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Song C, Xie K, Chen H, Xu S, Mao H. Wheat ESCRT-III protein TaSAL1 regulates male gametophyte transmission and controls tillering and heading date. JOURNAL OF EXPERIMENTAL BOTANY 2024; 75:2372-2384. [PMID: 38206130 DOI: 10.1093/jxb/erae012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Accepted: 01/10/2024] [Indexed: 01/12/2024]
Abstract
Charged multivesicular protein 1 (CHMP1) is a member of the endosomal sorting complex required for transport-III (ESCRT-III) complex that targets membrane localized signaling receptors to intralumenal vesicles in the multivesicular body of the endosome and eventually to the lysosome for degradation. Although CHMP1 plays roles in various plant growth and development processes, little is known about its function in wheat. In this study, we systematically analysed the members of the ESCRT-III complex in wheat (Triticum aestivum) and found that their orthologs were highly conserved in eukaryotic evolution. We identified CHMP1 homologous genes, TaSAL1s, and found that they were constitutively expressed in wheat tissues and essential for plant reproduction. Subcellular localization assays showed these proteins aggregated with and closely associated with the endoplasmic reticulum when ectopically expressed in tobacco leaves. We also found these proteins were toxic and caused leaf death. A genetic and reciprocal cross analysis revealed that TaSAL1 leads to defects in male gametophyte biogenesis. Moreover, phenotypic and metabolomic analysis showed that TaSAL1 may regulate tillering and heading date through phytohormone pathways. Overall, our results highlight the role of CHMP1 in wheat, particularly in male gametophyte biogenesis, with implications for improving plant growth and developing new strategies for plant breeding and genetic engineering.
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Affiliation(s)
- Chengxiang Song
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China
| | - Kaidi Xie
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China
| | - Hao Chen
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China
| | - Shuhao Xu
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China
| | - Hailiang Mao
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China
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Haag C, Klein T, Feldbrügge M. ESCRT Mutant Analysis and Imaging of ESCRT Components in the Model Fungus Ustilago maydis. Methods Mol Biol 2019; 1998:251-271. [PMID: 31250308 DOI: 10.1007/978-1-4939-9492-2_19] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The ESCRT machinery (endosomal sorting complex required for transport) is an evolutionarily highly conserved multiprotein complex involved in numerous cellular processes like endocytosis, membrane repair, or endosomal long-distance transport. In fungal hyphae, endocytosis and long-distance mRNA transport are tightly linked, as endocytotic vesicles are also the key carrier vehicles for mRNAs. Studying the regulatory component Did2 (CHMP1) in the plant pathogen Ustilago maydis revealed that loss of Did2 resulted in disturbed endosomal maturation, thereby causing defects in microtubule-dependent transport of early endosomes. Here, we describe methods and protocols that allow studying the role of ESCRT components during endosomal transport. We present experimental strategies to analyze U. maydis ESCRT mutant phenotypes and test complementation with heterologous components, such as ESCRT regulators from Drosophila melanogaster.
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Affiliation(s)
- Carl Haag
- Cluster of Excellence on Plant Sciences (CEPLAS), Institute for Microbiology, Heinrich-Heine University Düsseldorf, Düsseldorf, Germany
| | - Thomas Klein
- Institute of Genetics, Heinrich-Heine University Düsseldorf, Düsseldorf, Germany
| | - Michael Feldbrügge
- Cluster of Excellence on Plant Sciences (CEPLAS), Institute for Microbiology, Heinrich-Heine University Düsseldorf, Düsseldorf, Germany.
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Haag C, Pohlmann T, Feldbrügge M. The ESCRT regulator Did2 maintains the balance between long-distance endosomal transport and endocytic trafficking. PLoS Genet 2017; 13:e1006734. [PMID: 28422978 PMCID: PMC5415202 DOI: 10.1371/journal.pgen.1006734] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Revised: 05/03/2017] [Accepted: 04/04/2017] [Indexed: 01/01/2023] Open
Abstract
In highly polarised cells, like fungal hyphae, early endosomes function in both endocytosis as well as long-distance transport of various cargo including mRNA and protein complexes. However, knowledge on the crosstalk between these seemingly different trafficking processes is scarce. Here, we demonstrate that the ESCRT regulator Did2 coordinates endosomal transport in fungal hyphae of Ustilago maydis. Loss of Did2 results in defective vacuolar targeting, less processive long-distance transport and abnormal shuttling of early endosomes. Importantly, the late endosomal protein Rab7 and vacuolar protease Prc1 exhibit increased shuttling on these aberrant endosomes suggesting defects in endosomal maturation and identity. Consistently, molecular motors fail to attach efficiently explaining the disturbed processive movement. Furthermore, the endosomal mRNP linker protein Upa1 is hardly present on endosomes resulting in defects in long-distance mRNA transport. In conclusion, the ESCRT regulator Did2 coordinates precise maturation of endosomes and thus provides the correct membrane identity for efficient endosomal long-distance transport.
