive deficit phenotypes. The protein encoded by DTNBP1, dysbindin-1, is expressed in forebrain neurons where it interacts with proteins mediating vesicular trafficking and exocytosis. It has been shown that loss of dysbindin-1 results in a decrease in glutamate release in the prefrontal cortex; however the mechanisms underlying this decrease are not fully understood. In order to investigate this question, we evaluated dysbindin-1 null mutant mice, using electrophysiological recordings of prefrontal cortical neurons, imaging studies of vesicles, calcium dynamics and Western blot measures of synaptic proteins and Ca(2+) channels. Dysbindin-1 null mice showed a decrease in the ready releasable pool of synaptic vesicles, decreases in quantal size, decreases in the probability of release and deficits in the rate of endo- and exocytosis compared with wild-type controls. Moreover, the dysbindin-1 null mice show decreases in the [Ca(2+)]i,expression of L- and N-type Ca(2+)channels and several proteins involved in synaptic vesicle trafficking and priming. Our results provide new insights into the mechanisms of action of dysbindin-1.
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Affiliation(s)
- Shalini Saggu
- Dept of Neuroscience, Medical University of South Carolina, Charleston, SC
| | - Tyrone D. Cannon
- Depts of Psychology and Psychiatry & Biobehavioral Sciences, University of California, Los Angeles, CA
| | - J. David Jentsch
- Dept of Human Genetics, University of California, Los Angeles, CA
| | - Antonieta Lavin
- Dept of Neuroscience, Medical University of South Carolina, Charleston, SC
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Yu SC, Klosterman SM, Martin AA, Gracheva EO, Richmond JE. Differential roles for snapin and synaptotagmin in the synaptic vesicle cycle. PLoS One 2013; 8:e57842. [PMID: 23469084 PMCID: PMC3585204 DOI: 10.1371/journal.pone.0057842] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2012] [Accepted: 01/29/2013] [Indexed: 11/19/2022] Open
Abstract
Evoked synaptic transmission is dependent on interactions between the calcium sensor Synaptotagmin I and the SNARE complex, comprised of Syntaxin, SNAP-25, and Synaptobrevin. Recent evidence suggests that Snapin may be an important intermediate in this process, through simultaneous interactions of Snapin dimers with SNAP-25 and Synaptotagmin. In support of this model, cultured neurons derived from embryonically lethal Snapin null mutant mice exhibit desynchronized release and a reduced readily releasable vesicle pool. Based on evidence that a dimerization-defective Snapin mutation specifically disrupts priming, Snapin is hypothesized to stabilize primed vesicles by structurally coupling Synaptotagmin and SNAP-25. To explore this model in vivo we examined synaptic transmission in viable, adult C. elegans Snapin (snpn-1) mutants. The kinetics of synaptic transmission were unaffected at snpn-1 mutant neuromuscular junctions (NMJs), but the number of docked, fusion competent vesicles was significantly reduced. However, analyses of snt-1 and snt-1;snpn-1 double mutants suggest that the docking role of SNPN-1 is independent of Synaptotagmin. Based on these results we propose that the primary role of Snapin in C. elegans is to promote vesicle priming, consistent with the stabilization of SNARE complex formation through established interactions with SNAP-25 upstream of the actions of Synaptotagmin in calcium-sensing and endocytosis.
