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Hu G, Qu X, Bhalla K, Xue P, Bakkeren E, Lee CWJ, Kronstad JW. Loss of the putative Rab GTPase, Ypt7, impairs the virulence of Cryptococcus neoformans. Front Microbiol 2024; 15:1437579. [PMID: 39119141 PMCID: PMC11306161 DOI: 10.3389/fmicb.2024.1437579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2024] [Accepted: 07/16/2024] [Indexed: 08/10/2024] Open
Abstract
Small GTPases of the Rab family coordinate multiple membrane fusion and trafficking events in eukaryotes. In fungi, the Rab GTPase, Ypt7, plays a critical role in late endosomal trafficking, and is required for homotypic fusion events in vacuole biogenesis and inheritance. In this study, we identified a putative YPT7 homologue in Cryptococcus neoformans, a fungal pathogen causing life threatening meningoencephalitis in immunocompromised individuals. As part of an ongoing effort to understand mechanisms of iron acquisition in C. neoformans, we established a role for Ypt7 in growth on heme as the sole iron source. Deletion of YPT7 also caused abnormal vacuolar morphology, defective endocytic trafficking and autophagy, and mislocalization of Aph1, a secreted vacuolar acid phosphatase. Ypt7 localized to the vacuolar membrane and membrane contact sites between the vacuole and mitochondria (vCLAMPs), and loss of the protein impaired growth on inhibitors of the electron transport chain. Additionally, Ypt7 was required for robust growth at 39°C, a phenotype likely involving the calcineurin signaling pathway because ypt7 mutants displayed increased susceptibility to the calcineurin-specific inhibitors, FK506 and cyclosporin A; the mutants also had impaired growth in either limiting or high levels of calcium. Finally, Ypt7 was required for survival during interactions with macrophages, and ypt7 mutants were attenuated for virulence in a mouse inhalation model thus demonstrating the importance of membrane trafficking functions in cryptococcosis.
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Affiliation(s)
- Guanggan Hu
- The Michael Smith Laboratories, University of British Columbia, Vancouver, BC, Canada
| | - Xianya Qu
- The Michael Smith Laboratories, University of British Columbia, Vancouver, BC, Canada
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, BC, Canada
| | - Kabir Bhalla
- The Michael Smith Laboratories, University of British Columbia, Vancouver, BC, Canada
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, BC, Canada
| | - Peng Xue
- The Michael Smith Laboratories, University of British Columbia, Vancouver, BC, Canada
| | - Erik Bakkeren
- The Michael Smith Laboratories, University of British Columbia, Vancouver, BC, Canada
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, BC, Canada
| | - Christopher W. J. Lee
- The Michael Smith Laboratories, University of British Columbia, Vancouver, BC, Canada
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, BC, Canada
| | - James W. Kronstad
- The Michael Smith Laboratories, University of British Columbia, Vancouver, BC, Canada
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, BC, Canada
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Yan H, Zhou Z, Zhang H, Shim WB. Vacuole Proteins with Optimized Microtubule Assembly Is Required for Fum1 Protein Localization and Fumonisin Biosynthesis in Mycotoxigenic Fungus Fusarium verticillioides. J Fungi (Basel) 2023; 9:jof9020268. [PMID: 36836382 PMCID: PMC9961181 DOI: 10.3390/jof9020268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 02/09/2023] [Accepted: 02/13/2023] [Indexed: 02/19/2023] Open
Abstract
Fumonisin contamination of corn caused by Fusarium verticillioides is a major concern worldwide. While key genes involved in fumonisin biosynthesis are known, the location within the fungal cell where this process occurs has yet to be fully characterized. In this study, three key enzymes, i.e., Fum1, Fum8, and Fum6, associated with early steps of fumonisin biosynthesis pathway, were tagged with GFP, and we examined their cellular localization. Results showed that these three proteins co-localized with the vacuole. To further understand the role of the vacuole in fumonisin B1 (FB1) biosynthesis, we disrupted two predicted vacuole associated proteins, FvRab7 and FvVam7, resulting in a significant reduction of FB1 biosynthesis and a lack of Fum1-GFP fluorescence signal. Furthermore, we used the microtubule-targeting drug carbendazim to show that proper microtubule assembly is critical for proper Fum1 protein localization and FB1 biosynthesis. Additionally, we found that α1 tubulin is a negative regulator in FB1 biosynthesis. We concluded that vacuole proteins with optimized microtubule assembly play a crucial role in proper Fum1 protein localization and fumonisin production in F. verticillioides.
