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Small GTPase FoSec4-Mediated Protein Secretion Is Important for Polarized Growth, Reproduction and Pathogenicity in the Banana Fusarium Wilt Fungus Fusarium odoratissimum. J Fungi (Basel) 2022; 8:jof8080880. [PMID: 36012867 PMCID: PMC9410047 DOI: 10.3390/jof8080880] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2022] [Revised: 08/15/2022] [Accepted: 08/17/2022] [Indexed: 11/18/2022] Open
Abstract
Apical secretion at hyphal tips is important for the growth and development of filamentous fungi. In this study, we analyzed the role of the Rab GTPases FoSec4 involved in the secretion of the banana wilt fungal pathogen Fusarium odoratissimum. We found that the deletion of FoSEC4 affects the activity of extracellular hydrolases and protein secretion, indicating that FoSec4 plays an important role in the regulation of protein secretion in F. odoratissimum. As a typical Rab GTPase, Sec4 participates in the Rab cycle through the conversion between the active GTP-bound state and the inactive GDP-bound state, which is regulated by guanine nucleate exchange factors (GEFs) and GTPase-activating proteins (GAPs). We further found that FoSec2 can interact with dominant-negative FoSec4 (GDP-bound and nucleotide-free form, FoSec4DN), and that FoGyp5 can interact with dominant active FoSec4 (GTP-bound and constitutively active form, FoSec4CA). We evaluated the biofunctions of FoSec4, FoSec2 and FoGyp5, and found that FoSec4 is involved in the regulation of vegetative growth, reproduction, pathogenicity and the environmental stress response of F. odoratissimum, and that FocSec2 and FoGyp5 perform biofunctions consistent with FoSec4, indicating that FoSec2 and FoGyp5 may work as the GEF and the GAP, respectively, of FoSec4 in F. odoratissimum. We further found that the amino-terminal region and Sec2 domain are essential for the biological functions of FoSec2, while the carboxyl-terminal region and Tre-2/Bub2/Cdc16 (TBC) domain are essential for the biological functions of FoGyp5. In addition, FoSec4 mainly accumulated at the hyphal tips and partially colocalized with Spitzenkörper; however, FoGyp5 accumulated at the periphery of Spitzenkörper, suggesting that FoGyp5 may recognize and inactivate FoSec4 at a specific location in hyphal tips.
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Zheng H, Li L, Yu Z, Yuan Y, Zheng Q, Xie Q, Li G, Abubakar YS, Zhou J, Wang Z, Zheng W. FgSpa2 recruits FgMsb3, a Rab8 GAP, to the polarisome to regulate polarized trafficking, growth and pathogenicity in Fusarium graminearum. THE NEW PHYTOLOGIST 2021; 229:1665-1683. [PMID: 32978966 DOI: 10.1111/nph.16935] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Accepted: 09/01/2020] [Indexed: 06/11/2023]
Abstract
In filamentous fungi, hyphal growth depends on the continuous delivery of vesicles to the growing tips. It is unclear how fast-growing hyphae coordinate simultaneous cell extension and expansion in the tip cells. We have functionally characterized 12 TBC (Tre-2/Bub2/Cdc16) domain-containing proteins in Fusarium graminearum. Among them, FgMsb3 is found to regulate hyphal tip expansion and to be required for pathogenicity. The regulatory mechanism of FgMsb3 has been further investigated by genetic, high-resolution microscopy and high-throughput co-immunoprecipitation strategies. The FgMsb3 protein localizes at the polarisome and the hyphal apical dome (HAD) where it acts as a GTPase-activating protein for FgRab8 which is required for apical secretion-mediated growth and pathogenicity. Deletion of FgMSB3 causes excessive polarized trafficking but blocks the fusion of FgSnc1-associated vesicles to the plasma membrane. Moreover, we establish that FgSpa2 interacts with FgMsb3, enabling FgMsb3 tethering to the polarisome. Loss of FgSpa2 or other polarisome components (FgBud6 and FgPea2) causes complete shifting of FgMsb3 to the HAD and this affects the polarized growth and pathogenicity of the fungus. In summary, we conclude that FgSpa2 regulates FgMsb3-FgRab8 cascade and this is crucial for creating a steady-state equilibrium that maintains continuous polarized growth and contributes to the pathogenicity of F. graminearum.
