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Lameront P, Shabanian M, Currie LMJ, Fust C, Li C, Clews A, Meng B. Elucidating the Subcellular Localization of GLRaV-3 Proteins Encoded by the Unique Gene Block in N. benthamiana Suggests Implications on Plant Host Suppression. Biomolecules 2024; 14:977. [PMID: 39199365 PMCID: PMC11352578 DOI: 10.3390/biom14080977] [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: 07/02/2024] [Revised: 07/26/2024] [Accepted: 07/30/2024] [Indexed: 09/01/2024] Open
Abstract
Grapevine leafroll-associated virus 3 (GLRaV-3) is a formidable threat to the stability of the global grape and wine industries. It is the primary etiological agent of grapevine leafroll disease (GLD) and significantly impairs vine health, fruit quality, and yield. GLRaV-3 is a member of the genus Ampelovirus, Closteroviridae family. Viral genes within the 3' proximal unique gene blocks (UGB) remain highly variable and poorly understood. The UGBs of Closteroviridae viruses include diverse open reading frames (ORFs) that have been shown to contribute to viral functions such as the suppression of the host RNA silencing defense response and systemic viral spread. This study investigates the role of GLRaV-3 ORF8, ORF9, and ORF10, which encode the proteins p21, p20A, and p20B, respectively. These genes represent largely unexplored facets of the GLRaV-3 genome. Here, we visualize the subcellular localization of wildtype and mutagenized GLRaV-3 ORFs 8, 9, and 10, transiently expressed in Nicotiana benthamiana. Our results indicate that p21 localizes to the cytosol, p20A associates with microtubules, and p20B is trafficked into the nucleus to carry out the suppression of host RNA silencing. The findings presented herein provide a foundation for future research aimed at the characterization of the functions of these ORFs. In the long run, it would also facilitate the development of innovative strategies to understand GLRaV-3, mitigate its spread, and impacts on grapevines and the global wine industry.
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Affiliation(s)
- Patrick Lameront
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON N1G 2W1, Canada; (M.S.); (L.M.J.C.); (C.F.); (C.L.); (A.C.); (B.M.)
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2
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Zhang W, Zhang Z, Xiang Y, Gu DD, Chen J, Chen Y, Zhai S, Liu Y, Jiang T, Liu C, He B, Yan M, Wang Z, Xu J, Cao YL, Deng B, Zeng D, Lei J, Zhuo J, Lei X, Long Z, Jin B, Chen T, Li D, Shen Y, Hu J, Gao S, Liu Q. Aurora kinase A-mediated phosphorylation triggers structural alteration of Rab1A to enhance ER complexity during mitosis. Nat Struct Mol Biol 2024; 31:219-231. [PMID: 38177680 DOI: 10.1038/s41594-023-01165-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Accepted: 10/26/2023] [Indexed: 01/06/2024]
Abstract
Morphological rearrangement of the endoplasmic reticulum (ER) is critical for metazoan mitosis. Yet, how the ER is remodeled by the mitotic signaling remains unclear. Here, we report that mitotic Aurora kinase A (AURKA) employs a small GTPase, Rab1A, to direct ER remodeling. During mitosis, AURKA phosphorylates Rab1A at Thr75. Structural analysis demonstrates that Thr75 phosphorylation renders Rab1A in a constantly active state by preventing interaction with GDP-dissociation inhibitor (GDI). Activated Rab1A is retained on the ER and induces the oligomerization of ER-shaping protein RTNs and REEPs, eventually triggering an increase of ER complexity. In various models, from Caenorhabditis elegans and Drosophila to mammals, inhibition of Rab1AThr75 phosphorylation by genetic modifications disrupts ER remodeling. Thus, our study reveals an evolutionarily conserved mechanism explaining how mitotic kinase controls ER remodeling and uncovers a critical function of Rab GTPases in metaphase.
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Affiliation(s)
- Wei Zhang
- State Key Laboratory of Oncology in South China, Guangdong Provincial Clinical Research Center for Cancer, Sun Yat-sen University Cancer Center, Guangzhou, P.R. China
- Department of Clinical Immunology, The Third Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Zijian Zhang
- State Key Laboratory of Oncology in South China, Guangdong Provincial Clinical Research Center for Cancer, Sun Yat-sen University Cancer Center, Guangzhou, P.R. China
- Institute of Cancer Stem Cell, Dalian Medical University, Dalian, China
| | - Yun Xiang
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Dong-Dong Gu
- State Key Laboratory of Oncology in South China, Guangdong Provincial Clinical Research Center for Cancer, Sun Yat-sen University Cancer Center, Guangzhou, P.R. China
| | - Jinna Chen
- State Key Laboratory of Oncology in South China, Guangdong Provincial Clinical Research Center for Cancer, Sun Yat-sen University Cancer Center, Guangzhou, P.R. China
| | - Yifan Chen
- University of Chinese Academy of Sciences, Beijing, China
- State Key Laboratory of Cell Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, China
| | - Shixian Zhai
- MOE Key Laboratory of Laser Life Science and College of Biophotonics, South China Normal University, Guangzhou, China
| | - Yong Liu
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Tao Jiang
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Chong Liu
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Bin He
- State Key Laboratory of Oncology in South China, Guangdong Provincial Clinical Research Center for Cancer, Sun Yat-sen University Cancer Center, Guangzhou, P.R. China
| | - Min Yan
- State Key Laboratory of Oncology in South China, Guangdong Provincial Clinical Research Center for Cancer, Sun Yat-sen University Cancer Center, Guangzhou, P.R. China
| | - Zifeng Wang
- State Key Laboratory of Oncology in South China, Guangdong Provincial Clinical Research Center for Cancer, Sun Yat-sen University Cancer Center, Guangzhou, P.R. China
| | - Jie Xu
- Institute of Cancer Stem Cell, Dalian Medical University, Dalian, China
| | - Yu-Lu Cao
- State Key Laboratory of Oncology in South China, Guangdong Provincial Clinical Research Center for Cancer, Sun Yat-sen University Cancer Center, Guangzhou, P.R. China
| | - Bing Deng
- State Key Laboratory of Oncology in South China, Guangdong Provincial Clinical Research Center for Cancer, Sun Yat-sen University Cancer Center, Guangzhou, P.R. China
| | - Deshun Zeng
- State Key Laboratory of Oncology in South China, Guangdong Provincial Clinical Research Center for Cancer, Sun Yat-sen University Cancer Center, Guangzhou, P.R. China
| | - Jie Lei
- State Key Laboratory of Oncology in South China, Guangdong Provincial Clinical Research Center for Cancer, Sun Yat-sen University Cancer Center, Guangzhou, P.R. China
| | - Junxiao Zhuo
- State Key Laboratory of Oncology in South China, Guangdong Provincial Clinical Research Center for Cancer, Sun Yat-sen University Cancer Center, Guangzhou, P.R. China
| | - Xinxing Lei
- State Key Laboratory of Oncology in South China, Guangdong Provincial Clinical Research Center for Cancer, Sun Yat-sen University Cancer Center, Guangzhou, P.R. China
| | - Zijie Long
- Department of Hematology, The Third Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
- Institute of Hematology, Sun Yat-sen University, Guangzhou, China
| | - Bilian Jin
- Institute of Cancer Stem Cell, Dalian Medical University, Dalian, China
| | - Tongsheng Chen
- MOE Key Laboratory of Laser Life Science and College of Biophotonics, South China Normal University, Guangzhou, China
| | - Dong Li
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Yidong Shen
- University of Chinese Academy of Sciences, Beijing, China
- State Key Laboratory of Cell Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, China
| | - Junjie Hu
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.
- University of Chinese Academy of Sciences, Beijing, China.
| | - Song Gao
- State Key Laboratory of Oncology in South China, Guangdong Provincial Clinical Research Center for Cancer, Sun Yat-sen University Cancer Center, Guangzhou, P.R. China.
| | - Quentin Liu
- State Key Laboratory of Oncology in South China, Guangdong Provincial Clinical Research Center for Cancer, Sun Yat-sen University Cancer Center, Guangzhou, P.R. China.
- Institute of Cancer Stem Cell, Dalian Medical University, Dalian, China.
- Institute of Hematology, Sun Yat-sen University, Guangzhou, China.
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3
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Borah S, Dhanasekaran K, Kumar S. The LEM-ESCRT toolkit: Repair and maintenance of the nucleus. Front Cell Dev Biol 2022; 10:989217. [PMID: 36172278 PMCID: PMC9512039 DOI: 10.3389/fcell.2022.989217] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Accepted: 08/24/2022] [Indexed: 12/04/2022] Open
Abstract
The eukaryotic genome is enclosed in a nuclear envelope that protects it from potentially damaging cellular activities and physically segregates transcription and translation.Transport across the NE is highly regulated and occurs primarily via the macromolecular nuclear pore complexes.Loss of nuclear compartmentalization due to defects in NPC function and NE integrity are tied to neurological and ageing disorders like Alzheimer’s, viral pathogenesis, immune disorders, and cancer progression.Recent work implicates inner-nuclear membrane proteins of the conserved LEM domain family and the ESCRT machinery in NE reformation during cell division and NE repair upon rupture in migrating cancer cells, and generating seals over defective NPCs. In this review, we discuss the recent in-roads made into defining the molecular mechanisms and biochemical networks engaged by LEM and many other integral inner nuclear membrane proteins to preserve the nuclear barrier.
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Affiliation(s)
- Sapan Borah
- National Institute of Immunohaematology, Mumbai, Maharashtra, India
- *Correspondence: Sapan Borah, ; Karthigeyan Dhanasekaran, ; Santosh Kumar,
| | - Karthigeyan Dhanasekaran
- Regional Centre for Biotechnology, NCR Biotech Science Cluster, Faridabad, Haryana, India
- *Correspondence: Sapan Borah, ; Karthigeyan Dhanasekaran, ; Santosh Kumar,
| | - Santosh Kumar
- National Centre for Cell Science, Pune, Maharashtra, India
- *Correspondence: Sapan Borah, ; Karthigeyan Dhanasekaran, ; Santosh Kumar,
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4
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Ayala I, Colanzi A. Structural Organization and Function of the Golgi Ribbon During Cell Division. Front Cell Dev Biol 2022; 10:925228. [PMID: 35813197 PMCID: PMC9263219 DOI: 10.3389/fcell.2022.925228] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Accepted: 06/06/2022] [Indexed: 11/24/2022] Open
Abstract
The Golgi complex has a central role in the secretory traffic. In vertebrate cells it is generally organized in polarized stacks of cisternae that are laterally connected by membranous tubules, forming a structure known as Golgi ribbon. The steady state ribbon arrangement results from a dynamic equilibrium between formation and cleavage of the membrane tubules connecting the stacks. This balance is of great physiological relevance as the unlinking of the ribbon during G2 is required for mitotic entry. A block of this process induces a potent G2 arrest of the cell cycle, indicating that a mitotic “Golgi checkpoint” controls the correct pre-mitotic segregation of the Golgi ribbon. Then, after mitosis onset, the Golgi stacks undergo an extensive disassembly, which is necessary for proper spindle formation. Notably, several Golgi-associated proteins acquire new roles in spindle formation and mitotic progression during mitosis. Here we summarize the current knowledge about the basic principle of the Golgi architecture and its functional relationship with cell division to highlight crucial aspects that need to be addressed to help us understand the physiological significance of the ribbon and the pathological implications of alterations of this organization.
