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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Bao X, Wang Y, Qi Y, Lei C, Wang Y, Pan T, Yu M, Zhang Y, Wu H, Zhang P, Ji Y, Yang H, Jiang X, Jing R, Yan M, Zhang B, Gu C, Zhu J, Hao Y, Lei J, Zhang S, Chen X, Chen R, Sun Y, Zhu Y, Zhang X, Jiang L, Visser RGF, Ren Y, Wang Y, Wan J. A deleterious Sar1c variant in rice inhibits export of seed storage proteins from the endoplasmic reticulum. PLANT MOLECULAR BIOLOGY 2023; 111:291-307. [PMID: 36469200 DOI: 10.1007/s11103-022-01327-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Accepted: 11/27/2022] [Indexed: 06/17/2023]
Abstract
We identified a dosage-dependent dominant negative form of Sar1c, which confirms the essential role of COPII system in mediating ER export of storage proteins in rice endosperm. Higher plants accumlate large amounts of seed storage proteins (SSPs). However, mechanisms underlying SSP trafficking are largely unknown, especially the ER-Golgi anterograde process. Here, we showed that a rice glutelin precursor accumulation13 (gpa13) mutant exhibited floury endosperm and overaccumulated glutelin precursors, which phenocopied the reported RNAi-Sar1abc line. Molecular cloning revealed that the gpa13 allele encodes a mutated Sar1c (mSar1c) with a deletion of two conserved amino acids Pro134 and Try135. Knockdown or knockout of Sar1c alone caused no obvious phenotype, while overexpression of mSar1c resulted in seedling lethality similar to the gpa13 mutant. Transient expression experiment in tobacco combined with subcellular fractionation experiment in gpa13 demonstrated that the expression of mSar1c affects the subcellular distribution of all Sar1 isoforms and Sec23c. In addition, mSar1c failed to interact with COPII component Sec23. Conversely, mSar1c competed with Sar1a/b/d to interact with guanine nucleotide exchange factor Sec12. Together, we identified a dosage-dependent dominant negative form of Sar1c, which confirms the essential role of COPII system in mediating ER export of storage proteins in rice endosperm.
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Affiliation(s)
- Xiuhao Bao
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China
| | - Yongfei Wang
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China
| | - Yanzhou Qi
- National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100081, People's Republic of China
- Plant Breeding, Wageningen University & Research, PO Box 386, 6700 AJ, Wageningen, the Netherlands
| | - Cailin Lei
- National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100081, People's Republic of China
| | - Yunlong Wang
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China
| | - Tian Pan
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China
| | - Mingzhou Yu
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China
| | - Yu Zhang
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China
| | - Hongming Wu
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China
| | - Pengcheng Zhang
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China
| | - Yi Ji
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China
| | - Hang Yang
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China
| | - Xiaokang Jiang
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China
| | - Ruonan Jing
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China
| | - Mengyuan Yan
- National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100081, People's Republic of China
| | - Binglei Zhang
- National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100081, People's Republic of China
| | - Chuanwei Gu
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China
| | - Jianping Zhu
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China
| | - Yuanyuan Hao
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China
| | - Jie Lei
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China
| | - Shuang Zhang
- National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100081, People's Republic of China
| | - Xiaoli Chen
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China
| | - Rongbo Chen
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China
| | - Yinglun Sun
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China
| | - Yun Zhu
- National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100081, People's Republic of China
| | - Xin Zhang
- National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100081, People's Republic of China
| | - Ling Jiang
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China
| | - Richard G F Visser
- Plant Breeding, Wageningen University & Research, PO Box 386, 6700 AJ, Wageningen, the Netherlands
| | - Yulong Ren
- National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100081, People's Republic of China.
| | - Yihua Wang
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China.
| | - Jianmin Wan
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China
- National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100081, People's Republic of China
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3
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McGinness AJ, Schoberer J, Pain C, Brandizzi F, Kriechbaumer V. On the nature of the plant ER exit sites. FRONTIERS IN PLANT SCIENCE 2022; 13:1010569. [PMID: 36275575 PMCID: PMC9585722 DOI: 10.3389/fpls.2022.1010569] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Accepted: 09/14/2022] [Indexed: 06/16/2023]
Abstract
In plants, the endoplasmic reticulum (ER) and Golgi bodies are not only in close proximity, but are also physically linked. This unique organization raises questions about the nature of the transport vectors carrying cargo between the two organelles. Same as in metazoan and yeast cells, it was suggested that cargo is transported from the ER to Golgi cisternae via COPII-coated vesicles produced at ribosome-free ER exit sites (ERES). Recent developments in mammalian cell research suggest, though, that COPII helps to select secretory cargo, but does not coat the carriers leaving the ER. Furthermore, it was shown that mammalian ERES expand into a tubular network containing secretory cargo, but no COPII components. Because of the close association of the ER and Golgi bodies in plant cells, it was previously proposed that ERES and the Golgi comprise a secretory unit that travels over or with a motile ER membrane. In this study, we aimed to explore the nature of ERES in plant cells and took advantage of high-resolution confocal microscopy and imaged ERES labelled with canonical markers (Sar1a, Sec16, Sec24). We found that ERES are dynamically connected to Golgi bodies and most likely represent pre-cis-Golgi cisternae. Furthermore, we showed fine tubular connections from the ER to Golgi compartments (ERGo tubules) as well as fine protrusions from ERES/Golgi cisternae connecting with the ER. We suggest that these tubules observed between the ER and Golgi as well as between the ER and ERES are involved in stabilizing the physical connection between ER and ERES/Golgi cisternae, but may also be involved in cargo transport from the ER to Golgi bodies.
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Affiliation(s)
- Alastair J. McGinness
- Endomembrane Structure and Function Research Group, Department of Biological and Medical Sciences, Oxford Brookes University, Oxford, United Kingdom
| | - Jennifer Schoberer
- Department of Applied Genetics and Cell Biology, Institute of Plant Biotechnology and Cell Biology, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Charlotte Pain
- Endomembrane Structure and Function Research Group, Department of Biological and Medical Sciences, Oxford Brookes University, Oxford, United Kingdom
| | - Federica Brandizzi
- MSU-DOE Plant Research Lab, Michigan State University, East Lansing, MI, United States
- Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, MI, United States
- Department of Plant Biology, Michigan State University, East Lansing, MI, United States
| | - Verena Kriechbaumer
- Endomembrane Structure and Function Research Group, Department of Biological and Medical Sciences, Oxford Brookes University, Oxford, United Kingdom
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4
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Rui Q, Tan X, Liu F, Bao Y. An Update on the Key Factors Required for Plant Golgi Structure Maintenance. FRONTIERS IN PLANT SCIENCE 2022; 13:933283. [PMID: 35837464 PMCID: PMC9274083 DOI: 10.3389/fpls.2022.933283] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/30/2022] [Accepted: 05/30/2022] [Indexed: 06/15/2023]
Abstract
Plant Golgi apparatus serves as the central station of the secretory pathway and is the site where protein modification and cell wall matrix polysaccharides synthesis occur. The polarized and stacked cisternal structure is a prerequisite for Golgi function. Our understanding of Golgi structure maintenance and trafficking are largely obtained from mammals and yeast, yet, plant Golgi has many different aspects. In this review, we summarize the key players in Golgi maintenance demonstrated by genetic studies in plants, which function in ER-Golgi, intra-Golgi and post-Golgi transport pathways. Among these, we emphasize on players in intra-Golgi trafficking.
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5
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Kim JH, Lee HN, Huang X, Jung H, Otegui MS, Li F, Chung T. FYVE2, a phosphatidylinositol 3-phosphate effector, interacts with the COPII machinery to control autophagosome formation in Arabidopsis. THE PLANT CELL 2022; 34:351-373. [PMID: 34718777 PMCID: PMC8846182 DOI: 10.1093/plcell/koab263] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Accepted: 10/26/2021] [Indexed: 06/13/2023]
Abstract
Autophagy is an intracellular trafficking mechanism by which cytosolic macromolecules and organelles are sequestered into autophagosomes for degradation inside the vacuole. In various eukaryotes including yeast, metazoans, and plants, the precursor of the autophagosome, termed the phagophore, nucleates in the vicinity of the endoplasmic reticulum (ER) with the participation of phosphatidylinositol 3-phosphate (PI3P) and the coat protein complex II (COPII). Here we show that Arabidopsis thaliana FYVE2, a plant-specific PI3P-binding protein, provides a functional link between the COPII machinery and autophagy. FYVE2 interacts with the small GTPase Secretion-associated Ras-related GTPase 1 (SAR1), which is essential for the budding of COPII vesicles. FYVE2 also interacts with ATG18A, another PI3P effector on the phagophore membrane. Fluorescently tagged FYVE2 localized to autophagic membranes near the ER and was delivered to vacuoles. SAR1 fusion proteins were also targeted to the vacuole via FYVE2-dependent autophagy. Either mutations in FYVE2 or the expression of dominant-negative mutant SAR1B proteins resulted in reduced autophagic flux and the accumulation of autophagic organelles. We propose that FYVE2 regulates autophagosome biogenesis through its interaction with ATG18A and the COPII machinery, acting downstream of ATG2.
