1
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Chung KP, Frieboese D, Waltz F, Engel BD, Bock R. Identification and characterization of the COPII vesicle-forming GTPase Sar1 in Chlamydomonas. PLANT DIRECT 2024; 8:e614. [PMID: 38887666 PMCID: PMC11180857 DOI: 10.1002/pld3.614] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/04/2024] [Accepted: 05/29/2024] [Indexed: 06/20/2024]
Abstract
Eukaryotic cells are highly compartmentalized, requiring elaborate transport mechanisms to facilitate the movement of proteins between membrane-bound compartments. Most proteins synthesized in the endoplasmic reticulum (ER) are transported to the Golgi apparatus through COPII-mediated vesicular trafficking. Sar1, a small GTPase that facilitates the formation of COPII vesicles, plays a critical role in the early steps of this protein secretory pathway. Sar1 was characterized in yeast, animals and plants, but no Sar1 homolog has been identified and functionally analyzed in algae. Here we identified a putative Sar1 homolog (CrSar1) in the model green alga Chlamydomonas reinhardtii through amino acid sequence similarity. We employed site-directed mutagenesis to generate a dominant-negative mutant of CrSar1 (CrSar1DN). Using protein secretion assays, we demonstrate the inhibitory effect of CrSar1DN on protein secretion. However, different from previously studied organisms, ectopic expression of CrSar1DN did not result in collapse of the ER-Golgi interface in Chlamydomonas. Nonetheless, our data suggest a largely conserved role of CrSar1 in the ER-to-Golgi protein secretory pathway in green algae.
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Affiliation(s)
- Kin Pan Chung
- Max‐Planck‐Institut für Molekulare PflanzenphysiologiePotsdamGermany
| | - Daniel Frieboese
- Max‐Planck‐Institut für Molekulare PflanzenphysiologiePotsdamGermany
| | | | | | - Ralph Bock
- Max‐Planck‐Institut für Molekulare PflanzenphysiologiePotsdamGermany
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2
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Ito Y, Uemura T. Super resolution live imaging: The key for unveiling the true dynamics of membrane traffic around the Golgi apparatus in plant cells. FRONTIERS IN PLANT SCIENCE 2022; 13:1100757. [PMID: 36618665 PMCID: PMC9818705 DOI: 10.3389/fpls.2022.1100757] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Accepted: 12/12/2022] [Indexed: 06/17/2023]
Abstract
In contrast to the relatively static image of the plants, the world inside each cell is surprisingly dynamic. Membrane-bounded organelles move actively on the cytoskeletons and exchange materials by vesicles, tubules, or direct contact between each other. In order to understand what is happening during those events, it is essential to visualize the working components in vivo. After the breakthrough made by the application of fluorescent proteins, the development of light microscopy enabled many discoveries in cell biology, including those about the membrane traffic in plant cells. Especially, super-resolution microscopy, which is becoming more and more accessible, is now one of the most powerful techniques. However, although the spatial resolution has improved a lot, there are still some difficulties in terms of the temporal resolution, which is also a crucial parameter for the visualization of the living nature of the intracellular structures. In this review, we will introduce the super resolution microscopy developed especially for live-cell imaging with high temporal resolution, and show some examples that were made by this tool in plant membrane research.
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Affiliation(s)
- Yoko Ito
- Institute for Human Life Science, Ochanomizu University, Tokyo, Japan
| | - Tomohiro Uemura
- Graduate School of Humanities and Sciences, Ochanomizu University, Tokyo, Japan
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3
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Domozych DS, Sun L, Palacio-Lopez K, Reed R, Jeon S, Li M, Jiao C, Sørensen I, Fei Z, Rose JKC. Endomembrane architecture and dynamics during secretion of the extracellular matrix of the unicellular charophyte, Penium margaritaceum. JOURNAL OF EXPERIMENTAL BOTANY 2020; 71:3323-3339. [PMID: 31974570 PMCID: PMC7289721 DOI: 10.1093/jxb/eraa039] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Accepted: 01/21/2020] [Indexed: 05/02/2023]
Abstract
The extracellular matrix (ECM) of many charophytes, the assemblage of green algae that are the sister group to land plants, is complex, produced in large amounts, and has multiple essential functions. An extensive secretory apparatus and endomembrane system are presumably needed to synthesize and secrete the ECM, but structural details of such a system have not been fully characterized. Penium margaritaceum is a valuable unicellular model charophyte for studying secretion dynamics. We report that Penium has a highly organized endomembrane system, consisting of 150-200 non-mobile Golgi bodies that process and package ECM components into different sets of vesicles that traffic to the cortical cytoplasm, where they are transported around the cell by cytoplasmic streaming. At either fixed or transient areas, specific cytoplasmic vesicles fuse with the plasma membrane and secrete their constituents. Extracellular polysaccharide (EPS) production was observed to occur in one location of the Golgi body and sometimes in unique Golgi hybrids. Treatment of cells with brefeldin A caused disruption of the Golgi body, and inhibition of EPS secretion and cell wall expansion. The structure of the endomembrane system in Penium provides mechanistic insights into how extant charophytes generate large quantities of ECM, which in their ancestors facilitated the colonization of land.