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Affiliation(s)
- Carl Haag
- Heinrich Heine University Düsseldorf, Institute for Microbiology, Cluster of Excellence on Plant Sciences, Düsseldorf, Germany
| | - Thomas Pohlmann
- Heinrich Heine University Düsseldorf, Institute for Microbiology, Cluster of Excellence on Plant Sciences, Düsseldorf, Germany
| | - Michael Feldbrügge
- Heinrich Heine University Düsseldorf, Institute for Microbiology, Cluster of Excellence on Plant Sciences, Düsseldorf, Germany
- * E-mail:
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Valentine M, Hogan J, Collier S. The Drosophila Chmp1 protein determines wing cell fate through regulation of epidermal growth factor receptor signaling. Dev Dyn 2014; 243:977-87. [PMID: 24753138 DOI: 10.1002/dvdy.24140] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2013] [Revised: 04/11/2014] [Accepted: 04/12/2014] [Indexed: 11/06/2022] Open
Abstract
BACKGROUND Receptor down-regulation by the multivesicular body (MVB) pathway is critical for many cellular signaling events. MVB generation is mediated by the highly conserved ESCRT (0, I, II, and III) protein complexes. Chmp1 is an ESCRT-III component and a putative tumor suppressor in humans. However, published data on Chmp1 activity are conflicting and its role during tissue development is not well defined. RESULTS We investigated the function of Drosophila Chmp1 and found that it is an essential gene. In the wing, loss of Chmp1 activity causes a cell fate change from intervein to vein, and interactions between Chmp1 and Drosophila Epidermal Growth Factor Receptor (DER) regulators suggest that Chmp1 negatively regulates DER signaling. Chmp1 knockdown also decreases Blistered expression, which is repressed by DER signaling. We find that Chmp1 protein localizes to the late endosome in Drosophila embryos, which is consistent with its effects on DER signaling resulting from its function in the ESCRT-III complex. CONCLUSIONS Drosophila Chmp1 negatively regulates DER signaling, likely through its role in MVB formation. Loss of Chmp1 activity in the Drosophila wing induces a cell fate change from intervein to vein that should provide a useful tool for future studies of ESCRT protein activity.
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Affiliation(s)
- Meagan Valentine
- Department of Biomedical Sciences, Marshall University, Huntington, West Virginia
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Abenza JF, Galindo A, Pinar M, Pantazopoulou A, de los Ríos V, Peñalva MA. Endosomal maturation by Rab conversion in Aspergillus nidulans is coupled to dynein-mediated basipetal movement. Mol Biol Cell 2012; 23:1889-901. [PMID: 22456509 PMCID: PMC3350553 DOI: 10.1091/mbc.e11-11-0925] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Highly motile fungal early endosomes can be easily distinguished from more static late endosomes and vacuoles, a feature that is exploited to study endosomal maturation. RabA/RabB early endosomes mature into RabSRab7 late endosomes as they move away from the tip where endocytosis predominates, augmenting their size, with concomitant loss of motility. We exploit the ease with which highly motile early endosomes are distinguished from static late endosomes in order to study Aspergillus nidulans endosomal traffic. RabSRab7 mediates homotypic fusion of late endosomes/vacuoles in a homotypic fusion- and vacuole protein sorting/Vps41–dependent manner. Progression across the endocytic pathway involves endosomal maturation because the end products of the pathway in the absence of RabSRab7 are minivacuoles that are competent in multivesicular body sorting and cargo degradation but retain early endosomal features, such as the ability to undergo long-distance movement and propensity to accumulate in the tip region if dynein function is impaired. Without RabSRab7, early endosomal Rab5s—RabA and RabB—reach minivacuoles, in agreement with the view that Rab7 homologues facilitate the release of Rab5 homologues from endosomes. RabSRab7 is recruited to membranes already at the stage of late endosomes still lacking vacuolar morphology, but the transition between early and late endosomes is sharp, as only in a minor proportion of examples are RabA/RabB and RabSRab7 detectable in the same—frequently the less motile—structures. This early-to-late endosome/vacuole transition is coupled to dynein-dependent movement away from the tip, resembling the periphery-to-center traffic of endosomes accompanying mammalian cell endosomal maturation. Genetic studies establish that endosomal maturation is essential, whereas homotypic vacuolar fusion is not.