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Affiliation(s)
- Szi-Chieh Yu
- Biological Sciences, University of Illinois at Chicago, Chicago, Illinois, United States of America
| | - Susan M. Klosterman
- Biological Sciences, University of Illinois at Chicago, Chicago, Illinois, United States of America
| | - Ashley A. Martin
- Biological Sciences, University of Illinois at Chicago, Chicago, Illinois, United States of America
| | - Elena O. Gracheva
- Biological and Biomedical Sciences, Yale University, New Haven, Connecticut, United States of America
| | - Janet E. Richmond
- Biological Sciences, University of Illinois at Chicago, Chicago, Illinois, United States of America
- * E-mail:
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41
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Wheeler A, Smith HS. Botulinum toxins: mechanisms of action, antinociception and clinical applications. Toxicology 2013; 306:124-46. [PMID: 23435179 DOI: 10.1016/j.tox.2013.02.006] [Citation(s) in RCA: 103] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2012] [Revised: 02/07/2013] [Accepted: 02/10/2013] [Indexed: 10/27/2022]
Abstract
Botulinum toxin (BoNT) is a potent neurotoxin that is produced by the gram-positive, spore-forming, anaerobic bacterium, Clostridum botulinum. There are 7 known immunologically distinct serotypes of BoNT: types A, B, C1, D, E, F, and G. Clostridum neurotoxins are produced as a single inactive polypeptide chain of 150kDa, which is cleaved by tissue proteinases into an active di-chain molecule: a heavy chain (H) of ∼100 kDa and a light chain (L) of ∼50 kDa held together by a single disulfide bond. Each serotype demonstrates its own varied mechanisms of action and duration of effect. The heavy chain of each BoNT serotype binds to its specific neuronal ecto-acceptor, whereby, membrane translocation and endocytosis by intracellular synaptic vesicles occurs. The light chain acts to cleave SNAP-25, which inhibits synaptic exocytosis, and therefore, disables neural transmission. The action of BoNT to block the release of acetylcholine botulinum toxin at the neuromuscular junction is best understood, however, most experts acknowledge that this effect alone appears inadequate to explain the entirety of the neurotoxin's apparent analgesic activity. Consequently, scientific and clinical evidence has emerged that suggests multiple antinociceptive mechanisms for botulinum toxins in a variety of painful disorders, including: chronic musculoskeletal, neurological, pelvic, perineal, osteoarticular, and some headache conditions.
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Affiliation(s)
- Anthony Wheeler
- The Neurological Institute, 2219 East 7th Street, Charlotte, NC 28204, United States.
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Zhang Q, Li Y, Zhang L, Yang N, Meng J, Zuo P, Zhang Y, Chen J, Wang L, Gao X, Zhu D. E3 ubiquitin ligase RNF13 involves spatial learning and assembly of the SNARE complex. Cell Mol Life Sci 2013; 70:153-65. [PMID: 22890573 PMCID: PMC11113611 DOI: 10.1007/s00018-012-1103-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2012] [Revised: 07/01/2012] [Accepted: 07/19/2012] [Indexed: 11/26/2022]
Abstract
Changes in the structure and number of synapses modulate learning, memory and cognitive disorders. Ubiquitin-mediated protein modification is a key mechanism for regulating synaptic activity, though the precise control of this process remains poorly understood. RING finger protein 13 (RNF13) is a recently identified E3 ubiquitin ligase, and its in vivo function remains completely unknown. We show here that genetic deletion of RNF13 in mice leads to a significant deficit in spatial learning as determined by the Morris water maze test and Y-maze learning test. At the ultrastructral level, the synaptic vesicle density was decreased and the area of the active zone was increased at hippocampal synapses of RNF13-null mice compared with those of wild-type littermates. We found no change in the levels of SNARE (soluble N-ethylmaleimide-sensitive factor-attachment protein receptor) complex proteins in the hippocampus of RNF13-null mice, but impaired SNARE complex assembly. RNF13 directly interacted with snapin, a SNAP-25-interacting protein. Interestingly, snapin was ubiquitinated by RNF13 via the lysine-29 conjugated polyubiquitin chain, which in turn promoted the association of snapin with SNAP-25. Consistently, we found an attenuated interaction between snapin and SNAP-25 in the RNF13-null mice. Therefore, these results suggest that RNF13 is involved in the regulation of the SNARE complex, which thereby controls synaptic function.