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Affiliation(s)
- Jeong Hun Kim
- Department of Biological Sciences, Pusan National University, Busan 46241, Republic of Korea
| | - Han Nim Lee
- Department of Biological Sciences, Pusan National University, Busan 46241, Republic of Korea
- Department of Botany and Center for Quantitative Cell Imaging, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - Xiao Huang
- College of Life Sciences, South China Agricultural University, Guangzhou 510642, P. R. China
| | - Hyera Jung
- Department of Biological Sciences, Pusan National University, Busan 46241, Republic of Korea
| | - Marisa S Otegui
- Department of Botany and Center for Quantitative Cell Imaging, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - Faqiang Li
- College of Life Sciences, South China Agricultural University, Guangzhou 510642, P. R. China
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou 510642, P. R. China
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, South China Agricultural University, Guangzhou 510642, P. R. China
| | - Taijoon Chung
- Department of Biological Sciences, Pusan National University, Busan 46241, Republic of Korea
- Institute of Systems Biology, Pusan National University, Busan 46241, Republic of Korea
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6
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Vieira V, Pain C, Wojcik S, Spatola Rossi T, Denecke J, Osterrieder A, Hawes C, Kriechbaumer V. Living on the edge: the role of Atgolgin-84A at the plant ER-Golgi interface. J Microsc 2020; 280:158-173. [PMID: 32700322 DOI: 10.1111/jmi.12946] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 07/15/2020] [Accepted: 07/20/2020] [Indexed: 12/18/2022]
Abstract
The plant Golgi apparatus is responsible for the processing of proteins received from the endoplasmic reticulum (ER) and their distribution to multiple destinations within the cell. Golgi matrix components, such as golgins, have been identified and suggested to function as putative tethering factors to mediate the physical connections between Golgi bodies and the ER network. Golgins are proteins anchored to the Golgi membrane by the C-terminus either through transmembrane domains or interaction with small regulatory GTPases. The golgin N-terminus contains long coiled-coil domains, which consist of a number of α-helices wrapped around each other to form a structure similar to a rope being made from several strands, reaching into the cytoplasm. In animal cells, golgins are also implicated in specific recognition of cargo at the Golgi.Here, we investigate the plant golgin Atgolgin-84A for its subcellular localization and potential role as a tethering factor at the ER-Golgi interface. For this, fluorescent fusions of Atgolgin-84A and an Atgolgin-84A truncation lacking the coiled-coil domains (Atgolgin-84AΔ1-557) were transiently expressed in tobacco leaf epidermal cells and imaged using high-resolution confocal microscopy. We show that Atgolgin-84A localizes to a pre-cis-Golgi compartment that is also labelled by one of the COPII proteins as well as by the tether protein AtCASP. Upon overexpression of Atgolgin-84A or its deletion mutant, transport between the ER and Golgi bodies is impaired and cargo proteins are redirected to the vacuole. LAY DESCRIPTION: The Golgi apparatus is a specialised compartment found in mammalian and plant cells. It is the post office of the cell and packages proteins into small membrane boxes for transport to their destination in the cell. The plant Golgi apparatus consist of many separate Golgi bodies and is responsible for the processing of proteins received from the endoplasmic reticulum (ER) and their distribution to multiple destinations within the cell. Specialised proteins called golgins have been suggested to tether Golgi bodies and the ER. Here we investigate the plant golgin Atgolgin-84A for its exact within the Golgi body and its potential role as a tethering factor at the ER-Golgi interface. For this, we have fused Atgolgin-84A with a fluorescent protein from jellyfish and we are producing this combination in tobacco leaf cells. This allows us to see the protein using laser microscopy. We show that Atgolgin-84A localises to a compartment between the ER and Golgi that is also labelled by the tether protein AtCASP. When Atgolgin-84A is produced in high amounts in the cell, transport between the ER and Golgi bodies is inhibited and proteins are redirected to the vacuole.
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Affiliation(s)
- V Vieira
- Plant Cell Biology, Department of Biological and Medical Sciences, Oxford Brookes University, Oxford, U.K.,Department of Animal and Plant Sciences, The University of Sheffield, Western Bank, Sheffield, U.K
| | - C Pain
- Plant Cell Biology, Department of Biological and Medical Sciences, Oxford Brookes University, Oxford, U.K
| | - S Wojcik
- Plant Cell Biology, Department of Biological and Medical Sciences, Oxford Brookes University, Oxford, U.K
| | - T Spatola Rossi
- Plant Cell Biology, Department of Biological and Medical Sciences, Oxford Brookes University, Oxford, U.K
| | - J Denecke
- Centre for Plant Sciences, School of Biology, University of Leeds, Leeds, U.K
| | - A Osterrieder
- Plant Cell Biology, Department of Biological and Medical Sciences, Oxford Brookes University, Oxford, U.K.,Bioethics and Engagement, Mahidol Oxford Tropical Medicine Research Unit (MORU), Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, U.K
| | - C Hawes
- Plant Cell Biology, Department of Biological and Medical Sciences, Oxford Brookes University, Oxford, U.K
| | - V Kriechbaumer
- Plant Cell Biology, Department of Biological and Medical Sciences, Oxford Brookes University, Oxford, U.K
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7
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Sánchez-Simarro J, Bernat-Silvestre C, Gimeno-Ferrer F, Selvi-Martínez P, Montero-Pau J, Aniento F, Marcote MJ. Loss of Arabidopsis β-COP Function Affects Golgi Structure, Plant Growth and Tolerance to Salt Stress. FRONTIERS IN PLANT SCIENCE 2020; 11:430. [PMID: 32351533 PMCID: PMC7175232 DOI: 10.3389/fpls.2020.00430] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/27/2019] [Accepted: 03/24/2020] [Indexed: 05/20/2023]
Abstract
The early secretory pathway involves bidirectional transport between the endoplasmic reticulum (ER) and the Golgi apparatus and is mediated by coat protein complex I (COPI)-coated and coat protein complex II (COPII)-coated vesicles. COPII vesicles are involved in ER to Golgi transport meanwhile COPI vesicles mediate intra-Golgi transport and retrograde transport from the Golgi apparatus to the ER. The key component of COPI vesicles is the coatomer complex, that is composed of seven subunits (α/β/β'/γ/δ/ε/ζ). In Arabidopsis two genes coding for the β-COP subunit have been identified, which are the result of recent tandem duplication. Here we have used a loss-of-function approach to study the function of β-COP. The results we have obtained suggest that β-COP is required for plant growth and salt tolerance. In addition, β-COP function seems to be required for maintaining the structure of the Golgi apparatus.
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8
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Vieira V, Peixoto B, Costa M, Pereira S, Pissarra J, Pereira C. N-Linked Glycosylation Modulates Golgi-Independent Vacuolar Sorting Mediated by the Plant Specific Insert. PLANTS 2019; 8:plants8090312. [PMID: 31480247 PMCID: PMC6784193 DOI: 10.3390/plants8090312] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 08/23/2019] [Accepted: 08/28/2019] [Indexed: 01/06/2023]
Abstract
In plant cells, the conventional route to the vacuole involves the endoplasmic reticulum, the Golgi and the prevacuolar compartment. However, over the years, unconventional sorting to the vacuole, bypassing the Golgi, has been described, which is the case of the Plant-Specific Insert (PSI) of the aspartic proteinase cardosin A. Interestingly, this Golgi-bypass ability is not a characteristic shared by all PSIs, since two related PSIs showed to have different sensitivity to ER-to-Golgi blockage. Given the high sequence similarity between the PSI domains, we sought to depict the differences in terms of post-translational modifications. In fact, one feature that draws our attention is that one is N-glycosylated and the other one is not. Using site-directed mutagenesis to obtain mutated versions of the two PSIs, with and without the glycosylation motif, we observed that altering the glycosylation pattern interferes with the trafficking of the protein as the non-glycosylated PSI-B, unlike its native glycosylated form, is able to bypass ER-to-Golgi blockage and accumulate in the vacuole. This is also true when the PSI domain is analyzed in the context of the full-length cardosin. Regardless of opening exciting research gaps, the results obtained so far need a more comprehensive study of the mechanisms behind this unconventional direct sorting to the vacuole.