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5
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Sun X, Mahajan D, Chen B, Song Z, Lu L. A quantitative study of the Golgi retention of glycosyltransferases. J Cell Sci 2021; 134:272560. [PMID: 34533190 DOI: 10.1242/jcs.258564] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Accepted: 09/09/2021] [Indexed: 11/20/2022] Open
Abstract
How Golgi glycosyltransferases and glycosidases (hereafter glycosyltransferases) localize to the Golgi is still unclear. Here, we first investigated the post-Golgi trafficking of glycosyltransferases. We found that glycosyltransferases can escape the Golgi to the plasma membrane, where they are subsequently endocytosed to the endolysosome. Post-Golgi glycosyltransferases are probably degraded by ectodomain shedding. We discovered that most glycosyltransferases are not retrieved from post-Golgi sites, indicating that retention rather than retrieval is the primary mechanism for their Golgi localization. We therefore used the Golgi residence time to study Golgi retention of glycosyltransferases quantitatively and systematically. Quantitative analysis of chimeras of ST6GAL1 and either transferrin receptor or tumor necrosis factor α revealed the contributions of three regions of ST6GAL1, namely the N-terminal cytosolic tail, the transmembrane domain and the ectodomain, to Golgi retention. We found that each of the three regions is sufficient for Golgi retention in an additive manner. N-terminal cytosolic tail length negatively affects the Golgi retention of ST6GAL1, similar to effects observed for the transmembrane domain. Therefore, the long N-terminal cytosolic tail and transmembrane domain could act as Golgi export signals for transmembrane secretory cargos. This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Xiuping Sun
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore637551
| | - Divyanshu Mahajan
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore637551
| | - Bing Chen
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore637551
| | - Zhiwei Song
- Bioprocessing Technology Institute, Agency for Science, Technology and Research (A*STAR), 20 Biopolis Way, #06-01 Centros, Singapore138668
| | - Lei Lu
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore637551
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6
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Shomron O, Nevo-Yassaf I, Aviad T, Yaffe Y, Zahavi EE, Dukhovny A, Perlson E, Brodsky I, Yeheskel A, Pasmanik-Chor M, Mironov A, Beznoussenko GV, Mironov AA, Sklan EH, Patterson GH, Yonemura Y, Sannai M, Kaether C, Hirschberg K. COPII collar defines the boundary between ER and ER exit site and does not coat cargo containers. J Cell Biol 2021; 220:211990. [PMID: 33852719 PMCID: PMC8054201 DOI: 10.1083/jcb.201907224] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 01/14/2021] [Accepted: 03/11/2021] [Indexed: 12/13/2022] Open
Abstract
COPII and COPI mediate the formation of membrane vesicles translocating in opposite directions within the secretory pathway. Live-cell and electron microscopy revealed a novel mode of function for COPII during cargo export from the ER. COPII is recruited to membranes defining the boundary between the ER and ER exit sites, facilitating selective cargo concentration. Using direct observation of living cells, we monitored cargo selection processes, accumulation, and fission of COPII-free ERES membranes. CRISPR/Cas12a tagging, the RUSH system, and pharmaceutical and genetic perturbations of ER-Golgi transport demonstrated that the COPII coat remains bound to the ER–ERES boundary during protein export. Manipulation of the cargo-binding domain in COPII Sec24B prohibits cargo accumulation in ERES. These findings suggest a role for COPII in selecting and concentrating exported cargo rather than coating Golgi-bound carriers. These findings transform our understanding of coat proteins’ role in ER-to-Golgi transport.
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Affiliation(s)
- Olga Shomron
- Department of Pathology, Sackler School of Medicine, Tel-Aviv University, Tel Aviv, Israel
| | - Inbar Nevo-Yassaf
- Department of Pathology, Sackler School of Medicine, Tel-Aviv University, Tel Aviv, Israel
| | - Tamar Aviad
- Department of Pathology, Sackler School of Medicine, Tel-Aviv University, Tel Aviv, Israel
| | - Yakey Yaffe
- Department of Pathology, Sackler School of Medicine, Tel-Aviv University, Tel Aviv, Israel
| | - Eitan Erez Zahavi
- Department of Physiology and Pharmacology, Sackler School of Medicine, Tel-Aviv University, Tel Aviv, Israel
| | - Anna Dukhovny
- Department of Clinical Immunology and Microbiology, Sackler School of Medicine, Tel-Aviv University, Tel Aviv, Israel
| | - Eran Perlson
- Department of Physiology and Pharmacology, Sackler School of Medicine, Tel-Aviv University, Tel Aviv, Israel
| | - Ilya Brodsky
- Lomonosov Moscow State University, Andrey N. Belozersky Institute for Physico-Chemical Biology, Moscow, Russia
| | - Adva Yeheskel
- Bioinformatics Unit, George S. Wise Faculty of Life Sciences, Tel-Aviv University, Tel Aviv, Israel
| | - Metsada Pasmanik-Chor
- Bioinformatics Unit, George S. Wise Faculty of Life Sciences, Tel-Aviv University, Tel Aviv, Israel
| | - Anna Mironov
- Istituto Firc di Oncologia Molecolare, Fondazione Istituto Fondazione Italiana per la Ricerca sul Cancro di Oncologia Molecolare, Milan, Italy
| | - Galina V Beznoussenko
- Istituto Firc di Oncologia Molecolare, Fondazione Istituto Fondazione Italiana per la Ricerca sul Cancro di Oncologia Molecolare, Milan, Italy
| | - Alexander A Mironov
- Istituto Firc di Oncologia Molecolare, Fondazione Istituto Fondazione Italiana per la Ricerca sul Cancro di Oncologia Molecolare, Milan, Italy
| | - Ella H Sklan
- Department of Clinical Immunology and Microbiology, Sackler School of Medicine, Tel-Aviv University, Tel Aviv, Israel
| | - George H Patterson
- Section on Biophotonics, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, Rockville, MD
| | - Yoji Yonemura
- Leibniz Institute on Aging, Fritz Lipmann Institute, Jena, Germany
| | - Mara Sannai
- Leibniz Institute on Aging, Fritz Lipmann Institute, Jena, Germany
| | | | - Koret Hirschberg
- Department of Pathology, Sackler School of Medicine, Tel-Aviv University, Tel Aviv, Israel
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Lippincott-Schwartz J. The evolution of a cell biologist. Mol Biol Cell 2020; 31:2763-2767. [PMID: 33253077 PMCID: PMC7851866 DOI: 10.1091/mbc.e20-09-0603] [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] [Indexed: 11/11/2022] Open
Abstract
I am honored and humbled to receive the E. B. Wilson Medal and happy to share some reflections on my journey as a cell biologist. It took me a while to realize that my interest in biology would center on how cells are spatially and dynamically organized. From an initial fascination with cellular structures I came to appreciate that cells exhibit dynamism across all scales-from their molecules, to molecular complexes, to organelles. Uncovering the principles of this dynamism, including new ways to observe and quantify it, has been the guiding star of my work.
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8
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Mitotic ER Exit Site Disassembly and Reassembly Are Regulated by the Phosphorylation Status of TANGO1. Dev Cell 2020; 55:237-250.e5. [DOI: 10.1016/j.devcel.2020.07.017] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 06/24/2020] [Accepted: 07/22/2020] [Indexed: 11/20/2022]
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9
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Malik U, Zafar S, Younas N, Zerr I, Javed A. Unveiling the Physical and Functional Niches of FAM26F by Analyzing Its Subcellular Localization and Novel Interacting Partners. ACS OMEGA 2020; 5:22008-22020. [PMID: 32923759 PMCID: PMC7482079 DOI: 10.1021/acsomega.0c01249] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Accepted: 08/03/2020] [Indexed: 06/11/2023]
Abstract
The knowledge of a protein's subcellular localization and interacting partners are crucial for elucidating its cellular function and associated regulatory networks. Although FAM26F (family with sequence similarity 26, member F) has been recognized as a vital player in various infections, stimulation studies, cancer, and immune pathogenesis, the precise location and function of FAM26F are not well understood. The current study is the first to focus on functional characterization of FAM26F by analyzing its subcellular localization and identifying its novel interacting partners using advanced proteome approaches. The immunofluorescence and confocal microscopy results revealed FAM26F to be largely localized within the Golgi apparatus of the cell. However, its minor presence in endoplasmic reticulum (ER) pointed toward the probable retrograde transfer of FAM26F from Golgi to ER during adverse conditions. Moreover, co-immunoprecipitation and MS/MS results demonstrated a total of 85 proteins, 44 of which significantly copurified with FAM26F. Interestingly, out of these 44 MS/MS identified proteins, almost 52% were involved in innate immunity, 38.6% in neutrophil degranulation, and remaining 10% were either involved in phosphorylation, degradation, or regulation of apoptosis. Further characterization through Ingenuity Pathway Analysis showed that majority of these proteins was involved in maintaining calcium homeostasis of cell. Consequently, the validation of selected proteins uncovered the key interaction of FAM26F with Thioredoxin, which essentially paved the way for depicting its mechanism of action under stress or disease conditions. It is proposed that activation and inhibition of the cellular immune response is essentially dependent on whether FAM26F or Thioredoxin considerably interact with CD30R.
