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Richens JH, Dmitrieva M, Zenner HL, Muschalik N, Butler R, Glashauser J, Camelo C, Luschnig S, Munro S, Rittscher J, St Johnston D. MSP-tracker: A versatile vesicle tracking software tool used to reveal the spatial control of polarized secretion in Drosophila epithelial cells. PLoS Biol 2025; 23:e3003099. [PMID: 40208901 PMCID: PMC12021295 DOI: 10.1371/journal.pbio.3003099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2024] [Revised: 04/24/2025] [Accepted: 03/05/2025] [Indexed: 04/12/2025] Open
Abstract
Understanding how specific secretory cargoes are targeted to distinct domains of the plasma membrane in epithelial cells requires analyzing the trafficking of post-Golgi vesicles to their sites of secretion. We used the RUSH (retention using selective hooks) system to synchronously release an apical cargo, Cadherin 99C (Cad99C), and a basolateral cargo, the ECM protein Nidogen, from the endoplasmic reticulum and followed their movements to the plasma membrane. We also developed an interactive vesicle tracking framework, MSP-tracker and viewer, that exploits developments in computer vision and deep learning to determine vesicle trajectories in a noisy environment without the need for extensive training data. MSP-tracker outperformed other tracking software in detecting and tracking post-Golgi vesicles, revealing that Cad99c vesicles predominantly move apically with a mean speed of 1.1µm/sec. This is reduced to 0.85 µm/sec by a dominant slow dynein mutant, demonstrating that dynein transports Cad99C vesicles to the apical cortex. Furthermore, both the dynein mutant and microtubule depolymerization cause lateral Cad99C secretion. Thus, microtubule organization plays a central role in targeting apical secretion, suggesting that Drosophila does not have distinct apical versus basolateral vesicle fusion machinery. Nidogen vesicles undergo planar-polarized transport to the leading edge of follicle cells as they migrate over the ECM, whereas most Collagen is secreted at trailing edges. The follicle cells therefore bias secretion of different ECM components to opposite sides of the cell, revealing that the secretory pathway is more spatially organized than previously thought.
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Affiliation(s)
- Jennifer H. Richens
- The Gurdon Institute and the Department of Genetics, University of Cambridge, Cambridge, United Kingdom
| | - Mariia Dmitrieva
- Institute of Biomedical Engineering (IBME), Department of Engineering Science and the Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, United Kingdom
| | - Helen L. Zenner
- The Gurdon Institute and the Department of Genetics, University of Cambridge, Cambridge, United Kingdom
| | - Nadine Muschalik
- MRC-Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge, United Kingdom
| | - Richard Butler
- Department of Genetics, University of Cambridge, Cambridge, United Kingdom
| | - Jade Glashauser
- Institute of Integrative Cell Biology and Physiology, Cells in Motion (CiM) Interfaculty Centre, University of Münster, Münster, Germany
| | - Carolina Camelo
- Institute of Integrative Cell Biology and Physiology, Cells in Motion (CiM) Interfaculty Centre, University of Münster, Münster, Germany
| | - Stefan Luschnig
- Institute of Integrative Cell Biology and Physiology, Cells in Motion (CiM) Interfaculty Centre, University of Münster, Münster, Germany
| | - Sean Munro
- MRC-Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge, United Kingdom
| | - Jens Rittscher
- Institute of Biomedical Engineering (IBME), Department of Engineering Science and the Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, United Kingdom
- Ludwig Institute for Cancer Research, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, United Kingdom
| | - Daniel St Johnston
- The Gurdon Institute and the Department of Genetics, University of Cambridge, Cambridge, United Kingdom
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2
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Takagi J, Takahashi H, Moriya KC, Nagano M, Fukao Y, Ueda H, Tamura K, Shimada T, Hara-Nishimura I. Plant-specific tail-anchored coiled-coil protein MAG3 stabilizes Golgi-associated ERESs to facilitate protein exit from the ER. Commun Biol 2025; 8:358. [PMID: 40038456 PMCID: PMC11880317 DOI: 10.1038/s42003-025-07602-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2024] [Accepted: 01/24/2025] [Indexed: 03/06/2025] Open
Abstract
Endoplasmic reticulum exit sites (ERESs) are ER subdomains where coat protein complex II carriers are assembled for ER-to-Golgi transport. We previously proposed a dynamic capture-and-release model of ERESs by Golgi stacks in plants. However, how ERESs and Golgi stacks maintain a stable interaction in plant cells with vigorous cytoplasmic streaming is unknown. Here, we show that a plant-specific ER transmembrane protein, which we designate as MAG3, plays a crucial role in mediating the capture-and-release of ERESs in Arabidopsis. We isolated a mutant (mag3) defective in protein exit from the ER in seeds. MAG3 localized specifically to the ER-Golgi interface with Golgi-associated ERESs and remained there after ERES release. MAG3 deficiency caused a reduction in the amount of ERESs associated with each Golgi stack. MAG3 interacted with WPP DOMAIN PROTEINs, which are also plant-specific. These results suggest that plants have evolved a unique system to support ER-to-Golgi transport despite intracellular motility.
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Affiliation(s)
- Junpei Takagi
- Faculty of Science, Hokkaido University, Sapporo, Japan.
- Graduate School of Science, Kyoto University, Kyoto, Japan.
| | | | - Kenta C Moriya
- Center for Ecological Research, Kyoto University, Otsu, Japan
| | - Minoru Nagano
- Graduate School of Science, Kyoto University, Kyoto, Japan
- College of Life Sciences, Ritsumeikan University, Kusatsu, Japan
| | - Yoichiro Fukao
- College of Life Sciences, Ritsumeikan University, Kusatsu, Japan
| | - Haruko Ueda
- Graduate School of Science, Kyoto University, Kyoto, Japan
- Faculty of Science and Engineering, Konan University, Kobe, Japan
| | - Kentaro Tamura
- Graduate School of Science, Kyoto University, Kyoto, Japan
- Department of Environmental and Life Sciences, University of Shizuoka, Shizuoka, Japan
| | - Tomoo Shimada
- Graduate School of Science, Kyoto University, Kyoto, Japan
| | - Ikuko Hara-Nishimura
- Graduate School of Science, Kyoto University, Kyoto, Japan.
- Faculty of Science and Engineering, Konan University, Kobe, Japan.
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3
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Yorimitsu T, Sato K. Potential ER tubular lumen sensing by intrinsically disordered regions. J Cell Sci 2025; 138:JCS263696. [PMID: 39925135 PMCID: PMC11959615 DOI: 10.1242/jcs.263696] [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: 11/03/2024] [Accepted: 02/03/2025] [Indexed: 02/11/2025] Open
Abstract
Intrinsically disordered regions (IDRs) are known to sense the positive membrane curvature of vesicles and tubules. However, whether IDRs can sense the negative curvature of their luminal surfaces remains elusive. Here, we show that IDRs direct specific localization to endoplasmic reticulum (ER) tubules. In Saccharomyces cerevisiae, Sed4 interacts with Sec16 at the ER exit site (ERES) to promote ER export. Upon loss of this interaction, Sed4 failed to assemble at the ERES but was enriched in the ER tubules in a luminal region-dependent manner. Fusion of the Sed4 luminal region with Sec12 and Sec22, which localize throughout the ER, resulted in their enrichment in the tubules. The luminal regions of Sed4 or its homologs, predicted to be IDRs, localized to tubules when translocated alone into the ER lumen. The lumen-imported IDRs derived from cytosol-localizing Sec16 and Atg13 also exhibited tubule localization. Furthermore, Sed4 constructs in which the luminal region was replaced by these IDRs were concentrated at the ERES. Collectively, we suggest that the IDRs sense the properties of the tubule lumen, such as its surface, and facilitate Sed4 assembly at the ERES.
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Grants
- 18K06126, 21K06164 and 24K09361 Grant-in-Aid for Scientific Research from the Japanese Ministry of Education, Culture, Sports, Science and Technology
- 17KT0105, 19K06655 and 23K05692 Grant-in-Aid for Scientific Research from the Japanese Ministry of Education, Culture, Sports, Science and Technology
- 18K06126 Ministry of Education, Culture, Sports, Science and Technology
- University of Tokyo
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Affiliation(s)
- Tomohiro Yorimitsu
- Department of Life SciencesGraduate School of Arts and Sciences, University of Tokyo, Tokyo 153-8902, Japan
| | - Ken Sato
- Department of Life SciencesGraduate School of Arts and Sciences, University of Tokyo, Tokyo 153-8902, Japan
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4
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Milano SN, Bayer LV, Ko JJ, Casella CE, Bratu DP. The role of ER exit sites in maintaining P-body organization and integrity during Drosophila melanogaster oogenesis. EMBO Rep 2025; 26:494-520. [PMID: 39653851 PMCID: PMC11772875 DOI: 10.1038/s44319-024-00344-x] [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: 07/13/2024] [Revised: 11/08/2024] [Accepted: 11/15/2024] [Indexed: 12/12/2024] Open
Abstract
Processing bodies (P-bodies) are cytoplasmic membrane-less organelles which host multiple mRNA processing events. While the fundamental principles of P-body organization are beginning to be elucidated in vitro, a nuanced understanding of how their assembly is regulated in vivo remains elusive. Here, we investigate the potential link between ER exit sites and P-bodies in Drosophila melanogaster egg chambers. Employing a combination of live and super-resolution imaging, we find that P-bodies associated with ER exit sites are larger and less mobile than cytoplasmic P-bodies, indicating that they constitute a distinct class of P-bodies. Moreover, we demonstrate that altering the composition of ER exit sites has differential effects on core P-body proteins (Me31B, Cup, and Trailer Hitch), suggesting a potential role for ER exit sites in P-body organization. Furthermore, we show that in the absence of ER exit sites, P-body integrity is compromised and the stability and translational repression efficiency of the maternal mRNA, oskar, are reduced. Together, our data highlights the crucial role of ER exit sites in governing P-body organization.
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Affiliation(s)
- Samantha N Milano
- Department of Biological Sciences, Hunter College, City University of New York, New York, NY, 10065, USA
- Program in Molecular, Cellular, and Developmental Biology, The Graduate Center, City University of New York, New York, NY, 10016, USA
| | - Livia V Bayer
- Department of Biological Sciences, Hunter College, City University of New York, New York, NY, 10065, USA
| | - Julie J Ko
- Department of Biological Sciences, Hunter College, City University of New York, New York, NY, 10065, USA
| | - Caroline E Casella
- Department of Biological Sciences, Hunter College, City University of New York, New York, NY, 10065, USA
| | - Diana P Bratu
- Department of Biological Sciences, Hunter College, City University of New York, New York, NY, 10065, USA.
- Program in Molecular, Cellular, and Developmental Biology, The Graduate Center, City University of New York, New York, NY, 10016, USA.
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5
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Wang Y, Ren Y, Teng X, Wang F, Chen Y, Duan E, Wang X, Pan T, Zhang B, Wan G, Zhang Y, Zhang P, Sun X, Yang W, Zhu Y, Chen Y, Zhao W, Han X, Lei C, Zhu S, Liu S, Wang Y, Wan J. Functional diversification of Sec13 isoforms for storage protein trafficking in rice endosperm cells. PLANT PHYSIOLOGY 2024; 196:2405-2421. [PMID: 39351808 DOI: 10.1093/plphys/kiae513] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2024] [Accepted: 08/30/2024] [Indexed: 12/14/2024]
Abstract
Coat protein complex II (COPII) vesicles play crucial roles in mediating the endoplasmic reticulum (ER) exit of newly synthesized proteins to the Golgi in eukaryotic cells. However, the molecular functions of COPII components and their functional diversifications in plant seeds remain obscure. Here, we showed that the rice (Oryza sativa) glutelin precursor accumulation12 (gpa12) mutant is defective in storage protein export from the ER, resulting in the formation of aggregated protein bodies. Map-based cloning revealed that GPA12 encodes a COPII outer layer protein, Sec13a, that mainly localizes to endoplasmic reticulum exit sites (ERES) and partially localizes to the Golgi. Biochemical experiments verified that Sec13a physically interacts with Sec31 and Sec16, and mutation in Sec13 compromises its interaction with Sec31 and Sec16, thereby affecting the membrane association of the inner complex components Sar1b and Sec23c. Apart from Sec13a, the rice genome encodes 2 other Sec13 isoforms, Sec13b and Sec13c. Notably, we observed an abnormal accumulation of globular ER structures in the sec13bc double mutant but not in the single mutants, suggesting a functional redundancy of Sec13b and Sec13c in modulating ER morphology. Taken together, our results substantiated that Sec13a plays an important role in regulating storage protein export from the ER, while Sec13b and Sec13c are required for maintaining ER morphology in rice endosperm cells. Our findings provide insights into the functional diversification of COPII components in plants.