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Affiliation(s)
- Vanessa Vieira
- Faculdade de Ciências da Universidade do Porto, Rua do Campo Alegre, s/nº, 4169-007 Porto, Portugal
| | - Bruno Peixoto
- Faculdade de Ciências da Universidade do Porto, Rua do Campo Alegre, s/nº, 4169-007 Porto, Portugal
- Instituto Gulbenkian de Ciência, Rua da Quinta Grande 6, 2780-156 Oeiras, Portugal
| | - Mónica Costa
- Faculdade de Ciências da Universidade do Porto, Rua do Campo Alegre, s/nº, 4169-007 Porto, Portugal
- Instituto Gulbenkian de Ciência, Rua da Quinta Grande 6, 2780-156 Oeiras, Portugal
| | - Susana Pereira
- Faculdade de Ciências da Universidade do Porto, Rua do Campo Alegre, s/nº, 4169-007 Porto, Portugal
- GreenUPorto-Sustainable Agrifood Production Research Center, Campus de Vairão, Rua Padre Armando Quintas 7, 4485-661 Vila do Conde, Portugal
| | - José Pissarra
- Faculdade de Ciências da Universidade do Porto, Rua do Campo Alegre, s/nº, 4169-007 Porto, Portugal
- GreenUPorto-Sustainable Agrifood Production Research Center, Campus de Vairão, Rua Padre Armando Quintas 7, 4485-661 Vila do Conde, Portugal
| | - Cláudia Pereira
- Faculdade de Ciências da Universidade do Porto, Rua do Campo Alegre, s/nº, 4169-007 Porto, Portugal.
- GreenUPorto-Sustainable Agrifood Production Research Center, Campus de Vairão, Rua Padre Armando Quintas 7, 4485-661 Vila do Conde, Portugal.
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9
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A signal motif retains Arabidopsis ER-α-mannosidase I in the cis-Golgi and prevents enhanced glycoprotein ERAD. Nat Commun 2019; 10:3701. [PMID: 31420549 PMCID: PMC6697737 DOI: 10.1038/s41467-019-11686-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Accepted: 07/01/2019] [Indexed: 11/09/2022] Open
Abstract
The Arabidopsis ER-α-mannosidase I (MNS3) generates an oligomannosidic N-glycan structure that is characteristically found on ER-resident glycoproteins. The enzyme itself has so far not been detected in the ER. Here, we provide evidence that in plants MNS3 exclusively resides in the Golgi apparatus at steady-state. Notably, MNS3 remains on dispersed punctate structures when subjected to different approaches that commonly result in the relocation of Golgi enzymes to the ER. Responsible for this rare behavior is an amino acid signal motif (LPYS) within the cytoplasmic tail of MNS3 that acts as a specific Golgi retention signal. This retention is a means to spatially separate MNS3 from ER-localized mannose trimming steps that generate the glycan signal required for flagging terminally misfolded glycoproteins for ERAD. The physiological importance of the very specific MNS3 localization is demonstrated here by means of a structurally impaired variant of the brassinosteroid receptor BRASSINOSTEROID INSENSITIVE 1. The Arabidopsis ER-α-mannosidase I MNS3 generates N-glycan structures typical of ER-resident glycoproteins. Here Schoberer et al. identify a novel motif that anchors MNS3 to the cis-Golgi, spatially separating MNS3 from ER-localized mannose trimming associated with the ER-associated degradation pathway.
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10
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Campos WF, Dressano K, Ceciliato PHO, Guerrero-Abad JC, Silva AL, Fiori CS, Morato do Canto A, Bergonci T, Claus LAN, Silva-Filho MC, Moura DS. Arabidopsis thaliana rapid alkalinization factor 1-mediated root growth inhibition is dependent on calmodulin-like protein 38. J Biol Chem 2018; 293:2159-2171. [PMID: 29282286 PMCID: PMC5808775 DOI: 10.1074/jbc.m117.808881] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Revised: 12/09/2017] [Indexed: 11/06/2022] Open
Abstract
Arabidopsis thaliana rapid alkalinization factor 1 (AtRALF1) is a small secreted peptide hormone that inhibits root growth by repressing cell expansion. Although it is known that AtRALF1 binds the plasma membrane receptor FERONIA and conveys its signals via phosphorylation, the AtRALF1 signaling pathway is largely unknown. Here, using a yeast two-hybrid system to search for AtRALF1-interacting proteins in Arabidopsis, we identified calmodulin-like protein 38 (CML38) as an AtRALF1-interacting partner. We also found that CML38 and AtRALF1 are both secreted proteins that physically interact in a Ca2+- and pH-dependent manner. CML38-knockout mutants generated via T-DNA insertion were insensitive to AtRALF1, and simultaneous treatment with both AtRALF1 and CML38 proteins restored sensitivity in these mutants. Hybrid plants lacking CML38 and having high accumulation of the AtRALF1 peptide did not exhibit the characteristic short-root phenotype caused by AtRALF1 overexpression. Although CML38 was essential for AtRALF1-mediated root inhibition, it appeared not to have an effect on the AtRALF1-induced alkalinization response. Moreover, acridinium-labeling of AtRALF1 indicated that the binding of AtRALF1 to intact roots is CML38-dependent. In summary, we describe a new component of the AtRALF1 response pathway. The new component is a calmodulin-like protein that binds AtRALF1, is essential for root growth inhibition, and has no role in AtRALF1 alkalinization.
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Affiliation(s)
- Wellington F Campos
- From the Laboratório de Bioquímica de Proteínas, Departamento de Ciências Biológicas, Escola Superior de Agricultura Luiz de Queiroz, ESALQ, Universidade de São Paulo, USP, Piracicaba, SP, 13418-900 and
| | - Keini Dressano
- From the Laboratório de Bioquímica de Proteínas, Departamento de Ciências Biológicas, Escola Superior de Agricultura Luiz de Queiroz, ESALQ, Universidade de São Paulo, USP, Piracicaba, SP, 13418-900 and
| | - Paulo H O Ceciliato
- From the Laboratório de Bioquímica de Proteínas, Departamento de Ciências Biológicas, Escola Superior de Agricultura Luiz de Queiroz, ESALQ, Universidade de São Paulo, USP, Piracicaba, SP, 13418-900 and
| | - Juan Carlos Guerrero-Abad
- From the Laboratório de Bioquímica de Proteínas, Departamento de Ciências Biológicas, Escola Superior de Agricultura Luiz de Queiroz, ESALQ, Universidade de São Paulo, USP, Piracicaba, SP, 13418-900 and
| | - Aparecida Leonir Silva
- From the Laboratório de Bioquímica de Proteínas, Departamento de Ciências Biológicas, Escola Superior de Agricultura Luiz de Queiroz, ESALQ, Universidade de São Paulo, USP, Piracicaba, SP, 13418-900 and
| | - Celso S Fiori
- From the Laboratório de Bioquímica de Proteínas, Departamento de Ciências Biológicas, Escola Superior de Agricultura Luiz de Queiroz, ESALQ, Universidade de São Paulo, USP, Piracicaba, SP, 13418-900 and
| | - Amanda Morato do Canto
- From the Laboratório de Bioquímica de Proteínas, Departamento de Ciências Biológicas, Escola Superior de Agricultura Luiz de Queiroz, ESALQ, Universidade de São Paulo, USP, Piracicaba, SP, 13418-900 and
| | - Tábata Bergonci
- From the Laboratório de Bioquímica de Proteínas, Departamento de Ciências Biológicas, Escola Superior de Agricultura Luiz de Queiroz, ESALQ, Universidade de São Paulo, USP, Piracicaba, SP, 13418-900 and
| | - Lucas A N Claus
- From the Laboratório de Bioquímica de Proteínas, Departamento de Ciências Biológicas, Escola Superior de Agricultura Luiz de Queiroz, ESALQ, Universidade de São Paulo, USP, Piracicaba, SP, 13418-900 and
| | - Marcio C Silva-Filho
- the Laboratório de Biologia Molecular de Plantas, Departamento de Genética, Escola Superior de Agricultura Luiz de Queiroz, ESALQ, Universidade de São Paulo, USP, Piracicaba, SP, 13418-900, Brazil
| | - Daniel S Moura
- From the Laboratório de Bioquímica de Proteínas, Departamento de Ciências Biológicas, Escola Superior de Agricultura Luiz de Queiroz, ESALQ, Universidade de São Paulo, USP, Piracicaba, SP, 13418-900 and
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11
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Ito Y, Uemura T, Nakano A. The Golgi entry core compartment functions as a COPII-independent scaffold for ER-to-Golgi transport in plant cells. J Cell Sci 2018; 131:jcs.203893. [PMID: 28839076 DOI: 10.1242/jcs.203893] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Accepted: 08/17/2017] [Indexed: 12/12/2022] Open
Abstract