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Affiliation(s)
- Uzma Malik
- Department
of Healthcare Biotechnology, Atta-ur-Rahman School of Applied Biosciences
(ASAB), National University of Sciences
and Technology (NUST), H-12 Campus, 44000 Islamabad, Pakistan
- Department
of Neurology, University Medical Centre Göttingen (UMG), Georg-August-Universität Göttingen, 37075 Göttingen, Germany
| | - Saima Zafar
- Department
of Neurology, University Medical Centre Göttingen (UMG), Georg-August-Universität Göttingen, 37075 Göttingen, Germany
- Department
of Biomedical Engineering & Sciences, School of Mechanical &
Manufacturing Engineering (SMME), National
University of Sciences and Technology (NUST), H-12
Campus, 44000 Islamabad, Pakistan
| | - Neelam Younas
- Department
of Neurology, University Medical Centre Göttingen (UMG), Georg-August-Universität Göttingen, 37075 Göttingen, Germany
| | - Inga Zerr
- Department
of Neurology, University Medical Centre Göttingen (UMG), Georg-August-Universität Göttingen, 37075 Göttingen, Germany
| | - Aneela Javed
- Department
of Healthcare Biotechnology, Atta-ur-Rahman School of Applied Biosciences
(ASAB), National University of Sciences
and Technology (NUST), H-12 Campus, 44000 Islamabad, Pakistan
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10
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The Role of Hydrogen Peroxide and Peroxiredoxins throughout the Cell Cycle. Antioxidants (Basel) 2020; 9:antiox9040280. [PMID: 32224940 PMCID: PMC7222192 DOI: 10.3390/antiox9040280] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 03/23/2020] [Accepted: 03/24/2020] [Indexed: 01/22/2023] Open
Abstract
Hydrogen peroxide (H2O2) is an oxidizing agent that induces cellular damage at inappropriate concentrations and gives rise to an arrest during cell cycle progression, causing cell death. Recent evidence indicates that H2O2 also acts as a promoter for cell cycle progression by oxidizing specific thiol proteins. The intracellular concentration of H2O2 is regulated tightly, enabling its use as a cellular signaling molecule while minimizing its potential to cause cellular damage. Peroxiredoxins (Prxs) have peroxidase activity toward H2O2, organic hydroperoxides, and peroxynitrite for protecting cells from oxidative stress. They are suggested to work as signaling mediators, allowing the local accumulation of H2O2 by inactivating their peroxidase activity uniquely compared with other antioxidant proteins such as catalase and glutathione peroxidase. Given that Prxs are highly sensitive to oxidation by H2O2, they act as sensors and transducers of H2O2 signaling via transferring their oxidation state to effector proteins. The concentrations of intracellular H2O2 increase as the cell cycle progresses from G1 to mitosis. Here, we summarize the roles of Prxs with regard to the regulation of cell cycle-dependent kinase activity and anaphase-promoting complex/cyclosome in terms of changes in H2O2 levels. Protection of the cell from unwanted progression of the cell cycle is suggested to be a role of Prx. We discuss the possible roles of Prxs to control H2O2 levels.
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11
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Carlton JG, Jones H, Eggert US. Membrane and organelle dynamics during cell division. Nat Rev Mol Cell Biol 2020; 21:151-166. [DOI: 10.1038/s41580-019-0208-1] [Citation(s) in RCA: 71] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/20/2019] [Indexed: 12/31/2022]
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12
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Frisbie CP, Lushnikov AY, Krasnoslobodtsev AV, Riethoven JJM, Clarke JL, Stepchenkova EI, Petrosyan A. Post-ER Stress Biogenesis of Golgi Is Governed by Giantin. Cells 2019; 8:E1631. [PMID: 31847122 PMCID: PMC6953117 DOI: 10.3390/cells8121631] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Revised: 12/05/2019] [Accepted: 12/09/2019] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND The Golgi apparatus undergoes disorganization in response to stress, but it is able to restore compact and perinuclear structure under recovery. This self-organization mechanism is significant for cellular homeostasis, but remains mostly elusive, as does the role of giantin, the largest Golgi matrix dimeric protein. METHODS In HeLa and different prostate cancer cells, we used the model of cellular stress induced by Brefeldin A (BFA). The conformational structure of giantin was assessed by proximity ligation assay and atomic force microscopy. The post-BFA distribution of Golgi resident enzymes was examined by 3D SIM high-resolution microscopy. RESULTS We detected that giantin is rather flexible than an extended coiled-coil dimer and BFA-induced Golgi disassembly was associated with giantin monomerization. A fusion of the nascent Golgi membranes after BFA washout is forced by giantin re-dimerization via disulfide bond in its luminal domain and assisted by Rab6a GTPase. GM130-GRASP65-dependent enzymes are able to reach the nascent Golgi membranes, while giantin-sensitive enzymes appeared at the Golgi after its complete recovery via direct interaction of their cytoplasmic tail with N-terminus of giantin. CONCLUSION Post-stress recovery of Golgi is conducted by giantin dimer and Golgi proteins refill membranes according to their docking affiliation rather than their intra-Golgi location.
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Affiliation(s)
- Cole P. Frisbie
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE 68198-5870, USA;
| | - Alexander Y. Lushnikov
- Nanoimaging Core Facility, University of Nebraska Medical Center, Omaha, NE 68198-6025, USA; (A.Y.L.); (A.V.K.)
| | - Alexey V. Krasnoslobodtsev
- Nanoimaging Core Facility, University of Nebraska Medical Center, Omaha, NE 68198-6025, USA; (A.Y.L.); (A.V.K.)
- Department of Physics, University of Nebraska-Omaha, Omaha, NE 68182-0266, USA
| | - Jean-Jack M. Riethoven
- Center for Biotechnology, University of Nebraska-Lincoln, Lincoln, NE 68588-0665, USA;
- The Nebraska Center for Integrated Biomolecular Communication, University of Nebraska-Lincoln, Lincoln, NE 68588-0304, USA;
| | - Jennifer L. Clarke
- The Nebraska Center for Integrated Biomolecular Communication, University of Nebraska-Lincoln, Lincoln, NE 68588-0304, USA;
- Department of Statistics, University of Nebraska-Lincoln, Lincoln, NE 68583-0963, USA
| | - Elena I. Stepchenkova
- Vavilov Institute of General Genetics, Saint-Petersburg Branch, Russian Academy of Sciences, Saint-Petersburg 199034, Russia;
- Department of Genetics, Saint-Petersburg State University, Saint-Petersburg 199034, Russia
| | - Armen Petrosyan
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE 68198-5870, USA;
- The Nebraska Center for Integrated Biomolecular Communication, University of Nebraska-Lincoln, Lincoln, NE 68588-0304, USA;
- The Fred and Pamela Buffett Cancer Center, Omaha, NE 68198-5870, USA
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13
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Janáček J, Brejchová J, Svoboda P. Determination of δ-opioid receptor molecules mobility in living cells plasma membrane by novel method of FRAP analysis. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2019; 1861:1346-1354. [PMID: 31071299 DOI: 10.1016/j.bbamem.2019.04.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Revised: 04/09/2019] [Accepted: 04/29/2019] [Indexed: 11/18/2022]
Abstract
Fluorescence recovery after photobleaching (FRAP) is the preferred method for analyzing the lateral mobility of fluorescently-tagged proteins in the plasma membranes (PMs) of live cells. FRAP experiments are described as being easy to perform; however, the analysis of the acquired data can be difficult. The evaluation procedure must be properly combined with the imaging setup of the confocal microscope to provide unbiased results. With the aim of increasing the accuracy of determining the diffusion coefficient (D) and mobile fraction (Mf) of PM proteins, we developed a novel method for FRAP analysis in the equatorial plane of the cell. This method is based on the calculation of photobleaching characteristics, derived from the light intensity profile and optical parameters of the confocal microscope, and on the model of fluorescent molecule diffusion in PM regions outside of the focal plane. Furthermore, cell movement artifacts in the FRAP data are ameliorated by using a region of interest, which is not fixed but instead moves adaptively in coordination with the movement of cells. When this method was used to determine the mobility of the δ-opioid receptor-eYFP in HEK293 cells, a highly significant decrease in receptor mobility was detected in cholesterol-depleted cells. This decrease was fully reversible by the replenishment of cholesterol levels. Our results demonstrate the crucial role played by cholesterol in the dynamic organization of δ-opioid receptors in the PM under in vivo conditions. Our method may be applied for the determination of the D and Mf values of other PM proteins.
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Affiliation(s)
- Jiří Janáček
- Department of Biomathematics, Institute of Physiology of the Czech Academy of Sciences, Videnska 1083, 14220 Prague 4, Czech Republic.
| | - Jana Brejchová
- Department of Biomathematics, Institute of Physiology of the Czech Academy of Sciences, Videnska 1083, 14220 Prague 4, Czech Republic
| | - Petr Svoboda
- Department of Biomathematics, Institute of Physiology of the Czech Academy of Sciences, Videnska 1083, 14220 Prague 4, Czech Republic
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14
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Pre-embedding labeling for subcellular detection of molecules with electron microscopy. Tissue Cell 2019; 57:103-110. [DOI: 10.1016/j.tice.2018.11.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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15
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Publisher Note. Tissue Cell 2018. [DOI: 10.1016/j.tice.2018.09.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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16
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Giantin Is Required for Post-Alcohol Recovery of Golgi in Liver Cells. Biomolecules 2018; 8:biom8040150. [PMID: 30453527 PMCID: PMC6316505 DOI: 10.3390/biom8040150] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Revised: 11/09/2018] [Accepted: 11/12/2018] [Indexed: 12/17/2022] Open
Abstract
In hepatocytes and alcohol-metabolizing cultured cells, Golgi undergoes ethanol (EtOH)-induced disorganization. Perinuclear and organized Golgi is important in liver homeostasis, but how the Golgi remains intact is unknown. Work from our laboratories showed that EtOH-altered cellular function could be reversed after alcohol removal; we wanted to determine whether this recovery would apply to Golgi. We used alcohol-metabolizing HepG2 (VA-13) cells (cultured with or without EtOH for 72 h) and rat hepatocytes (control and EtOH-fed (Lieber–DeCarli diet)). For recovery, EtOH was removed and replenished with control medium (48 h for VA-13 cells) or control diet (10 days for rats). Results: EtOH-induced Golgi disassembly was associated with de-dimerization of the largest Golgi matrix protein giantin, along with impaired transport of selected hepatic proteins. After recovery from EtOH, Golgi regained their compact structure, and alterations in giantin and protein transport were restored. In VA-13 cells, when we knocked down giantin, Rab6a GTPase or non-muscle myosin IIB, minimal changes were observed in control conditions, but post-EtOH recovery was impaired. Conclusions: These data provide a link between Golgi organization and plasma membrane protein expression and identify several proteins whose expression is important to maintain Golgi structure during the recovery phase after EtOH administration.
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17
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PKA-site phosphorylation of importin13 regulates its subcellular localization and nuclear transport function. Biochem J 2018; 475:2699-2712. [PMID: 30045875 DOI: 10.1042/bcj20180082] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Revised: 07/12/2018] [Accepted: 07/16/2018] [Indexed: 01/25/2023]
Abstract
Importin 13 (IPO13) is a key member of the importin β superfamily, which can transport cargoes both into and out of the nucleus to contribute to a variety of important cellular processes. IPO13 is known to undergo phosphorylation, but the impact of this on function has not been investigated. Here, we show for the first time that IPO13 is phosphorylated by cAMP-dependent protein kinase A specifically at serine 193. Results from fluorescence recovery after photobleaching and fluorescence loss in photobleaching approaches establish that negative charge at serine 193 through phosphorylation or point mutation both reduces IPO13 nuclear import and increases its nuclear export. Importantly, phosphorylation also appears to enhance cargo interaction on the part of IPO13, with significant impact on localization, as shown for the Pax6 homeobox-containing transcription partner. This is the first report that IPO13 can be phosphorylated at Ser193 and that this modification regulates IPO13 subcellular localization and nucleocytoplasmic transport function, with important implications for IPO13's role in development and other processes.