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Affiliation(s)
- Huawei Zheng
- Marine and Agricultural Biotechnology Laboratory, Institute of Oceanography, Minjiang University, Fuzhou, 350108, China
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Lingping Li
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Zhi Yu
- Marine and Agricultural Biotechnology Laboratory, Institute of Oceanography, Minjiang University, Fuzhou, 350108, China
- Fujian Province Key Laboratory of Pathogenic Fungi and Mycotoxins, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Yanping Yuan
- Fujian Province Key Laboratory of Pathogenic Fungi and Mycotoxins, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Qiaojia Zheng
- Marine and Agricultural Biotechnology Laboratory, Institute of Oceanography, Minjiang University, Fuzhou, 350108, China
| | - Qiurong Xie
- Fujian Key Laboratory of Integrative Medicine on Geriatric, Academy of Integrative Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, 350122, China
| | - Guangpu Li
- Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA
| | - Yakubu Saddeeq Abubakar
- Department of Biochemistry, Faculty of Life Sciences, Ahmadu Bello University, Zaria, 810211, Nigeria
| | - Jie Zhou
- Fujian Province Key Laboratory of Pathogenic Fungi and Mycotoxins, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Zonghua Wang
- Marine and Agricultural Biotechnology Laboratory, Institute of Oceanography, Minjiang University, Fuzhou, 350108, China
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
- Fujian Province Key Laboratory of Pathogenic Fungi and Mycotoxins, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Wenhui Zheng
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
- Fujian Province Key Laboratory of Pathogenic Fungi and Mycotoxins, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
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Prigent M, Chaillot J, Tisserand H, Boy-Marcotte E, Cuif MH. Three members of the yeast N-BAR proteins family form heterogeneous lattices in vivo and interact differentially with two RabGAP proteins. Sci Rep 2020; 10:1698. [PMID: 32015451 PMCID: PMC6997364 DOI: 10.1038/s41598-020-58606-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Accepted: 01/08/2020] [Indexed: 11/26/2022] Open
Abstract
The yeast N-BAR (Bin/Amphiphysin/Rvs167) protein Rvs167 is recruited by the Rab GTPase Activating Proteins (RabGAP) Gyp5 and Gyl1 to the tip of small buds to act in exocytosis. Investigating other N-BAR proteins involved in Gyp5/Gyl1/Rvs167 complexes, we found that Rvs161, an Rvs167 paralog, is absent from the complexes formed at the tip of small buds. Immunoprecipitation and Bimolecular Fluorescence Complementation (BiFC) analysis show that both Rvs167 and Rvs161 interact in vivo with Gvp36, an N-BAR protein. Rvs167 molecules also interact independently of Rvs161 and Gvp36. Rvs167/Rvs167 and Rvs167/Gyp5 interactions predominate over other combinations at the tip of small buds, suggesting that N-BAR lattices enriched in Rvs167 molecules form at these sites. By combining BiFC with markers specific to each organelle, we analyzed systematically in living cells the locations of the BiFC signals generated by combinations of the three N-BAR proteins. We show that the BiFC signals differ according to organelle and cell site, strongly suggesting heterogeneity in the composition of N-BAR protein lattices in vivo. Our results reveal that the organization of N-BAR protein lattices in vivo is complex and are consistent with N-BAR proteins forming various types of dimers and lattices of variable composition.
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Affiliation(s)
- Magali Prigent
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198, Gif-sur-Yvette, France
| | - Julien Chaillot
- Institut sur la Nutrition et les Aliments Fonctionnels (INAF), Université Laval, 2440 Boulevard Hochelaga, Québec, QC, G1V 0A6, Canada
| | - Hélène Tisserand
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198, Gif-sur-Yvette, France
| | - Emmanuelle Boy-Marcotte
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198, Gif-sur-Yvette, France
| | - Marie-Hélène Cuif
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198, Gif-sur-Yvette, France.