Many questions remain about how the stacked structure of the Golgi is formed and maintained. In our previous study, we challenged this question using tobacco BY-2 cells and revealed that, upon Brefeldin A (BFA) treatment, previously undescribed small punctate structures containing a particular subset of cis-Golgi proteins are formed adjacent to the ER-exit sites and act as scaffolds for Golgi regeneration after BFA removal. In this study, we analyzed these structures further. The proteins that localize to these punctate structures originate from the cis-most cisternae. 3D time-lapse observations show that the trans-Golgi marker is transported through these structures during Golgi regeneration. These data indicate that the cis-most cisternae have a specialized region that receives cargo from the ER, which becomes obvious upon BFA treatment. Expression of a dominant mutant form of SAR1 does not affect the formation of the punctate structures. We propose to call these punctate structures the 'Golgi entry core compartment' (GECCO). They act as receivers for the rest of the Golgi materials and are formed independently of the COPII machinery.This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Yoko Ito
- Live Cell Super-Resolution Imaging Research Team, RIKEN Center for Advanced Photonics, Wako, Saitama 351-0198, Japan
| | - Tomohiro Uemura
- Laboratory of Developmental Cell Biology, Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Akihiko Nakano
- Live Cell Super-Resolution Imaging Research Team, RIKEN Center for Advanced Photonics, Wako, Saitama 351-0198, Japan.,Laboratory of Developmental Cell Biology, Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
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12
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Chung KP, Zeng Y, Li Y, Ji C, Xia Y, Jiang L. Signal motif-dependent ER export of the Qc-SNARE BET12 interacts with MEMB12 and affects PR1 trafficking in Arabidopsis. J Cell Sci 2018; 131:jcs.202838. [PMID: 28546447 DOI: 10.1242/jcs.202838] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Accepted: 05/23/2017] [Indexed: 12/27/2022] Open
Abstract
Soluble N-ethylmaleimide-sensitive fusion protein attachment protein receptors (SNAREs) are well-known for their role in controlling membrane fusion, the final, but crucial step, in vesicular transport in eukaryotes. SNARE proteins contribute to various biological processes including pathogen defense and channel activity regulation, as well as plant growth and development. Precise targeting of SNARE proteins to destined compartments is a prerequisite for their proper functioning. However, the underlying mechanism(s) for SNARE targeting in plants remains obscure. Here, we investigate the targeting mechanism of the Arabidopsis thaliana Qc-SNARE BET12, which is involved in protein trafficking in the early secretory pathway. Two distinct signal motifs that are required for efficient BET12 ER export were identified. Pulldown assays and in vivo imaging implicated that both the COPI and COPII pathways were required for BET12 targeting. Further studies using an ER-export-defective form of BET12 revealed that the Golgi-localized Qb-SNARE MEMB12, a negative regulator of pathogenesis-related protein 1 (PR1; At2g14610) secretion, was its interacting partner. Ectopic expression of BET12 caused no inhibition in the general ER-Golgi anterograde transport but caused intracellular accumulation of PR1, suggesting that BET12 has a regulatory role in PR1 trafficking in A. thaliana.
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Affiliation(s)
- Kin Pan Chung
- School of Life Sciences, Centre for Cell & Developmental Biology and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
| | - Yonglun Zeng
- School of Life Sciences, Centre for Cell & Developmental Biology and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
| | - Yimin Li
- Department of Biology, Hong Kong Baptist University, Hong Kong, China
| | - Changyang Ji
- School of Life Sciences, Centre for Cell & Developmental Biology and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
| | - Yiji Xia
- Department of Biology, Hong Kong Baptist University, Hong Kong, China
| | - Liwen Jiang
- School of Life Sciences, Centre for Cell & Developmental Biology and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China .,The Chinese University of Hong Kong Shenzhen Research Institute, Shenzhen 518057, China
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13
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Pastor-Cantizano N, Bernat-Silvestre C, Marcote MJ, Aniento F. Loss of Arabidopsis p24 function affects ERD2 trafficking and Golgi structure, and activates the unfolded protein response. J Cell Sci 2018; 131:jcs.203802. [PMID: 28871045 DOI: 10.1242/jcs.203802] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Accepted: 08/30/2017] [Indexed: 01/22/2023] Open
Abstract
The p24 family of proteins (also known as the TMED family) are key regulators of protein trafficking along the secretory pathway, but very little is known about their functions in plants. A quadruple loss-of-function mutant affecting the p24 genes from the δ-1 subclass of the p24δ subfamily (p24δ3δ4δ5δ6) showed alterations in the Golgi, suggesting that these p24 proteins play a role in the organization of the compartments of the early secretory pathway in Arabidopsis Loss of p24δ-1 proteins also induced the accumulation of the K/HDEL receptor ERD2a (ER lumen protein-retaining receptor A) at the Golgi and increased secretion of BiP family proteins, ER chaperones containing an HDEL signal, probably due to an inhibition of COPI-dependent Golgi-to-ER transport of ERD2a and thus retrieval of K/HDEL ligands. Although the p24δ3δ4δ5δ6 mutant showed enhanced sensitivity to salt stress, it did not show obvious phenotypic alterations under standard growth conditions. Interestingly, this mutant showed a constitutive activation of the unfolded protein response (UPR) and the transcriptional upregulation of the COPII subunit gene SEC31A, which may help the plant to cope with the transport defects seen in the absence of p24 proteins.
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Affiliation(s)
- Noelia Pastor-Cantizano
- Departamento de Bioquímica y Biología Molecular, Estructura de Recerca Interdisciplinar en Biotecnología i Biomedicina (ERI BIOTECMED), Facultat de Farmacia, Universitat de València, E-46100 Burjassot (Valencia), Spain
| | - Cesar Bernat-Silvestre
- Departamento de Bioquímica y Biología Molecular, Estructura de Recerca Interdisciplinar en Biotecnología i Biomedicina (ERI BIOTECMED), Facultat de Farmacia, Universitat de València, E-46100 Burjassot (Valencia), Spain
| | - María Jesús Marcote
- Departamento de Bioquímica y Biología Molecular, Estructura de Recerca Interdisciplinar en Biotecnología i Biomedicina (ERI BIOTECMED), Facultat de Farmacia, Universitat de València, E-46100 Burjassot (Valencia), Spain
| | - Fernando Aniento
- Departamento de Bioquímica y Biología Molecular, Estructura de Recerca Interdisciplinar en Biotecnología i Biomedicina (ERI BIOTECMED), Facultat de Farmacia, Universitat de València, E-46100 Burjassot (Valencia), Spain
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14
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Wang X, Chung KP, Lin W, Jiang L. Protein secretion in plants: conventional and unconventional pathways and new techniques. JOURNAL OF EXPERIMENTAL BOTANY 2017; 69:21-37. [PMID: 28992209 DOI: 10.1093/jxb/erx262] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Protein secretion is an essential process in all eukaryotic cells and its mechanisms have been extensively studied. Proteins with an N-terminal leading sequence or transmembrane domain are delivered through the conventional protein secretion (CPS) pathway from the endoplasmic reticulum (ER) to the Golgi apparatus. This feature is conserved in yeast, animals, and plants. In contrast, the transport of leaderless secretory proteins (LSPs) from the cytosol to the cell exterior is accomplished via the unconventional protein secretion (UPS) pathway. So far, the CPS pathway has been well characterized in plants, with several recent studies providing new information about the regulatory mechanisms involved. On the other hand, studies on UPS pathways in plants remain descriptive, although a connection between UPS and the plant defense response is becoming more and more apparent. In this review, we present an update on CPS and UPS. With the emergence of new techniques, a more comprehensive understanding of protein secretion in plants can be expected in the future.