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Affiliation(s)
- David S Domozych
- Department of Biology, Skidmore College, Saratoga Springs, NY, USA
- Correspondence:
| | - Li Sun
- Department of Biology, Skidmore College, Saratoga Springs, NY, USA
| | | | - Reagan Reed
- Department of Biology, Skidmore College, Saratoga Springs, NY, USA
| | - Susan Jeon
- Department of Biology, Skidmore College, Saratoga Springs, NY, USA
| | - Mingjia Li
- Department of Biology, Skidmore College, Saratoga Springs, NY, USA
| | - Chen Jiao
- Boyce Thompson Institute, Ithaca, NY, USA
| | - Iben Sørensen
- Plant Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, NY, USA
| | - Zhangjun Fei
- Boyce Thompson Institute, Ithaca, NY, USA
- U.S. Department of Agriculture-Agricultural Research Service, Robert W. Holley Center for Agriculture and Health, Ithaca, NY, USA
| | - Jocelyn K C Rose
- Plant Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, NY, USA
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4
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Ramos‐Martinez EM, Fimognari L, Sakuragi Y. High-yield secretion of recombinant proteins from the microalga Chlamydomonas reinhardtii. PLANT BIOTECHNOLOGY JOURNAL 2017; 15:1214-1224. [PMID: 28207991 PMCID: PMC5552477 DOI: 10.1111/pbi.12710] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Revised: 02/07/2017] [Accepted: 02/12/2017] [Indexed: 05/11/2023]
Abstract
Microalga-based biomanufacturing of recombinant proteins is attracting growing attention due to its advantages in safety, metabolic diversity, scalability and sustainability. Secretion of recombinant proteins can accelerate the use of microalgal platforms by allowing post-translational modifications and easy recovery of products from the culture media. However, currently, the yields of secreted recombinant proteins are low, which hampers the commercial application of this strategy. This study aimed at expanding the genetic tools for enhancing secretion of recombinant proteins in Chlamydomonas reinhardtii, a widely used green microalga as a model organism and a potential industrial biotechnology platform. We demonstrated that the putative signal sequence from C. reinhardtii gametolysin can assist the secretion of the yellow fluorescent protein Venus into the culture media. To increase the secretion yields, Venus was C-terminally fused with synthetic glycomodules comprised of tandem serine (Ser) and proline (Pro) repeats of 10 and 20 units [hereafter (SP)n , wherein n = 10 or 20]. The yields of the (SP)n -fused Venus were higher than Venus without the glycomodule by up to 12-fold, with the maximum yield of 15 mg/L. Moreover, the presence of the glycomodules conferred an enhanced proteolytic protein stability. The Venus-(SP)n proteins were shown to be glycosylated, and a treatment of the cells with brefeldin A led to a suggestion that glycosylation of the (SP)n glycomodules starts in the endoplasmic reticulum (ER). Taken together, the results demonstrate the utility of the gametolysin signal sequence and (SP)n glycomodule to promote a more efficient biomanufacturing of microalgae-based recombinant proteins.
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Affiliation(s)
- Erick Miguel Ramos‐Martinez
- Department of Plant and Environmental SciencesCopenhagen Plant Science CentreUniversity of CopenhagenFrederiksberg C, CopenhagenDenmark
| | - Lorenzo Fimognari
- Department of Plant and Environmental SciencesCopenhagen Plant Science CentreUniversity of CopenhagenFrederiksberg C, CopenhagenDenmark
| | - Yumiko Sakuragi
- Department of Plant and Environmental SciencesCopenhagen Plant Science CentreUniversity of CopenhagenFrederiksberg C, CopenhagenDenmark
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5
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Vanier G, Lucas PL, Loutelier-Bourhis C, Vanier J, Plasson C, Walet-Balieu ML, Tchi-Song PC, Remy-Jouet I, Richard V, Bernard S, Driouich A, Afonso C, Lerouge P, Mathieu-Rivet E, Bardor M. Heterologous expression of the N-acetylglucosaminyltransferase I dictates a reinvestigation of the N-glycosylation pathway in Chlamydomonas reinhardtii. Sci Rep 2017; 7:10156. [PMID: 28860654 PMCID: PMC5578997 DOI: 10.1038/s41598-017-10698-z] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Accepted: 08/14/2017] [Indexed: 12/31/2022] Open
Abstract
Eukaryotic N-glycosylation pathways are dependent of N-acetylglucosaminyltransferase I (GnTI), a key glycosyltransferase opening the door to the formation of complex-type N-glycans by transferring a N-acetylglucosamine residue onto the Man5GlcNAc2 intermediate. In contrast, glycans N-linked to Chlamydomonas reinhardtii proteins arise from a GnTI-independent Golgi processing of oligomannosides giving rise to Man5GlcNAc2 substituted eventually with one or two xylose(s). Here, complementation of C. reinhardtii with heterologous GnTI was investigated by expression of GnTI cDNAs originated from Arabidopsis and the diatom Phaeodactylum tricornutum. No modification of the N-glycans was observed in the GnTI transformed cells. Consequently, the structure of the Man5GlcNAc2 synthesized by C. reinhardtii was reinvestigated. Mass spectrometry analyses combined with enzyme sequencing showed that C. reinhardtii proteins carry linear Man5GlcNAc2 instead of the branched structure usually found in eukaryotes. Moreover, characterization of the lipid-linked oligosaccharide precursor demonstrated that C. reinhardtii exhibit a Glc3Man5GlcNAc2 dolichol pyrophosphate precursor. We propose that this precursor is then trimmed into a linear Man5GlcNAc2 that is not substrate for GnTI. Furthermore, cells expressing GnTI exhibited an altered phenotype with large vacuoles, increase of ROS production and accumulation of starch granules, suggesting the activation of stress responses likely due to the perturbation of the Golgi apparatus.