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Affiliation(s)
- Huijuan Yan
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, TX 77843, USA
| | - Zehua Zhou
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, TX 77843, USA
- College of Plant Protection & Hunan Provincial Key Laboratory for Biology and Control of Plant Diseases and Plant Pests, Hunan Agricultural University, Changsha 410128, China
| | - Huan Zhang
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, TX 77843, USA
- Correspondence: (H.Z.); (W.B.S.)
| | - Won Bo Shim
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, TX 77843, USA
- Correspondence: (H.Z.); (W.B.S.)
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Ferrara M, Perrone G, Gallo A. Recent advances in biosynthesis and regulatory mechanisms of principal mycotoxins. Curr Opin Food Sci 2022. [DOI: 10.1016/j.cofs.2022.100923] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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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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Zhou Z, Yan H, Kim MS, Shim WB. Distinct Function of Mediator Subunits in Fungal Development, Stress Response, and Secondary Metabolism in Maize Pathogen Fusarium verticillioides. PHYTOPATHOLOGY 2022; 112:1730-1738. [PMID: 35271780 DOI: 10.1094/phyto-12-21-0495-r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Mediator is a nucleus-localized, multisubunit protein complex highly conserved across eukaryotes. It interacts with RNA polymerase II transcription machinery as well as various transcription factors to regulate gene expression. However, systematic characterization of the Mediator complex has not been performed in filamentous fungi. In our study, the goal was to investigate key biological functions of Mediator subunits in a mycotoxigenic plant pathogen Fusarium verticillioides. Although there is some level of divergence in the constituent subunits, the overall structure was conserved between Saccharomyces cerevisiae and F. verticillioides. We generated 11 Mediator subunit deletion mutants and characterized vegetative growth, conidia formation, environmental stress response, carbon and fatty acid use, virulence, and fumonisin B1 (FB1) biosynthesis. Each Mediator subunit deletion mutant showed deficiencies in at least three of the phenotypes tested, suggesting that each subunit has different principal functions in F. verticillioides development, metabolism, and virulence. The deletion of FvMed1 led to increased FB1 production, and we confirmed that FvMed1 is transported from the nucleus to the cytoplasm under fumonisin-producing conditions. Taken together, our study characterized various important functional roles for Mediator subunits in F. verticillioides and suggests that select subunits can perform unique cytoplasmic functions independent of the core Mediator in fungal nucleus.
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Affiliation(s)
- Zehua Zhou
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, TX 77843, U.S.A
- Hunan Agricultural University, College of Plant Protection & Hunan Provincial Key Laboratory for Biology and Control of Plant Diseases and Plant Pests, Furong District, Changsha, Hunan 410128, China
| | - Huijuan Yan
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, TX 77843, U.S.A
- Department of Microbiology and Immunology, University of California at San Francisco, San Francisco, CA 94143, U.S.A
| | - Man S Kim
- Clinical Research Institute, College of Medicine, Kyung Hee University Hospital at Gangdong, Seoul, South Korea
| | - Won Bo Shim
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, TX 77843, U.S.A
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FfCOX17 is Involved in Fumonisins Production, Growth, Asexual Reproduction, and Fungicide Sensitivity in Fusarium fujikuroi. Toxins (Basel) 2022; 14:toxins14070427. [PMID: 35878165 PMCID: PMC9319711 DOI: 10.3390/toxins14070427] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2022] [Revised: 06/18/2022] [Accepted: 06/20/2022] [Indexed: 02/04/2023] Open
Abstract
Fusarium fujikuroi, a causal agent of Rice Bakanae Disease, produces secondary metabolites such as gibberellin, pigments bikaverin, and mycotoxins fumonisins. Fumonisins produced by F. fujikuroi pose a severe threat to human and animal health. The copper chaperone protein plays a critical role in different growth stages of plants, fungi, and yeasts, but their functions and regulation in fumonisin biosynthesis are still unclear. Here, a copper chaperone protein, FfCOX17, was identified in F. fujikuroi. The FfCOX17 deletion mutant (∆FfCOX17) exhibited decreased vegetative growth and asexual reproduction. The transcriptional level of the FfFUM2 gene was significantly induced in ∆FfCOX17, and the fumonisin production in ∆FfCOX17 mutants was significantly increased compared to wild-type F. fujikuroi, but the pathogenicity of ∆FfCOX17 mutants was unaffected, which may be caused by the no significantly changed gibberellin content. ∆FfCOX17 showed decreased sensitivity to oxidative stress, osmotic stress, and increased sensitivity to cell wall stress, heat shock stress, and high concentration glucose. In addition, ∆FfCOX17 also showed increased sensitivity to fungicide fluazinam and fludioxonil, and decreased sensitivity to phenamacril and prochloraz. Taken together, this study suggested that FfCOX17 is critical for fumonisin production, vegetative growth, asexual reproduction, and fungicide sensitivity, but is not required for the virulence function of F. fujikuroi on rice.