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The Rab GTPase activating protein Gyp2 contributes to UV stress tolerance in Metarhizium acridum. World J Microbiol Biotechnol 2018; 34:78. [DOI: 10.1007/s11274-018-2457-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Accepted: 05/19/2018] [Indexed: 01/26/2023]
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Requirement of Phosphoinositides Containing Stearic Acid To Control Cell Polarity. Mol Cell Biol 2015; 36:765-80. [PMID: 26711260 DOI: 10.1128/mcb.00843-15] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Accepted: 12/14/2015] [Indexed: 02/04/2023] Open
Abstract
Phosphoinositides (PIPs) are present in very small amounts but are essential for cell signaling, morphogenesis, and polarity. By mass spectrometry, we demonstrated that some PIPs with stearic acyl chains were strongly disturbed in a psi1Δ Saccharomyces cerevisiae yeast strain deficient in the specific incorporation of a stearoyl chain at the sn-1 position of phosphatidylinositol. The absence of PIPs containing stearic acid induced disturbances in intracellular trafficking, although the total amount of PIPs was not diminished. Changes in PIPs also induced alterations in the budding pattern and defects in actin cytoskeleton organization (cables and patches). Moreover, when the PSI1 gene was impaired, a high proportion of cells with bipolar cortical actin patches that occurred concomitantly with the bipolar localization of Cdc42p was specifically found among diploid cells. This bipolar cortical actin phenotype, never previously described, was also detected in a bud9Δ/bud9Δ strain. Very interestingly, overexpression of PSI1 reversed this phenotype.
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Jose M, Tollis S, Nair D, Mitteau R, Velours C, Massoni-Laporte A, Royou A, Sibarita JB, McCusker D. A quantitative imaging-based screen reveals the exocyst as a network hub connecting endocytosis and exocytosis. Mol Biol Cell 2015; 26:2519-34. [PMID: 25947137 PMCID: PMC4571305 DOI: 10.1091/mbc.e14-11-1527] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2014] [Accepted: 04/29/2015] [Indexed: 12/15/2022] Open
Abstract
The mechanisms governing the spatial organization of endocytosis and exocytosis are ill defined. A quantitative imaging screen and high-density single-vesicle tracking are used to identify mutants that are defective in endocytic and exocytic vesicle organization. The screen identifies a role for the exocyst complex in connecting the two pathways. The coupling of endocytosis and exocytosis underlies fundamental biological processes ranging from fertilization to neuronal activity and cellular polarity. However, the mechanisms governing the spatial organization of endocytosis and exocytosis require clarification. Using a quantitative imaging-based screen in budding yeast, we identified 89 mutants displaying defects in the localization of either one or both pathways. High-resolution single-vesicle tracking revealed that the endocytic and exocytic mutants she4∆ and bud6∆ alter post-Golgi vesicle dynamics in opposite ways. The endocytic and exocytic pathways display strong interdependence during polarity establishment while being more independent during polarity maintenance. Systems analysis identified the exocyst complex as a key network hub, rich in genetic interactions with endocytic and exocytic components. Exocyst mutants displayed altered endocytic and post-Golgi vesicle dynamics and interspersed endocytic and exocytic domains compared with control cells. These data are consistent with an important role for the exocyst in coordinating endocytosis and exocytosis.