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Affiliation(s)
- Gaëtan Vanier
- Normandie Univ, UNIROUEN, Laboratoire Glycobiologie et Matrice Extracellulaire végétale, EA 4358, 76000, Rouen, France.,UMR FARE 614, Fractionnement des AgroRessources et Environnement, Chaire AFERE, Université de Reims-Champagne-Ardenne, INRA, 51686, Reims Cedex, France
| | - Pierre-Louis Lucas
- Normandie Univ, UNIROUEN, Laboratoire Glycobiologie et Matrice Extracellulaire végétale, EA 4358, 76000, Rouen, France
| | - Corinne Loutelier-Bourhis
- Normandie Univ, UNIROUEN, COBRA, UMR 6014 et FR 3038, Université de Rouen, INSA de Rouen, CNRS, 76000, Rouen, France
| | - Jessica Vanier
- Normandie Univ, UNIROUEN, Laboratoire Glycobiologie et Matrice Extracellulaire végétale, EA 4358, 76000, Rouen, France
| | - Carole Plasson
- Normandie Univ, UNIROUEN, Laboratoire Glycobiologie et Matrice Extracellulaire végétale, EA 4358, 76000, Rouen, France
| | - Marie-Laure Walet-Balieu
- Normandie Univ, UNIROUEN, Plate-Forme de Protéomique PISSARO, 76000, Rouen, France.,Normandie Univ, UNIROUEN, Institut de Recherche et d'Innovation Biomédicale (IRIB), 76000, Rouen, France
| | - Philippe Chan Tchi-Song
- Normandie Univ, UNIROUEN, Plate-Forme de Protéomique PISSARO, 76000, Rouen, France.,Normandie Univ, UNIROUEN, Institut de Recherche et d'Innovation Biomédicale (IRIB), 76000, Rouen, France
| | - Isabelle Remy-Jouet
- Normandie Univ, UNIROUEN, Inserm UMR 1096, Plateforme BOSS, 76000, Rouen, France
| | - Vincent Richard
- Normandie Univ, UNIROUEN, Inserm UMR 1096, Plateforme BOSS, 76000, Rouen, France
| | - Sophie Bernard
- Normandie Univ, UNIROUEN, Laboratoire Glycobiologie et Matrice Extracellulaire végétale, EA 4358, 76000, Rouen, France.,Normandie Univ, UNIROUEN, Plate-forme, PRIMACEN, Cell Imaging Platform of Normandy, 76000, Rouen, France
| | - Azeddine Driouich
- Normandie Univ, UNIROUEN, Laboratoire Glycobiologie et Matrice Extracellulaire végétale, EA 4358, 76000, Rouen, France.,Normandie Univ, UNIROUEN, Plate-forme, PRIMACEN, Cell Imaging Platform of Normandy, 76000, Rouen, France
| | - Carlos Afonso
- Normandie Univ, UNIROUEN, COBRA, UMR 6014 et FR 3038, Université de Rouen, INSA de Rouen, CNRS, 76000, Rouen, France
| | - Patrice Lerouge
- Normandie Univ, UNIROUEN, Laboratoire Glycobiologie et Matrice Extracellulaire végétale, EA 4358, 76000, Rouen, France
| | - Elodie Mathieu-Rivet
- Normandie Univ, UNIROUEN, Laboratoire Glycobiologie et Matrice Extracellulaire végétale, EA 4358, 76000, Rouen, France
| | - Muriel Bardor
- Normandie Univ, UNIROUEN, Laboratoire Glycobiologie et Matrice Extracellulaire végétale, EA 4358, 76000, Rouen, France. .,Institut Universitaire de France (I.U.F.) 1, rue Descartes, 75231, Paris, Cedex 05, France.
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6
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Kumar D, Strenkert D, Patel-King RS, Leonard MT, Merchant SS, Mains RE, King SM, Eipper BA. A bioactive peptide amidating enzyme is required for ciliogenesis. eLife 2017; 6. [PMID: 28513435 PMCID: PMC5461114 DOI: 10.7554/elife.25728] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Accepted: 05/15/2017] [Indexed: 02/06/2023] Open
Abstract
The pathways controlling cilium biogenesis in different cell types have not been fully elucidated. We recently identified peptidylglycine α-amidating monooxygenase (PAM), an enzyme required for generating amidated bioactive signaling peptides, in Chlamydomonas and mammalian cilia. Here, we show that PAM is required for the normal assembly of motile and primary cilia in Chlamydomonas, planaria and mice. Chlamydomonas PAM knockdown lines failed to assemble cilia beyond the transition zone, had abnormal Golgi architecture and altered levels of cilia assembly components. Decreased PAM gene expression reduced motile ciliary density on the ventral surface of planaria and resulted in the appearance of cytosolic axonemes lacking a ciliary membrane. The architecture of primary cilia on neuroepithelial cells in Pam-/- mouse embryos was also aberrant. Our data suggest that PAM activity and alterations in post-Golgi trafficking contribute to the observed ciliogenesis defects and provide an unanticipated, highly conserved link between PAM, amidation and ciliary assembly.