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Affiliation(s)
- Qiang Zhang
- Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, School of Basic Medicine, Peking Union Medical College, Tsinghua University, Beijing, 100005 China
| | - Yanfeng Li
- Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, School of Basic Medicine, Peking Union Medical College, Tsinghua University, Beijing, 100005 China
| | - Lei Zhang
- Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, School of Basic Medicine, Peking Union Medical College, Tsinghua University, Beijing, 100005 China
| | - Nan Yang
- Department of Pharmacology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, School of Basic Medicine, Peking Union Medical College, Tsinghua University, Beijing, 100005 China
| | - Jiao Meng
- Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, School of Basic Medicine, Peking Union Medical College, Tsinghua University, Beijing, 100005 China
| | - Pingping Zuo
- Department of Pharmacology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, School of Basic Medicine, Peking Union Medical College, Tsinghua University, Beijing, 100005 China
| | - Yong Zhang
- Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, School of Basic Medicine, Peking Union Medical College, Tsinghua University, Beijing, 100005 China
| | - Jie Chen
- Department of Pathology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Tsinghua University, Beijing, 100730 China
| | - Li Wang
- Department of Epidemiology and Biostatistics, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, School of Basic Medicine, Peking Union Medical College, Tsinghua University, Beijing, 100005 China
| | - Xiang Gao
- Model Animal Research Center and MOE Key Laboratory of Model Animal for Disease Research, Nanjing University, Nanjing, 210061 China
| | - Dahai Zhu
- Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, School of Basic Medicine, Peking Union Medical College, Tsinghua University, Beijing, 100005 China
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43
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Wei AH, Li W. Hermansky-Pudlak syndrome: pigmentary and non-pigmentary defects and their pathogenesis. Pigment Cell Melanoma Res 2012; 26:176-92. [DOI: 10.1111/pcmr.12051] [Citation(s) in RCA: 91] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2012] [Accepted: 11/16/2012] [Indexed: 10/27/2022]
Affiliation(s)
| | - Wei Li
- State Key Laboratory of Molecular Developmental Biology; Institute of Genetics & Developmental Biology; Chinese Academy of Sciences; Beijing; China
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Kasai H, Takahashi N, Tokumaru H. Distinct Initial SNARE Configurations Underlying the Diversity of Exocytosis. Physiol Rev 2012; 92:1915-64. [DOI: 10.1152/physrev.00007.2012] [Citation(s) in RCA: 120] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The dynamics of exocytosis are diverse and have been optimized for the functions of synapses and a wide variety of cell types. For example, the kinetics of exocytosis varies by more than five orders of magnitude between ultrafast exocytosis in synaptic vesicles and slow exocytosis in large dense-core vesicles. However, in all cases, exocytosis is mediated by the same fundamental mechanism, i.e., the assembly of soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins. It is often assumed that vesicles need to be docked at the plasma membrane and SNARE proteins must be preassembled before exocytosis is triggered. However, this model cannot account for the dynamics of exocytosis recently reported in synapses and other cells. For example, vesicles undergo exocytosis without prestimulus docking during tonic exocytosis of synaptic vesicles in the active zone. In addition, epithelial and hematopoietic cells utilize cAMP and kinases to trigger slow exocytosis of nondocked vesicles. In this review, we summarize the manner in which the diversity of exocytosis reflects the initial configurations of SNARE assembly, including trans-SNARE, binary-SNARE, unitary-SNARE, and cis-SNARE configurations. The initial SNARE configurations depend on the particular SNARE subtype (syntaxin, SNAP25, or VAMP), priming proteins (Munc18, Munc13, CAPS, complexin, or snapin), triggering proteins (synaptotagmins, Doc2, and various protein kinases), and the submembraneous cytomatrix, and they are the key to determining the kinetics of subsequent exocytosis. These distinct initial configurations will help us clarify the common SNARE assembly processes underlying exocytosis and membrane trafficking in eukaryotic cells.
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Affiliation(s)
- Haruo Kasai
- Laboratory of Structural Physiology, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan; and Faculty of Pharmaceutical Sciences at Kagawa, Tokushima Bunri University, Kagawa, Japan
| | - Noriko Takahashi
- Laboratory of Structural Physiology, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan; and Faculty of Pharmaceutical Sciences at Kagawa, Tokushima Bunri University, Kagawa, Japan
| | - Hiroshi Tokumaru
- Laboratory of Structural Physiology, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan; and Faculty of Pharmaceutical Sciences at Kagawa, Tokushima Bunri University, Kagawa, Japan
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45
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Sato K. Disruption of spine homeostasis causes dopaminergic compensatory up-regulation, resulting in schizophrenia. Med Hypotheses 2012; 79:304-7. [DOI: 10.1016/j.mehy.2012.05.015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2012] [Revised: 04/03/2012] [Accepted: 05/10/2012] [Indexed: 10/28/2022]
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Abstract
The molecular mechanisms underlying the homeostatic modulation of presynaptic neurotransmitter release are largely unknown. We have previously used an electrophysiology-based forward genetic screen to assess the function of >400 neuronally expressed genes for a role in the homeostatic control of synaptic transmission at the neuromuscular junction of Drosophila melanogaster. This screen identified a critical function for dysbindin, a gene linked to schizophrenia in humans (Dickman and Davis, 2009). Biochemical studies in other systems have shown that Snapin interacts with Dysbindin, prompting us to test whether Snapin might be involved in the mechanisms of synaptic homeostasis. Here, we demonstrate that loss of snapin blocks the homeostatic modulation of presynaptic vesicle release following inhibition of postsynaptic glutamate receptors. This is true for both the rapid induction of synaptic homeostasis induced by pharmacological inhibition of postsynaptic glutamate receptors, and the long-term expression of synaptic homeostasis induced by the genetic deletion of the muscle-specific GluRIIA glutamate receptor subunit. Loss of snapin does not alter baseline synaptic transmission, synapse morphology, synapse growth, or the number or density of active zones, indicating that the block of synaptic homeostasis is not a secondary consequence of impaired synapse development. Additional genetic evidence suggests that snapin functions in concert with dysbindin to modulate vesicle release and possibly homeostatic plasticity. Finally, we provide genetic evidence that the interaction of Snapin with SNAP25, a component of the SNARE complex, is also involved in synaptic homeostasis.