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Affiliation(s)
- Yongfei Wang
- Stake Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Zhongshan Biological Breeding Laboratory, Jiangsu Nanjing Rice Germplasm Resources National Field Observation and Research Station, Nanjing Agricultural University, Nanjing 210095, China
| | - Yulong Ren
- State Key Laboratory of Crop Gene Resources and Breeding, National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Xuan Teng
- Stake Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Zhongshan Biological Breeding Laboratory, Jiangsu Nanjing Rice Germplasm Resources National Field Observation and Research Station, Nanjing Agricultural University, Nanjing 210095, China
| | - Fan Wang
- State Key Laboratory of Crop Gene Resources and Breeding, National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Yanyu Chen
- Stake Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Zhongshan Biological Breeding Laboratory, Jiangsu Nanjing Rice Germplasm Resources National Field Observation and Research Station, Nanjing Agricultural University, Nanjing 210095, China
| | - Erchao Duan
- Stake Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Zhongshan Biological Breeding Laboratory, Jiangsu Nanjing Rice Germplasm Resources National Field Observation and Research Station, Nanjing Agricultural University, Nanjing 210095, China
| | - Xin Wang
- State Key Laboratory of Crop Gene Resources and Breeding, National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Tian Pan
- Stake Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Zhongshan Biological Breeding Laboratory, Jiangsu Nanjing Rice Germplasm Resources National Field Observation and Research Station, Nanjing Agricultural University, Nanjing 210095, China
| | - Binglei Zhang
- Stake Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Zhongshan Biological Breeding Laboratory, Jiangsu Nanjing Rice Germplasm Resources National Field Observation and Research Station, Nanjing Agricultural University, Nanjing 210095, China
- State Key Laboratory of Crop Gene Resources and Breeding, National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Gexing Wan
- State Key Laboratory of Crop Gene Resources and Breeding, National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Yu Zhang
- Stake Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Zhongshan Biological Breeding Laboratory, Jiangsu Nanjing Rice Germplasm Resources National Field Observation and Research Station, Nanjing Agricultural University, Nanjing 210095, China
| | - Pengcheng Zhang
- Stake Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Zhongshan Biological Breeding Laboratory, Jiangsu Nanjing Rice Germplasm Resources National Field Observation and Research Station, Nanjing Agricultural University, Nanjing 210095, China
| | - Xiejun Sun
- State Key Laboratory of Crop Gene Resources and Breeding, National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Wenkun Yang
- State Key Laboratory of Crop Gene Resources and Breeding, National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Yun Zhu
- State Key Laboratory of Crop Gene Resources and Breeding, National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Yu Chen
- State Key Laboratory of Crop Gene Resources and Breeding, National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Wenjie Zhao
- Stake Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Zhongshan Biological Breeding Laboratory, Jiangsu Nanjing Rice Germplasm Resources National Field Observation and Research Station, Nanjing Agricultural University, Nanjing 210095, China
| | - Xiaohang Han
- State Key Laboratory of Crop Gene Resources and Breeding, National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Cailin Lei
- State Key Laboratory of Crop Gene Resources and Breeding, National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Shanshan Zhu
- State Key Laboratory of Crop Gene Resources and Breeding, National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Shijia Liu
- Stake Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Zhongshan Biological Breeding Laboratory, Jiangsu Nanjing Rice Germplasm Resources National Field Observation and Research Station, Nanjing Agricultural University, Nanjing 210095, China
| | - Yihua Wang
- Stake Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Zhongshan Biological Breeding Laboratory, Jiangsu Nanjing Rice Germplasm Resources National Field Observation and Research Station, Nanjing Agricultural University, Nanjing 210095, China
| | - Jianmin Wan
- Stake Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Zhongshan Biological Breeding Laboratory, Jiangsu Nanjing Rice Germplasm Resources National Field Observation and Research Station, Nanjing Agricultural University, Nanjing 210095, China
- State Key Laboratory of Crop Gene Resources and Breeding, National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China
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6
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Milano SN, Bayer LV, Ko JJ, Casella CE, Bratu DP. The role of ER exit sites in maintaining P-body organization and transmitting ER stress response during Drosophila melanogaster oogenesis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.03.601952. [PMID: 39005311 PMCID: PMC11245038 DOI: 10.1101/2024.07.03.601952] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/16/2024]
Abstract
Processing bodies (P-bodies) are cytoplasmic membrane-less organelles which host multiple mRNA processing events. While the fundamental principles of P-body organization are beginning to be elucidated in vitro, a nuanced understanding of how their assembly is regulated in vivo remains elusive. Here, we investigate the potential link between ER exit sites and P-bodies in Drosophila melanogaster egg chambers. Employing a combination of live and super-resolution imaging, we found that P-bodies associated with ER exit sites are larger and less mobile than cytoplasmic P-bodies, indicating that they constitute a distinct class of P-bodies which are more mature than their cytoplasmic counterparts. Moreover, we demonstrate that altering the composition of ER exit sites has differential effects on core P-body proteins (Me31B, Cup, and Trailer Hitch) suggesting a potential role for ER exit sites in P-body organization. We further show that in the absence of ER exit sites, P-body integrity is compromised and the stability and translational repression efficiency of the maternal mRNA, oskar, are reduced. Finally, we show that ER stress is communicated to P-bodies via ER exit sites, highlighting the pivotal role of ER exit sites as a bridge between membrane-bound and membrane-less organelles in ER stress response. Together, our data unveils the significance of ER exit sites not only in governing P-body organization, but also in facilitating inter-organellar communication during stress, potentially bearing implications for a variety of disease pathologies.
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Affiliation(s)
- Samantha N. Milano
- Department of Biological Sciences, Hunter College, City University of New York, NY, 10065 USA
- Program in Molecular, Cellular, and Developmental Biology, The Graduate Center, City University of New York, NY, 10016 USA
| | - Livia V. Bayer
- Department of Biological Sciences, Hunter College, City University of New York, NY, 10065 USA
| | - Julie J. Ko
- Department of Biological Sciences, Hunter College, City University of New York, NY, 10065 USA
| | - Caroline E. Casella
- Department of Biological Sciences, Hunter College, City University of New York, NY, 10065 USA
| | - Diana P. Bratu
- Department of Biological Sciences, Hunter College, City University of New York, NY, 10065 USA
- Program in Molecular, Cellular, and Developmental Biology, The Graduate Center, City University of New York, NY, 10016 USA
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7
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Yan B, Zhang L, Jiao K, Wang Z, Yong K, Lu M. Vesicle formation-related protein CaSec16 and its ankyrin protein partner CaANK2B jointly enhance salt tolerance in pepper. JOURNAL OF PLANT PHYSIOLOGY 2024; 296:154240. [PMID: 38603993 DOI: 10.1016/j.jplph.2024.154240] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Revised: 03/26/2024] [Accepted: 03/26/2024] [Indexed: 04/13/2024]
Abstract
Vesicle transport plays important roles in plant tolerance against abiotic stresses. However, the contribution of a vesicle formation related protein CaSec16 (COPII coat assembly protein Sec16-like) in pepper tolerance to salt stress remains unclear. In this study, we report that the expression of CaSec16 was upregulated by salt stress. Compared to the control, the salt tolerance of pepper with CaSec16-silenced was compromised, which was shown by the corresponding phenotypes and physiological indexes, such as the death of growing point, the aggravated leaf wilting, the higher increment of relative electric leakage (REL), the lower content of total chlorophyll, the higher accumulation of dead cells, H2O2, malonaldehyde (MDA), and proline (Pro), and the inhibited induction of marker genes for salt-tolerance and vesicle transport. In contrast, the salt tolerance of pepper was enhanced by the transient overexpression of CaSec16. In addition, heterogeneously induced CaSec16 protein did not enhance the salt tolerance of Escherichia coli, an organism lacking the vesicle transport system. By yeast two-hybrid method, an ankyrin protein, CaANK2B, was identified as the interacting protein of CaSec16. The expression of CaANK2B showed a downward trend during the process of salt stress. Compared with the control, pepper plants with transient-overexpression of CaANK2B displayed increased salt tolerance, whereas those with CaANK2B-silenced exhibited reduced salt tolerance. Taken together, both the vesicle formation related protein CaSec16 and its interaction partner CaANK2B can improve the pepper tolerance to salt stress.
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Affiliation(s)
- Bentao Yan
- College of Horticulture, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Linyang Zhang
- College of Horticulture, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Kexin Jiao
- College of Horticulture, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Zhenze Wang
- College of Horticulture, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Kang Yong
- College of Horticulture, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Minghui Lu
- College of Horticulture, Northwest A&F University, Yangling, Shaanxi, 712100, China.
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Rios T, Bomfim L, Pereira J, Miranda K, Majerowicz D, Pane A, Ramos I. Knockdown of Sec16 causes early lethality and defective deposition of the protein Rp30 in the eggshell of the vector Rhodnius prolixus. Front Cell Dev Biol 2024; 12:1332894. [PMID: 38711619 PMCID: PMC11070790 DOI: 10.3389/fcell.2024.1332894] [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: 11/03/2023] [Accepted: 03/18/2024] [Indexed: 05/08/2024] Open
Abstract
In nearly every species of insect, embryonic development takes place outside of the mother's body and is entirely dependent on the elements that the mother had previously stored within the eggs. It is well known that the follicle cells (FCs) synthesize the eggshell (chorion) components during the process of choriogenesis, the final step of oogenesis before fertilization. These cells have developed a specialization in the massive production of chorion proteins, which are essential for the protection and survival of the embryo. Here, we investigate the function of Sec16, a protein crucial for the endoplasmic reticulum (ER) to Golgi traffic, in the oocyte development in the insect Rhodnius prolixus. We discovered that Sec16 is strongly expressed in vitellogenic females' ovaries, particularly in the choriogenic oocyte and it is mainly associated with the FCs. Silencing of Sec16 by RNAi caused a sharp decline in oviposition rates, F1 viability, and longevity in adult females. In the FCs, genes involved in the unfolded protein response (UPR), the ubiquitin-proteasome system (UPS), and autophagy were massively upregulated, whereas the mRNAs of Rp30 and Rp45-which code for the two major chorion proteins - were downregulated as a result of Sec16 silencing, indicating general proteostasis disturbance. As a result, the outer surface ultrastructure of Sec16-silenced chorions was altered, with decreased thickness, dityrosine crosslinking, sulfur signals, and lower amounts of the chorion protein Rp30. These findings collectively demonstrate the critical role Sec16 plays in the proper functioning of the FCs, which impacts the synthesis and deposition of particular components of the chorion as well as the overall reproduction of this vector.
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Affiliation(s)
- Thamara Rios
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Larissa Bomfim
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Jéssica Pereira
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Kildare Miranda
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - David Majerowicz
- Departamento de Biotecnologia Farmacêutica, Faculdade de Farmácia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
- Programa de Pós-Graduação em Biociências, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Brazil
- Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular, Rio de Janeiro, Brazil
| | - Attilio Pane
- Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular, Rio de Janeiro, Brazil
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Isabela Ramos
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
- Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular, Rio de Janeiro, Brazil
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9
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Matsuura Y, Kaizuka K, Inoue YH. Essential Role of COPII Proteins in Maintaining the Contractile Ring Anchoring to the Plasma Membrane during Cytokinesis in Drosophila Male Meiosis. Int J Mol Sci 2024; 25:4526. [PMID: 38674111 PMCID: PMC11050551 DOI: 10.3390/ijms25084526] [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: 03/18/2024] [Revised: 04/16/2024] [Accepted: 04/17/2024] [Indexed: 04/28/2024] Open
Abstract
Coatomer Protein Complex-II (COPII) mediates anterograde vesicle transport from the endoplasmic reticulum (ER) to the Golgi apparatus. Here, we report that the COPII coatomer complex is constructed dependent on a small GTPase, Sar1, in spermatocytes before and during Drosophila male meiosis. COPII-containing foci co-localized with transitional endoplasmic reticulum (tER)-Golgi units. They showed dynamic distribution along astral microtubules and accumulated around the spindle pole, but they were not localized on the cleavage furrow (CF) sites. The depletion of the four COPII coatomer subunits, Sec16, or Sar1 that regulate COPII assembly resulted in multinucleated cell production after meiosis, suggesting that cytokinesis failed in both or either of the meiotic divisions. Although contractile actomyosin and anilloseptin rings were formed once plasma membrane ingression was initiated, they were frequently removed from the plasma membrane during furrowing. We explored the factors conveyed toward the CF sites in the membrane via COPII-mediated vesicles. DE-cadherin-containing vesicles were formed depending on Sar1 and were accumulated in the cleavage sites. Furthermore, COPII depletion inhibited de novo plasma membrane insertion. These findings suggest that COPII vesicles supply the factors essential for the anchoring and/or constriction of the contractile rings at cleavage sites during male meiosis in Drosophila.
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Affiliation(s)
- Yoshiki Matsuura
- Biomedical Research Center, Kyoto Institute of Technology, Mastugasaki, Kyoto 606-0962, Japan; (Y.M.); (K.K.)