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Affiliation(s)
- Dhivya Kumar
- Department of Molecular Biology and Biophysics, University of Connecticut Health Center, Farmington, United States
| | - Daniela Strenkert
- Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, United States
| | - Ramila S Patel-King
- Department of Molecular Biology and Biophysics, University of Connecticut Health Center, Farmington, United States
| | - Michael T Leonard
- Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, United States
| | - Sabeeha S Merchant
- Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, United States.,Institute for Genomics and Proteomics, University of California, Los Angeles, Los Angeles, United States
| | - Richard E Mains
- Department of Neuroscience, University of Connecticut Health Center, Farmington, United States
| | - Stephen M King
- Department of Molecular Biology and Biophysics, University of Connecticut Health Center, Farmington, United States
| | - Betty A Eipper
- Department of Molecular Biology and Biophysics, University of Connecticut Health Center, Farmington, United States.,Department of Neuroscience, University of Connecticut Health Center, Farmington, United States
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7
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Different Golgi ultrastructure across species and tissues: Implications under functional and pathological conditions, and an attempt at classification. Tissue Cell 2017; 49:186-201. [DOI: 10.1016/j.tice.2016.12.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2016] [Revised: 12/05/2016] [Accepted: 12/05/2016] [Indexed: 02/08/2023]
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8
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Kumar D, Blaby-Haas CE, Merchant SS, Mains RE, King SM, Eipper BA. Early eukaryotic origins for cilia-associated bioactive peptide-amidating activity. J Cell Sci 2016; 129:943-56. [PMID: 26787743 DOI: 10.1242/jcs.177410] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Accepted: 01/13/2016] [Indexed: 01/15/2023] Open
Abstract
Ciliary axonemes and basal bodies were present in the last eukaryotic common ancestor and play crucial roles in sensing and responding to environmental cues. Peptidergic signaling, generally considered a metazoan innovation, is essential for organismal development and homeostasis. Peptidylglycine α-amidating monooxygenase (PAM) is crucial for the last step of bioactive peptide biosynthesis. However, identification of a complete PAM-like gene in green algal genomes suggests ancient evolutionary roots for bioactive peptide signaling. We demonstrate that the Chlamydomonas reinhardtii PAM gene encodes an active peptide-amidating enzyme (CrPAM) that shares key structural and functional features with the mammalian enzyme, indicating that components of the peptide biosynthetic pathway predate multicellularity. In addition to its secretory pathway localization, CrPAM localizes to cilia and tightly associates with the axonemal superstructure, revealing a new axonemal enzyme activity. This localization pattern is conserved in mammals, with PAM present in both motile and immotile sensory cilia. The conserved ciliary localization of PAM adds to the known signaling capabilities of the eukaryotic cilium and provides a potential mechanistic link between peptidergic signaling and endocrine abnormalities commonly observed in ciliopathies.
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Affiliation(s)
- Dhivya Kumar
- Department of Molecular Biology and Biophysics, University of Connecticut Health Center, Farmington, CT 06030-3401, USA
| | - Crysten E Blaby-Haas
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095-1569, USA
| | - Sabeeha S Merchant
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095-1569, USA Institute for Genomics and Proteomics, University of California, Los Angeles, CA 90095-1569, USA
| | - Richard E Mains
- Department of Neuroscience, University of Connecticut Health Center, Farmington, CT 06030-3401, USA
| | - Stephen M King
- Department of Molecular Biology and Biophysics, University of Connecticut Health Center, Farmington, CT 06030-3401, USA
| | - Betty A Eipper
- Department of Molecular Biology and Biophysics, University of Connecticut Health Center, Farmington, CT 06030-3401, USA Department of Neuroscience, University of Connecticut Health Center, Farmington, CT 06030-3401, USA
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9
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Simioni C, Rover T, Schmidt ÉC, de L Felix MR, Polo LK, Santos RD, Costa GB, Kreusch M, Pereira DT, Ouriques LC, Bouzon ZL. Effects of brefeldin A on the endomembrane system and germ tube formation of the tetraspore of Gelidium floridanum (Rhodophyta, Florideophyceae). JOURNAL OF PHYCOLOGY 2014; 50:577-586. [PMID: 26988329 DOI: 10.1111/jpy.12187] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2014] [Accepted: 03/19/2014] [Indexed: 06/05/2023]
Abstract
Gelidium floridanum W.R. Taylor tetraspores are units of dispersal and are responsible for substrate attachment. This study aimed to examine evidence of direct interaction between germ tube formation and Golgi activity during tetraspore germination of G. floridanum. After release, the tetraspores were incubated with brefeldin A (BFA) in concentrations of 4 and 8 μM over a 6 h period. The controls and treatments were analyzed with light, fluorescence (FM4-64 dye) and transmission electron microscopy. In the control samples, the Golgi bodies were responsible for germ tube formation. In contrast, BFA-treated samples were observed to inhibit spore adhesion and germ tube formation. These tetraspores also showed an increase in volume (≥30 μm width). BFA treatment also resulted in the disassembly of Golgi cisternae and the formation of vesiculated areas of the cytoplasm, blocking the secretion of protein and amorphous matrix polysaccharides. When stained with FM4-64, the control samples showed fluorescence in the apical region of the germ tube, but the treated samples showed an intense fluorescence throughout the cytoplasm. From these results, we can conclude that the germ tube is formed by the incorporation of vesicles derived from Golgi. Thus, vesicle secretion and Golgi organization are basic processes and essential in adhesion and tube formation. By blocking the secretion of protein and amorphous matrix polysaccharides, BFA treatment precluded tetraspore germination.