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Yuan Y, Zhang M, Li J, Yang C, Abubakar YS, Chen X, Zheng W, Wang Z, Zheng H, Zhou J. The Small GTPase FgRab1 Plays Indispensable Roles in the Vegetative Growth, Vesicle Fusion, Autophagy and Pathogenicity of Fusarium graminearum. Int J Mol Sci 2022; 23:ijms23020895. [PMID: 35055095 PMCID: PMC8776137 DOI: 10.3390/ijms23020895] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 01/08/2022] [Accepted: 01/11/2022] [Indexed: 02/01/2023] Open
Abstract
Rab GTPases are key regulators of membrane and intracellular vesicle transports. However, the biological functions of FgRab1 are still unclear in the devastating wheat pathogen Fusarium graminearum. In this study, we generated constitutively active (CA) and dominant-negative (DN) forms of FgRAB1 from the wild-type PH-1 background for functional analyses. Phenotypic analyses of these mutants showed that FgRab1 is important for vegetative growth, cell wall integrity and hyphal branching. Compared to the PH-1 strain, the number of spores produced by the Fgrab1DN strain was significantly reduced, with obviously abnormal conidial morphology. The number of septa in the conidia of the Fgrab1DN mutant was fewer than that observed in the PH-1 conidia. Fgrab1DN was dramatically reduced in its ability to cause Fusarium head blight symptoms on wheat heads. GFP-FgRab1 was observed to partly localize to the Golgi apparatus, endoplasmic reticulum and Spitzenkörper. Furthermore, we found that FgRab1 inactivation blocks not only the transport of the v-SNARE protein FgSnc1 from the Golgi to the plasma membrane but also the fusion of endocytic vesicles with their target membranes and general autophagy. In summary, our results indicate that FgRab1 plays vital roles in vegetative growth, conidiogenesis, pathogenicity, autophagy, vesicle fusion and trafficking in F. graminearum.
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Affiliation(s)
- Yanping Yuan
- Fujian Universities Key Laboratory for Plant-Microbe Interaction, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (Y.Y.); (M.Z.); (J.L.); (C.Y.); (Y.S.A.); (Z.W.)
| | - Meiru Zhang
- Fujian Universities Key Laboratory for Plant-Microbe Interaction, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (Y.Y.); (M.Z.); (J.L.); (C.Y.); (Y.S.A.); (Z.W.)
| | - Jingjing Li
- Fujian Universities Key Laboratory for Plant-Microbe Interaction, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (Y.Y.); (M.Z.); (J.L.); (C.Y.); (Y.S.A.); (Z.W.)
| | - Chengdong Yang
- Fujian Universities Key Laboratory for Plant-Microbe Interaction, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (Y.Y.); (M.Z.); (J.L.); (C.Y.); (Y.S.A.); (Z.W.)
| | - Yakubu Saddeeq Abubakar
- Fujian Universities Key Laboratory for Plant-Microbe Interaction, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (Y.Y.); (M.Z.); (J.L.); (C.Y.); (Y.S.A.); (Z.W.)