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47
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Zhou B, Cai Q, Xie Y, Sheng ZH. Snapin recruits dynein to BDNF-TrkB signaling endosomes for retrograde axonal transport and is essential for dendrite growth of cortical neurons. Cell Rep 2012; 2:42-51. [PMID: 22840395 DOI: 10.1016/j.celrep.2012.06.010] [Citation(s) in RCA: 107] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2012] [Revised: 05/15/2012] [Accepted: 06/11/2012] [Indexed: 01/19/2023] Open
Abstract
Neurotrophin signaling is crucial for neuron growth. While the "signaling endosomes" hypothesis is one of the accepted models, the molecular machinery that drives retrograde axonal transport of TrkB signaling endosomes is largely unknown. In particular, mechanisms recruiting dynein to TrkB signaling endosomes have not been elucidated. Here, using snapin deficient mice and gene rescue experiments combined with compartmentalized cultures of live cortical neurons, we reveal that Snapin, as a dynein adaptor, mediates retrograde axonal transport of TrkB signaling endosomes. Such a role is essential for dendritic growth of cortical neurons. Deleting snapin or disrupting Snapin-dynein interaction abolishes TrkB retrograde transport, impairs BDNF-induced retrograde signaling from axonal terminals to the nucleus, and decreases dendritic growth. Such defects were rescued by reintroducing the snapin gene. Our study indicates that Snapin-dynein coupling is one of the primary mechanisms driving BDNF-TrkB retrograde transport, thus providing mechanistic insights into the regulation of neuronal growth and survival.
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Affiliation(s)
- Bing Zhou
- Synaptic Functions Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Building 35, Room 2B-215, 35 Convent Drive, Bethesda, MD 20892-3706, USA
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Yang Q, He X, Yang L, Zhou Z, Cullinane AR, Wei A, Zhang Z, Hao Z, Zhang A, He M, Feng Y, Gao X, Gahl WA, Huizing M, Li W. The BLOS1-interacting protein KXD1 is involved in the biogenesis of lysosome-related organelles. Traffic 2012; 13:1160-9. [PMID: 22554196 DOI: 10.1111/j.1600-0854.2012.01375.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2011] [Revised: 04/30/2012] [Accepted: 05/03/2012] [Indexed: 12/24/2022]
Abstract
Biogenesis of lysosome-related organelles (LROs) complex-1 (BLOC-1) is an eight-subunit complex involved in lysosomal trafficking. Interacting proteins of these subunits expand the understanding of its biological functions. With the implementation of the naïve Bayesian analysis, we found that a human uncharacterized 20 kDa coiled-coil KxDL protein, KXD1, is a BLOS1-interacting protein. In vitro binding assays confirmed the interaction between BLOS1 and KXD1. The mouse KXD1 homolog was widely expressed and absent in Kxd1 knockout (KO) mice. BLOS1 was apparently reduced in Kxd1-KO mice. Mild defects in the melanosomes of the retinal pigment epithelia and in the platelet dense granules of the Kxd1-KO mouse were observed, mimicking a mouse model of mild Hermansky-Pudlak syndrome that affects the biogenesis of LROs.