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Affiliation(s)
- Carmen Simioni
- Plant Cell Biology Laboratory, Department of Cell Biology, Embryology and Genetics, Federal University of Santa Catarina, CP 476, Florianópolis, Santa Catarina, 88049-900, Brazil
- Central Laboratory of Electron Microscopy, Federal University of Santa Catarina, CP 476, Florianópolis, Santa Catarina, 88049-900, Brazil
| | - Ticiane Rover
- Plant Cell Biology Laboratory, Department of Cell Biology, Embryology and Genetics, Federal University of Santa Catarina, CP 476, Florianópolis, Santa Catarina, 88049-900, Brazil
- Central Laboratory of Electron Microscopy, Federal University of Santa Catarina, CP 476, Florianópolis, Santa Catarina, 88049-900, Brazil
| | - Éder C Schmidt
- Plant Cell Biology Laboratory, Department of Cell Biology, Embryology and Genetics, Federal University of Santa Catarina, CP 476, Florianópolis, Santa Catarina, 88049-900, Brazil
- Central Laboratory of Electron Microscopy, Federal University of Santa Catarina, CP 476, Florianópolis, Santa Catarina, 88049-900, Brazil
| | - Marthiellen R de L Felix
- Plant Cell Biology Laboratory, Department of Cell Biology, Embryology and Genetics, Federal University of Santa Catarina, CP 476, Florianópolis, Santa Catarina, 88049-900, Brazil
- Central Laboratory of Electron Microscopy, Federal University of Santa Catarina, CP 476, Florianópolis, Santa Catarina, 88049-900, Brazil
| | - Luz Karime Polo
- Plant Cell Biology Laboratory, Department of Cell Biology, Embryology and Genetics, Federal University of Santa Catarina, CP 476, Florianópolis, Santa Catarina, 88049-900, Brazil
- Central Laboratory of Electron Microscopy, Federal University of Santa Catarina, CP 476, Florianópolis, Santa Catarina, 88049-900, Brazil
| | - Rodrigo Dos Santos
- Plant Cell Biology Laboratory, Department of Cell Biology, Embryology and Genetics, Federal University of Santa Catarina, CP 476, Florianópolis, Santa Catarina, 88049-900, Brazil
- Central Laboratory of Electron Microscopy, Federal University of Santa Catarina, CP 476, Florianópolis, Santa Catarina, 88049-900, Brazil
| | - Giulia Burle Costa
- Plant Cell Biology Laboratory, Department of Cell Biology, Embryology and Genetics, Federal University of Santa Catarina, CP 476, Florianópolis, Santa Catarina, 88049-900, Brazil
- Central Laboratory of Electron Microscopy, Federal University of Santa Catarina, CP 476, Florianópolis, Santa Catarina, 88049-900, Brazil
| | - Marianne Kreusch
- Plant Cell Biology Laboratory, Department of Cell Biology, Embryology and Genetics, Federal University of Santa Catarina, CP 476, Florianópolis, Santa Catarina, 88049-900, Brazil
- Central Laboratory of Electron Microscopy, Federal University of Santa Catarina, CP 476, Florianópolis, Santa Catarina, 88049-900, Brazil
| | - Debora T Pereira
- Plant Cell Biology Laboratory, Department of Cell Biology, Embryology and Genetics, Federal University of Santa Catarina, CP 476, Florianópolis, Santa Catarina, 88049-900, Brazil
- Central Laboratory of Electron Microscopy, Federal University of Santa Catarina, CP 476, Florianópolis, Santa Catarina, 88049-900, Brazil
| | - Luciane C Ouriques
- Plant Cell Biology Laboratory, Department of Cell Biology, Embryology and Genetics, Federal University of Santa Catarina, CP 476, Florianópolis, Santa Catarina, 88049-900, Brazil
- Central Laboratory of Electron Microscopy, Federal University of Santa Catarina, CP 476, Florianópolis, Santa Catarina, 88049-900, Brazil
| | - Zenilda L Bouzon
- Plant Cell Biology Laboratory, Department of Cell Biology, Embryology and Genetics, Federal University of Santa Catarina, CP 476, Florianópolis, Santa Catarina, 88049-900, Brazil
- Central Laboratory of Electron Microscopy, Federal University of Santa Catarina, CP 476, Florianópolis, Santa Catarina, 88049-900, Brazil
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10
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Kato N, Dong T, Bailey M, Lum T, Ingram D. Triacylglycerol mobilization is suppressed by brefeldin A in Chlamydomonas reinhardtii. PLANT & CELL PHYSIOLOGY 2013; 54:1585-99. [PMID: 23872273 PMCID: PMC4081630 DOI: 10.1093/pcp/pct103] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Brefeldin A suppresses vesicle trafficking by inhibiting exchange of GDP for GTP in ADP-ribosylation factor. We report that brefeldin A suppresses mobilization of triacylglycerols in Chlamydomonas reinhardtii, a model organism of green microalgae. Analyses revealed that brefeldin A causes Chlamydomonas to form lipid droplets in which triacylglycerols accumulate in a dose-dependent manner. Pulse labeling experiment using fluorescent fatty acids suggested that brefeldin A inhibits the cells from degrading fatty acids. The experiment also revealed that the cells transiently form novel compartments that accumulate exogenously added fatty acids in the cytoplasm, designated fatty acid-induced microbodies (FAIMs). Brefeldin A up-regulates the formation of FAIMs, whereas nitrogen deprivation that up-regulates triacylglycerol synthesis in Chlamydomonas does not cause the cells to form FAIMs. These results underscore the role of the vesicle trafficking machinery in triacylglycerol metabolism in green microalgae.