- Department of Biochemistry, Faculty of Life Sciences, Ahmadu Bello University, Zaria 810211, Nigeria
| | - Xin Chen
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (X.C.); (W.Z.)
| | - 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; (X.C.); (W.Z.)
| | - Zonghua Wang
- Fujian Universities Key Laboratory for Plant-Microbe Interaction, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (Y.Y.); (M.Z.); (J.L.); (C.Y.); (Y.S.A.); (Z.W.)
- Marine and Agricultural Biotechnology Laboratory, Institute of Oceanography, College of Geography and Oceanography, Minjiang University, Fuzhou 350108, China
| | - Huawei Zheng
- Marine and Agricultural Biotechnology Laboratory, Institute of Oceanography, College of Geography and Oceanography, Minjiang University, Fuzhou 350108, China
- Correspondence: (H.Z.); (J.Z.); Tel.: +86-15880036549 (H.Z.); +86-13860626041 (J.Z.)
| | - Jie Zhou
- Fujian Universities Key Laboratory for Plant-Microbe Interaction, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (Y.Y.); (M.Z.); (J.L.); (C.Y.); (Y.S.A.); (Z.W.)
- Correspondence: (H.Z.); (J.Z.); Tel.: +86-15880036549 (H.Z.); +86-13860626041 (J.Z.)
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8
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Deng Q, Wu H, Gu Q, Tang G, Liu W. Glycosyltransferase FvCpsA Regulates Fumonisin Biosynthesis and Virulence in Fusarium verticillioides. Toxins (Basel) 2021; 13:toxins13100718. [PMID: 34679011 PMCID: PMC8539240 DOI: 10.3390/toxins13100718] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Accepted: 09/29/2021] [Indexed: 12/18/2022] Open
Abstract
Fusarium verticillioides is the major maize pathogen associated with ear rot and stalk rot worldwide. Fumonisin B1 (FB1) produced by F. verticillioides, poses a serious threat to human and animal health. However, our understanding of FB1 synthesis and virulence mechanism in this fungus is still very limited. Glycosylation catalyzed by glycosyltransferases (GTs) has been identified as contributing to fungal infection and secondary metabolism synthesis. In this study, a family 2 glycosyltransferase, FvCpsA, was identified and characterized in F. verticillioides. ΔFvcpsA exhibited significant defects in vegetative growth. Moreover, ΔFvcpsA also increased resistance to osmotic and cell wall stress agents. In addition, expression levels of FUM genes involved in FB1 production were greatly up-regulated in ΔFvcpsA. HPLC (high performance liquid chromatography) analysis revealed that ΔFvcpsA significantly increased FB1 production. Interestingly, we found that the deletion of FvCPSA showed penetration defects on cellophane membrane, and thus led to obvious defects in pathogenicity. Characterization of FvCpsA domain experiments showed that conserved DXD and QXXRW domains were vital for the biological functions of FvCpsA. Taken together, our results indicate that FvCpsA is critical for fungal growth, FB1 biosynthesis and virulence in F. verticillioides.
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Affiliation(s)
- Qi Deng
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (Q.D.); (H.W.)
| | - Hanxiang Wu
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (Q.D.); (H.W.)
| | - Qin Gu
- Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, Key Laboratory of Monitoring and Management of Crop Diseases and Pest Insects, Ministry of Education, Nanjing 210095, China;
| | - Guangfei Tang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (Q.D.); (H.W.)
- Correspondence: (G.T.); (W.L.)
| | - Wende Liu
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (Q.D.); (H.W.)
- Correspondence: (G.T.); (W.L.)
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Li T, Su X, Qu H, Duan X, Jiang Y. Biosynthesis, regulation, and biological significance of fumonisins in fungi: current status and prospects. Crit Rev Microbiol 2021; 48:450-462. [PMID: 34550845 DOI: 10.1080/1040841x.2021.1979465] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Fumonisins are one of the most important mycotoxin classes due to their widespread occurrence and potential health threat to humans and animals. Currently, most of the research focuses on the control of fumonisin contamination in the food supply chain. In recent years, significant progress in biochemistry, enzymology, and genetic regulation of fumonisin biosynthesis has been achieved using molecular technology. Furthermore, new insights into the roles of fumonisins in the interaction between fungi and plant hosts have been reported. This review provides an overview of the current understanding of the biosynthesis and regulation of fumonisins. The ecological significance of fumonisins to Fusarium species that produce the toxins is discussed, and the complex regulatory networks of fumonisin synthesis is proposed.