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18
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Lippincott-Schwartz J, Snapp EL, Phair RD. The Development and Enhancement of FRAP as a Key Tool for Investigating Protein Dynamics. Biophys J 2018; 115:1146-1155. [PMID: 30219286 DOI: 10.1016/j.bpj.2018.08.007] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Revised: 07/27/2018] [Accepted: 08/06/2018] [Indexed: 01/18/2023] Open
Abstract
The saga of fluorescence recovery after photobleaching (FRAP) illustrates how disparate technical developments impact science. Starting with the classic 1976 Axelrod et al. work in Biophysical Journal, FRAP (originally fluorescence photobleaching recovery) opened the door to extraction of quantitative information from photobleaching experiments, laying the experimental and theoretical groundwork for quantifying both the mobility and the mobile fraction of a labeled population of proteins. Over the ensuing years, FRAP's reach dramatically expanded, with new developments in GFP technology and turn-key confocal microscopy, which enabled measurement of protein diffusion and binding/dissociation rates in virtually every compartment within the cell. The FRAP technique and data catalyzed an exchange of ideas between biophysicists studying membrane dynamics, cell biologists focused on intracellular dynamics, and systems biologists modeling the dynamics of cell activity. The outcome transformed the field of cellular biology, leading to a fundamental rethinking of long-held theories of cellular dynamism. Here, we review the pivotal FRAP studies that made these developments and conceptual changes possible, which gave rise to current models of complex cell dynamics.
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Affiliation(s)
| | - Erik Lee Snapp
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, Virginia.
| | - Robert D Phair
- Integrative Bioinformatics, Inc., Mountain View, California
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19
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Abstract
A portfolio is presented documenting economic, high-resolution correlative focused ion beam scanning electron microscopy (FIB/SEM) in routine, comprising: (i) the use of custom-labeled slides and coverslips, (ii) embedding of cells in thin, or ultra-thin resin layers for correlative light and electron microscopy (CLEM) and (iii) the claim to reach the highest resolution possible with FIB/SEM in xyz. Regions of interest (ROIs) defined in light microscope (LM), can be relocated quickly and precisely in SEM. As proof of principle, HeLa cells were investigated in 3D context at all stages of the cell cycle, documenting ultrastructural changes during mitosis: nuclear envelope breakdown and reassembly, Golgi degradation and reconstitution and the formation of the midzone and midbody.
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20
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Jackson CL. Activators and Effectors of the Small G Protein Arf1 in Regulation of Golgi Dynamics During the Cell Division Cycle. Front Cell Dev Biol 2018; 6:29. [PMID: 29632863 PMCID: PMC5879097 DOI: 10.3389/fcell.2018.00029] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Accepted: 03/08/2018] [Indexed: 12/23/2022] Open
Abstract
When eukaryotic cells divide, they must faithfully segregate not only the genetic material but also their membrane-bound organelles into each daughter cell. To assure correct partitioning of cellular contents, cells use regulatory mechanisms to verify that each stage of cell division has been correctly accomplished before proceeding to the next step. A great deal is known about mechanisms that regulate chromosome segregation during cell division, but we know much less about the mechanisms by which cellular organelles are partitioned, and how these processes are coordinated. The Golgi apparatus, the central sorting and modification station of the secretory pathway, disassembles during mitosis, a process that depends on Arf1 and its regulators and effectors. Prior to total disassembly, the Golgi ribbon in mammalian cells, composed of alternating cisternal stacks and tubular networks, undergoes fission of the tubular networks to produce individual stacks. Failure to carry out this unlinking leads to cell division arrest at late G2 prior to entering mitosis, an arrest that can be relieved by inhibition of Arf1 activation. The level of active Arf1-GTP drops during mitosis, due to inactivation of the major Arf1 guanine nucleotide exchange factor at the Golgi, GBF1. Expression of constitutively active Arf1 prevents Golgi disassembly, and leads to defects in chromosome segregation and cytokinesis. In this review, we describe recent advances in understanding the functions of Arf1 regulators and effectors in the crosstalk between Golgi structure and cell cycle regulation.
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Affiliation(s)
- Catherine L Jackson
- Institut Jacques Monod, Centre Nationnal de la Recherche Scientifique, UMR 7592, Université Paris Diderot, Sorbonne Paris Cité, Paris, France
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21
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A Plasmodium plasma membrane reporter reveals membrane dynamics by live-cell microscopy. Sci Rep 2017; 7:9740. [PMID: 28851956 PMCID: PMC5575152 DOI: 10.1038/s41598-017-09569-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Accepted: 07/26/2017] [Indexed: 11/08/2022] Open
Abstract
During asexual replication within the Anopheles mosquito and their vertebrate host, Plasmodium parasites depend on the generation of a massive amount of new plasma membrane to produce thousands of daughter parasites. How the parasite plasma membrane (PPM) is formed has mostly been studied by electron microscopy, which does not allow an insight into the dynamics of this process. We generated a Plasmodium berghei reporter parasite line by GFP-tagging of a non-essential PPM-localized protein, and followed plasma membrane development in living parasites through the entire Plasmodium life cycle. By generating double-fluorescent parasites in which the PPM is visualized in combination with the parasite endoplasmic reticulum, we show that membrane contact sites are formed between both membrane systems during oocyst and liver stage development that might be used to deliver lipids to the dramatically expanding PPM. In conclusion, we have established a powerful tool to follow PPM development in living parasites, which promises to greatly expand our knowledge of membrane biology in the Plasmodium parasite.
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22
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Dörr JM, van Coevorden-Hameete MH, Hoogenraad CC, Killian JA. Solubilization of human cells by the styrene-maleic acid copolymer: Insights from fluorescence microscopy. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2017; 1859:2155-2160. [PMID: 28847501 DOI: 10.1016/j.bbamem.2017.08.010] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 08/08/2017] [Accepted: 08/13/2017] [Indexed: 12/20/2022]
Abstract
Extracting membrane proteins from biological membranes by styrene-maleic acid copolymers (SMAs) in the form of nanodiscs has developed into a powerful tool in membrane research. However, the mode of action of membrane (protein) solubilization in a cellular context is still poorly understood and potential specificity for cellular compartments has not been investigated. Here, we use fluorescence microscopy to visualize the process of SMA solubilization of human cells, exemplified by the immortalized human HeLa cell line. Using fluorescent protein fusion constructs that mark distinct subcellular compartments, we found that SMA solubilizes membranes in a concentration-dependent multi-stage process. While all major intracellular compartments were affected without a strong preference, plasma membrane solubilization was found to be generally slower than the solubilization of organelle membranes. Interestingly, some plasma membrane-localized proteins were more resistant against solubilization than others, which might be explained by their presence in specific membrane domains with differing properties. Our results support the general applicability of SMA for the isolation of membrane proteins from different types of (sub)cellular membranes.
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Affiliation(s)
- Jonas M Dörr
- Membrane Biochemistry and Biophysics, Bijvoet Center for Biomolecular Research, Institute of Biomembranes, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands.
| | | | - Casper C Hoogenraad
- Cell Biology, Department of Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
| | - J Antoinette Killian
- Membrane Biochemistry and Biophysics, Bijvoet Center for Biomolecular Research, Institute of Biomembranes, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands.
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23
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Pantazopoulou A. The Golgi apparatus: insights from filamentous fungi. Mycologia 2017; 108:603-22. [DOI: 10.3852/15-309] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Accepted: 01/01/2016] [Indexed: 02/06/2023]
Affiliation(s)
- Areti Pantazopoulou
- Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas, CSIC, Ramiro de Maeztu 9, Madrid 28040, Spain
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24
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Cellular Reorganization during Mitotic Entry. Trends Cell Biol 2017; 27:26-41. [DOI: 10.1016/j.tcb.2016.07.004] [Citation(s) in RCA: 93] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Revised: 07/14/2016] [Accepted: 07/18/2016] [Indexed: 12/27/2022]
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25
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Villeneuve J, Duran J, Scarpa M, Bassaganyas L, Van Galen J, Malhotra V. Golgi enzymes do not cycle through the endoplasmic reticulum during protein secretion or mitosis. Mol Biol Cell 2016; 28:141-151. [PMID: 27807044 PMCID: PMC5221618 DOI: 10.1091/mbc.e16-08-0560] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Revised: 10/21/2016] [Accepted: 10/26/2016] [Indexed: 01/08/2023] Open
Abstract
The question of whether the Golgi complex is a stable compartment or is constantly regenerated from the endoplasmic reticulum (ER) is an important issue under debate. Using an ER trapping procedure and Golgi-specific O-linked glycosylation of a resident ER protein, this study demonstrates that Golgi enzymes do not cycle through the ER during secretion and mitosis. Golgi-specific sialyltransferase (ST) expressed as a chimera with the rapamycin-binding domain of mTOR, FRB, relocates to the endoplasmic reticulum (ER) in cells exposed to rapamycin that also express invariant chain (Ii)-FKBP in the ER. This result has been taken to indicate that Golgi-resident enzymes cycle to the ER constitutively. We show that ST-FRB is trapped in the ER even without Ii-FKBP upon rapamycin addition. This is because ER-Golgi–cycling FKBP proteins contain a C-terminal KDEL-like sequence, bind ST-FRB in the Golgi, and are transported together back to the ER by KDEL receptor–mediated retrograde transport. Moreover, depletion of KDEL receptor prevents trapping of ST-FRB in the ER by rapamycin. Thus ST-FRB cycles artificially by binding to FKBP domain–containing proteins. In addition, Golgi-specific O-linked glycosylation of a resident ER protein occurs only upon artificial fusion of Golgi membranes with ER. Together these findings support the consensus view that there is no appreciable mixing of Golgi-resident enzymes with ER under normal conditions.
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Affiliation(s)
- Julien Villeneuve
- Cell and Developmental Biology Department, Centre for Genomic Regulation, Barcelona Institute for Science and Technology, 08003 Barcelona, Spain.,Department of Molecular and Cell Biology and Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, CA 94720
| | - Juan Duran
- Cell and Developmental Biology Department, Centre for Genomic Regulation, Barcelona Institute for Science and Technology, 08003 Barcelona, Spain.,Universitat Pompeu Fabra, 08002 Barcelona, Spain
| | - Margherita Scarpa
- Cell and Developmental Biology Department, Centre for Genomic Regulation, Barcelona Institute for Science and Technology, 08003 Barcelona, Spain
| | - Laia Bassaganyas
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA 94143.,Institute for Human Genetics, University of California, San Francisco, San Francisco, CA 94143
| | - Josse Van Galen
- Cell and Developmental Biology Department, Centre for Genomic Regulation, Barcelona Institute for Science and Technology, 08003 Barcelona, Spain
| | - Vivek Malhotra
- Cell and Developmental Biology Department, Centre for Genomic Regulation, Barcelona Institute for Science and Technology, 08003 Barcelona, Spain .,Universitat Pompeu Fabra, 08002 Barcelona, Spain.,Institució Catalana de Recerca i Estudis Avançats, 08010 Barcelona, Spain
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26
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Mitotic Golgi disassembly is required for bipolar spindle formation and mitotic progression. Proc Natl Acad Sci U S A 2016; 113:E6590-E6599. [PMID: 27791030 DOI: 10.1073/pnas.1610844113] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
During mitosis, the mammalian Golgi vesiculates and, upon partitioning, reassembles in each daughter cell; however, it is not clear whether the disassembly process per se is important for partitioning or is merely an outcome of mitotic entry. Here, we show that Golgi vesiculation is required for progression to metaphase. To prevent Golgi disassembly, we expressed HRP linked to a Golgi-resident protein and acutely triggered the polymerization of 3,3'-diaminobenzidine (DAB) in the Golgi lumen. The DAB polymer does not affect interphase cell viability, but inhibits Golgi fragmentation by nocodazole and brefeldin A and also halts cells in early mitosis. The arrest is Golgi specific and does not occur when DAB is polymerized in the endosomes. Cells with a DAB polymer in the Golgi enter mitosis normally but arrest with an intact Golgi clustered at a monopolar spindle and an active spindle assembly checkpoint (SAC). Mitotic progression is restored upon centrosome depletion by the Polo-like kinase 4 inhibitor, centrinone, indicating that the link between the Golgi and the centrosomes must be dissolved to reach metaphase. These results demonstrate that Golgi disassembly is required for mitotic progression because failure to vesiculate the Golgi activates the canonical SAC. This requirement suggests that cells actively monitor Golgi integrity in mitosis.