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Affiliation(s)
- Xiangfeng Wang
- State Key Laboratory of Agrobiotechnology, Centre for Cell and Developmental Biology, School of Life Sciences, The Chinese University of Hong Kong, Shatin, China
| | - Kin Pan Chung
- State Key Laboratory of Agrobiotechnology, Centre for Cell and Developmental Biology, School of Life Sciences, The Chinese University of Hong Kong, Shatin, China
| | - Weili Lin
- State Key Laboratory of Agrobiotechnology, Centre for Cell and Developmental Biology, School of Life Sciences, The Chinese University of Hong Kong, Shatin, China
| | - Liwen Jiang
- State Key Laboratory of Agrobiotechnology, Centre for Cell and Developmental Biology, School of Life Sciences, The Chinese University of Hong Kong, Shatin, China
- CUHK Shenzhen Research Institute, The Chinese University of Hong Kong, China
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15
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Kwaaitaal M, Nielsen ME, Böhlenius H, Thordal-Christensen H. The plant membrane surrounding powdery mildew haustoria shares properties with the endoplasmic reticulum membrane. JOURNAL OF EXPERIMENTAL BOTANY 2017; 68:5731-5743. [PMID: 29237056 PMCID: PMC5854130 DOI: 10.1093/jxb/erx403] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Accepted: 10/26/2017] [Indexed: 05/18/2023]
Abstract
Many filamentous plant pathogens place specialized feeding structures, called haustoria, inside living host cells. As haustoria grow, they are believed to manipulate plant cells to generate a specialized, still enigmatic extrahaustorial membrane (EHM) around them. Here, we focused on revealing properties of the EHM. With the help of membrane-specific dyes and transient expression of membrane-associated proteins fused to fluorescent tags, we studied the nature of the EHM generated by barley leaf epidermal cells around powdery mildew haustoria. Observations suggesting that endoplasmic reticulum (ER) membrane-specific dyes labelled the EHM led us to find that Sar1 and RabD2a GTPases bind this membrane. These proteins are usually associated with the ER and the ER/cis-Golgi membrane, respectively. In contrast, transmembrane and luminal ER and Golgi markers failed to label the EHM, suggesting that it is not a continuum of the ER. Furthermore, GDP-locked Sar1 and a nucleotide-free RabD2a, which block ER to Golgi exit, did not hamper haustorium formation. These results indicated that the EHM shares features with the plant ER membrane, but that the EHM membrane is not dependent on conventional secretion. This raises the prospect that an unconventional secretory pathway from the ER may provide this membrane's material. Understanding these processes will assist future approaches to providing resistance by preventing EHM generation.
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Affiliation(s)
- Mark Kwaaitaal
- Section for Plant and Soil Science, Department of Plant and Environmental Sciences, Copenhagen Plant Science Center (CPSC), Faculty of Science, University of Copenhagen, Denmark
| | - Mads Eggert Nielsen
- Section for Plant and Soil Science, Department of Plant and Environmental Sciences, Copenhagen Plant Science Center (CPSC), Faculty of Science, University of Copenhagen, Denmark
| | - Henrik Böhlenius
- Section for Plant and Soil Science, Department of Plant and Environmental Sciences, Copenhagen Plant Science Center (CPSC), Faculty of Science, University of Copenhagen, Denmark
| | - Hans Thordal-Christensen
- Section for Plant and Soil Science, Department of Plant and Environmental Sciences, Copenhagen Plant Science Center (CPSC), Faculty of Science, University of Copenhagen, Denmark
- Correspondence:
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16
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Brandizzi F. Transport from the endoplasmic reticulum to the Golgi in plants: Where are we now? Semin Cell Dev Biol 2017; 80:94-105. [PMID: 28688928 DOI: 10.1016/j.semcdb.2017.06.024] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Revised: 05/11/2017] [Accepted: 06/27/2017] [Indexed: 11/26/2022]
Abstract
The biogenesis of about one third of the cellular proteome is initiated in the endoplasmic reticulum (ER), which exports proteins to the Golgi apparatus for sorting to their final destination. Notwithstanding the close proximity of the ER with other secretory membranes (e.g., endosomes, plasma membrane), the ER is also important for the homeostasis of non-secretory organelles such as mitochondria, peroxisomes, and chloroplasts. While how the plant ER interacts with most of the non-secretory membranes is largely unknown, the knowledge on the mechanisms for ER-to-Golgi transport is relatively more advanced. Indeed, over the last fifteen years or so, a large number of exciting results have contributed to draw parallels with non-plant species but also to highlight the complexity of the plant ER-Golgi interface, which bears unique features. This review reports and discusses results on plant ER-to-Golgi traffic, focusing mainly on research on COPII-mediated transport in the model species Arabidopsis thaliana.
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Affiliation(s)
- Federica Brandizzi
- MSU-DOE Plant Research Lab and Plant Biology Department, Michigan State University, East Lansing, MI 48824, USA; Department of Plant Biology, Michigan State University, East Lansing, MI 48824, USA; Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, MI 48824, USA.
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17
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Osterrieder A, Sparkes IA, Botchway SW, Ward A, Ketelaar T, de Ruijter N, Hawes C. Stacks off tracks: a role for the golgin AtCASP in plant endoplasmic reticulum-Golgi apparatus tethering. JOURNAL OF EXPERIMENTAL BOTANY 2017; 68:3339-3350. [PMID: 28605454 PMCID: PMC5853478 DOI: 10.1093/jxb/erx167] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Accepted: 04/25/2017] [Indexed: 05/18/2023]
Abstract
The plant Golgi apparatus modifies and sorts incoming proteins from the endoplasmic reticulum (ER) and synthesizes cell wall matrix material. Plant cells possess numerous motile Golgi bodies, which are connected to the ER by yet to be identified tethering factors. Previous studies indicated a role for cis-Golgi plant golgins, which are long coiled-coil domain proteins anchored to Golgi membranes, in Golgi biogenesis. Here we show a tethering role for the golgin AtCASP at the ER-Golgi interface. Using live-cell imaging, Golgi body dynamics were compared in Arabidopsis thaliana leaf epidermal cells expressing fluorescently tagged AtCASP, a truncated AtCASP-ΔCC lacking the coiled-coil domains, and the Golgi marker STtmd. Golgi body speed and displacement were significantly reduced in AtCASP-ΔCC lines. Using a dual-colour optical trapping system and a TIRF-tweezer system, individual Golgi bodies were captured in planta. Golgi bodies in AtCASP-ΔCC lines were easier to trap and the ER-Golgi connection was more easily disrupted. Occasionally, the ER tubule followed a trapped Golgi body with a gap, indicating the presence of other tethering factors. Our work confirms that the intimate ER-Golgi association can be disrupted or weakened by expression of truncated AtCASP-ΔCC and suggests that this connection is most likely maintained by a golgin-mediated tethering complex.
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Affiliation(s)
- Anne Osterrieder
- Department of Biological and Medical Sciences, Faculty of Health and Life Sciences, Oxford Brookes University, Gipsy Lane, Headington, Oxford, UK
| | - Imogen A Sparkes
- Department of Biological and Medical Sciences, Faculty of Health and Life Sciences, Oxford Brookes University, Gipsy Lane, Headington, Oxford, UK
| | - Stan W Botchway
- Central Laser Facility, Science and Technology Facilities Council, Research Complex at Harwell, Didcot, Oxon, UK
| | - Andy Ward
- Central Laser Facility, Science and Technology Facilities Council, Research Complex at Harwell, Didcot, Oxon, UK
| | - Tijs Ketelaar
- Laboratory of Cell Biology, Wageningen University, Droevendaalsesteeg, Wageningen, The Netherlands
| | - Norbert de Ruijter
- Laboratory of Cell Biology, Wageningen University, Droevendaalsesteeg, Wageningen, The Netherlands
| | - Chris Hawes
- Department of Biological and Medical Sciences, Faculty of Health and Life Sciences, Oxford Brookes University, Gipsy Lane, Headington, Oxford, UK
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18
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Gimeno-Ferrer F, Pastor-Cantizano N, Bernat-Silvestre C, Selvi-Martínez P, Vera-Sirera F, Gao C, Perez-Amador MA, Jiang L, Aniento F, Marcote MJ. α2-COP is involved in early secretory traffic in Arabidopsis and is required for plant growth. JOURNAL OF EXPERIMENTAL BOTANY 2017; 68:391-401. [PMID: 28025315 PMCID: PMC5441910 DOI: 10.1093/jxb/erw446] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
COP (coat protein) I-coated vesicles mediate intra-Golgi transport and retrograde transport from the Golgi to the endoplasmic reticulum. These vesicles form through the action of the small GTPase ADP-ribosylation factor 1 (ARF1) and the COPI heptameric protein complex (coatomer), which consists of seven subunits (α-, β-, β'-, γ-, δ-, ε- and ζ-COP). In contrast to mammals and yeast, several isoforms for coatomer subunits, with the exception of γ and δ, have been identified in Arabidopsis. To understand the role of COPI proteins in plant biology, we have identified and characterized a loss-of-function mutant of α2-COP, an Arabidopsis α-COP isoform. The α2-cop mutant displayed defects in plant growth, including small rosettes, stems and roots and mislocalization of p24δ5, a protein of the p24 family containing a C-terminal dilysine motif involved in COPI binding. The α2-cop mutant also exhibited abnormal morphology of the Golgi apparatus. Global expression analysis of the α2-cop mutant revealed altered expression of plant cell wall-associated genes. In addition, a strong upregulation of SEC31A, which encodes a subunit of the COPII coat, was observed in the α2-cop mutant; this also occurs in a mutant of a gene upstream of COPI assembly, GNL1, which encodes an ARF-guanine nucleotide exchange factor (GEF). These findings suggest that loss of α2-COP affects the expression of secretory pathway genes.