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Affiliation(s)
- Juan F Abenza
- Departamento de Medicina Molecular y Celular, Centro de Investigaciones Biológicas del Consejo Superior de Investigaciones Cientificas, 28040 Madrid, Spain
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Galindo A, Calcagno-Pizarelli AM, Arst HN, Peñalva MÁ. An ordered pathway for the assembly of fungal ESCRT-containing ambient pH signalling complexes at the plasma membrane. J Cell Sci 2012; 125:1784-95. [PMID: 22344261 PMCID: PMC3346829 DOI: 10.1242/jcs.098897] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The fungal pal/RIM signalling pathway, which regulates gene expression in response to environmental pH involves, in addition to dedicated proteins, several components of ESCRT complexes, which suggested that pH signalling proteins assemble on endosomal platforms. In Aspergillus nidulans, dedicated Pal proteins include the plasma membrane receptor PalH and its coupled arrestin, PalF, which becomes ubiquitylated in alkaline pH conditions, and three potentially endosomal ESCRT-III associates, including Vps32 interactors PalA and PalC and Vps24 interactor calpain-like PalB. We studied the subcellular locations at which signalling takes place after activating the pathway by shifting ambient pH to alkalinity. Rather than localising to endosomes, Vps32 interactors PalA and PalC transiently colocalise at alkaline-pH-induced cortical structures in a PalH-, Vps23- and Vps32-dependent but Vps27-independent manner. These cortical structures are much more stable when Vps4 is deficient, indicating that their half-life depends on ESCRT-III disassembly. Pull-down studies revealed that Vps23 interacts strongly with PalF, but co-immunoprecipitates exclusively with ubiquitylated PalF forms from extracts. We demonstrate that Vps23-GFP, expressed at physiological levels, is also recruited to cortical structures, very conspicuous in vps27Δ cells in which the prominent signal of Vps23-GFP on endosomes is eliminated, in a PalF- and alkaline pH-dependent manner. Dual-channel epifluorescence microscopy showed that PalC arrives at cortical complexes before PalA. As PalC recruitment is PalA independent and PalA recruitment is PalC dependent but PalB independent, these data complete the participation order of Pal proteins in the pathway and strongly support a model in which pH signalling takes place in ESCRT-containing, plasma-membrane-associated, rather than endosome-associated, complexes.
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Affiliation(s)
- Antonio Galindo
- Department of Molecular Medicine, Centro de Investigaciones Biológicas CSIC, Madrid, Spain
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Peñalva MA, Galindo A, Abenza JF, Pinar M, Calcagno-Pizarelli AM, Arst Jr HN, Pantazopoulou A. Searching for gold beyond mitosis: Mining intracellular membrane traffic in Aspergillus nidulans. CELLULAR LOGISTICS 2012; 2:2-14. [PMID: 22645705 PMCID: PMC3355971 DOI: 10.4161/cl.19304] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/03/2011] [Revised: 01/09/2012] [Accepted: 01/09/2012] [Indexed: 12/29/2022]
Abstract
The genetically tractable filamentous ascomycete fungus Aspergillus nidulans has been successfully exploited to gain major insight into the eukaryotic cell cycle. More recently, its amenability to in vivo multidimensional microscopy has fueled a potentially gilded second age of A. nidulans cell biology studies. This review specifically deals with studies on intracellular membrane traffic in A. nidulans. The cellular logistics are subordinated to the needs imposed by the polarized mode of growth of the multinucleated hyphal tip cells, whereas membrane traffic is adapted to the large intracellular distances. Recent work illustrates the usefulness of this fungus for morphological and biochemical studies on endosome and Golgi maturation, and on the role of microtubule-dependent motors in the long-distance movement of endosomes. The fungus is ideally suited for genetic studies on the secretory pathway, as mutations impairing secretion reduce apical extension rates, resulting in phenotypes detectable by visual inspection of colonies.