- Graduate School of Science and Technology, Kyoto Institute of Technology, Matsugasaki, Sakyo, Kyoto 606-0962, Japan
| | - Kana Kaizuka
- Biomedical Research Center, Kyoto Institute of Technology, Mastugasaki, Kyoto 606-0962, Japan; (Y.M.); (K.K.)
| | - Yoshihiro H. Inoue
- Biomedical Research Center, Kyoto Institute of Technology, Mastugasaki, Kyoto 606-0962, Japan; (Y.M.); (K.K.)
- Graduate School of Science and Technology, Kyoto Institute of Technology, Matsugasaki, Sakyo, Kyoto 606-0962, Japan
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10
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Gallo R, Rai AK, McIntyre ABR, Meyer K, Pelkmans L. DYRK3 enables secretory trafficking by maintaining the liquid-like state of ER exit sites. Dev Cell 2023; 58:1880-1897.e11. [PMID: 37643612 DOI: 10.1016/j.devcel.2023.08.005] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Revised: 02/16/2023] [Accepted: 08/01/2023] [Indexed: 08/31/2023]
Abstract
The dual-specificity kinase DYRK3 controls the formation and dissolution of multiple biomolecular condensates, regulating processes including stress recovery and mitotic progression. Here, we report that DYRK3 functionally interacts with proteins associated with endoplasmic reticulum (ER) exit sites (ERESs) and that inhibition of DYRK3 perturbs the organization of the ERES-Golgi interface and secretory trafficking. DYRK3-mediated regulation of ERES depends on the N-terminal intrinsically disordered region (IDR) of the peripheral membrane protein SEC16A, which co-phase separates with ERES components to form liquid-like condensates on the surface of the ER. By modulating the liquid-like properties of ERES, we show that their physical state is essential for functional cargo trafficking through the early secretory pathway. Our findings support a mechanism whereby phosphorylation by DYRK3 and its reversal by serine-threonine phosphatases regulate the material properties of ERES to create a favorable physicochemical environment for directional membrane traffic in eukaryotic cells.
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Affiliation(s)
- Raffaella Gallo
- Department of Molecular Life Sciences, University of Zurich, 8046 Zurich, Switzerland
| | - Arpan Kumar Rai
- Department of Molecular Life Sciences, University of Zurich, 8046 Zurich, Switzerland.
| | - Alexa B R McIntyre
- Department of Molecular Life Sciences, University of Zurich, 8046 Zurich, Switzerland
| | - Katrina Meyer
- Department of Molecular Life Sciences, University of Zurich, 8046 Zurich, Switzerland
| | - Lucas Pelkmans
- Department of Molecular Life Sciences, University of Zurich, 8046 Zurich, Switzerland.
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11
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Morón-Oset J, Fischer LKS, Jauré N, Zhang P, Jahn AJ, Supèr T, Pahl A, Isaacs AM, Grönke S, Partridge L. Repeat length of C9orf72-associated glycine-alanine polypeptides affects their toxicity. Acta Neuropathol Commun 2023; 11:140. [PMID: 37644512 PMCID: PMC10463776 DOI: 10.1186/s40478-023-01634-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Accepted: 08/05/2023] [Indexed: 08/31/2023] Open
Abstract
G4C2 hexanucleotide repeat expansions in a non-coding region of the C9orf72 gene are the most common cause of familial amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). G4C2 insertion length is variable, and patients can carry up to several thousand repeats. Dipeptide repeat proteins (DPRs) translated from G4C2 transcripts are thought to be a main driver of toxicity. Experiments in model organisms with relatively short DPRs have shown that arginine-rich DPRs are most toxic, while polyGlycine-Alanine (GA) DPRs cause only mild toxicity. However, GA is the most abundant DPR in patient brains, and experimental work in animals has generally relied on the use of low numbers of repeats, with DPRs often tagged for in vivo tracking. Whether repeat length or tagging affect the toxicity of GA has not been systematically assessed. Therefore, we generated Drosophila fly lines expressing GA100, GA200 or GA400 specifically in adult neurons. Consistent with previous studies, expression of GA100 and GA200 caused only mild toxicity. In contrast, neuronal expression of GA400 drastically reduced climbing ability and survival of flies, indicating that long GA DPRs can be highly toxic in vivo. This toxicity could be abolished by tagging GA400. Proteomics analysis of fly brains showed a repeat-length-dependent modulation of the brain proteome, with GA400 causing earlier and stronger changes than shorter GA proteins. PolyGA expression up-regulated proteins involved in ER to Golgi trafficking, and down-regulated proteins involved in insulin signalling. Experimental down-regulation of Tango1, a highly conserved regulator of ER-to Golgi transport, partially rescued GA400 toxicity, suggesting that misregulation of this process contributes to polyGA toxicity. Experimentally increasing insulin signaling also rescued GA toxicity. In summary, our data show that long polyGA proteins can be highly toxic in vivo, and that they may therefore contribute to ALS/FTD pathogenesis in patients.
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Affiliation(s)
- Javier Morón-Oset
- Max Planck Institute for Biology of Ageing, Joseph-Stelzmann-Strasse 9B, 50931, Cologne, Germany
| | | | - Nathalie Jauré
- Max Planck Institute for Biology of Ageing, Joseph-Stelzmann-Strasse 9B, 50931, Cologne, Germany
| | - Pingze Zhang
- Max Planck Institute for Biology of Ageing, Joseph-Stelzmann-Strasse 9B, 50931, Cologne, Germany
| | - Annika Julia Jahn
- Max Planck Institute for Biology of Ageing, Joseph-Stelzmann-Strasse 9B, 50931, Cologne, Germany
| | - Tessa Supèr
- Max Planck Institute for Biology of Ageing, Joseph-Stelzmann-Strasse 9B, 50931, Cologne, Germany
| | - André Pahl
- Max Planck Institute for Biology of Ageing, Joseph-Stelzmann-Strasse 9B, 50931, Cologne, Germany
| | - Adrian M Isaacs
- Department of Neurodegenerative Disease, UCL Institute of Neurology, Queen Square, London, WC1N 3BG, UK
- UK Dementia Research Institute at UCL, UCL Queen Square Institute of Neurology, London, WC1N 3BG, UK
| | - Sebastian Grönke
- Max Planck Institute for Biology of Ageing, Joseph-Stelzmann-Strasse 9B, 50931, Cologne, Germany.
| | - Linda Partridge
- Max Planck Institute for Biology of Ageing, Joseph-Stelzmann-Strasse 9B, 50931, Cologne, Germany.
- Department of Genetics, Evolution and Environment, Institute of Healthy Ageing, University College London, Darwin Building, Gower Street, London, WC1E 6BT, UK.
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12
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Raote I, Saxena S, Malhotra V. Sorting and Export of Proteins at the Endoplasmic Reticulum. Cold Spring Harb Perspect Biol 2023; 15:a041258. [PMID: 35940902 PMCID: PMC10153803 DOI: 10.1101/cshperspect.a041258] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Secretory proteins are transported from the endoplasmic reticulum (ER) to the Golgi complex in carriers that are formed by the concerted activities of cytoplasmic proteins in the coat protein complex II (COPII). COPII was first described in Saccharomyces cerevisiae and its basic functions are largely conserved throughout eukaryotes. The discovery of the TANGO1 (transport and Golgi organization 1) family of proteins is revealing insights into how cells can adapt COPII proteins to reorganize the ER exit site for the export of the most abundant and bulky molecules, collagens.
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Affiliation(s)
- Ishier Raote
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Barcelona 08003, Spain
| | - Sonashree Saxena
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Barcelona 08003, Spain
| | - Vivek Malhotra
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Barcelona 08003, Spain
- Universitat Pompeu Fabra (UPF), Barcelona 08002, Spain
- ICREA, Barcelona 08010, Spain
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13
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Yorimitsu T, Sato K. Sec16 and Sed4 interdependently function as interaction and localization partners at ER exit sites. J Cell Sci 2023; 136:308925. [PMID: 37158682 PMCID: PMC10184828 DOI: 10.1242/jcs.261094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Accepted: 04/06/2023] [Indexed: 05/10/2023] Open
Abstract
COPII proteins assemble at ER exit sites (ERES) to form transport carriers. The initiation of COPII assembly in the yeast Saccharomyces cerevisiae is triggered by the ER membrane protein Sec12. Sec16, which plays a critical role in COPII organization, localizes to ERES independently of Sec12. However, the mechanism underlying Sec16 localization is poorly understood. Here, we show that a Sec12 homolog, Sed4, is concentrated at ERES and mediates ERES localization of Sec16. We found that the interaction between Sec16 and Sed4 ensures their correct localization to ERES. Loss of the interaction with Sec16 leads to redistribution of Sed4 from the ERES specifically to high-curvature ER areas, such as the tubules and edges of the sheets. The luminal domain of Sed4 mediates this distribution, which is required for Sed4, but not for Sec16, to be concentrated at ERES. We further show that the luminal domain and its O-mannosylation are involved in the self-interaction of Sed4. Our findings provide insight into how Sec16 and Sed4 function interdependently at ERES.
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Affiliation(s)
- Tomohiro Yorimitsu
- Department of Life Sciences, Graduate School of Arts and Sciences, University of Tokyo, Tokyo 153-8902, Japan
| | - Ken Sato
- Department of Life Sciences, Graduate School of Arts and Sciences, University of Tokyo, Tokyo 153-8902, Japan
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14
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Shi R, Lu W, Tian Y, Wang B. Intestinal SEC16B modulates obesity by regulating chylomicron metabolism. Mol Metab 2023; 70:101693. [PMID: 36796587 PMCID: PMC9976576 DOI: 10.1016/j.molmet.2023.101693] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Revised: 01/30/2023] [Accepted: 02/08/2023] [Indexed: 02/16/2023] Open
Abstract
OBJECTIVE Genome-wide association studies (GWAS) have identified genetic variants in SEC16 homolog B (SEC16B) locus to be associated with obesity and body mass index (BMI) in various populations. SEC16B encodes a scaffold protein located at endoplasmic reticulum (ER) exit sites that is implicated to participate in the trafficking of COPII vesicles in mammalian cells. However, the function of SEC16B in vivo, especially in lipid metabolism, has not been investigated. METHODS We generated Sec16b intestinal knockout (IKO) mice and assessed the impact of its deficiency on high-fat diet (HFD) induced obesity and lipid absorption in both male and female mice. We examined lipid absorption in vivo by acute oil challenge and fasting/HFD refeeding. Biochemical analyses and imaging studies were performed to understand the underlying mechanisms. RESULTS Our results showed that Sec16b intestinal knockout (IKO) mice, especially female mice, were protected from HFD-induced obesity. Loss of Sec16b in intestine dramatically reduced postprandial serum triglyceride output upon intragastric lipid load or during overnight fasting and HFD refeeding. Further studies showed that intestinal Sec16b deficiency impaired apoB lipidation and chylomicron secretion. CONCLUSIONS Our studies demonstrated that intestinal SEC16B is required for dietary lipid absorption in mice. These results revealed that SEC16B plays important roles in chylomicron metabolism, which may shed light on the association between variants in SEC16B and obesity in human.
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Affiliation(s)
- Ruicheng Shi
- Department of Comparative Biosciences, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Wei Lu
- Department of Comparative Biosciences, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Ye Tian
- Department of Comparative Biosciences, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Bo Wang
- Department of Comparative Biosciences, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Urbana, IL, USA; Division of Nutritional Sciences, College of Agricultural, Consumer and Environmental Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, USA; Cancer Center at Illinois, University of Illinois at Urbana-Champaign, Urbana, IL, USA.
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15
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Glashauser J, Camelo C, Hollmann M, Backer W, Jacobs T, Sanchez JI, Schleutker R, Förster D, Berns N, Riechmann V, Luschnig S. Acute manipulation and real-time visualization of membrane trafficking and exocytosis in Drosophila. Dev Cell 2023; 58:709-723.e7. [PMID: 37023749 DOI: 10.1016/j.devcel.2023.03.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Revised: 01/05/2023] [Accepted: 03/07/2023] [Indexed: 04/08/2023]
Abstract
Intracellular trafficking of secretory proteins plays key roles in animal development and physiology, but so far, tools for investigating the dynamics of membrane trafficking have been limited to cultured cells. Here, we present a system that enables acute manipulation and real-time visualization of membrane trafficking through the reversible retention of proteins in the endoplasmic reticulum (ER) in living multicellular organisms. By adapting the "retention using selective hooks" (RUSH) approach to Drosophila, we show that trafficking of GPI-linked, secreted, and transmembrane proteins can be controlled with high temporal precision in intact animals and cultured organs. We demonstrate the potential of this approach by analyzing the kinetics of ER exit and apical secretion and the spatiotemporal dynamics of tricellular junction assembly in epithelia of living embryos. Furthermore, we show that controllable ER retention enables tissue-specific depletion of secretory protein function. The system is broadly applicable to visualizing and manipulating membrane trafficking in diverse cell types in vivo.
