scholarly journals Identification and Characterization of Two Transmembrane Proteins Required for Virulence of Ustilago maydis

2021 ◽  
Vol 12 ◽  
Author(s):  
Paul Weiland ◽  
Florian Altegoer
Keyword(s):  
Virulence Factors ◽  
Biochemical Analysis ◽  
Transmembrane Proteins ◽  
Ustilago Maydis ◽  
Effector Proteins ◽  
Smut Fungi ◽  
Initial Characterization ◽  
Associated Proteins ◽  
Identification And Characterization

Smut fungi comprise a large group of biotrophic phytopathogens infecting important crops such as wheat and corn. Through the secretion of effector proteins, the fungus actively suppresses plant immune reactions and modulates its host’s metabolism. Consequently, how soluble effector proteins contribute to virulence is already characterized in a range of phytopathogens. However, membrane-associated virulence factors have been much less studied to date. Here, we investigated six transmembrane (TM) proteins that show elevated gene expression during biotrophic development of the maize pathogen Ustilago maydis. We show that two of the six proteins, named Vmp1 and Vmp2 (virulence-associated membrane protein), are essential for the full virulence of U. maydis. The deletion of the corresponding genes leads to a substantial attenuation in the virulence of U. maydis. Furthermore, both are conserved in various related smuts and contain no domains of known function. Our biochemical analysis clearly shows that Vmp1 and Vmp2 are membrane-associated proteins, potentially localizing to the U. maydis plasma membrane. Mass photometry and light scattering suggest that Vmp1 mainly occurs as a monomer, while Vmp2 is dimeric. Notably, the large and partially unstructured C-terminal domain of Vmp2 is crucial for virulence while not contributing to dimerization. Taken together, we here provide an initial characterization of two membrane proteins as virulence factors of U. maydis.

scholarly journals Identification and characterization of two transmembrane proteins required for virulence of Ustilago maydis

2021 ◽  
Author(s):  
Paul Weiland ◽  
Florian Altegoer
Keyword(s):  
Virulence Factors ◽  
Biochemical Analysis ◽  
Transmembrane Proteins ◽  
Ustilago Maydis ◽  
Effector Proteins ◽  
Smut Fungi ◽  
Initial Characterization ◽  
Associated Proteins ◽  
Identification And Characterization

AbstractSmut fungi comprise a large group of biotrophic phytopathogens infecting important crops such as wheat and corn. Through the secretion of effector proteins, the fungus actively suppresses plant immune reactions and modulates its host’s metabolism. Consequently, how soluble effector proteins contribute to virulence is already characterized in a range of phytopathogens. However, membrane-associated virulence factors have been much less studied to date. Here, we investigated six transmembrane (TM) proteins that show elevated gene expression during biotrophic development of the maize pathogen Ustilago maydis. We show that two of the six proteins, named Vmp1 and Vmp2 (virulence-associated membrane protein), are essential for the full virulence of U. maydis. The deletion of the corresponding genes lead to a substantial attenuation in the virulence of U. maydis. Furthermore, both are conserved in various related smuts and contain no domains of known function. Our biochemical analysis clearly shows that Vmp1 and Vmp2 are membrane-associated proteins, potentially localizing to the U. maydis plasma membrane. Mass photometry and light scattering suggest that Vmp1 mainly occurs as a monomer, while Vmp2 is dimeric. Notably, the large and partially unstructured C-terminal domain of Vmp2 is crucial for virulence while not contributing to dimerization. Taken together, we here provide an initial characterization of two membrane proteins as virulence factors of U. maydis.

scholarly journals Identification and Characterization of Mycobacterium tuberculosis (Mtb) Effector Proteins

2017 ◽  
Vol 4 (suppl_1) ◽  
pp. S722-S723
Author(s):  
Sujittra Chaisavaneeyakorn ◽  
Chelsea E Stamm ◽  
Michael U Shiloh
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Effector Proteins ◽  
Identification And Characterization

scholarly journals Identification and Characterization of Two Novel Proteins Affecting Fission Yeast γ-tubulin Complex Function

2004 ◽  
Vol 15 (5) ◽  
pp. 2287-2301 ◽  
Author(s):  
Srinivas Venkatram ◽  
Joseph J. Tasto ◽  
Anna Feoktistova ◽  
Jennifer L. Jennings ◽  
Andrew J. Link ◽  
...  
Keyword(s):  
Fission Yeast ◽  
Complex Function ◽  
Novel Proteins ◽  
Astral Microtubule ◽  
Different Types ◽  
Associated Proteins ◽  
Microtubule Formation ◽  
Identification And Characterization ◽  
Microtubule Function