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Affiliation(s)
- Taotao Li
- Key Laboratory of Plant Resource Conservation and Sustainable Utilization, Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
| | - Xinguo Su
- Tropical Agriculture and Forestry Department, Guangdong AIB Polytechnic College, Guangzhou, China
| | - Hongxia Qu
- Key Laboratory of Plant Resource Conservation and Sustainable Utilization, Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
| | - Xuewu Duan
- Key Laboratory of Plant Resource Conservation and Sustainable Utilization, Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
| | - Yueming Jiang
- Key Laboratory of Plant Resource Conservation and Sustainable Utilization, Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China.,College of Life Sciences, Gannan Normal University, Ganzhou, China
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10
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Delivering the goods: Fungal secretion modulates virulence during host–pathogen interactions. FUNGAL BIOL REV 2021. [DOI: 10.1016/j.fbr.2021.03.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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Yan H, Zhou Z, Shim WB. Two regulators of G-protein signaling (RGS) proteins FlbA1 and FlbA2 differentially regulate fumonisin B1 biosynthesis in Fusarium verticillioides. Curr Genet 2021; 67:305-315. [PMID: 33392742 DOI: 10.1007/s00294-020-01140-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 11/23/2020] [Accepted: 11/30/2020] [Indexed: 11/28/2022]
Abstract
Fumonisins are a group of mycotoxins produced by maize pathogen Fusarium verticillioides that pose health concerns to humans and animals. Yet we still lack a clear understanding of the mechanism of fumonisins regulation during pathogenesis. The heterotrimeric G protein complex, which consists of canonical subunits and various regulators of G-protein signaling (RGS) proteins, plays an important role in transducing signals under environmental stress. Earlier studies demonstrated that Gα and Gβ subunits are positive regulators of fumonisin B1 (FB1) biosynthesis and that two RGS genes, FvFlbA1 and FvFlbA2, were highly upregulated in Gβ deletion mutant ∆Fvgbb1. Notably, FvFlbA2 has a negative role in FB1 regulation. While many fungi contain a single copy of FlbA, F. verticillioides harbors two putative FvFlbA paralogs, FvFlbA1 and FvFlbA2. In this study, we further characterized functional roles of FvFlbA1 and FvFlbA2. While ∆FvflbA1 deletion mutant exhibited no significant defects, ∆FvflbA2 and ∆FvflbA2/A1 mutants showed thinner aerial hyphal growth while promoting FB1 production. FvFlbA2 is required for proper expression of key conidia regulation genes, including putative FvBRLA, FvWETA, and FvABAA, while suppressing FUM21, FUM1, and FUM8 expression. Split luciferase assays determined that FvFlbA paralogs interact with key heterotrimeric G protein components, which in turn will lead altered G-protein-mediated signaling pathways that regulate FB1 production and asexual development in F. verticillioides.
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Affiliation(s)
- Huijuan Yan
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, TX, 77843, USA
| | - Zehua Zhou
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, TX, 77843, USA.,College of Plant Protection, Nanjing Agricultural University, Nanjing, 210095, China
| | - Won Bo Shim
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, TX, 77843, USA.