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Affiliation(s)
- Jade Glashauser
- Institute of Integrative Cell Biology and Physiology, Faculty of Biology and Cells in Motion (CiM) Interfaculty Center, University of Münster, 48149 Münster, Germany
| | - Carolina Camelo
- Institute of Integrative Cell Biology and Physiology, Faculty of Biology and Cells in Motion (CiM) Interfaculty Center, University of Münster, 48149 Münster, Germany
| | - Manuel Hollmann
- Institute of Integrative Cell Biology and Physiology, Faculty of Biology and Cells in Motion (CiM) Interfaculty Center, University of Münster, 48149 Münster, Germany
| | - Wilko Backer
- Institute of Integrative Cell Biology and Physiology, Faculty of Biology and Cells in Motion (CiM) Interfaculty Center, University of Münster, 48149 Münster, Germany
| | - Thea Jacobs
- Institute of Integrative Cell Biology and Physiology, Faculty of Biology and Cells in Motion (CiM) Interfaculty Center, University of Münster, 48149 Münster, Germany
| | - Jone Isasti Sanchez
- Institute of Integrative Cell Biology and Physiology, Faculty of Biology and Cells in Motion (CiM) Interfaculty Center, University of Münster, 48149 Münster, Germany
| | - Raphael Schleutker
- Institute of Integrative Cell Biology and Physiology, Faculty of Biology and Cells in Motion (CiM) Interfaculty Center, University of Münster, 48149 Münster, Germany
| | - Dominique Förster
- Institute of Integrative Cell Biology and Physiology, Faculty of Biology and Cells in Motion (CiM) Interfaculty Center, University of Münster, 48149 Münster, Germany
| | - Nicola Berns
- Department of Cell and Molecular Biology, Medical Faculty Mannheim, Heidelberg University, 68167 Mannheim, Germany
| | - Veit Riechmann
- Department of Cell and Molecular Biology, Medical Faculty Mannheim, Heidelberg University, 68167 Mannheim, Germany
| | - Stefan Luschnig
- Institute of Integrative Cell Biology and Physiology, Faculty of Biology and Cells in Motion (CiM) Interfaculty Center, University of Münster, 48149 Münster, Germany.
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16
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Zhang C, Kalaitsidou E, Damen JMA, Grond R, Rabouille C, Wu W. Novel Components of the Stress Assembly Sec Body Identified by Proximity Labeling. Cells 2023; 12:cells12071055. [PMID: 37048128 PMCID: PMC10093351 DOI: 10.3390/cells12071055] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Revised: 03/27/2023] [Accepted: 03/28/2023] [Indexed: 04/03/2023] Open
Abstract
Sec bodies are membraneless stress-induced assemblies that form by the coalescence of endoplasmic reticulum exit sites (ERES). Through APEX2 tagging of Sec24AB, we biotinylated and identified the full complement of Sec body proteins. In the presence of biotin-phenol and H2O2 (APEX on), APEX2 facilitates the transfer of a biotin moiety to nearby interactors of chimeric Sec24AB. Using this unbiased approach comparing APEX on and off (−H2O2) conditions, we identified 52 proteins specifically enriched in Sec bodies. These include a large proportion of ER and Golgi proteins, packaged without defined stoichiometry, which we could selectively verify by imaging. Interestingly, Sec body components are neither transcriptionally nor translationally regulated under the conditions that induce Sec body formation, suggesting that incorporation of these proteins into granules may be driven instead by the aggregation of nucleating proteins with a high content of intrinsically disordered regions. This reinforces the notion that Sec bodies may act as storage for ERES, ER and Golgi components during stress.
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17
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Van der Verren SE, Zanetti G. The small GTPase Sar1, control centre of COPII trafficking. FEBS Lett 2023; 597:865-882. [PMID: 36737236 DOI: 10.1002/1873-3468.14595] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Revised: 01/23/2023] [Accepted: 01/25/2023] [Indexed: 02/05/2023]
Abstract
Sar1 is a small GTPase of the ARF family. Upon exchange of GDP for GTP, Sar1 associates with the endoplasmic reticulum (ER) membrane and recruits COPII components, orchestrating cargo concentration and membrane deformation. Many aspects of the role of Sar1 and regulation of its GTP cycle remain unclear, especially as complexity increases in higher organisms that secrete a wider range of cargoes. This review focusses on the regulation of GTP hydrolysis and its role in coat assembly, as well as the mechanism of Sar1-induced membrane deformation and scission. Finally, we highlight the additional specialisation in higher eukaryotes and the outstanding questions on how Sar1 functions are orchestrated.
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Affiliation(s)
| | - Giulia Zanetti
- Institute of Structural and Molecular Biology, Birkbeck College London, UK
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18
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dSec16 Acting in Insulin-like Peptide Producing Cells Controls Energy Homeostasis in Drosophila. LIFE (BASEL, SWITZERLAND) 2022; 13:life13010081. [PMID: 36676030 PMCID: PMC9862641 DOI: 10.3390/life13010081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Revised: 11/29/2022] [Accepted: 12/08/2022] [Indexed: 12/29/2022]
Abstract
Many studies show that genetics play a major contribution to the onset of obesity. Human genome-wide association studies (GWASs) have identified hundreds of genes that are associated with obesity. However, the majority of them have not been functionally validated. SEC16B has been identified in multiple obesity GWASs but its physiological role in energy homeostasis remains unknown. Here, we use Drosophila to determine the physiological functions of dSec16 in energy metabolism. Our results showed that global RNAi of dSec16 increased food intake and triglyceride (TAG) levels. Furthermore, this TAG increase was observed in flies with a specific RNAi of dSec16 in insulin-like peptide producing cells (IPCs) with an alteration of endocrine peptides. Together, our study demonstrates that dSec16 acting in IPCs controls energy balance and advances the molecular understanding of obesity.
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19
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van Leeuwen W, Nguyen DTM, Grond R, Veenendaal T, Rabouille C, Farías GG. Stress-induced phase separation of ERES components into Sec bodies precedes ER exit inhibition in mammalian cells. J Cell Sci 2022; 135:jcs260294. [PMID: 36325988 PMCID: PMC10112967 DOI: 10.1242/jcs.260294] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Accepted: 10/27/2022] [Indexed: 11/06/2022] Open
Abstract
Phase separation of components of ER exit sites (ERES) into membraneless compartments, the Sec bodies, occurs in Drosophila cells upon exposure to specific cellular stressors, namely, salt stress and amino acid starvation, and their formation is linked to the early secretory pathway inhibition. Here, we show Sec bodies also form in secretory mammalian cells upon the same stress. These reversible and membraneless structures are positive for ERES components, including both Sec16A and Sec16B isoforms and COPII subunits. We find that Sec16A, but not Sec16B, is a driver for Sec body formation, and that the coalescence of ERES components into Sec bodies occurs by fusion. Finally, we show that the stress-induced coalescence of ERES components into Sec bodies precedes ER exit inhibition, leading to their progressive depletion from ERES that become non-functional. Stress relief causes an immediate dissolution of Sec bodies and the concomitant restoration of ER exit. We propose that the dynamic conversion between ERES and Sec body assembly, driven by Sec16A, regulates protein exit from the ER during stress and upon stress relief in mammalian cells, thus providing a conserved pro-survival mechanism in response to stress.
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Affiliation(s)
- Wessel van Leeuwen
- Hubrecht Institute of the KNAW & UMC Utrecht, Utrecht 3584 CT, The Netherlands
| | - Dan T. M. Nguyen
- Cell Biology, Neurobiology and Biophysics. Department of Biology, Faculty of Science, Utrecht University, Utrecht 3584 CH, The Netherlands
| | - Rianne Grond
- Hubrecht Institute of the KNAW & UMC Utrecht, Utrecht 3584 CT, The Netherlands
| | - Tineke Veenendaal
- Section Cell Biology, Center for Molecular Medicine, University Medical Center Utrecht, Utrecht 3584 CX, The Netherlands
| | - Catherine Rabouille
- Hubrecht Institute of the KNAW & UMC Utrecht, Utrecht 3584 CT, The Netherlands
- Section Cell Biology, Center for Molecular Medicine, University Medical Center Utrecht, Utrecht 3584 CX, The Netherlands
- Department of Biomedical Sciences in Cells and Systems, UMC Groningen, Groningen 9713 AV, The Netherlands
| | - Ginny G. Farías
- Cell Biology, Neurobiology and Biophysics. Department of Biology, Faculty of Science, Utrecht University, Utrecht 3584 CH, The Netherlands
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20
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Park SY, Muschalik N, Chadwick J, Munro S. In vivo characterization of Drosophila golgins reveals redundancy and plasticity of vesicle capture at the Golgi apparatus. Curr Biol 2022; 32:4549-4564.e6. [PMID: 36103876 PMCID: PMC9849145 DOI: 10.1016/j.cub.2022.08.054] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Revised: 06/29/2022] [Accepted: 08/18/2022] [Indexed: 01/26/2023]
Abstract
The Golgi is the central sorting station in the secretory pathway and thus the destination of transport vesicles arriving from the endoplasmic reticulum and endosomes and from within the Golgi itself. Cell viability, therefore, requires that the Golgi accurately receives multiple classes of vesicle. One set of proteins proposed to direct vesicle arrival at the Golgi are the golgins, long coiled-coil proteins localized to specific parts of the Golgi stack. In mammalian cells, three of the golgins, TMF, golgin-84, and GMAP-210, can capture intra-Golgi transport vesicles when placed in an ectopic location. However, the individual golgins are not required for cell viability, and mouse knockout mutants only have defects in specific tissues. To further illuminate this system, we examine the Drosophila orthologs of these three intra-Golgi golgins. We show that ectopic forms can capture intra-Golgi transport vesicles, but strikingly, the cargo present in the vesicles captured by each golgin varies between tissues. Loss-of-function mutants show that the golgins are individually dispensable, although the loss of TMF recapitulates the male fertility defects observed in mice. However, the deletion of multiple golgins results in defects in glycosylation and loss of viability. Examining the vesicles captured by a particular golgin when another golgin is missing reveals that the vesicle content in one tissue changes to resemble that of a different tissue. This reveals a plasticity in Golgi organization between tissues, providing an explanation for why the Golgi is sufficiently robust to tolerate the loss of many of the individual components of its membrane traffic machinery.
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Affiliation(s)
- Sung Yun Park
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Nadine Muschalik
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Jessica Chadwick
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Sean Munro
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK.
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21
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Identification of two pathways mediating protein targeting from ER to lipid droplets. Nat Cell Biol 2022; 24:1364-1377. [PMID: 36050470 PMCID: PMC9481466 DOI: 10.1038/s41556-022-00974-0] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Accepted: 07/05/2022] [Indexed: 11/20/2022]
Abstract
Pathways localizing proteins to their sites of action are essential for eukaryotic cell organization and function. Although mechanisms of protein targeting to many organelles have been defined, how proteins, such as metabolic enzymes, target from the endoplasmic reticulum (ER) to cellular lipid droplets (LDs) is poorly understood. Here we identify two distinct pathways for ER-to-LD protein targeting: early targeting at LD formation sites during formation, and late targeting to mature LDs after their formation. Using systematic, unbiased approaches in Drosophila cells, we identified specific membrane-fusion machinery, including regulators, a tether and SNARE proteins, that are required for the late targeting pathway. Components of this fusion machinery localize to LD–ER interfaces and organize at ER exit sites. We identified multiple cargoes for early and late ER-to-LD targeting pathways. Our findings provide a model for how proteins target to LDs from the ER either during LD formation or by protein-catalysed formation of membrane bridges. Song et al. identify two protein-targeting pathways from the endoplasmic reticulum to (1) early lipid droplets (LDs) and (2) mature lipid droplets. They define key factors mediating the second, late pathway and its many cargoes.
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22
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Zhang C, van Leeuwen W, Blotenburg M, Aguilera-Gomez A, Brussee S, Grond R, Kampinga HH, Rabouille C. Activation of salt Inducible Kinases, IRE1 and PERK leads to Sec bodies formation in Drosophila S2 cells. J Cell Sci 2021; 134:272062. [PMID: 34350957 PMCID: PMC8445602 DOI: 10.1242/jcs.258685] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Accepted: 07/21/2021] [Indexed: 11/20/2022] Open
Abstract
The phase separation of the non-membrane bound Sec bodies occurs in Drosophila S2 cells by coalescence of components of the endoplasmic reticulum (ER) exit sites under the stress of amino acid starvation. Here, we address which signaling pathways cause Sec body formation and find that two pathways are critical. The first is the activation of the salt-inducible kinases (SIKs; SIK2 and SIK3) by Na+ stress, which, when it is strong, is sufficient. The second is activation of IRE1 and PERK (also known as PEK in flies) downstream of ER stress induced by the absence of amino acids, which needs to be combined with moderate salt stress to induce Sec body formation. SIK, and IRE1 and PERK activation appear to potentiate each other through the stimulation of the unfolded protein response, a key parameter in Sec body formation. This work shows the role of SIKs in phase transition and re-enforces the role of IRE1 and PERK as a metabolic sensor for the level of circulating amino acids and salt. This article has an associated First Person interview with the first author of the paper. Summary: In S2 cells, the phase-separated Sec bodies form upon the combined activation of salt-inducible kinases, IRE1 and PERK.