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Affiliation(s)
- Naohiro Kato
- Department of Biological Sciences, Louisiana State University, 226 Life Sciences Building, Baton Rouge, LA 70803, USA
- *Corresponding author: E-mail: ; Fax: +1-225-578-2597
| | - Trung Dong
- Department of Biological Sciences, Louisiana State University, 226 Life Sciences Building, Baton Rouge, LA 70803, USA
| | - Michael Bailey
- Department of Biological Sciences, Louisiana State University, 226 Life Sciences Building, Baton Rouge, LA 70803, USA
| | - Tony Lum
- Department of Biological Sciences, Louisiana State University, 226 Life Sciences Building, Baton Rouge, LA 70803, USA
| | - Drury Ingram
- Cell Biology & Bioimaging Core, Pennington Biomedical Research Center, 6400 Perkins Rd., Baton Rouge, LA 70808, USA
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11
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Hummel E, Guttmann P, Werner S, Tarek B, Schneider G, Kunz M, Frangakis AS, Westermann B. 3D Ultrastructural organization of whole Chlamydomonas reinhardtii cells studied by nanoscale soft x-ray tomography. PLoS One 2012; 7:e53293. [PMID: 23300909 PMCID: PMC3534036 DOI: 10.1371/journal.pone.0053293] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2012] [Accepted: 11/27/2012] [Indexed: 11/30/2022] Open
Abstract
The complex architecture of their structural elements and compartments is a hallmark of eukaryotic cells. The creation of high resolution models of whole cells has been limited by the relatively low resolution of conventional light microscopes and the requirement for ultrathin sections in transmission electron microscopy. We used soft x-ray tomography to study the 3D ultrastructural organization of whole cells of the unicellular green alga Chlamydomonas reinhardtii at unprecedented spatial resolution. Intact frozen hydrated cells were imaged using the natural x-ray absorption contrast of the sample without any staining. We applied different fiducial-based and fiducial-less alignment procedures for the 3D reconstructions. The reconstructed 3D volumes of the cells show features down to 30 nm in size. The whole cell tomograms reveal ultrastructural details such as nuclear envelope membranes, thylakoids, basal apparatus, and flagellar microtubule doublets. In addition, the x-ray tomograms provide quantitative data from the cell architecture. Therefore, nanoscale soft x-ray tomography is a new valuable tool for numerous qualitative and quantitative applications in plant cell biology.
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Affiliation(s)
- Eric Hummel
- Institut für Zellbiologie, Universität Bayreuth, Bayreuth, Germany.
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12
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Langhans M, Meckel T, Kress A, Lerich A, Robinson DG. ERES (ER exit sites) and the "secretory unit concept". J Microsc 2012; 247:48-59. [PMID: 22360601 DOI: 10.1111/j.1365-2818.2011.03597.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The higher plant Golgi apparatus consists of hundreds of individual Golgi stacks which move along the cortical ER, propelled by the actomysin system. Anterograde and retrograde transport between the endoplasmic reticulum (ER) and the plant Golgi occurs over a narrow interface (around 500 nm) and is generally considered to be mediated by COP-coated vesicles. Previously, ER exit sites (ERES) have been identified on the basis of to localization of transiently expressed COPII-coat proteins. As a consequence it has been held that ERES in higher plants are intimately associated with Golgi stacks, and that both move together as an integrated structure: the "secretory unit". Using a new COPII marker, as well as YFP-SEC24 (a bona fide COPII coat protein), we have made observations on tobacco leaf epidermis at high resolution in the CLSM. Our data clearly shows that COPII fluorescence is associated with the Golgi stacks rather than the surface of the ER and probably represents the temporary accumulation of COPII vesicles in the Golgi matrix prior to fusion with the cis-Golgi cisternae. We have calculated the numbers of COPII vesicles which would be required to provide a typical Golgi-associated COPII-fluorescent signal as being much less than 20. We have discussed the consequences of this and question the continued usage of the term "secretory unit".
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Affiliation(s)
- M Langhans
- Department of Plant Cell Biology, Centre for Organismal Biology, University of Heidelberg, Germany
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13
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Lerich A, Hillmer S, Langhans M, Scheuring D, van Bentum P, Robinson DG. ER Import Sites and Their Relationship to ER Exit Sites: A New Model for Bidirectional ER-Golgi Transport in Higher Plants. FRONTIERS IN PLANT SCIENCE 2012; 3:143. [PMID: 22876251 PMCID: PMC3410614 DOI: 10.3389/fpls.2012.00143] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2012] [Accepted: 06/12/2012] [Indexed: 05/08/2023]
Abstract
Per definition, ER exit sites are COPII vesiculation events at the surface of the ER and in higher plants are only visualizable in the electron microscope through cryofixation techniques. Fluorescent COPII labeling moves with Golgi stacks and locates to the interface between the ER and the Golgi. In contrast, the domain of the ER where retrograde COPI vesicles fuse, i.e., ER import sites (ERIS), has remained unclear. To identify ERIS we have employed ER-located SNAREs and tethering factors. We screened several SNAREs (SYP81, the SYP7 family, and USE1) to find a SNARE whose overexpression did not disrupt ER-Golgi traffic and which gave rise to discrete fluorescent punctae when expressed with an XFP tag. Only the Qc-SNARE SYP72 fulfilled these criteria. When coexpressed with SYP72-YFP, both the type I-membrane protein RFP-p24δ5 and the luminal marker CFP-HDEL whose ER localization are due to an efficient COPI-mediated recycling, form nodules along the tubular ER network. SYP72-YFP colocalizes with these nodules which are not seen when RFP-p24δ5 or CFP-HDEL is expressed alone or when SYP72-YFP is coexpressed with a mutant form of RFP-p24δ5 that cannot exit the ER. SYP72-YFP does not colocalize with Golgi markers, except when the Golgi stacks are immobilized through actin depolymerization. Endogenous SYP7 SNAREs, also colocalize with immobilized COPII/Golgi. In contrast, XFP-tagged versions of plant homologs to TIP20 of the Dsl1 COPI-tethering factor complex, and the COPII-tethering factor p115 colocalize perfectly with Golgi stacks irrespective of the motile status. These data suggest that COPI vesicle fusion with the ER is restricted to periods when Golgi stacks are stationary, but that when moving both COPII and COPI vesicles are tethered and collect in the ER-Golgi interface. Thus, the Golgi stack and an associated domain of the ER thereby constitute a mobile secretory and recycling unit: a unique feature in eukaryotic cells.