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Affiliation(s)
- Fátima Gimeno-Ferrer
- Departamento de Bioquímica y Biología Molecular, Facultad de Farmacia, Universitat de València, Burjassot, Spain
| | - Noelia Pastor-Cantizano
- Departamento de Bioquímica y Biología Molecular, Facultad de Farmacia, Universitat de València, Burjassot, Spain
- Estructura de Recerca Interdisciplinar en Biotecnología i Biomedicina (ERI BIOTECMED), Universitat de València, Burjassot, Spain
| | - César Bernat-Silvestre
- Departamento de Bioquímica y Biología Molecular, Facultad de Farmacia, Universitat de València, Burjassot, Spain
- Estructura de Recerca Interdisciplinar en Biotecnología i Biomedicina (ERI BIOTECMED), Universitat de València, Burjassot, Spain
| | - Pilar Selvi-Martínez
- Departamento de Bioquímica y Biología Molecular, Facultad de Farmacia, Universitat de València, Burjassot, Spain
| | - Francisco Vera-Sirera
- Instituto de Biología Molecular y Celular de Plantas (IBMCP), Universidad Politécnica de Valencia-Consejo Superior de Investigaciones Científicas (CSIC), Valencia, Spain
| | - Caiji Gao
- School of Life Sciences, Centre for Cell and Developmental Biology and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Hong Kong, China
| | - Miguel Angel Perez-Amador
- Instituto de Biología Molecular y Celular de Plantas (IBMCP), Universidad Politécnica de Valencia-Consejo Superior de Investigaciones Científicas (CSIC), Valencia, Spain
| | - Liwen Jiang
- School of Life Sciences, Centre for Cell and Developmental Biology and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Hong Kong, China
| | - Fernando Aniento
- Departamento de Bioquímica y Biología Molecular, Facultad de Farmacia, Universitat de València, Burjassot, Spain
- Estructura de Recerca Interdisciplinar en Biotecnología i Biomedicina (ERI BIOTECMED), Universitat de València, Burjassot, Spain
| | - María Jesús Marcote
- Departamento de Bioquímica y Biología Molecular, Facultad de Farmacia, Universitat de València, Burjassot, Spain
- Estructura de Recerca Interdisciplinar en Biotecnología i Biomedicina (ERI BIOTECMED), Universitat de València, Burjassot, Spain
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Lütz-Meindl U, Luckner M, Andosch A, Wanner G. Structural stress responses and degradation of dictyosomes in algae analysed by TEM and FIB-SEM tomography. J Microsc 2015; 263:129-41. [PMID: 26708415 DOI: 10.1111/jmi.12369] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Accepted: 11/25/2015] [Indexed: 12/17/2022]
Abstract
Stress-induced physiological deficiencies in cells are reflected in structural, morphological and functional reactions of organelles. Although numerous investigations have focused on chloroplasts and mitochondria as main targets of different stressors in plant cells, there is insufficient information on the plant Golgi apparatus as stress sensor. By using the advantages of field emission scanning electron microscopy tomography in combination with classical ultrathin sectioning and transmission electron microscopic analyses, we provide structural evidence for common stress responses of the large and highly stable dictyosomes in the algal model system Micrasterias. Stress is induced by different metals such as manganese and lead, by starvation in 9 weeks of darkness or by inhibiting photosynthesis or glycolysis and by disturbing ionic homeostasis via KCl. For the first time a stress-induced degradation pathway of dictyosomes is described that does not follow "classical" autophagy but occurs by disintegration of cisternae into single membrane balls that seem to be finally absorbed by the endoplasmic reticulum (ER). Comparison of the morphological features that accompany dictyosomal degradation in Micrasterias to similar reactions observed during the same stress application in Nitella indicates an ubiquitous degradation process at least in algae. As the algae investigated belong to the closest relatives of higher land plants these results may also be relevant for understanding dictyosomal stress and degradation responses in the latter phylogenetic group. In addition, this study shows that two-dimensional transmission electron microscopy is insufficient for elucidating complex processes such as organelle degradation, and that information from three-dimensional reconstructions as provided by field emission scanning electron microscopy tomography is absolutely required for a comprehensive understanding of the phenomenon.
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Affiliation(s)
- U Lütz-Meindl
- Plant Physiology Division, Cell Biology Department, University of Salzburg, Salzburg, Austria
| | - M Luckner
- Ultrastructural Research, Faculty of Biology, Ludwig-Maximilians-University, Munich, Germany
| | - A Andosch
- Plant Physiology Division, Cell Biology Department, University of Salzburg, Salzburg, Austria
| | - G Wanner
- Ultrastructural Research, Faculty of Biology, Ludwig-Maximilians-University, Munich, Germany
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Hawes C, Kiviniemi P, Kriechbaumer V. The endoplasmic reticulum: a dynamic and well-connected organelle. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2015; 57:50-62. [PMID: 25319240 DOI: 10.1111/jipb.12297] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2014] [Accepted: 10/09/2014] [Indexed: 06/04/2023]
Abstract
The endoplasmic reticulum forms the first compartment in a series of organelles which comprise the secretory pathway. It takes the form of an extremely dynamic and pleomorphic membrane-bounded network of tubules and cisternae which have numerous different cellular functions. In this review, we discuss the nature of endoplasmic reticulum structure and dynamics, its relationship with closely associated organelles, and its possible function as a highway for the distribution and delivery of a diverse range of structures from metabolic complexes to viral particles.
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Affiliation(s)
- Chris Hawes
- Department of Biological and Medical Sciences, Oxford Brookes University, Oxford, OX3 0BP, UK
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21
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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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22
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Abstract
Plants are permanently situated in a fixed location and thus are well adapted to sense and respond to environmental stimuli and developmental cues. At the cellular level, several of these responses require delicate adjustments that affect the activity and steady-state levels of plasma membrane proteins. These adjustments involve both vesicular transport to the plasma membrane and protein internalization via endocytic sorting. A substantial part of our current knowledge of plant plasma membrane protein sorting is based on studies of PIN-FORMED (PIN) auxin transport proteins, which are found at distinct plasma membrane domains and have been implicated in directional efflux of the plant hormone auxin. Here, we discuss the mechanisms involved in establishing such polar protein distributions, focusing on PINs and other key plant plasma membrane proteins, and we highlight the pathways that allow for dynamic adjustments in protein distribution and turnover, which together constitute a versatile framework that underlies the remarkable capabilities of plants to adjust growth and development in their ever-changing environment.
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Affiliation(s)
- Christian Luschnig
- Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences, Vienna (BOKU), Muthgasse 18, Vienna 1190, Austria
| | - Grégory Vert
- Institut des Sciences du Végétal, CNRS UPR 2355, 1 Avenue de la Terrasse, Bâtiment 23A, Gif-sur-Yvette 91190, France
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Yorimitsu T, Sato K, Takeuchi M. Molecular mechanisms of Sar/Arf GTPases in vesicular trafficking in yeast and plants. FRONTIERS IN PLANT SCIENCE 2014; 5:411. [PMID: 25191334 PMCID: PMC4140167 DOI: 10.3389/fpls.2014.00411] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2014] [Accepted: 08/03/2014] [Indexed: 05/21/2023]
Abstract
Small GTPase proteins play essential roles in the regulation of vesicular trafficking systems in eukaryotic cells. Two types of small GTPases, secretion-associated Ras-related protein (Sar) and ADP-ribosylation factor (Arf), act in the biogenesis of transport vesicles. Sar/Arf GTPases function as molecular switches by cycling between active, GTP-bound and inactive, GDP-bound forms, catalyzed by guanine nucleotide exchange factors and GTPase-activating proteins, respectively. Activated Sar/Arf GTPases undergo a conformational change, exposing the N-terminal amphipathic α-helix for insertion into membranes. The process triggers the recruitment and assembly of coat proteins to the membranes, followed by coated vesicle formation and scission. In higher plants, Sar/Arf GTPases also play pivotal roles in maintaining the dynamic identity of organelles in the secretory pathway. Sar1 protein strictly controls anterograde transport from the endoplasmic reticulum (ER) through the recruitment of plant COPII coat components onto membranes. COPII vesicle transport is responsible for the organization of highly conserved polygonal ER networks. In contrast, Arf proteins contribute to the regulation of multiple trafficking routes, including transport through the Golgi complex and endocytic transport. These transport systems have diversified in the plant kingdom independently and exhibit several plant-specific features with respect to Golgi organization, endocytic cycling, cell polarity and cytokinesis. The functional diversification of vesicular trafficking systems ensures the multicellular development of higher plants. This review focuses on the current knowledge of Sar/Arf GTPases, highlighting the molecular details of GTPase regulation in vesicle formation in yeast and advances in knowledge of the characteristics of vesicle trafficking in plants.