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27
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Vanhoutte D, Schips TG, Kwong JQ, Davis J, Tjondrokoesoemo A, Brody MJ, Sargent MA, Kanisicak O, Yi H, Gao QQ, Rabinowitz JE, Volk T, McNally EM, Molkentin JD. Thrombospondin expression in myofibers stabilizes muscle membranes. eLife 2016; 5. [PMID: 27669143 PMCID: PMC5063588 DOI: 10.7554/elife.17589] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Accepted: 09/21/2016] [Indexed: 12/26/2022] Open
Abstract
Skeletal muscle is highly sensitive to mutations in genes that participate in membrane stability and cellular attachment, which often leads to muscular dystrophy. Here we show that Thrombospondin-4 (Thbs4) regulates skeletal muscle integrity and its susceptibility to muscular dystrophy through organization of membrane attachment complexes. Loss of the Thbs4 gene causes spontaneous dystrophic changes with aging and accelerates disease in 2 mouse models of muscular dystrophy, while overexpression of mouse Thbs4 is protective and mitigates dystrophic disease. In the myofiber, Thbs4 selectively enhances vesicular trafficking of dystrophin-glycoprotein and integrin attachment complexes to stabilize the sarcolemma. In agreement, muscle-specific overexpression of Drosophila Tsp or mouse Thbs4 rescues a Drosophila model of muscular dystrophy with augmented membrane residence of βPS integrin. This functional conservation emphasizes the fundamental importance of Thbs' as regulators of cellular attachment and membrane stability and identifies Thbs4 as a potential therapeutic target for muscular dystrophy.
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Affiliation(s)
- Davy Vanhoutte
- Cincinnati Children's Hospital Medical Center, Department of Pediatrics, University of Cincinnati, Cincinnati, United States
| | - Tobias G Schips
- Cincinnati Children's Hospital Medical Center, Department of Pediatrics, University of Cincinnati, Cincinnati, United States
| | - Jennifer Q Kwong
- Cincinnati Children's Hospital Medical Center, Department of Pediatrics, University of Cincinnati, Cincinnati, United States
| | - Jennifer Davis
- Cincinnati Children's Hospital Medical Center, Department of Pediatrics, University of Cincinnati, Cincinnati, United States
| | - Andoria Tjondrokoesoemo
- Cincinnati Children's Hospital Medical Center, Department of Pediatrics, University of Cincinnati, Cincinnati, United States
| | - Matthew J Brody
- Cincinnati Children's Hospital Medical Center, Department of Pediatrics, University of Cincinnati, Cincinnati, United States
| | - Michelle A Sargent
- Cincinnati Children's Hospital Medical Center, Department of Pediatrics, University of Cincinnati, Cincinnati, United States
| | - Onur Kanisicak
- Cincinnati Children's Hospital Medical Center, Department of Pediatrics, University of Cincinnati, Cincinnati, United States
| | - Hong Yi
- Robert P. Apkarian Integrated Electron Microscopy Core, Emory University, Atlanta, United States
| | - Quan Q Gao
- Center for Genetic Medicine, Northwestern University, Chicago, United States
| | | | - Talila Volk
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Elizabeth M McNally
- Center for Genetic Medicine, Northwestern University, Chicago, United States
| | - Jeffery D Molkentin
- Cincinnati Children's Hospital Medical Center, Department of Pediatrics, University of Cincinnati, Cincinnati, United States.,Howard Hughes Medical Institute, Cincinnati Children's Hospital Medical Center, Cincinnati, United States
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28
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Growth of the Mammalian Golgi Apparatus during Interphase. Mol Cell Biol 2016; 36:2344-59. [PMID: 27325676 DOI: 10.1128/mcb.00046-16] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2016] [Accepted: 06/14/2016] [Indexed: 12/11/2022] Open
Abstract
During the cell cycle, genetic materials and organelles are duplicated to ensure that there is sufficient cellular content for daughter cells. While Golgi growth in interphase has been observed in lower eukaryotes, the elaborate ribbon structure of the mammalian Golgi apparatus has made it challenging to monitor. Here we demonstrate the growth of the mammalian Golgi apparatus in its protein content and volume during interphase. Through ultrastructural analyses, physical growth of the Golgi apparatus was revealed to occur by cisternal elongation of the individual Golgi stacks. By examining the timing and regulation of Golgi growth, we established that Golgi growth starts after passage through the cell growth checkpoint at late G1 phase and continues in a manner highly correlated with cell size growth. Finally, by identifying S6 kinase 1 as a major player in Golgi growth, we revealed the coordination between cell size and Golgi growth via activation of the protein synthesis machinery in early interphase.
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29
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Rodrigues FF, Shao W, Harris TJC. The Arf GAP Asap promotes Arf1 function at the Golgi for cleavage furrow biosynthesis in Drosophila. Mol Biol Cell 2016; 27:3143-3155. [PMID: 27535433 PMCID: PMC5063621 DOI: 10.1091/mbc.e16-05-0272] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Accepted: 08/11/2016] [Indexed: 11/11/2022] Open
Abstract
Drosophila embryo cleavage requires the conserved Arf GAP Asap. Asap seems to recycle Arf1 to the Golgi from post-Golgi membranes for optimal Golgi output and cleavage furrow biosynthesis. Biosynthetic traffic from the Golgi drives plasma membrane growth. For Drosophila embryo cleavage, this growth is rapid but regulated for cycles of furrow ingression and regression. The highly conserved small G protein Arf1 organizes Golgi trafficking. Arf1 is activated by guanine nucleotide exchange factors, but essential roles for Arf1 GTPase-activating proteins (GAPs) are less clear. We report that the conserved Arf GAP Asap is required for cleavage furrow ingression in the early embryo. Because Asap can affect multiple subcellular processes, we used genetic approaches to dissect its primary effect. Our data argue against cytoskeletal or endocytic involvement and reveal a common role for Asap and Arf1 in Golgi organization. Although Asap lacked Golgi enrichment, it was necessary and sufficient for Arf1 accumulation at the Golgi, and a conserved Arf1-Asap binding site was required for Golgi organization and output. Of note, Asap relocalized to the nuclear region at metaphase, a shift that coincided with subtle Golgi reorganization preceding cleavage furrow regression. We conclude that Asap is essential for Arf1 to function at the Golgi for cleavage furrow biosynthesis. Asap may recycle Arf1 to the Golgi from post-Golgi membranes, providing optimal Golgi output for specific stages of the cell cycle.
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Affiliation(s)
- Francisco F Rodrigues
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON M5S 3G5, Canada
| | - Wei Shao
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON M5S 3G5, Canada
| | - Tony J C Harris
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON M5S 3G5, Canada
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30
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Taverna E, Mora-Bermúdez F, Strzyz PJ, Florio M, Icha J, Haffner C, Norden C, Wilsch-Bräuninger M, Huttner WB. Non-canonical features of the Golgi apparatus in bipolar epithelial neural stem cells. Sci Rep 2016; 6:21206. [PMID: 26879757 PMCID: PMC4754753 DOI: 10.1038/srep21206] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Accepted: 01/19/2016] [Indexed: 12/13/2022] Open
Abstract
Apical radial glia (aRG), the stem cells in developing neocortex, are unique bipolar epithelial cells, extending an apical process to the ventricle and a basal process to the basal lamina. Here, we report novel features of the Golgi apparatus, a central organelle for cell polarity, in mouse aRGs. The Golgi was confined to the apical process but not associated with apical centrosome(s). In contrast, in aRG-derived, delaminating basal progenitors that lose apical polarity, the Golgi became pericentrosomal. The aRG Golgi underwent evolutionarily conserved, accordion-like compression and extension concomitant with cell cycle-dependent nuclear migration. Importantly, in line with endoplasmic reticulum but not Golgi being present in the aRG basal process, its plasma membrane contained glycans lacking Golgi processing, consistent with direct ER-to-cell surface membrane traffic. Our study reveals hitherto unknown complexity of neural stem cell polarity, differential Golgi contribution to their specific architecture, and fundamental Golgi re-organization upon cell fate change.
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Affiliation(s)
- Elena Taverna
- Max-Planck Inst. of Mol. Cell Biol. and Genetics, Pfotenhauerstr. 108, 01307 Dresden, Germany
| | - Felipe Mora-Bermúdez
- Max-Planck Inst. of Mol. Cell Biol. and Genetics, Pfotenhauerstr. 108, 01307 Dresden, Germany
| | - Paulina J Strzyz
- Max-Planck Inst. of Mol. Cell Biol. and Genetics, Pfotenhauerstr. 108, 01307 Dresden, Germany
| | - Marta Florio
- Max-Planck Inst. of Mol. Cell Biol. and Genetics, Pfotenhauerstr. 108, 01307 Dresden, Germany
| | - Jaroslav Icha
- Max-Planck Inst. of Mol. Cell Biol. and Genetics, Pfotenhauerstr. 108, 01307 Dresden, Germany
| | - Christiane Haffner
- Max-Planck Inst. of Mol. Cell Biol. and Genetics, Pfotenhauerstr. 108, 01307 Dresden, Germany
| | - Caren Norden
- Max-Planck Inst. of Mol. Cell Biol. and Genetics, Pfotenhauerstr. 108, 01307 Dresden, Germany
| | | | - Wieland B Huttner
- Max-Planck Inst. of Mol. Cell Biol. and Genetics, Pfotenhauerstr. 108, 01307 Dresden, Germany
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31
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Valente C, Colanzi A. Mechanisms and Regulation of the Mitotic Inheritance of the Golgi Complex. Front Cell Dev Biol 2015; 3:79. [PMID: 26734607 PMCID: PMC4679863 DOI: 10.3389/fcell.2015.00079] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Accepted: 11/27/2015] [Indexed: 11/13/2022] Open
Abstract
In mammalian cells, the Golgi complex is structured in the form of a continuous membranous system composed of stacks connected by tubular bridges: the "Golgi ribbon." At the onset of mitosis, the Golgi complex undergoes a multi-step fragmentation process that is required for its correct partition into the dividing cells. Importantly, inhibition of Golgi disassembly results in cell-cycle arrest at the G2 stage, which indicates that accurate inheritance of the Golgi complex is monitored by a "Golgi mitotic checkpoint." Moreover, mitotic Golgi disassembly correlates with the release of a set of Golgi-localized proteins that acquire specific functions during mitosis, such as mitotic spindle formation and regulation of the spindle checkpoint. Most of these events are regulated by small GTPases of the Arf and Rab families. Here, we review recent studies that are revealing the fundamental mechanisms, the molecular players, and the biological significance of mitotic inheritance of the Golgi complex in mammalian cells. We also briefly comment on how Golgi partitioning is coordinated with mitotic progression.