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Affiliation(s)
- Mini Jose
- Dynamics of Cell Growth and Division, European Institute of Chemistry and Biology, F-33607 Bordeaux, France Institut de Biochimie et Génétique Cellulaires, CNRS UMR 5095, Université Bordeaux, F-33000 Bordeaux, France Centre for Neuroscience, Indian Institute of Science, Bangalore 560012, India
| | - Sylvain Tollis
- Dynamics of Cell Growth and Division, European Institute of Chemistry and Biology, F-33607 Bordeaux, France Institut de Biochimie et Génétique Cellulaires, CNRS UMR 5095, Université Bordeaux, F-33000 Bordeaux, France
| | - Deepak Nair
- Centre for Neuroscience, Indian Institute of Science, Bangalore 560012, India Institut Interdisciplinaire de Neurosciences, CNRS UMR 5297, Université Bordeaux, F-33000 Bordeaux, France
| | - Romain Mitteau
- Dynamics of Cell Growth and Division, European Institute of Chemistry and Biology, F-33607 Bordeaux, France Institut de Biochimie et Génétique Cellulaires, CNRS UMR 5095, Université Bordeaux, F-33000 Bordeaux, France
| | - Christophe Velours
- Dynamics of Cell Growth and Division, European Institute of Chemistry and Biology, F-33607 Bordeaux, France Institut de Biochimie et Génétique Cellulaires, CNRS UMR 5095, Université Bordeaux, F-33000 Bordeaux, France
| | - Aurelie Massoni-Laporte
- Dynamics of Cell Growth and Division, European Institute of Chemistry and Biology, F-33607 Bordeaux, France Institut de Biochimie et Génétique Cellulaires, CNRS UMR 5095, Université Bordeaux, F-33000 Bordeaux, France
| | - Anne Royou
- Institut de Biochimie et Génétique Cellulaires, CNRS UMR 5095, Université Bordeaux, F-33000 Bordeaux, France Institut de Biochimie et Génétique Cellulaires, CNRS UMR 5095, Université Bordeaux, F-33000 Bordeaux, France
| | - Jean-Baptiste Sibarita
- Institut Interdisciplinaire de Neurosciences, CNRS UMR 5297, Université Bordeaux, F-33000 Bordeaux, France
| | - Derek McCusker
- Dynamics of Cell Growth and Division, European Institute of Chemistry and Biology, F-33607 Bordeaux, France Institut de Biochimie et Génétique Cellulaires, CNRS UMR 5095, Université Bordeaux, F-33000 Bordeaux, France
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Ruiz-Vázquez RM, Nicolás FE, Torres-Martínez S, Garre V. Distinct RNAi Pathways in the Regulation of Physiology and Development in the Fungus Mucor circinelloides. ADVANCES IN GENETICS 2015; 91:55-102. [DOI: 10.1016/bs.adgen.2015.07.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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8
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Glycolysis controls plasma membrane glucose sensors to promote glucose signaling in yeasts. Mol Cell Biol 2014; 35:747-57. [PMID: 25512610 DOI: 10.1128/mcb.00515-14] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Sensing of extracellular glucose is necessary for cells to adapt to glucose variation in their environment. In the respiratory yeast Kluyveromyces lactis, extracellular glucose controls the expression of major glucose permease gene RAG1 through a cascade similar to the Saccharomyces cerevisiae Snf3/Rgt2/Rgt1 glucose signaling pathway. This regulation depends also on intracellular glucose metabolism since we previously showed that glucose induction of the RAG1 gene is abolished in glycolytic mutants. Here we show that glycolysis regulates RAG1 expression through the K. lactis Rgt1 (KlRgt1) glucose signaling pathway by targeting the localization and probably the stability of Rag4, the single Snf3/Rgt2-type glucose sensor of K. lactis. Additionally, the control exerted by glycolysis on glucose signaling seems to be conserved in S. cerevisiae. This retrocontrol might prevent yeasts from unnecessary glucose transport and intracellular glucose accumulation.