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Affiliation(s)
- Tomohiro Yorimitsu
- Department of Life Sciences, Graduate School of Arts and Sciences, University of TokyoTokyo, Japan
| | - Ken Sato
- Department of Life Sciences, Graduate School of Arts and Sciences, University of TokyoTokyo, Japan
| | - Masaki Takeuchi
- Department of Chemistry, Graduate School of Science, University of TokyoTokyo, Japan
- *Correspondence: Masaki Takeuchi, Department of Chemistry, Graduate School of Science, University of Tokyo, Tokyo 113-0033, Japan e-mail:
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24
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Takagi J, Renna L, Takahashi H, Koumoto Y, Tamura K, Stefano G, Fukao Y, Kondo M, Nishimura M, Shimada T, Brandizzi F, Hara-Nishimura I. MAIGO5 functions in protein export from Golgi-associated endoplasmic reticulum exit sites in Arabidopsis. THE PLANT CELL 2013; 25:4658-75. [PMID: 24280388 PMCID: PMC3875742 DOI: 10.1105/tpc.113.118158] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2013] [Revised: 10/08/2013] [Accepted: 10/22/2013] [Indexed: 05/19/2023]
Abstract
Plant cells face unique challenges to efficiently export cargo from the endoplasmic reticulum (ER) to mobile Golgi stacks. Coat protein complex II (COPII) components, which include two heterodimers of Secretory23/24 (Sec23/24) and Sec13/31, facilitate selective cargo export from the ER; however, little is known about the mechanisms that regulate their recruitment to the ER membrane, especially in plants. Here, we report a protein transport mutant of Arabidopsis thaliana, named maigo5 (mag5), which abnormally accumulates precursor forms of storage proteins in seeds. mag5-1 has a deletion in the putative ortholog of the Saccharomyces cerevisiae and Homo sapiens Sec16, which encodes a critical component of ER exit sites (ERESs). mag mutants developed abnormal structures (MAG bodies) within the ER and exhibited compromised ER export. A functional MAG5/SEC16A-green fluorescent protein fusion localized at Golgi-associated cup-shaped ERESs and cycled on and off these sites at a slower rate than the COPII coat. MAG5/SEC16A interacted with SEC13 and SEC31; however, in the absence of MAG5/SEC16A, recruitment of the COPII coat to ERESs was accelerated. Our results identify a key component of ER export in plants by demonstrating that MAG5/SEC16A is required for protein export at ERESs that are associated with mobile Golgi stacks, where it regulates COPII coat turnover.
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Affiliation(s)
- Junpei Takagi
- Department of Botany, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan
| | - Luciana Renna
- Department of Energy, Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
| | - Hideyuki Takahashi
- Department of Botany, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan
| | - Yasuko Koumoto
- Department of Botany, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan
| | - Kentaro Tamura
- Department of Botany, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan
| | - Giovanni Stefano
- Department of Energy, Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
| | - Yoichiro Fukao
- Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma 630-0101, Japan
| | - Maki Kondo
- Department of Cell Biology, National Institute for Basic Biology, Okazaki 444-8585, Japan
| | - Mikio Nishimura
- Department of Cell Biology, National Institute for Basic Biology, Okazaki 444-8585, Japan
| | - Tomoo Shimada
- Department of Botany, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan
| | - Federica Brandizzi
- Department of Energy, Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
| | - Ikuko Hara-Nishimura
- Department of Botany, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan
- Address correspondence to
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25
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Brandizzi F, Barlowe C. Organization of the ER-Golgi interface for membrane traffic control. Nat Rev Mol Cell Biol 2013; 14:382-92. [PMID: 23698585 DOI: 10.1038/nrm3588] [Citation(s) in RCA: 363] [Impact Index Per Article: 33.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Coat protein complex I (COPI) and COPII are required for bidirectional membrane trafficking between the endoplasmic reticulum (ER) and the Golgi. While these core coat machineries and other transport factors are highly conserved across species, high-resolution imaging studies indicate that the organization of the ER-Golgi interface is varied in eukaryotic cells. Regulation of COPII assembly, in some cases to manage distinct cellular cargo, is emerging as one important component in determining this structure. Comparison of the ER-Golgi interface across different systems, particularly mammalian and plant cells, reveals fundamental elements and distinct organization of this interface. A better understanding of how these interfaces are regulated to meet varying cellular secretory demands should provide key insights into the mechanisms that control efficient trafficking of proteins and lipids through the secretory pathway.
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Affiliation(s)
- Federica Brandizzi
- DOE Plant Research Laboratory and Department of Plant Biology, Michigan State University, East Lansing, Michigan 48824, USA
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26
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Tian L, Dai LL, Yin ZJ, Fukuda M, Kumamaru T, Dong XB, Xu XP, Qu LQ. Small GTPase Sar1 is crucial for proglutelin and α-globulin export from the endoplasmic reticulum in rice endosperm. JOURNAL OF EXPERIMENTAL BOTANY 2013; 64:2831-45. [PMID: 23682119 PMCID: PMC3697955 DOI: 10.1093/jxb/ert128] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Rice seed storage proteins glutelin and α-globulin are synthesized in the endoplasmic reticulum (ER) and deposited in protein storage vacuoles (PSVs). Sar1, a small GTPase, acts as a molecular switch to regulate the assembly of coat protein complex II, which exports secretory protein from the ER to the Golgi apparatus. To reveal the route by which glutelin and α-globulin exit the ER, four putative Sar1 genes (OsSar1a/b/c/d) were cloned from rice, and transgenic rice were generated with Sar1 overexpressed or suppressed by RNA interference (RNAi) specifically in the endosperm under the control of the rice glutelin promoter. Overexpression or suppression of any OsSar1 did not alter the phenotype. However, simultaneous knockdown of OsSar1a/b/c resulted in floury and shrunken seeds, with an increased level of glutelin precursor and decreased level of the mature α- and β-subunit. OsSar1abc RNAi endosperm generated numerous, spherical, novel protein bodies with highly electron-dense matrixes containing both glutelin and α-globulin. Notably, the novel protein bodies were surrounded by ribosomes, showing that they were derived from the ER. Some of the ER-derived dense protein bodies were attached to a blebbing structure containing prolamin. These results indicated that OsSar1a/b/c play a crucial role in storage proteins exiting from the ER, with functional redundancy in rice endosperm, and glutelin and α-globulin transported together from the ER to the Golgi apparatus by a pathway mediated by coat protein complex II.
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Affiliation(s)
- Lihong Tian
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, the Chinese Academy of Sciences, Beijing 100093, China
| | - Ling Ling Dai
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, the Chinese Academy of Sciences, Beijing 100093, China
| | - Zhi Jie Yin
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, the Chinese Academy of Sciences, Beijing 100093, China
| | - Masako Fukuda
- Faculty of Agriculture, Kyushu University, Fukuoka 812–8581, Japan
| | | | - Xiang Bai Dong
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, the Chinese Academy of Sciences, Beijing 100093, China
| | - Xiu Ping Xu
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, the Chinese Academy of Sciences, Beijing 100093, China
| | - Le Qing Qu
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, the Chinese Academy of Sciences, Beijing 100093, China
- *To whom correspondence should be addressed. E-mail:
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27
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Abstract
As plant Golgi bodies move through the cell along the actin cytoskeleton, they face the need to maintain their polarized stack structure whilst receiving, processing and distributing protein cargo destined for secretion. Structural proteins, or Golgi matrix proteins, help to hold cisternae together and tethering factors direct cargo carriers to the correct target membranes. This review focuses on golgins, a protein family containing long coiled-coil regions, summarizes their known functions in animal cells and highlights recent findings about plant golgins and their putative roles in the plant secretory pathway.
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Affiliation(s)
- A Osterrieder
- Department of Biological and Medical Sciences, Faculty of Health and Life Sciences, Oxford Brookes University, Oxford, UK.