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Affiliation(s)
- Alexander Lerich
- Department of Plant Cell Biology, Centre for Organismal Studies, University of HeidelbergHeidelberg, Germany
| | - Stefan Hillmer
- Department of Plant Cell Biology, Centre for Organismal Studies, University of HeidelbergHeidelberg, Germany
| | - Markus Langhans
- Department of Plant Cell Biology, Centre for Organismal Studies, University of HeidelbergHeidelberg, Germany
| | - David Scheuring
- Department of Plant Cell Biology, Centre for Organismal Studies, University of HeidelbergHeidelberg, Germany
| | - Paulien van Bentum
- Department of Plant Cell Biology, Centre for Organismal Studies, University of HeidelbergHeidelberg, Germany
| | - David G. Robinson
- Department of Plant Cell Biology, Centre for Organismal Studies, University of HeidelbergHeidelberg, Germany
- *Correspondence: David G. Robinson, Department Plant Cell Biology, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 230, D-69120 Heidelberg, Germany. e-mail:
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14
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Schoberer J, Runions J, Steinkellner H, Strasser R, Hawes C, Osterrieder A. Sequential depletion and acquisition of proteins during Golgi stack disassembly and reformation. Traffic 2010; 11:1429-44. [PMID: 20716110 PMCID: PMC3039244 DOI: 10.1111/j.1600-0854.2010.01106.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2010] [Revised: 07/22/2010] [Accepted: 07/22/2010] [Indexed: 12/22/2022]
Abstract
Herein, we report the stepwise transport of multiple plant Golgi membrane markers during disassembly of the Golgi apparatus in tobacco leaf epidermal cells in response to the induced expression of the GTP-locked Sar1p or Brefeldin A (BFA), and reassembly on BFA washout. The distribution of fluorescent Golgi-resident N-glycan processing enzymes and matrix proteins (golgins) with specific cis-trans-Golgi sub-locations was followed by confocal microscopy during disassembly and reassembly. The first event during Golgi disassembly was the loss of trans-Golgi enzymes and golgins from Golgi membranes, followed by a sequential redistribution of medial and cis-Golgi enzymes into the endoplasmic reticulum (ER), whilst golgins were relocated to the ER or cytoplasm. This event was confirmed by fractionation and immuno-blotting. The sequential redistribution of Golgi components in a trans-cis sequence may highlight a novel retrograde trafficking pathway between the trans-Golgi and the ER in plants. Release of Golgi markers from the ER upon BFA washout occurred in the opposite sequence, with cis-matrix proteins labelling Golgi-like structures before cis/medial enzymes. Trans-enzyme location was preceded by trans-matrix proteins being recruited back to Golgi membranes. Our results show that Golgi disassembly and reassembly occur in a highly ordered fashion in plants.
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Affiliation(s)
- Jennifer Schoberer
- Department of Applied Genetics and Cell Biology, University of Natural Resources and Applied Life SciencesVienna, Muthgasse 18, 1190 Vienna, Austria
| | - John Runions
- School of Life Sciences, Oxford Brookes University, Headington CampusGipsy Lane, Oxford OX3 0BP, UK
| | - Herta Steinkellner
- Department of Applied Genetics and Cell Biology, University of Natural Resources and Applied Life SciencesVienna, Muthgasse 18, 1190 Vienna, Austria
| | - Richard Strasser
- Department of Applied Genetics and Cell Biology, University of Natural Resources and Applied Life SciencesVienna, Muthgasse 18, 1190 Vienna, Austria
| | - Chris Hawes
- School of Life Sciences, Oxford Brookes University, Headington CampusGipsy Lane, Oxford OX3 0BP, UK
| | - Anne Osterrieder
- School of Life Sciences, Oxford Brookes University, Headington CampusGipsy Lane, Oxford OX3 0BP, UK
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Hummel E, Osterrieder A, Robinson DG, Hawes C. Inhibition of Golgi function causes plastid starch accumulation. JOURNAL OF EXPERIMENTAL BOTANY 2010; 61:2603-14. [PMID: 20423939 PMCID: PMC2882258 DOI: 10.1093/jxb/erq091] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2009] [Revised: 02/15/2010] [Accepted: 03/19/2010] [Indexed: 05/08/2023]
Abstract
Little is known about possible interactions between chloroplasts and the Golgi apparatus, although there is increasing evidence for a direct Golgi to chloroplast transport pathway targeting proteins to their destinations within the membranes and stroma of plastids. Here data are presented showing that a blockage of secretion results in a significant increase of starch within plastids. Golgi disassembly promoted either by the secretory inhibitor brefeldin A or through an inducible Sar1-GTP system leads to dramatic starch accumulation in plastids, thus providing evidence for a direct interaction between plastids and Golgi activity. The possibility that starch accumulation is due either to elevated levels of cytosolic sugars because of loss of secretory Golgi activity or even to a blockage of amylase transport from the Golgi to the chloroplast is discussed.
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Affiliation(s)
- Eric Hummel
- School of Life Sciences, Oxford Brookes University, Oxford, UK.
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Osterrieder A, Hummel E, Carvalho CM, Hawes C. Golgi membrane dynamics after induction of a dominant-negative mutant Sar1 GTPase in tobacco. JOURNAL OF EXPERIMENTAL BOTANY 2009; 61:405-22. [PMID: 19861656 DOI: 10.1093/jxb/erp315] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
An inducible system has been established in Nicotiana tabacum plants allowing controlled expression of Sar1-GTP and thus the investigation of protein dynamics after inhibition of endoplasmic reticulum (ER) to Golgi transport. Complete Golgi disassembly and redistribution of Golgi markers into the ER was observed within 18-24h after induction. At the ultrastructural level Sar1-GTP expression led to a decrease in Golgi stack size followed by Golgi fragmentation and accumulation of vesicle remnants. Induction of Sar1-GTP resulted in redistribution of the green fluorescent protein (GFP)-tagged Arabidopsis golgins AtCASP and GC1 (golgin candidate 1, an Arabidopsis golgin 84 isoform) into the ER or cytoplasm, respectively. Additionally, both fusion proteins were observed in punctate structures, which co-located with a yellow fluorescent protein (YFP)-tagged version of Sar1-GTP. The Sar1-GTP-inducible system is compared with constitutive Sar1-GTP expression and brefeldin A treatment, and its potential for the study of the composition of ER exit sites and early cis-Golgi structures is discussed.