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Affiliation(s)
- Chujun Zhang
- Hubrecht Institute of the KNAW & UMC Utrecht, Utrecht, The Netherlands
| | | | | | | | - Sem Brussee
- Hubrecht Institute of the KNAW & UMC Utrecht, Utrecht, The Netherlands
| | - Rianne Grond
- Hubrecht Institute of the KNAW & UMC Utrecht, Utrecht, The Netherlands
| | - Harm H Kampinga
- Department of Biomedical Sciences in Cells and Systems, UMC Groningen, The Netherlands
| | - Catherine Rabouille
- Hubrecht Institute of the KNAW & UMC Utrecht, Utrecht, The Netherlands.,Department of Biomedical Sciences in Cells and Systems, UMC Groningen, The Netherlands.,Section Cell Biology, Center for Molecular Medicine, University Medical Center Utrecht, The Netherlands
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23
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Mangleburg CG, Wu T, Yalamanchili HK, Guo C, Hsieh YC, Duong DM, Dammer EB, De Jager PL, Seyfried NT, Liu Z, Shulman JM. Integrated analysis of the aging brain transcriptome and proteome in tauopathy. Mol Neurodegener 2020; 15:56. [PMID: 32993812 PMCID: PMC7526226 DOI: 10.1186/s13024-020-00405-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2020] [Accepted: 09/18/2020] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND Tau neurofibrillary tangle pathology characterizes Alzheimer's disease and other neurodegenerative tauopathies. Brain gene expression profiles can reveal mechanisms; however, few studies have systematically examined both the transcriptome and proteome or differentiated Tau- versus age-dependent changes. METHODS Paired, longitudinal RNA-sequencing and mass-spectrometry were performed in a Drosophila model of tauopathy, based on pan-neuronal expression of human wildtype Tau (TauWT) or a mutant form causing frontotemporal dementia (TauR406W). Tau-induced, differentially expressed transcripts and proteins were examined cross-sectionally or using linear regression and adjusting for age. Hierarchical clustering was performed to highlight network perturbations, and we examined overlaps with human brain gene expression profiles in tauopathy. RESULTS TauWT induced 1514 and 213 differentially expressed transcripts and proteins, respectively. TauR406W had a substantially greater impact, causing changes in 5494 transcripts and 697 proteins. There was a ~ 70% overlap between age- and Tau-induced changes and our analyses reveal pervasive bi-directional interactions. Strikingly, 42% of Tau-induced transcripts were discordant in the proteome, showing opposite direction of change. Tau-responsive gene expression networks strongly implicate innate immune activation. Cross-species analyses pinpoint human brain gene perturbations specifically triggered by Tau pathology and/or aging, and further differentiate between disease amplifying and protective changes. CONCLUSIONS Our results comprise a powerful, cross-species functional genomics resource for tauopathy, revealing Tau-mediated disruption of gene expression, including dynamic, age-dependent interactions between the brain transcriptome and proteome.
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Affiliation(s)
- Carl Grant Mangleburg
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030 USA
- Medical Scientist Training Program, Baylor College of Medicine, Houston, TX 77030 USA
| | - Timothy Wu
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030 USA
- Medical Scientist Training Program, Baylor College of Medicine, Houston, TX 77030 USA
| | - Hari K. Yalamanchili
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030 USA
| | - Caiwei Guo
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030 USA
| | - Yi-Chen Hsieh
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030 USA
| | - Duc M. Duong
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322 USA
| | - Eric B. Dammer
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322 USA
| | - Philip L. De Jager
- Center for Translational & Computational Neuroimmunology, Department of Neurology and Taub Institute for the study of Alzheimer’s disease and the aging brain, Columbia University Medical Center, New York, NY 10032 USA
- Cell Circuits Program, Broad Institute, Cambridge, MA 02142 USA
| | - Nicholas T. Seyfried
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322 USA
- Department of Neurology, Emory University School of Medicine, Atlanta, GA 30322 USA
| | - Zhandong Liu
- Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030 USA
- Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, 1250 Moursund St., Suite N.1150, Houston, TX 77030 USA
| | - Joshua M. Shulman
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030 USA
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030 USA
- Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, 1250 Moursund St., Suite N.1150, Houston, TX 77030 USA
- Department of Neurology, Baylor College of Medicine, Houston, TX 77030 USA
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24
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Cendrowski J, Kaczmarek M, Mazur M, Kuzmicz-Kowalska K, Jastrzebski K, Brewinska-Olchowik M, Kominek A, Piwocka K, Miaczynska M. Splicing variation of BMP2K balances abundance of COPII assemblies and autophagic degradation in erythroid cells. eLife 2020; 9:e58504. [PMID: 32795391 PMCID: PMC7473771 DOI: 10.7554/elife.58504] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2020] [Accepted: 08/13/2020] [Indexed: 12/26/2022] Open
Abstract
Intracellular transport undergoes remodeling upon cell differentiation, which involves cell type-specific regulators. Bone morphogenetic protein 2-inducible kinase (BMP2K) has been potentially implicated in endocytosis and cell differentiation but its molecular functions remained unknown. We discovered that its longer (L) and shorter (S) splicing variants regulate erythroid differentiation in a manner unexplainable by their involvement in AP-2 adaptor phosphorylation and endocytosis. However, both variants interact with SEC16A and could localize to the juxtanuclear secretory compartment. Variant-specific depletion approach showed that BMP2K isoforms constitute a BMP2K-L/S regulatory system that controls the distribution of SEC16A and SEC24B as well as SEC31A abundance at COPII assemblies. Finally, we found L to promote and S to restrict autophagic degradation and erythroid differentiation. Hence, we propose that BMP2K-L and BMP2K-S differentially regulate abundance and distribution of COPII assemblies as well as autophagy, possibly thereby fine-tuning erythroid differentiation.
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Affiliation(s)
- Jaroslaw Cendrowski
- Laboratory of Cell Biology, International Institute of Molecular and Cell BiologyWarsawPoland
| | - Marta Kaczmarek
- Laboratory of Cell Biology, International Institute of Molecular and Cell BiologyWarsawPoland
| | - Michał Mazur
- Laboratory of Cell Biology, International Institute of Molecular and Cell BiologyWarsawPoland
| | | | - Kamil Jastrzebski
- Laboratory of Cell Biology, International Institute of Molecular and Cell BiologyWarsawPoland
| | | | - Agata Kominek
- Laboratory of Cytometry, Nencki Institute of Experimental BiologyWarsawPoland
| | - Katarzyna Piwocka
- Laboratory of Cytometry, Nencki Institute of Experimental BiologyWarsawPoland
| | - Marta Miaczynska
- Laboratory of Cell Biology, International Institute of Molecular and Cell BiologyWarsawPoland
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25
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Takagi J, Kimori Y, Shimada T, Hara-Nishimura I. Dynamic Capture and Release of Endoplasmic Reticulum Exit Sites by Golgi Stacks in Arabidopsis. iScience 2020; 23:101265. [PMID: 32585594 PMCID: PMC7322076 DOI: 10.1016/j.isci.2020.101265] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Revised: 05/09/2020] [Accepted: 06/08/2020] [Indexed: 12/21/2022] Open
Abstract
Protein transport from the endoplasmic reticulum (ER) to Golgi stacks is mediated by the coat protein complex COPII, which is assembled at an ER subdomain called ER exit site (ERES). However, the dynamic relationship between ERESs and Golgi stacks is unknown. Here, we propose a dynamic capture-and-release model of ERESs by Golgi stacks in Arabidopsis thaliana. Using variable-angle epifluorescence microscopy with high-temporal-resolution imaging, COPII-component-bound ERESs were detected as punctate structures with sizes of 300–500 nm. Some punctate ERESs are distributed on ER tubules and sheet rims, whereas others gather around a Golgi stack in an ER-network cavity to form a beaded-ring structure. Free ERESs that wander into an ER cavity are captured by a Golgi stack in a cytoskeleton-independent manner. Then, they are released by the Golgi stack for recycling. The dynamic ERES cycling might contribute to efficient transfer of de novo synthesized cargo proteins from the ER to Golgi stacks. VAEM images show dynamic behavior of minimal punctate ERESs Most of punctate ERESs are distributed on the ER network tubes Several punctate ERESs contact with a Golgi stack in an ER network cavity ERESs are dynamically captured and released by Golgi stacks
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Affiliation(s)
- Junpei Takagi
- Faculty of Science and Engineering, Konan University, Kobe 658-8501, Japan
| | - Yoshitaka Kimori
- Faculty of Environmental and Information Sciences, Fukui University of Technology, Fukui 910-8505, Japan
| | - Tomoo Shimada
- Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
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26
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Abstract
In consistent with other membrane-bound and secretory proteins, immune checkpoint proteins go through a set of modifications in the endoplasmic reticulum (ER) to acquire their native functional structures before they function at their destinations. There are various ER-resident chaperones and enzymes synergistically regulate and catalyze the glycosylation, folding and transporting of proteins. The whole processing is under the surveillance of ER quality control system which allows the correctly folded proteins to exit from the ER with the help of coat proteinII(COPII) coated vesicles, while retains the rest of terminally misfolded ones in the ER and then eliminates them via ER-associated degradation (ERAD) or ER-to-lysosomes-associated degradation (ERLAD). The dysfunction of the ER causes ER stress which triggers unfolded protein response (UPR) to restore ER proteostasis. Unsolvable prolonged ER stress ultimately results in cell death. This chapter reviews the process that proteins undergo in the ER, and the glycosylation, folding and degradation of immune checkpoint proteins as well as the associated potential immunotherapies to date.
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27
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The organization of Golgi in Drosophila bristles requires microtubule motor protein function and a properly organized microtubule array. PLoS One 2019; 14:e0223174. [PMID: 31577833 PMCID: PMC6774520 DOI: 10.1371/journal.pone.0223174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2019] [Accepted: 09/16/2019] [Indexed: 11/20/2022] Open
Abstract
In the present report, we used highly elongated Drosophila bristle cells to dissect the role of dynein heavy chain (Dhc64C) in Golgi organization. We demonstrated that whereas in the bristle "somal" region Golgi units are composed of cis-, medial, and trans-Golgi compartments ("complete Golgi"), the bristle shaft contains Golgi satellites that lack the trans-Golgi compartment (hereafter referred to as "incomplete Golgi") and which are static and localized at the base area. However, in Dhc64C mutants, the entire bristle shaft was filled with complete Golgi units containing ectopic trans-Golgi components. To further understand Golgi bristle organization, we tested the roles of microtubule (MT) polarity and the Dhc-opposing motor, kinesin heavy chain (Khc). For our surprise, we found that in Khc and Ik2Dominant-negative (DN) flies in which the polarized organization of MTs is affected, the bristle shaft was filled with complete Golgi, similarly to what is seen in Dhc64C flies. Thus, we demonstrated that MTs and the motor proteins Dhc and Khc are required for bristle Golgi organization. However, the fact that both Dhc64C and Khc flies showed similar Golgi defects calls for an additional work to elucidate the molecular mechanism describing why these factors are required for bristle Golgi organization.
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28
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Zhang C, Rabouille C. Membrane-Bound Meet Membraneless in Health and Disease. Cells 2019; 8:cells8091000. [PMID: 31470564 PMCID: PMC6770257 DOI: 10.3390/cells8091000] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 08/26/2019] [Accepted: 08/27/2019] [Indexed: 12/12/2022] Open
Abstract
Membraneless organelles (MLOs) are defined as cellular structures that are not sealed by a lipidic membrane and are shown to form by phase separation. They exist in both the nucleus and the cytoplasm that is also heavily populated by numerous membrane-bound organelles. Even though the name membraneless suggests that MLOs are free of membrane, both membrane and factors regulating membrane trafficking steps are emerging as important components of MLO formation and function. As a result, we name them biocondensates. In this review, we examine the relationships between biocondensates and membrane. First, inhibition of membrane trafficking in the early secretory pathway leads to the formation of biocondensates (P-bodies and Sec bodies). In the same vein, stress granules have a complex relationship with the cyto-nuclear transport machinery. Second, membrane contributes to the regulated formation of phase separation in the cells and we will present examples including clustering at the plasma membrane and at the synapse. Finally, the whole cell appears to transit from an interphase phase-separated state to a mitotic diffuse state in a DYRK3 dependent manner. This firmly establishes a crosstalk between the two types of cell organization that will need to be further explored.