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Affiliation(s)
- Qing Yang
- State Key Laboratory of Molecular and Developmental Biology, Institute of Genetics & Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
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Navarro A, Encinar JA, López-Méndez B, Aguado-Llera D, Prieto J, Gómez J, Martínez-Cruz LA, Millet O, González-Ros JM, Fernández-Ballester G, Neira JL, Ferrer-Montiel A. Mutation of Ser-50 and Cys-66 in Snapin Modulates Protein Structure and Stability. Biochemistry 2012; 51:3470-84. [DOI: 10.1021/bi201574t] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Aaron Navarro
- Instituto de Biología Molecular
y Celular, Universidad Miguel Hernández, 03202 Elche, Spain
| | - José A. Encinar
- Instituto de Biología Molecular
y Celular, Universidad Miguel Hernández, 03202 Elche, Spain
| | | | - David Aguado-Llera
- Instituto de Biología Molecular
y Celular, Universidad Miguel Hernández, 03202 Elche, Spain
| | - Jesús Prieto
- Departamento de Biología
Estructural y Biocomputación, CNIO, 28029 Madrid, Spain
| | - Javier Gómez
- Instituto de Biología Molecular
y Celular, Universidad Miguel Hernández, 03202 Elche, Spain
| | | | - Oscar Millet
- Structural
Biology Unit, CIC bioGUNE, 48160 Derio,
Spain
| | | | | | - José L. Neira
- Instituto de Biología Molecular
y Celular, Universidad Miguel Hernández, 03202 Elche, Spain
- Complex Systems Physics Institute, 50009
Zaragoza, Spain
| | - Antonio Ferrer-Montiel
- Instituto de Biología Molecular
y Celular, Universidad Miguel Hernández, 03202 Elche, Spain
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50
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Larimore J, Tornieri K, Ryder PV, Gokhale A, Zlatic SA, Craige B, Lee JD, Talbot K, Pare JF, Smith Y, Faundez V. The schizophrenia susceptibility factor dysbindin and its associated complex sort cargoes from cell bodies to the synapse. Mol Biol Cell 2011; 22:4854-67. [PMID: 21998198 PMCID: PMC3237628 DOI: 10.1091/mbc.e11-07-0592] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2011] [Revised: 09/08/2011] [Accepted: 10/07/2011] [Indexed: 11/11/2022] Open
Abstract
Dysbindin assembles into the biogenesis of lysosome-related organelles complex 1 (BLOC-1), which interacts with the adaptor protein complex 3 (AP-3), mediating a common endosome-trafficking route. Deficiencies in AP-3 and BLOC-1 affect synaptic vesicle composition. However, whether AP-3-BLOC-1-dependent sorting events that control synapse membrane protein content take place in cell bodies upstream of nerve terminals remains unknown. We tested this hypothesis by analyzing the targeting of phosphatidylinositol-4-kinase type II α (PI4KIIα), a membrane protein present in presynaptic and postsynaptic compartments. PI4KIIα copurified with BLOC-1 and AP-3 in neuronal cells. These interactions translated into a decreased PI4KIIα content in the dentate gyrus of dysbindin-null BLOC-1 deficiency and AP-3-null mice. Reduction of PI4KIIα in the dentate reflects a failure to traffic from the cell body. PI4KIIα was targeted to processes in wild-type primary cultured cortical neurons and PC12 cells but failed to reach neurites in cells lacking either AP-3 or BLOC-1. Similarly, disruption of an AP-3-sorting motif in PI4KIIα impaired its sorting into processes of PC12 and primary cultured cortical neuronal cells. Our findings indicate a novel vesicle transport mechanism requiring BLOC-1 and AP-3 complexes for cargo sorting from neuronal cell bodies to neurites and nerve terminals.
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Affiliation(s)
| | - Karine Tornieri
- Department of Cell Biology, Emory University, Atlanta, GA 30322
| | - Pearl V. Ryder
- Department of Cell Biology, Emory University, Atlanta, GA 30322
- Graduate Program in Biochemistry, Cell, and Developmental Biology, Emory University, Atlanta, GA 30322
| | - Avanti Gokhale
- Department of Cell Biology, Emory University, Atlanta, GA 30322
| | - Stephanie A. Zlatic
- Department of Cell Biology, Emory University, Atlanta, GA 30322
- Graduate Program in Biochemistry, Cell, and Developmental Biology, Emory University, Atlanta, GA 30322
| | - Branch Craige
- Department of Cell Biology, Emory University, Atlanta, GA 30322
- Graduate Program in Biochemistry, Cell, and Developmental Biology, Emory University, Atlanta, GA 30322
| | - Joshua D. Lee
- Center for Neurobiology and Behavior, Department of Psychiatry, University of Pennsylvania, Philadelphia, PA 19104
| | - Konrad Talbot
- Center for Neurobiology and Behavior, Department of Psychiatry, University of Pennsylvania, Philadelphia, PA 19104
| | | | - Yoland Smith
- Department of Neurology and Yerkes National Primate Research Center
| | - Victor Faundez
- Department of Cell Biology, Emory University, Atlanta, GA 30322
- Graduate Program in Biochemistry, Cell, and Developmental Biology, Emory University, Atlanta, GA 30322
- Center for Neurodegenerative Disease, Emory University, Atlanta, GA 30322
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