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Affiliation(s)
- Anne Osterrieder
- School of Life Sciences, Oxford Brookes University, Headington, Oxford, UK
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17
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Abstract
The interface between the endoplasmic reticulum (ER) and the Golgi apparatus is a critical junction in the secretory pathway mediating the transport of both soluble and membrane cargo between the two organelles. Such transport can be bidirectional and is mediated by coated membranes. In this review, we consider the organization and dynamics of this interface in plant cells, the putative structure of which has caused some controversy in the literature, and we speculate on the stages of Golgi biogenesis from the ER and the role of the Golgi and ER on each other's motility.
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Affiliation(s)
- Chris Hawes
- School of Life Sciences, Oxford Brookes University, Headington, Oxford, UK.
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18
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Limbach C, Staehelin LA, Sievers A, Braun M. Electron tomographic characterization of a vacuolar reticulum and of six vesicle types that occupy different cytoplasmic domains in the apex of tip-growing Chara rhizoids. PLANTA 2008; 227:1101-14. [PMID: 18193275 DOI: 10.1007/s00425-007-0684-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2007] [Accepted: 12/12/2007] [Indexed: 05/10/2023]
Abstract
We provide a 3D ultrastructural analysis of the membrane systems involved in tip growth of rhizoids of the green alga Chara. Electron tomography of cells preserved by high-pressure freeze fixation has enabled us to distinguish six different types of vesicles in the apical cytoplasm where the tip growth machinery is accommodated. The vesicle types are: dark and light secretory vesicles, plasma membrane-associated clathrin-coated vesicles (PM-CCVs), Spitzenkoerper-associated clathrin-coated vesicles (Sp-CCVs) and coated vesicles (Sp-CVs), and microvesicles. Each of these vesicle types exhibits a distinct distribution pattern, which provides insights into their possible function for tip growth. The PM-CCVs are confined to the cytoplasm adjacent to the apical plasma membrane. Within this space they are arranged in clusters often surrounding tubular plasma membrane invaginations from which CCVs bud. This suggests that endocytosis and membrane recycling are locally confined to specialized apical endocytosis sites. In contrast, exocytosis of secretory vesicles occurs over the entire membrane area of the apical dome. The Sp-CCVs and the Sp-CVs are associated with the aggregate of endoplasmic reticulum membranes in the center of the growth-organizing Spitzenkoerper complex. Here, Sp-CCVs are seen to bud from undefined tubular membranes. The subapical region of rhizoids contains a vacuolar reticulum that extends along the longitudinal cell axis and consists of large, vesicle-like segments interconnected by thin tubular domains. The tubular domains are encompassed by thin filamentous structures resembling dynamin spirals which could drive peristaltic movements of the vacuolar reticulum similar to those observed in fungal hyphae. The vacuolar reticulum appears to serve as a lytic compartment into which multivesicular bodies deliver their internal vesicles for molecular recycling and degradation.
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Affiliation(s)
- Christoph Limbach
- Gravitationsbiologie, Institut für Molekulare Physiologie und Biotechnologie der Pflanzen, Universität Bonn, Kirschallee 1, Bonn, Germany.
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Langhans M, Hawes C, Hillmer S, Hummel E, Robinson DG. Golgi regeneration after brefeldin A treatment in BY-2 cells entails stack enlargement and cisternal growth followed by division. PLANT PHYSIOLOGY 2007; 145:527-38. [PMID: 17704232 PMCID: PMC2048719 DOI: 10.1104/pp.107.104919] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2007] [Accepted: 08/02/2007] [Indexed: 05/05/2023]
Abstract
Brefeldin A (BFA) treatment stops secretion and leads to the resorption of much of the Golgi apparatus into the endoplasmic reticulum. This effect is reversible upon washing out the drug, providing a situation for studying Golgi biogenesis. In this investigation Golgi regeneration in synchronized tobacco BY-2 cells was followed by electron microscopy and by the immunofluorescence detection of ARF1, which localizes to the rims of Golgi cisternae and serves as an indicator of COPI vesiculation. Beginning as clusters of vesicles that are COPI positive, mini-Golgi stacks first become recognizable 60 min after BFA washout. They continue to increase in terms of numbers and length of cisternae for a further 90 min before overshooting the size of control Golgi stacks. As a result, increasing numbers of dividing Golgi stacks were observed 120 min after BFA washout. BFA-regeneration experiments performed on cells treated with BFA (10 microg mL(-1)) for only short periods (30-45 min) showed that the formation of ER-Golgi hybrid structures, once initiated by BFA treatment, is an irreversible process, the further incorporation of Golgi membranes into the ER continuing during a subsequent drug washout. Application of the protein kinase A inhibitor H-89, which effectively blocks the reassembly of the Golgi apparatus in mammalian cells, also prevented stack regeneration in BY-2 cells, but only at very high, almost toxic concentrations (>200 microm). Our data suggest that under normal conditions mitosis-related Golgi stack duplication may likely occur via cisternal growth followed by fission.
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Affiliation(s)
- Markus Langhans
- Department of Cell Biology, Heidelberg Institute for Plant Sciences, University of Heidelberg, 69120 Heidelberg, Germany
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