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Affiliation(s)
- Carmen Valente
- Institute of Protein Biochemistry, National Research Council Naples, Italy
| | - Antonino Colanzi
- Institute of Protein Biochemistry, National Research Council Naples, Italy
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32
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ER trapping reveals Golgi enzymes continually revisit the ER through a recycling pathway that controls Golgi organization. Proc Natl Acad Sci U S A 2015; 112:E6752-61. [PMID: 26598700 DOI: 10.1073/pnas.1520957112] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Whether Golgi enzymes remain localized within the Golgi or constitutively cycle through the endoplasmic reticulum (ER) is unclear, yet is important for understanding Golgi dependence on the ER. Here, we demonstrate that the previously reported inefficient ER trapping of Golgi enzymes in a rapamycin-based assay results from an artifact involving an endogenous ER-localized 13-kD FK506 binding protein (FKBP13) competing with the FKBP12-tagged Golgi enzyme for binding to an FKBP-rapamycin binding domain (FRB)-tagged ER trap. When we express an FKBP12-tagged ER trap and FRB-tagged Golgi enzymes, conditions precluding such competition, the Golgi enzymes completely redistribute to the ER upon rapamycin treatment. A photoactivatable FRB-Golgi enzyme, highlighted only in the Golgi, likewise redistributes to the ER. These data establish Golgi enzymes constitutively cycle through the ER. Using our trapping scheme, we identify roles of rab6a and calcium-independent phospholipase A2 (iPLA2) in Golgi enzyme recycling, and show that retrograde transport of Golgi membrane underlies Golgi dispersal during microtubule depolymerization and mitosis.
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33
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Tenorio MJ, Luchsinger C, Mardones GA. Protein kinase A activity is necessary for fission and fusion of Golgi to endoplasmic reticulum retrograde tubules. PLoS One 2015; 10:e0135260. [PMID: 26258546 PMCID: PMC4530959 DOI: 10.1371/journal.pone.0135260] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Accepted: 07/20/2015] [Indexed: 11/18/2022] Open
Abstract
It is becoming increasingly accepted that together with vesicles, tubules play a major role in the transfer of cargo between different cellular compartments. In contrast to our understanding of the molecular mechanisms of vesicular transport, little is known about tubular transport. How signal transduction molecules regulate these two modes of membrane transport processes is also poorly understood. In this study we investigated whether protein kinase A (PKA) activity regulates the retrograde, tubular transport of Golgi matrix proteins from the Golgi to the endoplasmic reticulum (ER). We found that Golgi-to-ER retrograde transport of the Golgi matrix proteins giantin, GM130, GRASP55, GRASP65, and p115 was impaired in the presence of PKA inhibitors. In addition, we unexpectedly found accumulation of tubules containing both Golgi matrix proteins and resident Golgi transmembrane proteins. These tubules were still attached to the Golgi and were highly dynamic. Our data suggest that both fission and fusion of retrograde tubules are mechanisms regulated by PKA activity.
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Affiliation(s)
- María J. Tenorio
- Instituto de Fisiología, Facultad de Medicina, and Centro Interdisciplinario de Estudios del Sistema Nerviso, Universidad Austral de Chile, Valdivia, Chile
| | - Charlotte Luchsinger
- Instituto de Fisiología, Facultad de Medicina, and Centro Interdisciplinario de Estudios del Sistema Nerviso, Universidad Austral de Chile, Valdivia, Chile
| | - Gonzalo A. Mardones
- Instituto de Fisiología, Facultad de Medicina, and Centro Interdisciplinario de Estudios del Sistema Nerviso, Universidad Austral de Chile, Valdivia, Chile
- * E-mail:
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34
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The trials and tubule-ations of Rab6 involvement in Golgi-to-ER retrograde transport. Biochem Soc Trans 2015; 42:1453-9. [PMID: 25233431 DOI: 10.1042/bst20140178] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
In the early secretory pathway, membrane flow in the anterograde direction from the endoplasmic reticulum (ER) to the Golgi complex needs to be tightly co-ordinated with retrograde flow to maintain the size, composition and functionality of these two organelles. At least two mechanisms of transport move material in the retrograde direction: one regulated by the cytoplasmic coatomer protein I complex (COPI), and a second COPI-independent pathway utilizing the small GTP-binding protein Rab6. Although the COPI-independent pathway was discovered 15 years ago, it remains relatively poorly characterized, with only a handful of machinery molecules associated with its operation. One feature that makes this pathway somewhat unusual, and potentially difficult to study, is that the transport carriers predominantly seem to be tubular rather than vesicular in nature. This suggests that the regulatory machinery is likely to be different from that associated with vesicular transport pathways controlled by conventional coat complexes. In the present mini-review, we have highlighted the key experiments that have characterized this transport pathway so far and also have discussed the challenges that lie ahead with respect to its further characterization.
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35
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Schuberth CE, Tängemo C, Coneva C, Tischer C, Pepperkok R. Self-organization of core Golgi material is independent of COPII-mediated endoplasmic reticulum export. J Cell Sci 2015; 128:1279-93. [PMID: 25717003 DOI: 10.1242/jcs.154443] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The Golgi is a highly organized and dynamic organelle that receives and distributes material from and to the endoplasmic reticulum (ER) and the endocytic pathway. One open question about Golgi organization is whether it is solely based on ER-to-Golgi transport. Here, we analyzed the kinetics of Golgi breakdown in the absence of COPII-dependent ER export with high temporal and spatial resolution using quantitative fluorescence microscopy. We found that Golgi breakdown occurred in two phases. While Golgi enzymes continuously redistributed to the ER, we consistently observed extensive Golgi fragmentation at the beginning of the breakdown, followed by microtubule-dependent formation of a Golgi remnant structure (phase 1). Further Golgi disintegration occurred less uniformly (phase 2). Remarkably, cisternal Golgi morphology was lost early in phase 1 and Golgi fragments instead corresponded to variably sized vesicle clusters. These breakdown intermediates were devoid of COPI-dependent recycling material, but contained typical 'core' Golgi components. Furthermore, Golgi breakdown intermediates were able to disassemble and reassemble following cell division, indicating that they retained important regulatory capabilities. Taken together, these findings support the view that Golgi self-organization exists independently of ER-to-Golgi transport.
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Affiliation(s)
- Christian E Schuberth
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory (EMBL), Meyerhofstr. 1, 69117 Heidelberg, Germany Institute of Cell Dynamics and Imaging, University of Muenster, von-Esmarch-Str. 56, 48149 Muenster, Germany Cells in Motion Cluster of Excellence (EXC1003-CiM), University of Muenster, von-Esmarch-Str. 56, 48149 Muenster, Germany
| | - Carolina Tängemo
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory (EMBL), Meyerhofstr. 1, 69117 Heidelberg, Germany
| | - Cvetalina Coneva
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory (EMBL), Meyerhofstr. 1, 69117 Heidelberg, Germany
| | - Christian Tischer
- Advanced Light Microscopy Facility, European Molecular Biology Laboratory (EMBL), Meyerhofstr. 1, 69117 Heidelberg, Germany
| | - Rainer Pepperkok
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory (EMBL), Meyerhofstr. 1, 69117 Heidelberg, Germany Advanced Light Microscopy Facility, European Molecular Biology Laboratory (EMBL), Meyerhofstr. 1, 69117 Heidelberg, Germany
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36
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Ito Y, Uemura T, Nakano A. Formation and maintenance of the Golgi apparatus in plant cells. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2014; 310:221-87. [PMID: 24725428 DOI: 10.1016/b978-0-12-800180-6.00006-2] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The Golgi apparatus plays essential roles in intracellular trafficking, protein and lipid modification, and polysaccharide synthesis in eukaryotic cells. It is well known for its unique stacked structure, which is conserved among most eukaryotes. However, the mechanisms of biogenesis and maintenance of the structure, which are deeply related to ER-Golgi and intra-Golgi transport systems, have long been mysterious. Now having extremely powerful microscopic technologies developed for live-cell imaging, the plant Golgi apparatus provides an ideal system to resolve the question. The plant Golgi apparatus has unique features that are not conserved in other kingdoms, which will also give new insights into the Golgi functions in plant life. In this review, we will summarize the features of the plant Golgi apparatus and transport mechanisms around it, with a focus on recent advances in Golgi biogenesis by live imaging of plants cells.
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Affiliation(s)
- Yoko Ito
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Tomohiro Uemura
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Akihiko Nakano
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, Bunkyo-ku, Tokyo, Japan; Live Cell Molecular Imaging Research Team, RIKEN Center for Advanced Photonics, Wako, Saitama, Japan.
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37
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Jongsma MLM, Berlin I, Neefjes J. On the move: organelle dynamics during mitosis. Trends Cell Biol 2014; 25:112-24. [PMID: 25466831 DOI: 10.1016/j.tcb.2014.10.005] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2014] [Revised: 10/23/2014] [Accepted: 10/28/2014] [Indexed: 10/24/2022]
Abstract
A cell constitutes the minimal self-replicating unit of all organisms, programmed to propagate its genome as it proceeds through mitotic cell division. The molecular processes entrusted with ensuring high fidelity of DNA replication and subsequent segregation of chromosomes between daughter cells have therefore been studied extensively. However, to process the information encoded in its genome a cell must also pass on its non-genomic identity to future generations. To achieve productive sharing of intracellular organelles, cells have evolved complex mechanisms of organelle inheritance. Many membranous compartments undergo vast spatiotemporal rearrangements throughout mitosis. These controlled organizational changes are crucial to enabling completion of the division cycle and ensuring successful progeny. Herein we review current understanding of intracellular organelle segregation during mitotic division in mammalian cells, with a focus on compartment organization and integrity throughout the inheritance process.
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Affiliation(s)
- Marlieke L M Jongsma
- Division of Cell Biology, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands
| | - Ilana Berlin
- Division of Cell Biology, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands
| | - Jacques Neefjes
- Division of Cell Biology, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands.