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Secretory pathway-dependent localization of the Saccharomyces cerevisiae Rho GTPase-activating protein Rgd1p at growth sites. EUKARYOTIC CELL 2012; 11:590-600. [PMID: 22447923 DOI: 10.1128/ec.00042-12] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Establishment and maintenance of cell polarity in eukaryotes depends upon the regulation of Rho GTPases. In Saccharomyces cerevisiae, the Rho GTPase activating protein (RhoGAP) Rgd1p stimulates the GTPase activities of Rho3p and Rho4p, which are involved in bud growth and cytokinesis, respectively. Consistent with the distribution of Rho3p and Rho4p, Rgd1p is found mostly in areas of polarized growth during cell cycle progression. Rgd1p was mislocalized in mutants specifically altered for Golgi apparatus-based phosphatidylinositol 4-P [PtdIns(4)P] synthesis and for PtdIns(4,5)P(2) production at the plasma membrane. Analysis of Rgd1p distribution in different membrane-trafficking mutants suggested that Rgd1p was delivered to growth sites via the secretory pathway. Rgd1p may associate with post-Golgi vesicles by binding to PtdIns(4)P and then be transported by secretory vesicles to the plasma membrane. In agreement, we show that Rgd1p coimmunoprecipitated and localized with markers specific to secretory vesicles and cofractionated with a plasma membrane marker. Moreover, in vivo imaging revealed that Rgd1p was transported in an anterograde manner from the mother cell to the daughter cell in a vectoral manner. Our data indicate that secretory vesicles are involved in the delivery of RhoGAP Rgd1p to the bud tip and bud neck.
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Prigent M, Boy-Marcotte E, Chesneau L, Gibson K, Dupré-Crochet S, Tisserand H, Verbavatz JM, Cuif MH. The RabGAP proteins Gyp5p and Gyl1p recruit the BAR domain protein Rvs167p for polarized exocytosis. Traffic 2011; 12:1084-97. [PMID: 21554509 DOI: 10.1111/j.1600-0854.2011.01218.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The Rab GTPase-activating proteins (GAP) Gyp5p and Gyl1p are involved in the control of polarized exocytosis at the small-bud stage in Saccharomyces cerevisiae. Both Gyp5p and Gyl1p interact with the N-Bin1/Amphiphysin/Rvs167 (BAR) domain protein Rvs167p, but the biological function of this interaction is unclear. We show here that Gyp5p and Gyl1p recruit Rvs167p to the small-bud tip, where it plays a role in polarized exocytosis. In gyp5Δgyl1Δ cells, Rvs167p is not correctly localized to the small-bud tip. Both P473L mutation in the SH3 domain of Rvs167p and deletion of the proline-rich regions of Gyp5p and Gyl1p disrupt the interaction of Rvs167p with Gyp5p and Gyl1p and impair the localization of Rvs167p to the tips of small buds. We provide evidence for the accumulation of secretory vesicles in small buds of rvs167Δ cells and for defective Bgl2p secretion in rvs167Δ cultures enriched in small-budded cells at 13°C, implicating Rvs167p in polarized exocytosis. Moreover, both the accumulation of secretory vesicles in Rvs167p P473L cells cultured at 13°C and secretion defects in cells producing Gyp5p and Gyl1p without proline-rich regions strongly suggest that the function of Rvs167p in exocytosis depends on its ability to interact with Gyp5p and Gyl1p.
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Affiliation(s)
- Magali Prigent
- Univ Paris-Sud, Institut de Génétique et Microbiologie, CNRS UMR8621, Bâtiment 400, Orsay F-91405, France
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Barr F, Lambright DG. Rab GEFs and GAPs. Curr Opin Cell Biol 2010; 22:461-70. [PMID: 20466531 PMCID: PMC2929657 DOI: 10.1016/j.ceb.2010.04.007] [Citation(s) in RCA: 339] [Impact Index Per Article: 24.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2010] [Revised: 04/05/2010] [Accepted: 04/16/2010] [Indexed: 10/19/2022]
Abstract
Rabs are GTP-binding proteins with conserved functions in membrane trafficking. They are regulated by a diverse group of structurally unrelated GDP-GTP exchange factors (GEFs), and a family of GTP-hydrolysis activating proteins (GAPs) containing the conserved TBC domain. Recent structural and cell biological studies shed new light on the mechanisms of Rab GEF and GAP action, and the cellular trafficking pathways they act in.