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Affiliation(s)
- Chujun Zhang
- Hubrecht Institute of the Royal Netherlands Academy of Arts and Sciences, and University Medical Center Utrecht, 3584 CT Utrecht, The Netherlands
| | - Catherine Rabouille
- Hubrecht Institute of the Royal Netherlands Academy of Arts and Sciences, and University Medical Center Utrecht, 3584 CT Utrecht, The Netherlands.
- Department of Biomedical Science of Cells and Systems, University Medical Center Groningen, 9713 AV Groningen, The Netherlands.
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29
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Centonze FG, Farhan H. Crosstalk of endoplasmic reticulum exit sites and cellular signaling. FEBS Lett 2019; 593:2280-2288. [DOI: 10.1002/1873-3468.13569] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Revised: 07/28/2019] [Accepted: 07/29/2019] [Indexed: 12/21/2022]
Affiliation(s)
- Federica G. Centonze
- Institute of Basic Medical Sciences, Department of Molecular Medicine University of Oslo Norway
| | - Hesso Farhan
- Institute of Basic Medical Sciences, Department of Molecular Medicine University of Oslo Norway
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30
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Aridor M. COPII gets in shape: Lessons derived from morphological aspects of early secretion. Traffic 2018; 19:823-839. [DOI: 10.1111/tra.12603] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Revised: 06/26/2018] [Accepted: 07/04/2018] [Indexed: 12/13/2022]
Affiliation(s)
- Meir Aridor
- Department of Cell Biology; University of Pittsburgh School of Medicine; Pittsburgh Pennsylvania
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31
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Aguilera-Gomez A, Zacharogianni M, van Oorschot MM, Genau H, Grond R, Veenendaal T, Sinsimer KS, Gavis ER, Behrends C, Rabouille C. Phospho-Rasputin Stabilization by Sec16 Is Required for Stress Granule Formation upon Amino Acid Starvation. Cell Rep 2018; 20:935-948. [PMID: 28746877 DOI: 10.1016/j.celrep.2017.06.042] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Revised: 04/22/2017] [Accepted: 06/16/2017] [Indexed: 12/15/2022] Open
Abstract
Most cellular stresses induce protein translation inhibition and stress granule formation. Here, using Drosophila S2 cells, we investigate the role of G3BP/Rasputin in this process. In contrast to arsenite treatment, where dephosphorylated Ser142 Rasputin is recruited to stress granules, we find that, upon amino acid starvation, only the phosphorylated Ser142 form is recruited. Furthermore, we identify Sec16, a component of the endoplasmic reticulum exit site, as a Rasputin interactor and stabilizer. Sec16 depletion results in Rasputin degradation and inhibition of stress granule formation. However, in the absence of Sec16, pharmacological stabilization of Rasputin is not enough to rescue the assembly of stress granules. This is because Sec16 specifically interacts with phosphorylated Ser142 Rasputin, the form required for stress granule formation upon amino acid starvation. Taken together, these results demonstrate that stress granule formation is fine-tuned by specific signaling cues that are unique to each stress. These results also expand the role of Sec16 as a stress response protein.
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Affiliation(s)
- Angelica Aguilera-Gomez
- Hubrecht Institute-KNAW & University Medical Center (UMC) Utrecht, Uppsalalaan 8, 3584 CT Utrecht, the Netherlands
| | - Margarita Zacharogianni
- Hubrecht Institute-KNAW & University Medical Center (UMC) Utrecht, Uppsalalaan 8, 3584 CT Utrecht, the Netherlands
| | - Marinke M van Oorschot
- Hubrecht Institute-KNAW & University Medical Center (UMC) Utrecht, Uppsalalaan 8, 3584 CT Utrecht, the Netherlands
| | - Heide Genau
- Institute of Biochemistry II, Medical School Goethe University, 60323 Frankfurt am Main, Germany
| | - Rianne Grond
- Hubrecht Institute-KNAW & University Medical Center (UMC) Utrecht, Uppsalalaan 8, 3584 CT Utrecht, the Netherlands
| | - Tineke Veenendaal
- Department of Cell Biology, UMC Utrecht, 3584 CT Utrecht, the Netherlands
| | - Kristina S Sinsimer
- Department of Molecular Biology, Princeton University, Washington Road, Princeton, NJ 08544, USA
| | - Elizabeth R Gavis
- Department of Molecular Biology, Princeton University, Washington Road, Princeton, NJ 08544, USA
| | - Christian Behrends
- Institute of Biochemistry II, Medical School Goethe University, 60323 Frankfurt am Main, Germany
| | - Catherine Rabouille
- Hubrecht Institute-KNAW & University Medical Center (UMC) Utrecht, Uppsalalaan 8, 3584 CT Utrecht, the Netherlands; Department of Cell Biology, UMC Utrecht, 3584 CT Utrecht, the Netherlands; Department of Cell Biology, UMC Groningen, 9713 GZ Groningen, the Netherlands.
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32
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van Leeuwen W, van der Krift F, Rabouille C. Modulation of the secretory pathway by amino-acid starvation. J Cell Biol 2018; 217:2261-2271. [PMID: 29669743 PMCID: PMC6028531 DOI: 10.1083/jcb.201802003] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Revised: 03/28/2018] [Accepted: 03/29/2018] [Indexed: 12/30/2022] Open
Abstract
As a major anabolic pathway, the secretory pathway needs to adapt to the demands of the surrounding environment and responds to different exogenous signals and stimuli. In this context, the transport in the early secretory pathway from the endoplasmic reticulum (ER) to the Golgi apparatus appears particularly regulated. For instance, protein export from the ER is critically stimulated by growth factors. Conversely, nutrient starvation also modulates functions of the early secretory pathway in multiple ways. In this review, we focus on amino-acid starvation and how the function of the early secretory pathway is redirected to fuel autophagy, how the ER exit sites are remodeled into novel cytoprotective stress assemblies, and how secretion is modulated in vivo in starving organisms. With the increasingly exciting knowledge on mechanistic target of rapamycin complex 1 (mTORC1), the major nutrient sensor, it is also a good moment to establish how the modulation of the secretory pathway by amino-acid restriction intersects with this major signaling hub.
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Affiliation(s)
- Wessel van Leeuwen
- Hubrecht Institute of the Royal Netherlands Academy of Arts and Sciences and University Medical Center Utrecht, Utrecht, Netherlands
| | - Felix van der Krift
- Hubrecht Institute of the Royal Netherlands Academy of Arts and Sciences and University Medical Center Utrecht, Utrecht, Netherlands
| | - Catherine Rabouille
- Hubrecht Institute of the Royal Netherlands Academy of Arts and Sciences and University Medical Center Utrecht, Utrecht, Netherlands .,Department of Cell Biology, University Medical Center Groningen, Groningen, Netherlands
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33
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Bourke AM, Bowen AB, Kennedy MJ. New approaches for solving old problems in neuronal protein trafficking. Mol Cell Neurosci 2018; 91:48-66. [PMID: 29649542 DOI: 10.1016/j.mcn.2018.04.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Revised: 04/05/2018] [Accepted: 04/06/2018] [Indexed: 11/16/2022] Open
Abstract
Fundamental cellular properties are determined by the repertoire and abundance of proteins displayed on the cell surface. As such, the trafficking mechanisms for establishing and maintaining the surface proteome must be tightly regulated for cells to respond appropriately to extracellular cues, yet plastic enough to adapt to ever-changing environments. Not only are the identity and abundance of surface proteins critical, but in many cases, their regulated spatial positioning within surface nanodomains can greatly impact their function. In the context of neuronal cell biology, surface levels and positioning of ion channels and neurotransmitter receptors play essential roles in establishing important properties, including cellular excitability and synaptic strength. Here we review our current understanding of the trafficking pathways that control the abundance and localization of proteins important for synaptic function and plasticity, as well as recent technological advances that are allowing the field to investigate protein trafficking with increasing spatiotemporal precision.
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Affiliation(s)
- Ashley M Bourke
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO, United States
| | - Aaron B Bowen
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO, United States
| | - Matthew J Kennedy
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO, United States.
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34
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Wang Q, Wang Y, Yu F. Yif1 associates with Yip1 on Golgi and regulates dendrite pruning in sensory neurons during Drosophila metamorphosis. Development 2018; 145:dev.164475. [DOI: 10.1242/dev.164475] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Accepted: 05/09/2018] [Indexed: 01/21/2023]
Abstract
Pruning that selectively removes unnecessary neurites without causing neuronal death is essential for sculpting the mature nervous system during development. In Drosophila, ddaC sensory neurons specifically prune their larval dendrites with intact axons during metamorphosis. However, it remains unknown about an important role of ER-to-Golgi transport in dendrite pruning. Here, in a clonal screen we identified Yif1, an uncharacterized Drosophila homologue of Yif1p that is known as a regulator of ER-to-Golgi transport in yeast. We show that Yif1 is required for dendrite pruning of ddaC neurons but not for apoptosis of ddaF neurons. We further identified the Yif1-binding partner Yip1 which is also crucial for dendrite pruning. Yif1 forms a protein complex with Yip1 in S2 cells and ddaC neurons. Yip1 and Yif1 colocalize on ER/Golgi and are required for the integrity of Golgi apparatus and outposts. Moreover, we show that two GTPases Rab1 and Sar1, known to regulate ER-to-Golgi transport, are essential for dendrite pruning of ddaC neurons. Finally, our data reveal that ER-to-Golgi transport promotes endocytosis and downregulation of cell adhesion molecule Neuroglian and thereby dendrite pruning.
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Affiliation(s)
- Qiwei Wang
- Temasek Life Sciences Laboratory and Department of Biological Sciences, 1 Research Link, National University of Singapore, Singapore 117604
| | - Yan Wang
- Temasek Life Sciences Laboratory and Department of Biological Sciences, 1 Research Link, National University of Singapore, Singapore 117604
- NUS Graduate School for Integrative Sciences and Engineering, Centre for Life Sciences, Singapore 117456
| | - Fengwei Yu
- Temasek Life Sciences Laboratory and Department of Biological Sciences, 1 Research Link, National University of Singapore, Singapore 117604
- NUS Graduate School for Integrative Sciences and Engineering, Centre for Life Sciences, Singapore 117456
- Neuroscience and Behavioral Disorder Program, Duke-NUS Graduate Medical School Singapore, 8 College Road, Singapore 169857
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35
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Riedel F, Galindo A, Muschalik N, Munro S. The two TRAPP complexes of metazoans have distinct roles and act on different Rab GTPases. J Cell Biol 2017; 217:601-617. [PMID: 29273580 PMCID: PMC5800803 DOI: 10.1083/jcb.201705068] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Revised: 10/19/2017] [Accepted: 11/27/2017] [Indexed: 12/03/2022] Open
Abstract
In yeast, the TRAPP complexes activate Rab1 with TRAPPII also activating Rab11, but less is known about the two TRAPPs in metazoans. Riedel et al. show that in Drosophila melanogaster, TRAPPIII is an essential Rab1 activator, and TRAPPII activates Rab1 and Rab11 and becomes essential when an unrelated Rab11 activator is deleted. Originally identified in yeast, transport protein particle (TRAPP) complexes are Rab GTPase exchange factors that share a core set of subunits. TRAPPs were initially found to act on Ypt1, the yeast orthologue of Rab1, but recent studies have found that yeast TRAPPII can also activate the Rab11 orthologues Ypt31/32. Mammals have two TRAPP complexes, but their role is less clear, and they contain subunits that are not found in the yeast complexes but are essential for cell growth. To investigate TRAPP function in metazoans, we show that Drosophila melanogaster have two TRAPP complexes similar to those in mammals and that both activate Rab1, whereas one, TRAPPII, also activates Rab11. TRAPPII is not essential but becomes so in the absence of the gene parcas that encodes the Drosophila orthologue of the SH3BP5 family of Rab11 guanine nucleotide exchange factors (GEFs). Thus, in metazoans, Rab1 activation requires TRAPP subunits not found in yeast, and Rab11 activation is shared by TRAPPII and an unrelated GEF that is metazoan specific.