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38
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Barrantes FJ. Cell-surface translational dynamics of nicotinic acetylcholine receptors. Front Synaptic Neurosci 2014; 6:25. [PMID: 25414663 PMCID: PMC4220116 DOI: 10.3389/fnsyn.2014.00025] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2014] [Accepted: 10/08/2014] [Indexed: 12/20/2022] Open
Abstract
Synapse efficacy heavily relies on the number of neurotransmitter receptors available at a given time. In addition to the equilibrium between the biosynthetic production, exocytic delivery and recycling of receptors on the one hand, and the endocytic internalization on the other, lateral diffusion and clustering of receptors at the cell membrane play key roles in determining the amount of active receptors at the synapse. Mobile receptors traffic between reservoir compartments and the synapse by thermally driven Brownian motion, and become immobilized at the peri-synaptic region or the synapse by: (a) clustering mediated by homotropic inter-molecular receptor–receptor associations; (b) heterotropic associations with non-receptor scaffolding proteins or the subjacent cytoskeletal meshwork, leading to diffusional “trapping,” and (c) protein-lipid interactions, particularly with the neutral lipid cholesterol. This review assesses the contribution of some of these mechanisms to the supramolecular organization and dynamics of the paradigm neurotransmitter receptor of muscle and neuronal cells -the nicotinic acetylcholine receptor (nAChR). Currently available information stemming from various complementary biophysical techniques commonly used to interrogate the dynamics of cell-surface components is critically discussed. The translational mobility of nAChRs at the cell surface differs between muscle and neuronal receptors in terms of diffusion coefficients and residence intervals at the synapse, which cover an ample range of time regimes. A peculiar feature of brain α7 nAChR is its ability to spend much of its time confined peri-synaptically, vicinal to glutamatergic (excitatory) and GABAergic (inhibitory) synapses. An important function of the α7 nAChR may thus be visiting the territories of other neurotransmitter receptors, differentially regulating the dynamic equilibrium between excitation and inhibition, depending on its residence time in each domain.
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Affiliation(s)
- Francisco J Barrantes
- Laboratory of Molecular Neurobiology, Institute of Biomedical Research, Faculty of Medical Sciences, Pontifical Catholic University of Argentina-National Scientific and Technical Research Council Buenos Aires, Argentina
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39
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Ronchi P, Tischer C, Acehan D, Pepperkok R. Positive feedback between Golgi membranes, microtubules and ER exit sites directs de novo biogenesis of the Golgi. J Cell Sci 2014; 127:4620-33. [PMID: 25189616 DOI: 10.1242/jcs.150474] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The Golgi complex is the central organelle of the secretory pathway. It undergoes dynamic changes during the cell cycle, but how it acquires and maintains its complex structure is unclear. To address this question, we have used laser nanosurgery to deplete BSC1 cells of the Golgi complex and have monitored its biogenesis by quantitative time-lapse microscopy and correlative electron microscopy. After Golgi depletion, endoplasmic reticulum (ER) export is inhibited and the number of ER exit sites (ERES) is reduced and does not increase for several hours. Occasional fusion of small post-ER carriers to form the first larger structures triggers a rapid and drastic growth of Golgi precursors, due to the capacity of these structures to attract more carriers by microtubule nucleation and to stimulate ERES biogenesis. Increasing the chances of post-ER carrier fusion close to ERES by depolymerizing microtubules results in the acceleration of Golgi and ERES biogenesis. Taken together, on the basis of our results, we propose a self-organizing principle of the early secretory pathway that integrates Golgi biogenesis, ERES biogenesis and the organization of the microtubule network by positive-feedback loops.
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Affiliation(s)
- Paolo Ronchi
- European Molecular Biology Laboratory (EMBL), Cell biology and biophysics unit
| | - Christian Tischer
- European Molecular Biology Laboratory (EMBL), Advanced Light Microscopy
| | - Devrim Acehan
- European Molecular Biology Laboratory (EMBL), Electron Microscopy Core Facilities, Meyerhofstrasse 1, 69117 Heidelberg, Germany
| | - Rainer Pepperkok
- European Molecular Biology Laboratory (EMBL), Cell biology and biophysics unit European Molecular Biology Laboratory (EMBL), Advanced Light Microscopy
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40
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Jensen CS, Misonou H. Live-cell imaging of post-golgi transport vesicles in cultured hippocampal neurons. Cell Mol Neurobiol 2014; 35:123-35. [PMID: 25182224 DOI: 10.1007/s10571-014-0103-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2014] [Accepted: 08/23/2014] [Indexed: 11/26/2022]
Abstract
The subcellular localization of neuronal membrane signaling molecules such as receptors and ion channels depends on intracellular trafficking mechanisms. Essentially, vesicular trafficking mechanisms ensure that a large number of membrane proteins are correctly targeted to different subcellular compartments of neurons. In the past two decades, the establishment and advancement of fluorescent protein technology have provided us with opportunities to study how proteins are trafficked in living cells. However, live imaging of trafficking processes in neurons necessitate imaging tools to distinguish the several different routes that neurons use for protein trafficking. Here we provide a novel protocol to selectively visualize post-Golgi transport vesicles carrying fluorescent-labeled ion channel proteins in living neurons. Further, we provide a number of analytical tools we developed to quantify characteristics of different types of transport vesicles. We demonstrate the application of our protocol to investigate whether ion channels are sorted into distinct vesicular populations at the Golgi apparatus. We also demonstrate how these techniques are suitable for pharmacological dissection of the transport mechanisms by which post-Golgi vesicles are trafficked in neurons. Our protocol uniquely combines the classic temperature-block with close monitoring of the transient expression of transfected protein tagged with fluorescent proteins, and provides a quick and easy way to study protein trafficking in living neurons. We believe that the procedures described here are useful for researchers who are interested in studying molecular mechanisms of protein trafficking in neurons.
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Affiliation(s)
- Camilla Stampe Jensen
- Department of Neural and Pain Sciences, University of Maryland, Baltimore, MD, 21201, USA
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41
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Gregori J, Méndez O, Katsila T, Pujals M, Salvans C, Villarreal L, Arribas J, Tabernero J, Sánchez A, Villanueva J. Enhancing the Biological Relevance of Secretome-Based Proteomics by Linking Tumor Cell Proliferation and Protein Secretion. J Proteome Res 2014; 13:3706-3721. [PMID: 24897304 DOI: 10.1021/pr500304g] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Secretome profiling has become a methodology of choice for the identification of tumor biomarkers. We hypothesized that due to the dynamic nature of secretomes cellular perturbations could affect their composition but also change the global amount of protein secreted per cell. We confirmed our hypothesis by measuring the levels of secreted proteins taking into account the amount of proteome produced per cell. Then, we established a correlation between cell proliferation and protein secretion that explained the observed changes in global protein secretion. Next, we implemented a normalization correcting the statistical results of secretome studies by the global protein secretion of cells into a generalized linear model (GLM). The application of the normalization to two biological perturbations on tumor cells resulted in drastic changes in the list of statistically significant proteins. Furthermore, we found that known epithelial-to-mesenchymal transition (EMT) effectors were only statistically significant when the normalization was applied. Therefore, the normalization proposed here increases the sensitivity of statistical tests by increasing the number of true-positives. From an oncology perspective, the correlation between protein secretion and cellular proliferation suggests that slow-growing tumors could have high-protein secretion rates and consequently contribute strongly to tumor paracrine signaling.
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Affiliation(s)
- Josep Gregori
- Vall d'Hebron Institute of Oncology (VHIO), Universitat Autònoma de Barcelona (UAB) , Psg. Vall d'Hebron 119-129, 08035 Barcelona, Spain.,Statistics Department, University of Barcelona (UB) , Avda Diagonal 643, 08028 Barcelona, Spain
| | - Olga Méndez
- Vall d'Hebron Institute of Oncology (VHIO), Universitat Autònoma de Barcelona (UAB) , Psg. Vall d'Hebron 119-129, 08035 Barcelona, Spain
| | - Theodora Katsila
- Vall d'Hebron Institute of Oncology (VHIO), Universitat Autònoma de Barcelona (UAB) , Psg. Vall d'Hebron 119-129, 08035 Barcelona, Spain
| | - Mireia Pujals
- Vall d'Hebron Institute of Oncology (VHIO), Universitat Autònoma de Barcelona (UAB) , Psg. Vall d'Hebron 119-129, 08035 Barcelona, Spain
| | - Cándida Salvans
- Vall d'Hebron Institute of Oncology (VHIO), Universitat Autònoma de Barcelona (UAB) , Psg. Vall d'Hebron 119-129, 08035 Barcelona, Spain
| | - Laura Villarreal
- Vall d'Hebron Institute of Oncology (VHIO), Universitat Autònoma de Barcelona (UAB) , Psg. Vall d'Hebron 119-129, 08035 Barcelona, Spain
| | - Joaquin Arribas
- Vall d'Hebron Institute of Oncology (VHIO), Universitat Autònoma de Barcelona (UAB) , Psg. Vall d'Hebron 119-129, 08035 Barcelona, Spain
| | - Josep Tabernero
- Vall d'Hebron Institute of Oncology (VHIO), Universitat Autònoma de Barcelona (UAB) , Psg. Vall d'Hebron 119-129, 08035 Barcelona, Spain
| | - Alex Sánchez
- Statistics Department, University of Barcelona (UB) , Avda Diagonal 643, 08028 Barcelona, Spain.,Statistics and Bioinformatics Unit, Vall d'Hebron Institut de Recerca , Psg. Vall d'Hebron 119-129, 08035 Barcelona, Spain
| | - Josep Villanueva
- Vall d'Hebron Institute of Oncology (VHIO), Universitat Autònoma de Barcelona (UAB) , Psg. Vall d'Hebron 119-129, 08035 Barcelona, Spain
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42
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Aranovich A, Hua R, Rutenberg AD, Kim PK. PEX16 contributes to peroxisome maintenance by constantly trafficking PEX3 via the ER. J Cell Sci 2014; 127:3675-86. [PMID: 25002403 PMCID: PMC4172262 DOI: 10.1242/jcs.146282] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The endoplasmic reticulum (ER) is required for the de novo biogenesis of peroxisomes in mammalian cells. However, its role in peroxisome maintenance is unclear. To explore ER involvement in the maintenance of peroxisomes, we redirect a peroxisomal membrane protein (PMP), PEX3, to directly target to the ER using the N-terminal ER signal sequence from preprolactin. Using biochemical techniques and fluorescent imaging, we find that ER-targeting PEX3 (ssPEX3) is continuously imported into pre-existing peroxisomes. This suggests that the ER constitutively provides membrane proteins and associated lipids to pre-existing peroxisomes. Using quantitative time-lapse live-cell fluorescence microscopy applied to cells that were either depleted of or exogenously expressing PEX16, we find that PEX16 mediates the peroxisomal trafficking of two distinct peroxisomal membrane proteins, PEX3 and PMP34, via the ER. These results not only provide insight into peroxisome maintenance and PMP trafficking in mammalian cells but also highlight important similarities and differences in the mechanisms of PMP import between the mammalian and yeast systems.