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Affiliation(s)
- Francis Barr
- University of Liverpool, Cancer Research Centre, 200 London Road, Liverpool L3 9TA, UK
| | - David G. Lambright
- Program in Molecular Medicine and Department of Biochemistry & Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA 01605
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Nicolas FE, Moxon S, de Haro JP, Calo S, Grigoriev IV, Torres-Martínez S, Moulton V, Ruiz-Vázquez RM, Dalmay T. Endogenous short RNAs generated by Dicer 2 and RNA-dependent RNA polymerase 1 regulate mRNAs in the basal fungus Mucor circinelloides. Nucleic Acids Res 2010; 38:5535-41. [PMID: 20427422 PMCID: PMC2938224 DOI: 10.1093/nar/gkq301] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Endogenous short RNAs (esRNAs) play diverse roles in eukaryotes and usually are produced from double-stranded RNA (dsRNA) by Dicer. esRNAs are grouped into different classes based on biogenesis and function but not all classes are present in all three eukaryotic kingdoms. The esRNA register of fungi is poorly described compared to other eukaryotes and it is not clear what esRNA classes are present in this kingdom and whether they regulate the expression of protein coding genes. However, evidence that some dicer mutant fungi display altered phenotypes suggests that esRNAs play an important role in fungi. Here, we show that the basal fungus Mucor circinelloides produces new classes of esRNAs that map to exons and regulate the expression of many protein coding genes. The largest class of these exonic-siRNAs (ex-siRNAs) are generated by RNA-dependent RNA Polymerase 1 (RdRP1) and dicer-like 2 (DCL2) and target the mRNAs of protein coding genes from which they were produced. Our results expand the range of esRNAs in eukaryotes and reveal a new role for esRNAs in fungi.
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Chesneau L, Prigent M, Boy-Marcotte E, Daraspe J, Fortier G, Jacquet M, Verbavatz JM, Cuif MH. Interdependence of the Ypt/RabGAP Gyp5p and Gyl1p for Recruitment to the Sites of Polarized Growth. Traffic 2008; 9:608-22. [DOI: 10.1111/j.1600-0854.2007.00699.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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14
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Swennen D, Beckerich JM. Yarrowia lipolytica vesicle-mediated protein transport pathways. BMC Evol Biol 2007; 7:219. [PMID: 17997821 PMCID: PMC2241642 DOI: 10.1186/1471-2148-7-219] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2007] [Accepted: 11/12/2007] [Indexed: 02/02/2023] Open
Abstract
BACKGROUND Protein secretion is a universal cellular process involving vesicles which bud and fuse between organelles to bring proteins to their final destination. Vesicle budding is mediated by protein coats; vesicle targeting and fusion depend on Rab GTPase, tethering factors and SNARE complexes. The Génolevures II sequencing project made available entire genome sequences of four hemiascomycetous yeasts, Yarrowia lipolytica, Debaryomyces hansenii, Kluyveromyces lactis and Candida glabrata. Y. lipolytica is a dimorphic yeast and has good capacities to secrete proteins. The translocation of nascent protein through the endoplasmic reticulum membrane was well studied in Y. lipolytica and is largely co-translational as in the mammalian protein secretion pathway. RESULTS We identified S. cerevisiae proteins involved in vesicular secretion and these protein sequences were used for the BLAST searches against Génolevures protein database (Y. lipolytica, C. glabrata, K. lactis and D. hansenii). These proteins are well conserved between these yeasts and Saccharomyces cerevisiae. We note several specificities of Y. lipolytica which may be related to its good protein secretion capacities and to its dimorphic aspect. An expansion of the Y. lipolytica Rab protein family was observed with autoBLAST and the Rab2- and Rab4-related members were identified with BLAST against NCBI protein database. An expansion of this family is also found in filamentous fungi and may reflect the greater complexity of the Y. lipolytica secretion pathway. The Rab4p-related protein may play a role in membrane recycling as rab4 deleted strain shows a modification of colony morphology, dimorphic transition and permeability. Similarly, we find three copies of the gene (SSO) encoding the plasma membrane SNARE protein. Quantification of the percentages of proteins with the greatest homology between S. cerevisiae, Y. lipolytica and animal homologues involved in vesicular transport shows that 40% of Y. lipolytica proteins are closer to animal ones, whereas they are only 13% in the case of S. cerevisiae. CONCLUSION These results provide further support for the idea, previously noted about the endoplasmic reticulum translocation pathway, that Y. lipolytica is more representative of vesicular secretion of animals and other fungi than is S. cerevisiae.