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Shi LW, Zhao ZB, Zhong L, Gao J, Gong JP, Chen H, Min Y, Zhang YY, Li Z. Overexpression of Rab40b Promotes Hepatocellular Carcinoma Cell Proliferation and Metastasis via PI3K/AKT Signaling Pathway. Cancer Manag Res 2020; 12:10139-10150. [PMID: 33116869 PMCID: PMC7569249 DOI: 10.2147/cmar.s255870] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Accepted: 09/12/2020] [Indexed: 12/17/2022] Open
Abstract
Background Rab40b is an evolutionarily conserved Rab GTPase that plays an important role in intracellular trafficking and is closely related to cancer progression. However, the role and potential molecular mechanism of Rab40b in hepatocellular carcinoma (HCC) have not yet been elucidated. Materials and Methods The expression of Rab40b in HCC tissues and peritumour tissues was tested by qRT-PCR, Western blotting and histological analysis. A Kaplan-Meier survival curve was generated based on the expression of Rab40b in the HCC samples. Cell proliferation assays, wound healing assays, and transwell assays are used to examine the effect of Rab40b on HCC cell growth in vitro. The effect of Rab40b on cell cycle was examined by flow cytometry. A xenograft implantation model was used to assess the effect of Rab40b on the development of HCC cells in vivo. Results Rab40b protein expression is upregulated in HCC tissues, and this upregulation is associated with high pathological stage and poor prognosis in HCC patients. Rab40b overexpression promotes the proliferation and metastasis of HCC cells by upregulating cyclin D1, cyclin E1 and matrix metalloproteinase 2 (MMP2) through the PI3K/AKT signalling pathway. Conversely, Rab40b inhibitors can significantly inhibit the proliferation and metastasis of HCC cell lines and induce G0/G1 cell cycle arrest and apoptosis. Studies of a nude mouse xenograft model demonstrated that Rab40b knockdown can significantly inhibit the proliferation and progression of HCC tumours in vivo. Conclusion Overall, this study demonstrates that Rab40b is an important oncoprotein that promotes HCC progression by regulating the expression of cyclin D1, cyclin E1, p21 and MMP2 through the PI3K/AKT signalling pathway.
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Affiliation(s)
- Li-Wei Shi
- Department of Gastroenterology, The Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, People's Republic of China.,Department of Gastroenterology, Chongqing People's Hospital, Chongqing 400010, People's Republic of China
| | - Zhi-Bo Zhao
- Department of Hepatobiliary Surgery, The Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, People's Republic of China
| | - Li Zhong
- Department of Gastroenterology, The Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, People's Republic of China
| | - Jian Gao
- Department of Gastroenterology, The Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, People's Republic of China
| | - Jian-Ping Gong
- Department of Hepatobiliary Surgery, The Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, People's Republic of China
| | - Hang Chen
- Department of Breast & Thyroid Surgery, The Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, People's Republic of China
| | - Yu Min
- Department of Breast & Thyroid Surgery, The Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, People's Republic of China
| | - Yi-Yin Zhang
- Department of Anesthesiology, Chongqing Hospital of Traditional Chinese Medicine, Chongqing 401120, People's Republic of China
| | - Zhi Li
- Department of Breast & Thyroid Surgery, The Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, People's Republic of China
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Yan H, Shim WB. Characterization of non-canonical G beta-like protein FvGbb2 and its relationship with heterotrimeric G proteins in Fusarium verticillioides. Environ Microbiol 2019; 22:615-628. [PMID: 31760684 DOI: 10.1111/1462-2920.14875] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Revised: 11/19/2019] [Accepted: 11/21/2019] [Indexed: 11/29/2022]
Abstract
Fusarium verticillioides is a fungal pathogen that is responsible for maize ear rot and stalk rot diseases worldwide. The fungus also produces carcinogenic mycotoxins, fumonisins on infested maize. Unfortunately, we still lack clear understanding of how the pathogen responds to host and environmental stimuli to trigger fumonisin biosynthesis. The heterotrimeric G protein complex, consisting of canonical Gα, Gβ and Gγ subunits, is involved in transducing signals from external stimuli to regulate downstream signal transduction pathways. Previously, we demonstrated that Gβ protein FvGbb1 directly impacts fumonisin regulation but not other physiological aspects in F. verticillioides. In this study, we identified and characterized a RACK1 (Receptor for Activated C Kinase 1) homolog FvGbb2 as a putative Gβ-like protein in F. verticillioides. The mutant exhibited severe defects not only in fumonisin biosynthesis but also vegetative growth and conidiation. FvGbb2 was positively associated with carbon source utilization and stress agents but negatively regulated general amino acid control. While FvGbb2 does not interact with canonical G protein subunits, it may associate with diverse proteins in the cytoplasm to regulate vegetative growth, virulence, fumonisin biosynthesis and stress response in F. verticillioides.
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Affiliation(s)
- Huijuan Yan
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, TX, 77843, USA
| | - Won Bo Shim
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, TX, 77843, USA
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