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Affiliation(s)
- Alexander Aranovich
- Program in Cell Biology, Hospital for Sick Children, Toronto, ON M5G 0A4, Canada
| | - Rong Hua
- Program in Cell Biology, Hospital for Sick Children, Toronto, ON M5G 0A4, Canada Department of Biochemistry, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Andrew D Rutenberg
- Department of Physics and Atmospheric Science, Dalhousie University, Halifax, NS B3H 1Z9, Canada
| | - Peter K Kim
- Program in Cell Biology, Hospital for Sick Children, Toronto, ON M5G 0A4, Canada Department of Biochemistry, University of Toronto, Toronto, ON M5S 1A8, Canada
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43
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Pageon SV, Aquino G, Lagrue K, Köhler K, Endres RG, Davis DM. Dynamics of natural killer cell receptor revealed by quantitative analysis of photoswitchable protein. Biophys J 2014; 105:1987-96. [PMID: 24209843 DOI: 10.1016/j.bpj.2013.09.025] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2013] [Revised: 08/27/2013] [Accepted: 09/18/2013] [Indexed: 10/26/2022] Open
Abstract
Natural Killer (NK) cell activation is dynamically regulated by numerous activating and inhibitory surface receptors that accumulate at the immune synapse. Quantitative analysis of receptor dynamics has been limited by methodologies that rely on indirect measurements such as fluorescence recovery after photobleaching. Here, we report an apparently novel approach to study how proteins traffic to and from the immune synapse using NK cell receptors tagged with the photoswitchable fluorescent protein tdEosFP, which can be irreversibly photoswitched from a green to red fluorescent state by ultraviolet light. Thus, after a localized switching event, the movement of the photoswitched molecules can be temporally and spatially resolved by monitoring fluorescence in two regions of interest. By comparing images with mathematical models, we evaluated the diffusion coefficient of the receptor KIR2DL1 (0.23 ± 0.06 μm(2) s(-1)) and assessed how synapse formation affects receptor dynamics. Our data conclude that the inhibitory NK cell receptor KIR2DL1 is continually trafficked into the synapse, and remains surprisingly stable there. Unexpectedly, however, in NK cells forming synapses with multiple target cells simultaneously, KIR2DL1 at one synapse can relocate to another synapse. Thus, our results reveal a previously undetected intersynaptic exchange of protein.
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Affiliation(s)
- Sophie V Pageon
- Department of Life Sciences, Imperial College London, Exhibition Road, London, United Kingdom
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44
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Ramadas R, Thattai M. New organelles by gene duplication in a biophysical model of eukaryote endomembrane evolution. Biophys J 2014; 104:2553-63. [PMID: 23746528 DOI: 10.1016/j.bpj.2013.03.066] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2012] [Revised: 03/05/2013] [Accepted: 03/11/2013] [Indexed: 12/13/2022] Open
Abstract
Extant eukaryotic cells have a dynamic traffic network that consists of diverse membrane-bound organelles exchanging matter via vesicles. This endomembrane system arose and diversified during a period characterized by massive expansions of gene families involved in trafficking after the acquisition of a mitochondrial endosymbiont by a prokaryotic host cell >1.8 billion years ago. Here we investigate the mechanistic link between gene duplication and the emergence of new nonendosymbiotic organelles, using a minimal biophysical model of traffic. Our model incorporates membrane-bound compartments, coat proteins and adaptors that drive vesicles to bud and segregate cargo from source compartments, and SNARE proteins and associated factors that cause vesicles to fuse into specific destination compartments. In simulations, arbitrary numbers of compartments with heterogeneous initial compositions segregate into a few compositionally distinct subsets that we term organelles. The global structure of the traffic system (i.e., the number, composition, and connectivity of organelles) is determined completely by local molecular interactions. On evolutionary timescales, duplication of the budding and fusion machinery followed by loss of cross-interactions leads to the emergence of new organelles, with increased molecular specificity being necessary to maintain larger organellar repertoires. These results clarify potential modes of early eukaryotic evolution as well as more recent eukaryotic diversification.
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Affiliation(s)
- Rohini Ramadas
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bangalore, India
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45
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Golgi depletion from living cells with laser nanosurgery. Methods Cell Biol 2013. [PMID: 24295315 DOI: 10.1016/b978-0-12-417164-0.00019-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
How Golgi biogenesis occurs in mammalian cells is a controversial problem. Can the Golgi complex (GC) form de novo from ER membranes or does it require a template? The method described in this chapter uses growth of cells on micropatterns to displace the GC from its juxtanuclear position and laser nanosurgery to subsequently deplete it from living cells. Golgi-depleted karyoplasts can be followed by time-lapse microscopy to address if and how the GC can be de novo synthesized from ER membranes. Furthermore, the study of different processes in the absence of the GC can shed light on the role of this organelle in the intracellular signaling and homeostasis.
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Oddoux S, Zaal KJ, Tate V, Kenea A, Nandkeolyar SA, Reid E, Liu W, Ralston E. Microtubules that form the stationary lattice of muscle fibers are dynamic and nucleated at Golgi elements. ACTA ACUST UNITED AC 2013; 203:205-13. [PMID: 24145165 PMCID: PMC3812964 DOI: 10.1083/jcb.201304063] [Citation(s) in RCA: 114] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Live imaging reveals that muscle microtubules are highly dynamic and build a durable network nucleated by static Golgi elements. Skeletal muscle microtubules (MTs) form a nonclassic grid-like network, which has so far been documented in static images only. We have now observed and analyzed dynamics of GFP constructs of MT and Golgi markers in single live fibers and in the whole mouse muscle in vivo. Using confocal, intravital, and superresolution microscopy, we find that muscle MTs are dynamic, growing at the typical speed of ∼9 µm/min, and forming small bundles that build a durable network. We also show that static Golgi elements, associated with the MT-organizing center proteins γ-tubulin and pericentrin, are major sites of muscle MT nucleation, in addition to the previously identified sites (i.e., nuclear membranes). These data give us a framework for understanding how muscle MTs organize and how they contribute to the pathology of muscle diseases such as Duchenne muscular dystrophy.
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Affiliation(s)
- Sarah Oddoux
- Light Imaging Section, Office of Science and Technology, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD 20892
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Costantini L, Snapp E. Probing endoplasmic reticulum dynamics using fluorescence imaging and photobleaching techniques. CURRENT PROTOCOLS IN CELL BIOLOGY 2013; 60:21.7.1-21.7.29. [PMID: 24510787 PMCID: PMC3920296 DOI: 10.1002/0471143030.cb2107s60] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
This unit describes approaches and tools for studying the dynamics and organization of endoplasmic reticulum (ER) membranes and proteins in living cells using fluorescence microscopy. The ER plays a key role in secretory protein biogenesis, calcium regulation, and lipid synthesis. However, study of these processes has often been restricted to biochemical assays that average millions of lysed cells or imaging of static fixed cells. With new fluorescent protein (FP) reporter tools, sensitive commercial microscopes, and photobleaching techniques, investigators can interrogate the behaviors of ER proteins, membranes, and stress pathways in single live cells. Solutions are described for imaging challenges relevant to the ER, including the mobility of ER membranes, a range of ER structures, and the influence of post-translational modifications on FP reporters. Considerations for performing photobleaching assays for ER proteins are discussed. Finally, reporters and drugs for studying misfolded secretory protein stress and the unfolded protein response are described.
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Affiliation(s)
- Lindsey Costantini
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461
| | - Erik Snapp
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461
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Abstract
To maintain cellular homeostasis against the demands of the extracellular environment, a precise regulation of kinases and phosphatases is essential. In cell cycle regulation mechanisms, activation of the cyclin-dependent kinase (CDK1) and cyclin B complex (CDK1:cyclin B) causes a remarkable change in protein phosphorylation. Activation of CDK1:cyclin B is regulated by two auto-amplification loops-CDK1:cyclin B activates Cdc25, its own activating phosphatase, and inhibits Wee1, its own inhibiting kinase. Recent biological evidence has revealed that the inhibition of its counteracting phosphatase activity also occurs, and it is parallel to CDK1:cyclin B activation during mitosis. Phosphatase regulation of mitotic kinases and their substrates is essential to ensure that the progression of the cell cycle is ordered. Outlining how the mutual control of kinases and phosphatases governs the localization and timing of cell division will give us a new understanding about cell cycle regulation.
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Affiliation(s)
| | - Young Yang
- Center for Women’s Disease, Department of Biological Science, Sookmyung Women’s University, Seoul 140-742, Korea
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Totsukawa G, Matsuo A, Kubota A, Taguchi Y, Kondo H. Mitotic phosphorylation of VCIP135 blocks p97ATPase-mediated Golgi membrane fusion. Biochem Biophys Res Commun 2013; 433:237-42. [PMID: 23500464 DOI: 10.1016/j.bbrc.2013.02.090] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2013] [Accepted: 02/27/2013] [Indexed: 10/27/2022]
Abstract
In mammals, the Golgi apparatus is disassembled early mitosis and reassembled at the end of mitosis. For Golgi disassembly, membrane fusion needs to be blocked. Golgi biogenesis requires two distinct p97ATPase-mediated membrane fusion, the p97/p47 and p97/p37 pathways. We previously reported that p47 phosphorylation on Serine-140 and p37 phosphorylation on Serine-56 and Threonine-59 result in mitotic inhibition of the p97/p47 and the p97/p37 pathways, respectively [11,14]. In this study, we show another mechanism of mitotic inhibition of p97-mediated Golgi membrane fusion. We clarified that VCIP135, an essential factor in both p97 membrane fusion pathways, is phosphorylated on Threonine-760 and Serine-767 by Cdc2 at mitosis and that this phosphorylated VCIP135 does not bind to p97. An in vitro Golgi reassembly assay revealed that VCIP135(T760E, S767E), which mimics mitotic phosphorylation, caused no cisternal regrowth. Our results indicate that the phosphorylation of VCIP135 on Threonine-760 and Serine-767 inhibits p97-mediated Golgi membrane fusion at mitosis.
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Affiliation(s)
- Go Totsukawa
- Department of Molecular Cell Biology, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582, Japan
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Sengupta P, Lippincott-Schwartz J. Photohighlighting approaches to access membrane dynamics of the Golgi apparatus. Methods Cell Biol 2013; 118:217-34. [PMID: 24295309 DOI: 10.1016/b978-0-12-417164-0.00013-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
By providing quantitative, visual data of live cells, fluorescent protein-based microscopy techniques are furnishing novel insights into the complexities of membrane trafficking pathways and organelle dynamics. In this chapter, we describe experimental protocols employing fluorescent protein-based photohighlighting techniques to quantify protein movement into and out of the Golgi apparatus, an organelle that serves as the central sorting and processing station of the secretory pathway. The methods allow kinetic characteristics of Golgi-associated protein trafficking to be deciphered, which can help clarify how the Golgi maintains itself as a steady-state structure despite a continuous flux of secretory cargo passing into and out of this organelle. The guidelines presented in this chapter can also be applied to examine the dynamics of other intracellular organelle systems, elucidating mechanisms for how proteins are maintained in specific organelles and/or circulated to other destinations within the cell.
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Affiliation(s)
- Prabuddha Sengupta
- The Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland, USA
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