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Affiliation(s)
- Miguel A. Peñalva
- Departamento de Medicina Molecular; Centro de Investigaciones Biológicas CSIC; Madrid, Spain
| | - Antonio Galindo
- Departamento de Medicina Molecular; Centro de Investigaciones Biológicas CSIC; Madrid, Spain
| | - Juan F. Abenza
- Departamento de Medicina Molecular; Centro de Investigaciones Biológicas CSIC; Madrid, Spain
| | - Mario Pinar
- Departamento de Medicina Molecular; Centro de Investigaciones Biológicas CSIC; Madrid, Spain
| | | | | | - Areti Pantazopoulou
- Departamento de Medicina Molecular; Centro de Investigaciones Biológicas CSIC; Madrid, Spain
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Calcagno-Pizarelli AM, Hervás-Aguilar A, Galindo A, Abenza JF, Peñalva MA, Arst HN. Rescue of Aspergillus nidulans severely debilitating null mutations in ESCRT-0, I, II and III genes by inactivation of a salt-tolerance pathway allows examination of ESCRT gene roles in pH signalling. J Cell Sci 2011; 124:4064-76. [PMID: 22135362 PMCID: PMC3244986 DOI: 10.1242/jcs.088344] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The Aspergillus pal pathway hijacks ESCRT proteins into ambient pH signalling complexes. We show that components of ESCRT-0, ESCRT-I, ESCRT-II and ESCRT-III are nearly essential for growth, precluding assessment of null mutants for pH signalling or trafficking. This severely debilitating effect is rescued by loss-of-function mutations in two cation tolerance genes, one of which, sltA, encodes a transcription factor whose inactivation promotes hypervacuolation. Exploiting a conditional expression sltA allele, we demonstrate that deletion of vps27 (ESCRT-0), vps23 (ESCRT-I), vps36 (ESCRT-II), or vps20 or vps32 (both ESCRT-III) leads to numerous small vacuoles, a phenotype also suppressed by SltA downregulation. This situation contrasts with normal vacuoles and vacuole-associated class E compartments seen in Saccharomyces cerevisiae ESCRT null mutants. Exploiting the suppressor phenotype of sltA− mutations, we establish that Vps23, Vps36, Vps20 and Vps32 are essential for pH signalling. Phosphatidylinositol 3-phosphate-recognising protein Vps27 (ESCRT-0) is not, consistent with normal pH signalling in rabB null mutants unable to recruit Vps34 kinase to early endosomes. In contrast to the lack of pH signalling in the absence of Vps20 or Vps32, detectable signalling occurs in the absence of ESCRT-III subunit Vps24. Our data support a model in which certain ESCRT proteins are recruited to the plasma membrane to mediate pH signalling.
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Affiliation(s)
- Ana M Calcagno-Pizarelli
- Section of Microbiology, Imperial College London, Flowers Building, Armstrong Road, London SW7 2AZ, UK
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Peñalva MÁ. Endocytosis in filamentous fungi: Cinderella gets her reward. Curr Opin Microbiol 2010; 13:684-92. [PMID: 20920884 DOI: 10.1016/j.mib.2010.09.005] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2010] [Revised: 09/07/2010] [Accepted: 09/08/2010] [Indexed: 12/27/2022]
Abstract
Endocytosis has been the Cinderella of membrane trafficking studies in filamentous fungi until recent work involving genetically tractable models has boosted interest in the field. Endocytic internalization predominates in the hyphal tips, spatially coupled to secretion. Early endosomes (EEs) show characteristic long-distance motility, riding on microtubule motors. The fungal tip contains a region baptised the 'dynein loading zone' where acropetally moving endosomes reaching the tip shift from a kinesin to dynein, reversing the direction of their movement. Multivesicular body biogenesis starts from these motile EEs. Maturation of EEs into late endosomes and vacuoles appears to be essential. The similarities between fungal and mammalian endocytic trafficking suggest that conditional mutant genetic screens would yield valuable information.
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Affiliation(s)
- Miguel Ángel Peñalva
- Department of Molecular and Cellular Medicine, Centro de Investigaciones Biológicas del CSIC, Ramiro de Maeztu 9, Madrid 28040, Spain.
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Endocytic machinery protein SlaB is dispensable for polarity establishment but necessary for polarity maintenance in hyphal tip cells of Aspergillus nidulans. EUKARYOTIC CELL 2010; 9:1504-18. [PMID: 20693304 DOI: 10.1128/ec.00119-10] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The Aspergillus nidulans endocytic internalization protein SlaB is essential, in agreement with the key role in apical extension attributed to endocytosis. We constructed, by gene replacement, a nitrate-inducible, ammonium-repressible slaB1 allele for conditional SlaB expression. Video microscopy showed that repressed slaB1 cells are able to establish but unable to maintain a stable polarity axis, arresting growth with budding-yeast-like morphology shortly after initially normal germ tube emergence. Using green fluorescent protein (GFP)-tagged secretory v-SNARE SynA, which continuously recycles to the plasma membrane after being efficiently endocytosed, we establish that SlaB is crucial for endocytosis, although it is dispensable for the anterograde traffic of SynA and of the t-SNARE Pep12 to the plasma and vacuolar membrane, respectively. By confocal microscopy, repressed slaB1 germlings show deep plasma membrane invaginations. Ammonium-to-nitrate medium shift experiments demonstrated reversibility of the null polarity maintenance phenotype and correlation of normal apical extension with resumption of SynA endocytosis. In contrast, SlaB downregulation in hyphae that had progressed far beyond germ tube emergence led to marked polarity maintenance defects correlating with deficient SynA endocytosis. Thus, the strict correlation between abolishment of endocytosis and disability of polarity maintenance that we report here supports the view that hyphal growth requires coupling of secretion and endocytosis. However, downregulated slaB1 cells form F-actin clumps containing the actin-binding protein AbpA, and thus F-actin misregulation cannot be completely disregarded as a possible contributor to defective apical extension. Latrunculin B treatment of SlaB-downregulated tips reduced the formation of AbpA clumps without promoting growth and revealed the formation of cortical "comets" of AbpA.
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