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28
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Hawes C. The ER/Golgi Interface - Is There Anything in-between? FRONTIERS IN PLANT SCIENCE 2012; 3:73. [PMID: 22645598 PMCID: PMC3355773 DOI: 10.3389/fpls.2012.00073] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2011] [Accepted: 03/29/2012] [Indexed: 05/23/2023]
Affiliation(s)
- Chris Hawes
- Plant Cell Biology, Department of Biological and Medical Sciences, Oxford Brookes UniversityOxford, UK
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Su CL, Chao YT, Alex Chang YC, Chen WC, Chen CY, Lee AY, Hwa KT, Shih MC. De novo assembly of expressed transcripts and global analysis of the Phalaenopsis aphrodite transcriptome. PLANT & CELL PHYSIOLOGY 2011; 52:1501-14. [PMID: 21771864 DOI: 10.1093/pcp/pcr097] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Being one of the largest families in the angiosperms, Orchidaceae display a great biodiversity resulting from adaptation to diverse habitats. Genomic information on orchids is rather limited, despite their unique and interesting biological features, thus impeding advanced molecular research. Here we report a strategy to integrate sequence outputs of the moth orchid, Phalaenopsis aphrodite, from two high-throughput sequencing platform technologies, Roche 454 and Illumina/Solexa, in order to maximize assembly efficiency. Tissues collected for cDNA library preparation included a wide range of vegetative and reproductive tissues. We also designed an effective workflow for annotation and functional analysis. After assembly and trimming processes, 233,823 unique sequences were obtained. Among them, 42,590 contigs averaging 875 bp in length were annotated to protein-coding genes, of which 7,263 coding genes were found to be nearly full length. The sequence accuracy of the assembled contigs was validated to be as high as 99.9%. Genes with tissue-specific expression were also categorized by profiling analysis with RNA-Seq. Gene products targeted to specific subcellular localizations were identified by their annotations. We concluded that, with proper assembly to combine outputs of next-generation sequencing platforms, transcriptome information can be enriched in gene discovery, functional annotation and expression profiling of a non-model organism.
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Affiliation(s)
- Chun-lin Su
- Agricultural Biotechnology Research Center, Academia Sinica, Taipei, 11529, Taiwan
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30
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Madison SL, Nebenführ A. Live-cell imaging of dual-labeled Golgi stacks in tobacco BY-2 cells reveals similar behaviors for different cisternae during movement and brefeldin A treatment. MOLECULAR PLANT 2011; 4:896-908. [PMID: 21873295 DOI: 10.1093/mp/ssr067] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
In plant cells, the Golgi apparatus consists of numerous stacks that, in turn, are composed of several flattened cisternae with a clear cis-to-trans polarity. During normal functioning within living cells, this unusual organelle displays a wide range of dynamic behaviors such as whole stack motility, constant membrane flux through the cisternae, and Golgi enzyme recycling through the ER. In order to further investigate various aspects of Golgi stack dynamics and integrity, we co-expressed pairs of established Golgi markers in tobacco BY-2 cells to distinguish sub-compartments of the Golgi during monensin treatments, movement, and brefeldin A (BFA)-induced disassembly. A combination of cis and trans markers revealed that Golgi stacks remain intact as they move through the cytoplasm. The Golgi stack orientation during these movements showed a slight preference for the cis side moving ahead, but trans cisternae were also found at the leading edge. During BFA treatments, the different sub-compartments of about half of the observed stacks fused with the ER sequentially; however, no consistent order could be detected. In contrast, the ionophore monensin resulted in swelling of trans cisternae while medial and particularly cis cisternae were mostly unaffected. Our results thus demonstrate a remarkable equivalence of the different cisternae with respect to movement and BFA-induced fusion with the ER. In addition, we propose that a combination of dual-label fluorescence microscopy and drug treatments can provide a simple alternative approach to the determination of protein localization to specific Golgi sub-compartments.
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Affiliation(s)
- Stephanie L Madison
- Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996-0840, USA
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31
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Wang P, Hummel E, Osterrieder A, Meyer AJ, Frigerio L, Sparkes I, Hawes C. KMS1 and KMS2, two plant endoplasmic reticulum proteins involved in the early secretory pathway. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2011; 66:613-28. [PMID: 21294794 DOI: 10.1111/j.1365-313x.2011.04522.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
We have identified two endoplasmic reticulum (ER)-associated Arabidopsis proteins, KMS1 and KMS2, which are conserved among most species. Fluorescent protein fusions of KMS1 localised to the ER in plant cells, and over-expression induced the formation of a membrane structure, identified as ER whorls by electron microscopy. Hydrophobicity analysis suggested that KMS1 and KMS2 are integral membrane proteins bearing six transmembrane domains. Membrane protein topology was assessed by a redox-based topology assay (ReTA) with redox-sensitive GFP and confirmed by a protease protection assay. A major loop domain between transmembrane domains 2 and 3, plus the N- and C-termini were found on the cytosolic side of the ER. A C-terminal di(tri)-lysine motif is involved in retrieval of KMS1 and deletion led to a reduction of the GFP-KMS1 signal in the ER. Over-expression of KMS1/KMS2 truncations perturbed ER and Golgi morphology and similar effects were also seen when KMS1/KMS2 were knocked-down by RNA interference. Microscopy and biochemical experiments suggested that expression of KMS1/KMS2 truncations inhibited ER to Golgi protein transport.
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Affiliation(s)
- Pengwei Wang
- School of Life Sciences, Oxford Brookes University, Headington, Oxford OX3 0BP, UK
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32
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Schoberer J, Strasser R. Sub-compartmental organization of Golgi-resident N-glycan processing enzymes in plants. MOLECULAR PLANT 2011; 4:220-8. [PMID: 21307368 PMCID: PMC3063520 DOI: 10.1093/mp/ssq082] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2010] [Accepted: 12/17/2010] [Indexed: 05/17/2023]
Abstract
In all eukaryotes, the Golgi apparatus is the main site of protein glycosylation. It is widely accepted that the glycosidases and glycosyltransferases involved in N-glycan processing are found concentrated within the Golgi stack where they provide their function. This means that enzymes catalyzing early steps in the processing pathway are located mainly at the cis-side, whereas late-acting enzymes mostly locate to the trans-side of the stacks, creating a non-uniform distribution along the cis-trans axis of the Golgi. There is compelling evidence that the information for their sorting to specific Golgi cisternae depends on signals encoded in the proteins themselves as well as on the trafficking machinery that recognizes these signals and it is believed that cisternal sub-compartmentalization is achieved and maintained by a combination of retention and retrieval mechanisms. Yet, the signals, mechanism(s), and molecular factors involved are still unknown. Here, we address recent findings and summarize the current understanding of this fundamental process in plant cell biology.
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Affiliation(s)
- Jennifer Schoberer
- School of Life Sciences, Oxford Brookes University, Headington Campus, Gipsy Lane, Oxford, OX3 0BP, UK
| | - Richard Strasser
- Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences, Vienna, Austria
- To whom correspondence should be addressed. E-mail , fax +43 1 47654 6392, tel. +43 1 47654 6700
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33
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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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34
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Kühnle J, Shillcock J, Mouritsen OG, Weiss M. A modeling approach to the self-assembly of the Golgi apparatus. Biophys J 2010; 98:2839-47. [PMID: 20550896 DOI: 10.1016/j.bpj.2010.03.035] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2010] [Revised: 03/02/2010] [Accepted: 03/16/2010] [Indexed: 11/19/2022] Open
Abstract
The dynamic compartmentalization of eukaryotic cells is a fascinating phenomenon that is not yet understood. A prominent example of this challenge is the Golgi apparatus, the central hub for protein sorting and lipid metabolism in the secretory pathway. Despite major advances in elucidating its molecular biology, the fundamental question of how the morphogenesis of this organelle is organized on a system level has remained elusive. Here, we have formulated a coarse-grained computational model that captures key features of the dynamic morphogenesis of a Golgi apparatus. In particular, our model relates the experimentally observed Golgi phenotypes, the typical turnover times, and the size and number of cisternae to three basic, experimentally accessible quantities: the rates for material influx from the endoplasmic reticulum, and the anterograde and retrograde transport rates. Based on these results, we propose which molecular factors should be mutated to alter the organelle's phenotype and dynamics.
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Affiliation(s)
- Jens Kühnle
- Cellular Biophysics Group (BIOMS), German Cancer Research Center, c/o BIOQUANT, Heidelberg, Germany
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35
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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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36
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Abstract
It has long been assumed that the individual cisternal stacks that comprise the plant Golgi apparatus multiply by some kind of fission process. However, more recently, it has been demonstrated that the Golgi apparatus can be experimentally disassembled and the reformation process from the ER (endoplasmic reticulum) monitored sequentially using confocal fluorescence and electron microscopy. Some other evidence suggests that Golgi stacks may arise de novo in cells. In the present paper, we review some of the more recent findings on plant Golgi stack biogenesis and propose a new model for their growth de novo from ER exit sites.
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Affiliation(s)
- Chris Hawes
- School of Life Sciences, Oxford Brookes University, Oxford OX3 0BP, UK.
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