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Affiliation(s)
- Falko Riedel
- Medical Research Council Laboratory of Molecular Biology, Cambridge, England, UK
| | - Antonio Galindo
- Medical Research Council Laboratory of Molecular Biology, Cambridge, England, UK
| | - Nadine Muschalik
- Medical Research Council Laboratory of Molecular Biology, Cambridge, England, UK
| | - Sean Munro
- Medical Research Council Laboratory of Molecular Biology, Cambridge, England, UK
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36
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Saito K, Maeda M, Katada T. Regulation of the Sar1 GTPase Cycle Is Necessary for Large Cargo Secretion from the Endoplasmic Reticulum. Front Cell Dev Biol 2017; 5:75. [PMID: 28879181 PMCID: PMC5572378 DOI: 10.3389/fcell.2017.00075] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Accepted: 08/10/2017] [Indexed: 12/22/2022] Open
Abstract
Proteins synthesized within the endoplasmic reticulum (ER) are transported to the Golgi via coat protein complex II (COPII)-coated vesicles. The formation of COPII-coated vesicles is regulated by the GTPase cycle of Sar1. Activated Sar1 is recruited to ER membranes and forms a pre-budding complex with cargoes and the inner-coat complex. The outer-coat complex then stimulates Sar1 inactivation and completes vesicle formation. The mechanisms of forming transport carriers are well-conserved among species; however, in mammalian cells, several cargo molecules such as collagen, and chylomicrons are too large to be accommodated in conventional COPII-coated vesicles. Thus, special cargo-receptor complexes are required for their export from the ER. cTAGE5/TANGO1 complexes and their isoforms have been identified as cargo receptors for these macromolecules. Recent reports suggest that the cTAGE5/TANGO1 complex interacts with the GEF and the GAP of Sar1 and tightly regulates its GTPase cycle to accomplish large cargo secretion.
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Affiliation(s)
- Kota Saito
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, University of TokyoTokyo, Japan
| | - Miharu Maeda
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, University of TokyoTokyo, Japan
| | - Toshiaki Katada
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, University of TokyoTokyo, Japan
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37
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Iwasaki H, Yorimitsu T, Sato K. Microscopy analysis of reconstituted COPII coat polymerization and Sec16 dynamics. J Cell Sci 2017; 130:2893-2902. [PMID: 28747320 DOI: 10.1242/jcs.203844] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Accepted: 07/14/2017] [Indexed: 01/10/2023] Open
Abstract
The COPII coat and the small GTPase Sar1 mediate protein export from the endoplasmic reticulum (ER) via specialized domains known as the ER exit sites. The peripheral ER protein Sec16 has been proposed to organize ER exit sites. However, it remains unclear how these molecules drive COPII coat polymerization. Here, we characterized the spatiotemporal relationships between the Saccharomyces cerevisiae COPII components during their polymerization by performing fluorescence microscopy of an artificial planar membrane. We demonstrated that Sar1 dissociates from the membrane shortly after the COPII coat recruitment, and Sar1 is then no longer required for the COPII coat to bind to the membrane. Furthermore, we found that Sec16 is incorporated within the COPII-cargo clusters, and that this is dependent on the Sar1 GTPase cycle. These data show how Sar1 drives the polymerization of COPII coat and how Sec16 is spatially distributed during COPII coat polymerization.
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Affiliation(s)
- Hirohiko Iwasaki
- Department of Life Sciences, Graduate School of Arts and Sciences, University of Tokyo, Komaba, Meguro-ku, Tokyo 153-8902, Japan
| | - Tomohiro Yorimitsu
- Department of Life Sciences, Graduate School of Arts and Sciences, University of Tokyo, Komaba, Meguro-ku, Tokyo 153-8902, Japan
| | - Ken Sato
- Department of Life Sciences, Graduate School of Arts and Sciences, University of Tokyo, Komaba, Meguro-ku, Tokyo 153-8902, Japan
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38
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Joshi AS, Zhang H, Prinz WA. Organelle biogenesis in the endoplasmic reticulum. Nat Cell Biol 2017; 19:876-882. [DOI: 10.1038/ncb3579] [Citation(s) in RCA: 71] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2017] [Accepted: 06/21/2017] [Indexed: 12/16/2022]
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39
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Cook MS, Cazin C, Amoyel M, Yamamoto S, Bach E, Nystul T. Neutral Competition for Drosophila Follicle and Cyst Stem Cell Niches Requires Vesicle Trafficking Genes. Genetics 2017; 206:1417-1428. [PMID: 28512187 PMCID: PMC5500140 DOI: 10.1534/genetics.117.201202] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Accepted: 05/10/2017] [Indexed: 12/03/2022] Open
Abstract
The process of selecting for cellular fitness through competition plays a critical role in both development and disease. The germarium, a structure at the tip of the ovariole of a Drosophila ovary, contains two follicle stem cells (FSCs) that undergo neutral competition for the stem cell niche. Using the FSCs as a model, we performed a genetic screen through a collection of 126 mutants in essential genes on the X chromosome to identify candidates that increase or decrease competition for the FSC niche. We identified ∼55 and 6% of the mutations screened as putative FSC hypo- or hyper-competitors, respectively. We found that a large majority of mutations in vesicle trafficking genes (11 out of the 13 in the collection of mutants) are candidate hypo-competition alleles, and we confirmed the hypo-competition phenotype for four of these alleles. We also show that Sec16 and another COPII vesicle trafficking component, Sar1, are required for follicle cell differentiation. Lastly, we demonstrate that, although some components of vesicle trafficking are also required for neutral competition in the cyst stem cells of the testis, there are important tissue-specific differences. Our results demonstrate a critical role for vesicle trafficking in stem cell niche competition and differentiation, and we identify a number of putative candidates for further exploration.
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Affiliation(s)
- Matthew S Cook
- Center for Reproductive Sciences, University of California, San Francisco, California 94143-0452
- Department of Anatomy, University of California, San Francisco, California 94143-0452
- Department of Obstetrics, Gynecology and Reproductive Sciences, University of California, San Francisco, California 94143-0452
| | - Coralie Cazin
- The Helen and Martin Kimmel Center for Stem Cell Biology, New York University School of Medicine, New York 10016
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York 10016
| | - Marc Amoyel
- The Helen and Martin Kimmel Center for Stem Cell Biology, New York University School of Medicine, New York 10016
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York 10016
- School of Cellular and Molecular Medicine, University of Bristol, BS8 1TD, United Kingdom
| | - Shinya Yamamoto
- Department of Molecular and Human Genetics, Program in Developmental Biology, Baylor College of Medicine, Houston, Texas 77030
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, Texas 77030
| | - Erika Bach
- The Helen and Martin Kimmel Center for Stem Cell Biology, New York University School of Medicine, New York 10016
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York 10016
| | - Todd Nystul
- Center for Reproductive Sciences, University of California, San Francisco, California 94143-0452
- Department of Anatomy, University of California, San Francisco, California 94143-0452
- Department of Obstetrics, Gynecology and Reproductive Sciences, University of California, San Francisco, California 94143-0452
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40
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Maeda M, Katada T, Saito K. TANGO1 recruits Sec16 to coordinately organize ER exit sites for efficient secretion. J Cell Biol 2017; 216:1731-1743. [PMID: 28442536 PMCID: PMC5461033 DOI: 10.1083/jcb.201703084] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Revised: 04/11/2017] [Accepted: 04/12/2017] [Indexed: 12/27/2022] Open
Abstract
Mammalian endoplasmic reticulum (ER) exit sites export a variety of cargo molecules including oversized cargoes such as collagens. However, the mechanisms of their assembly and organization are not fully understood. TANGO1L is characterized as a collagen receptor, but the function of TANGO1S remains to be investigated. Here, we show that direct interaction between both isoforms of TANGO1 and Sec16 is not only important for their correct localization but also critical for the organization of ER exit sites. The depletion of TANGO1 disassembles COPII components as well as membrane-bound ER-resident complexes, resulting in fewer functional ER exit sites and delayed secretion. The ectopically expressed TANGO1 C-terminal domain responsible for Sec16 binding in mitochondria is capable of recruiting Sec16 and other COPII components. Moreover, TANGO1 recruits membrane-bound macromolecular complexes consisting of cTAGE5 and Sec12 to the ER exit sites. These data suggest that mammalian ER exit sites are organized by TANGO1 acting as a scaffold, in cooperation with Sec16 for efficient secretion.
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Affiliation(s)
- Miharu Maeda
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, University of Tokyo, Tokyo 113-0033, Japan
| | - Toshiaki Katada
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, University of Tokyo, Tokyo 113-0033, Japan
| | - Kota Saito
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, University of Tokyo, Tokyo 113-0033, Japan
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41
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Liu M, Feng Z, Ke H, Liu Y, Sun T, Dai J, Cui W, Pastor-Pareja JC. Tango1 spatially organizes ER exit sites to control ER export. J Cell Biol 2017; 216:1035-1049. [PMID: 28280122 PMCID: PMC5379956 DOI: 10.1083/jcb.201611088] [Citation(s) in RCA: 70] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Revised: 01/10/2017] [Accepted: 01/11/2017] [Indexed: 01/03/2023] Open
Abstract
Exit of secretory cargo from the endoplasmic reticulum (ER) takes place at specialized domains called ER exit sites (ERESs). In mammals, loss of TANGO1 and other MIA/cTAGE (melanoma inhibitory activity/cutaneous T cell lymphoma-associated antigen) family proteins prevents ER exit of large cargoes such as collagen. Here, we show that Drosophila melanogaster Tango1, the only MIA/cTAGE family member in fruit flies, is a critical organizer of the ERES-Golgi interface. Tango1 rings hold COPII (coat protein II) carriers and Golgi in close proximity at their center. Loss of Tango1, present at ERESs in all tissues, reduces ERES size and causes ERES-Golgi uncoupling, which impairs secretion of not only collagen, but also all other cargoes we examined. Further supporting an organizing role of Tango1, its overexpression creates more and larger ERESs. Our results suggest that spatial coordination of ERES, carrier, and Golgi elements through Tango1's multiple interactions increases secretory capacity in Drosophila and allows secretion of large cargo.
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Affiliation(s)
- Min Liu
- School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Zhi Feng
- School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Hongmei Ke
- School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Ying Liu
- School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Tianhui Sun
- School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Jianli Dai
- School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Wenhong Cui
- School of Life Sciences, Tsinghua University, Beijing 100084, China
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42
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Vonk JJ, Yeshaw WM, Pinto F, Faber AIE, Lahaye LL, Kanon B, van der Zwaag M, Velayos-Baeza A, Freire R, van IJzendoorn SC, Grzeschik NA, Sibon OCM. Drosophila Vps13 Is Required for Protein Homeostasis in the Brain. PLoS One 2017; 12:e0170106. [PMID: 28107480 PMCID: PMC5249141 DOI: 10.1371/journal.pone.0170106] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Accepted: 12/10/2016] [Indexed: 11/22/2022] Open
Abstract
Chorea-Acanthocytosis is a rare, neurodegenerative disorder characterized by progressive loss of locomotor and cognitive function. It is caused by loss of function mutations in the Vacuolar Protein Sorting 13A (VPS13A) gene, which is conserved from yeast to human. The consequences of VPS13A dysfunction in the nervous system are still largely unspecified. In order to study the consequences of VPS13A protein dysfunction in the ageing central nervous system we characterized a Drosophila melanogaster Vps13 mutant line. The Drosophila Vps13 gene encoded a protein of similar size as human VPS13A. Our data suggest that Vps13 is a peripheral membrane protein located to endosomal membranes and enriched in the fly head. Vps13 mutant flies showed a shortened life span and age associated neurodegeneration. Vps13 mutant flies were sensitive to proteotoxic stress and accumulated ubiquitylated proteins. Levels of Ref(2)P, the Drosophila orthologue of p62, were increased and protein aggregates accumulated in the central nervous system. Overexpression of the human Vps13A protein in the mutant flies partly rescued apparent phenotypes. This suggests a functional conservation of human VPS13A and Drosophila Vps13. Our results demonstrate that Vps13 is essential to maintain protein homeostasis in the larval and adult Drosophila brain. Drosophila Vps13 mutants are suitable to investigate the function of Vps13 in the brain, to identify genetic enhancers and suppressors and to screen for potential therapeutic targets for Chorea-Acanthocytosis.
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Affiliation(s)
- Jan J. Vonk
- Department of Cell Biology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Wondwossen M. Yeshaw
- Department of Cell Biology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Francesco Pinto
- Department of Cell Biology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Anita I. E. Faber
- Department of Cell Biology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Liza L. Lahaye
- Department of Cell Biology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Bart Kanon
- Department of Cell Biology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Marianne van der Zwaag
- Department of Cell Biology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | | | - Raimundo Freire
- Unidad de Investigación, Hospital Universitario de Canarias, Instituto de Tecnologías Biomédicas, Ofra s/n, La Laguna, Tenerife, Spain
| | - Sven C. van IJzendoorn
- Department of Cell Biology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Nicola A. Grzeschik
- Department of Cell Biology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Ody C. M. Sibon
- Department of Cell Biology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
- * E-mail:
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43
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Piao H, Kim J, Noh SH, Kweon HS, Kim JY, Lee MG. Sec16A is critical for both conventional and unconventional secretion of CFTR. Sci Rep 2017; 7:39887. [PMID: 28067262 PMCID: PMC5220342 DOI: 10.1038/srep39887] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2016] [Accepted: 11/29/2016] [Indexed: 12/16/2022] Open
Abstract
CFTR is a transmembrane protein that reaches the cell surface via the conventional Golgi mediated secretion pathway. Interestingly, ER-to-Golgi blockade or ER stress induces alternative GRASP-mediated, Golgi-bypassing unconventional trafficking of wild-type CFTR and the disease-causing ΔF508-CFTR, which has folding and trafficking defects. Here, we show that Sec16A, the key regulator of conventional ER-to-Golgi transport, plays a critical role in the ER exit of protein cargos during unconventional secretion. In an initial gene silencing screen, Sec16A knockdown abolished the unconventional secretion of wild-type and ΔF508-CFTR induced by ER-to-Golgi blockade, whereas the knockdown of other COPII-related components did not. Notably, during unconventional secretion, Sec16A was redistributed to cell periphery and associated with GRASP55 in mammalian cells. Molecular and morphological analyses revealed that IRE1α-mediated signaling is an upstream regulator of Sec16A during ER-to-Golgi blockade or ER stress associated unconventional secretion. These findings highlight a novel function of Sec16A as an essential mediator of ER stress-associated unconventional secretion.