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Affiliation(s)
- Dominique Swennen
- Laboratoire de Microbiologie et Génétique Moléculaire INRA-CNRS-AgroParisTech UMR 1238 CBAI BP01 F-78850 Thiverval Grignon, France.
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Ren G, Vajjhala P, Lee JS, Winsor B, Munn AL. The BAR domain proteins: molding membranes in fission, fusion, and phagy. Microbiol Mol Biol Rev 2006; 70:37-120. [PMID: 16524918 PMCID: PMC1393252 DOI: 10.1128/mmbr.70.1.37-120.2006] [Citation(s) in RCA: 147] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
The Bin1/amphiphysin/Rvs167 (BAR) domain proteins are a ubiquitous protein family. Genes encoding members of this family have not yet been found in the genomes of prokaryotes, but within eukaryotes, BAR domain proteins are found universally from unicellular eukaryotes such as yeast through to plants, insects, and vertebrates. BAR domain proteins share an N-terminal BAR domain with a high propensity to adopt alpha-helical structure and engage in coiled-coil interactions with other proteins. BAR domain proteins are implicated in processes as fundamental and diverse as fission of synaptic vesicles, cell polarity, endocytosis, regulation of the actin cytoskeleton, transcriptional repression, cell-cell fusion, signal transduction, apoptosis, secretory vesicle fusion, excitation-contraction coupling, learning and memory, tissue differentiation, ion flux across membranes, and tumor suppression. What has been lacking is a molecular understanding of the role of the BAR domain protein in each process. The three-dimensional structure of the BAR domain has now been determined and valuable insight has been gained in understanding the interactions of BAR domains with membranes. The cellular roles of BAR domain proteins, characterized over the past decade in cells as distinct as yeasts, neurons, and myocytes, can now be understood in terms of a fundamental molecular function of all BAR domain proteins: to sense membrane curvature, to bind GTPases, and to mold a diversity of cellular membranes.
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Affiliation(s)
- Gang Ren
- Institute for Molecular Bioscience, University of Queensland, St. Lucia, Queensland 4072, Australia
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Friesen H, Humphries C, Ho Y, Schub O, Colwill K, Andrews B. Characterization of the yeast amphiphysins Rvs161p and Rvs167p reveals roles for the Rvs heterodimer in vivo. Mol Biol Cell 2006; 17:1306-21. [PMID: 16394103 PMCID: PMC1382319 DOI: 10.1091/mbc.e05-06-0476] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2005] [Revised: 12/13/2005] [Accepted: 12/27/2005] [Indexed: 11/11/2022] Open
Abstract
We have used comprehensive synthetic lethal screens and biochemical assays to examine the biological role of the yeast amphiphysin homologues Rvs161p and Rvs167p, two proteins that play a role in regulation of the actin cytoskeleton, endocytosis, and sporulation. We found that unlike some forms of amphiphysin, Rvs161p-Rvs167p acts as an obligate heterodimer during vegetative growth and neither Rvs161p nor Rvs167p forms a homodimer in vivo. RVS161 and RVS167 have an identical set of 49 synthetic lethal interactions, revealing functions for the Rvs proteins in cell polarity, cell wall synthesis, and vesicle trafficking as well as a shared role in mating. Consistent with these roles, we show that the Rvs167p-Rvs161p heterodimer, like its amphiphysin homologues, can bind to phospholipid membranes in vitro, suggesting a role in vesicle formation and/or fusion. Our genetic screens also reveal that the interaction between Abp1p and the Rvs167p Src homology 3 (SH3) domain may be important under certain conditions, providing the first genetic evidence for a role for the SH3 domain of Rvs167p. Our studies implicate heterodimerization of amphiphysin family proteins in various functions related to cell polarity, cell integrity, and vesicle trafficking during vegetative growth and the mating response.