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44
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Aguilera-Gomez A, van Oorschot MM, Veenendaal T, Rabouille C. In vivo vizualisation of mono-ADP-ribosylation by dPARP16 upon amino-acid starvation. eLife 2016; 5. [PMID: 27874829 PMCID: PMC5127640 DOI: 10.7554/elife.21475] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Accepted: 11/21/2016] [Indexed: 01/08/2023] Open
Abstract
PARP catalysed ADP-ribosylation is a post-translational modification involved in several physiological and pathological processes, including cellular stress. In order to visualise both Poly-, and Mono-, ADP-ribosylation in vivo, we engineered specific fluorescent probes. Using them, we show that amino-acid starvation triggers an unprecedented display of mono-ADP-ribosylation that governs the formation of Sec body, a recently identified stress assembly that forms in Drosophila cells. We show that dPARP16 catalytic activity is necessary and sufficient for both amino-acid starvation induced mono-ADP-ribosylation and subsequent Sec body formation and cell survival. Importantly, dPARP16 catalyses the modification of Sec16, a key Sec body component, and we show that it is a critical event for the formation of this stress assembly. Taken together our findings establish a novel example for the role of mono-ADP-ribosylation in the formation of stress assemblies, and link this modification to a metabolic stress. DOI:http://dx.doi.org/10.7554/eLife.21475.001
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Affiliation(s)
- Angelica Aguilera-Gomez
- Hubrecht Institute-KNAW, Utrecht, The Netherlands.,University Medical Center Utrecht, Utrecht, Netherlands
| | - Marinke M van Oorschot
- Hubrecht Institute-KNAW, Utrecht, The Netherlands.,University Medical Center Utrecht, Utrecht, Netherlands
| | - Tineke Veenendaal
- Department of Cell Biology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Catherine Rabouille
- Hubrecht Institute-KNAW, Utrecht, The Netherlands.,University Medical Center Utrecht, Utrecht, Netherlands.,Department of Cell Biology, University Medical Center Utrecht, Utrecht, The Netherlands
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45
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Sec16 alternative splicing dynamically controls COPII transport efficiency. Nat Commun 2016; 7:12347. [PMID: 27492621 PMCID: PMC4980449 DOI: 10.1038/ncomms12347] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Accepted: 06/24/2016] [Indexed: 12/18/2022] Open
Abstract
The transport of secretory proteins from the endoplasmic reticulum (ER) to the Golgi depends on COPII-coated vesicles. While the basic principles of the COPII machinery have been identified, it remains largely unknown how COPII transport is regulated to accommodate tissue- or activation-specific differences in cargo load and identity. Here we show that activation-induced alternative splicing of Sec16 controls adaptation of COPII transport to increased secretory cargo upon T-cell activation. Using splice-site blocking morpholinos and CRISPR/Cas9-mediated genome engineering, we show that the number of ER exit sites, COPII dynamics and transport efficiency depend on Sec16 alternative splicing. As the mechanistic basis, we suggest the C-terminal Sec16 domain to be a splicing-controlled protein interaction platform, with individual isoforms showing differential abilities to recruit COPII components. Our work connects the COPII pathway with alternative splicing, adding a new regulatory layer to protein secretion and its adaptation to changing cellular environments. The transport of secretory proteins from the endoplasmic reticulum to the Golgi depends on COPII-coated vesicles. Here, the authors show that activation-induced alternative splicing of Sec16 controls adaptation of COPII transport to increased secretory cargo upon T cell activation.
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46
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Kurokawa K, Suda Y, Nakano A. Sar1 localizes at the rims of COPII-coated membranes in vivo. J Cell Sci 2016; 129:3231-7. [PMID: 27432890 PMCID: PMC5047700 DOI: 10.1242/jcs.189423] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Accepted: 07/12/2016] [Indexed: 12/31/2022] Open
Abstract
The Sar1 GTPase controls coat assembly on coat protein complex II (COPII)-coated vesicles, which mediate protein transport from the endoplasmic reticulum (ER) to the Golgi. The GTP-bound form of Sar1, activated by the ER-localized guanine nucleotide exchange factor (GEF) Sec12, associates with the ER membrane. GTP hydrolysis by Sar1, stimulated by the COPII-vesicle-localized GTPase-activating protein (GAP) Sec23, in turn causes Sar1 to dissociate from the membrane. Thus, Sar1 is cycled between active and inactive states, and on and off vesicle membranes, but its precise spatiotemporal regulation remains unknown. Here, we examined Sar1 localization on COPII-coated membranes in living Saccharomyces cerevisiae cells. Two-dimensional (2D) observation demonstrated that Sar1 showed modest accumulation around the ER exit sites (ERES) in a manner that was dependent on Sec16 function. Detailed three-dimensional (3D) observation further demonstrated that Sar1 localized at the rims of the COPII-coated membranes, but was excluded from the rest of the COPII membranes. Additionally, a GTP-locked form of Sar1 induced abnormally enlarged COPII-coated structures and covered the entirety of these structures. These results suggested that the reversible membrane association of Sar1 GTPase leads to its localization being restricted to the rims of COPII-coated membranes in vivo.
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Affiliation(s)
- Kazuo Kurokawa
- Live Cell Super-Resolution Imaging Research Team, RIKEN Center for Advanced Photonics, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Yasuyuki Suda
- Live Cell Super-Resolution Imaging Research Team, RIKEN Center for Advanced Photonics, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan Laboratory of Molecular Cell Biology, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
| | - Akihiko Nakano
- Live Cell Super-Resolution Imaging Research Team, RIKEN Center for Advanced Photonics, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
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47
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Riedel F, Gillingham AK, Rosa-Ferreira C, Galindo A, Munro S. An antibody toolkit for the study of membrane traffic in Drosophila melanogaster. Biol Open 2016; 5:987-92. [PMID: 27256406 PMCID: PMC4958275 DOI: 10.1242/bio.018937] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The use of Drosophila melanogaster as a model organism has been pivotal to understanding the developmental processes of metazoans. However, the use of flies for studying subcellular organization is hampered by a paucity of reliable reagents to label specific organelles. Here, we describe the generation of mouse monoclonal antibodies against a set of markers of the secretory and endocytic pathways, along with goat polyclonal antibodies against two Golgi proteins. We show that the monoclonal antibodies are highly specific and sufficiently sensitive to detect endogenous proteins in crude extracts by immunoblotting with little background staining. By immunofluorescence the major compartments of the membrane traffic system (including the endoplasmic reticulum, the Golgi, and early and late endosomes) are labeled by at least one antibody. Moreover, the antibodies can be used to label organelles in fly tissues including salivary glands and wing imaginal discs. We anticipate that these antibodies will provide a useful tool kit to facilitate the investigation of how the endomembrane system functions and varies in the diverse tissue types of metazoans. Summary: We report the generation and characterization of set of monoclonal and polyclonal antibodies for labeling the major compartments of the secretory and endocytic pathways in Drosophila melanogaster.
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Affiliation(s)
- Falko Riedel
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Alison K Gillingham
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Cláudia Rosa-Ferreira
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Antonio Galindo
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Sean Munro
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Francis Crick Avenue, Cambridge CB2 0QH, UK
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48
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Hanna MG, Mela I, Wang L, Henderson RM, Chapman ER, Edwardson JM, Audhya A. Sar1 GTPase Activity Is Regulated by Membrane Curvature. J Biol Chem 2015; 291:1014-27. [PMID: 26546679 PMCID: PMC4714187 DOI: 10.1074/jbc.m115.672287] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Indexed: 12/15/2022] Open
Abstract
The majority of biosynthetic secretory proteins initiate their journey through the endomembrane system from specific subdomains of the endoplasmic reticulum. At these locations, coated transport carriers are generated, with the Sar1 GTPase playing a critical role in membrane bending, recruitment of coat components, and nascent vesicle formation. How these events are appropriately coordinated remains poorly understood. Here, we demonstrate that Sar1 acts as the curvature-sensing component of the COPII coat complex and highlight the ability of Sar1 to bind more avidly to membranes of high curvature. Additionally, using an atomic force microscopy-based approach, we further show that the intrinsic GTPase activity of Sar1 is necessary for remodeling lipid bilayers. Consistent with this idea, Sar1-mediated membrane remodeling is dramatically accelerated in the presence of its guanine nucleotide-activating protein (GAP), Sec23-Sec24, and blocked upon addition of guanosine-5′-[(β,γ)-imido]triphosphate, a poorly hydrolysable analog of GTP. Our results also indicate that Sar1 GTPase activity is stimulated by membranes that exhibit elevated curvature, potentially enabling Sar1 membrane scission activity to be spatially restricted to highly bent membranes that are characteristic of a bud neck. Taken together, our data support a stepwise model in which the amino-terminal amphipathic helix of GTP-bound Sar1 stably penetrates the endoplasmic reticulum membrane, promoting local membrane deformation. As membrane bending increases, Sar1 membrane binding is elevated, ultimately culminating in GTP hydrolysis, which may destabilize the bilayer sufficiently to facilitate membrane fission.
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Affiliation(s)
- Michael G Hanna
- From the Department of Biomolecular Chemistry, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin 53706
| | - Ioanna Mela
- the Department of Pharmacology, University of Cambridge, Tennis Court Road, CB2 1PD Cambridge, United Kingdom, and
| | - Lei Wang
- From the Department of Biomolecular Chemistry, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin 53706
| | - Robert M Henderson
- the Department of Pharmacology, University of Cambridge, Tennis Court Road, CB2 1PD Cambridge, United Kingdom, and
| | - Edwin R Chapman
- the Department of Neuroscience, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin 53705
| | - J Michael Edwardson
- the Department of Pharmacology, University of Cambridge, Tennis Court Road, CB2 1PD Cambridge, United Kingdom, and
| | - Anjon Audhya
- From the Department of Biomolecular Chemistry, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin 53706,
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49
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Abstract
Protein export from the endoplasmic reticulum (ER), the first step in protein transport through the secretory pathway, is mediated by coatomer protein II (COPII)-coated vesicles at ER exit sites. COPII coat assembly on the ER is well understood and the conserved large hydrophilic protein Sec16 clearly has a role to play in COPII coat dynamics. Sec16 localizes to ER exit sites, its loss of function impairs their functional organization in all species where it has been studied, and it interacts with COPII coat subunits. However, its exact function in COPII dynamics is debated, as Sec16 is proposed to act as a scaffold to recruit COPII components and as a device to regulate the Sar1 activity in uncoating, in such a way that the coat is released only when the vesicle is fully formed and loaded with cargo. Furthermore, Sec16 has been shown to respond to nutrient signalling, thus coupling environmental stimuli to secretory capacity.
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50
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Saito K, Katada T. Mechanisms for exporting large-sized cargoes from the endoplasmic reticulum. Cell Mol Life Sci 2015; 72:3709-20. [PMID: 26082182 PMCID: PMC4565863 DOI: 10.1007/s00018-015-1952-9] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2015] [Revised: 05/18/2015] [Accepted: 06/08/2015] [Indexed: 12/14/2022]
Abstract
Cargo proteins exported from the endoplasmic reticulum to the Golgi apparatus are typically transported in coat protein complex II (COPII)-coated vesicles of 60–90 nm diameter. Several cargo molecules including collagens and chylomicrons form structures that are too large to be accommodated by these vesicles, but their secretion still requires COPII proteins. Here, we first review recent progress on large cargo secretions derived especially from animal models and human diseases, which indicate the importance of COPII proteins. We then discuss the recent isolation of specialized factors that modulate the process of COPII-dependent cargo formation to facilitate the exit of large-sized cargoes from the endoplasmic reticulum. Based on these findings, we propose a model that describes the importance of the GTPase cycle for secretion of oversized cargoes. Next, we summarize reports that describe the structures of COPII proteins and how these results provide insight into the mechanism of assembly of the large cargo carriers. Finally, we discuss what issues remain to be solved in the future.
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Affiliation(s)
- Kota Saito
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan.
| | - Toshiaki Katada
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
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