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Affiliation(s)
- Helena Friesen
- Department of Medical Genetics and Microbiology, Banting and Best Department of Medical Research, University of Toronto, Toronto, Ontario, Canada M5S 1A8
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Zhang XM, Walsh B, Mitchell CA, Rowe T. TBC domain family, member 15 is a novel mammalian Rab GTPase-activating protein with substrate preference for Rab7. Biochem Biophys Res Commun 2005; 335:154-61. [PMID: 16055087 DOI: 10.1016/j.bbrc.2005.07.070] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2005] [Accepted: 07/12/2005] [Indexed: 10/25/2022]
Abstract
Ypt/Rabs are Ras-related GTPases that function as key regulators of intracellular vesicular trafficking. Their slow intrinsic rates of GTP hydrolysis are catalyzed by GTPase-activating proteins (GAPs). Ypt/Rab-GAPs constitute a family of proteins that contain a TBC (Tre-2/Bub2/Cdc16) domain. Only three of the 51 family members predicted in the human genome are confirmed Ypt/Rab-GAPs. Here, we report the identification and characterization of a novel mammalian Ypt/Rab-GAP, TBC domain family, member 15 (TBC1D15). TBC1D15 is ubiquitously expressed and localized predominantly to the cytosol. The TBC domain of TBC1D15 exhibits relatively high homology with that of Gyp7p, a yeast Ypt/Rab-GAP. Furthermore, TBC1D15 stimulates the intrinsic GTPase activity of Rab7, and to a lesser extent Rab11, but is essentially inactive towards Rab4 or Rab6. These data increase the number of mammalian TBC domain family members with demonstrated Rab-GAP activity to four, and suggest that TBC1D15 may be involved in Rab7-mediated late endosomal trafficking.
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Affiliation(s)
- Xiang-Ming Zhang
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, Vic. 3800, Australia
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Current awareness on yeast. Yeast 2005; 22:503-10. [PMID: 15918233 DOI: 10.1002/yea.1162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Friesen H, Colwill K, Robertson K, Schub O, Andrews B. Interaction of the Saccharomyces cerevisiae cortical actin patch protein Rvs167p with proteins involved in ER to Golgi vesicle trafficking. Genetics 2005; 170:555-68. [PMID: 15802519 PMCID: PMC1450407 DOI: 10.1534/genetics.104.040063] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
We have used affinity chromatography to identify two proteins that bind to the SH3 domain of the actin cytoskeleton protein Rvs167p: Gyp5p and Gyl1p. Gyp5p has been shown to be a GTPase activating protein (GAP) for Ypt1p, a Rab GTPase involved in ER to Golgi trafficking; Gyl1p is a protein that resembles Gyp5p and has recently been shown to colocalize with and belong to the same protein complex as Gyp5p. We show that Gyl1p and Gyp5p interact directly with each other, likely through their carboxy-terminal coiled-coil regions. In assays of GAP activity, Gyp5p had GAP activity toward Ypt1p and we found that this activity was stimulated by the addition of Gyl1p. Gyl1p had no GAP activity toward Ypt1p. Genetic experiments suggest a role for Gyp5p and Gyl1p in ER to Golgi trafficking, consistent with their biochemical role. Since Rvs167p has a previously characterized role in endocytosis and we have shown here that it interacts with proteins involved in Golgi vesicle trafficking, we suggest that Rvs167p may have a general role in vesicle trafficking.
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Affiliation(s)
- Helena Friesen
- Department of Molecular and Medical Genetics, University of Toronto, Ontario, Canada
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