The γ-tubulin complex, via its ability to organize microtubules, is critical for accurate chromosome segregation and cytokinesis in the fission yeast, Schizosaccharomyces pombe. To better understand its roles, we have purified the S. pombe γ-tubulin complex. Mass spectrometric analyses of the purified complex revealed known components and identified two novel proteins (i.e., Mbo1p and Gfh1p) with homology to γ-tubulin–associated proteins from other organisms. We show that both Mbo1p and Gfh1p localize to microtubule organizing centers. Although cells deleted for either mbo1+ or gfh1+ are viable, they exhibit a number of defects associated with altered microtubule function such as defects in cell polarity, nuclear positioning, spindle orientation, and cleavage site specification. In addition, mbo1Δ and gfh1Δ cells exhibit defects in astral microtubule formation and anchoring, suggesting that these proteins have specific roles in astral microtubule function. This study expands the known roles of γ-tubulin complex components in organizing different types of microtubule structures in S. pombe.

scholarly journals A cell surface-exposed protein complex with an essential virulence function in Ustilago maydis

2021 ◽  
Author(s):  
Nicole Ludwig ◽  
Stefanie Reissmann ◽  
Kerstin Schipper ◽  
Carla Gonzalez ◽  
Daniela Assmann ◽  
...  
Keyword(s):  
Membrane Proteins ◽  
Protein Complex ◽  
Pathogenic Bacteria ◽  
Constitutive Expression ◽  
Pathogenic Fungi ◽  
Ustilago Maydis ◽  
Effector Proteins ◽  
Host Cells ◽  
Smut Fungi ◽  
Living Plant

AbstractPlant pathogenic fungi colonizing living plant tissue secrete a cocktail of effector proteins to suppress plant immunity and reprogramme host cells. Although many of these effectors function inside host cells, delivery systems used by pathogenic bacteria to translocate effectors into host cells have not been detected in fungi. Here, we show that five unrelated effectors and two membrane proteins from Ustilago maydis, a biotrophic fungus causing smut disease in corn, form a stable protein complex. All seven genes appear co-regulated and are only expressed during colonization. Single mutants arrest in the epidermal layer, fail to suppress host defence responses and fail to induce non-host resistance, two reactions that likely depend on translocated effectors. The complex is anchored in the fungal membrane, protrudes into host cells and likely contacts channel-forming plant plasma membrane proteins. Constitutive expression of all seven complex members resulted in a surface-exposed form in cultured U. maydis cells. As orthologues of the complex-forming proteins are conserved in smut fungi, the complex may become an interesting fungicide target.

scholarly journals Identification and Characterization of Pathogenic Aeromonas veronii Biovar Sobria Associated with Epizootic Ulcerative Syndrome in Fish in Bangladesh

2002 ◽  
Vol 68 (2) ◽  
pp. 650-655 ◽  
Author(s):  
Mokhlasur Rahman ◽  
Patricia Colque-Navarro ◽  
Inger K�hn ◽  
Geert Huys ◽  
Jean Swings ◽  
...  
Keyword(s):  
Virulence Factors ◽  
Acid Methyl Ester ◽  
Fish Cell ◽  
Environmental Isolates ◽  
Fish Cell Lines ◽  
Aeromonas Veronii ◽  
Diseased Fish ◽  
Epizootic Ulcerative Syndrome ◽  
Identification And Characterization

ABSTRACT Sparse information is available on the virulence factors of Aeromonas strains isolated from diseased fish, from the environment, and from humans. In the present study, 52 Aeromonas isolates obtained from epizootic ulcerative syndrome (EUS) lesions in fish, from the aquatic environment, and from children with diarrhea in Bangladesh were identified by biochemical phenotyping (i.e., PhenePlate [PhP] typing) and DNA fingerprinting and then characterized with respect to certain putative virulence factors. The isolates from the fish exhibiting EUS symptoms were identified to be Aeromonas veronii biovar sobria by fatty acid methyl ester analysis and amplified fragment length polymorphism fingerprinting. Biochemical phenotyping revealed that all EUS-associated isolates belonged to a unique phenotype which was not identified among more than 1,600 environmental and diarrheal isolates in a previously collected database of PhP types of Bangladeshi Aeromonas isolates. The 52 Aeromonas isolates were investigated for the production of hemolysin and cytotoxin; for hemagglutination with erythrocytes from fish, human, and rabbit sources; for the presence of a cytolytic enterotoxin gene; and for adhesion to and invasion into fish cell lines. All of the EUS isolates produced all of the virulence factors investigated, as did also some of the environmental isolates, but the isolates from EUS were unique in their ability to agglutinate fish erythrocytes. Our results suggest that a clonal group of A. veronii biovar sobria is associated with, and may be a causative agent of, EUS in fish in Bangladesh.

scholarly journals Profile of Secreted Hydrolases, Associated Proteins, and SlpA in Thermoanaerobacterium saccharolyticum during the Degradation of Hemicellulose

2014 ◽  
Vol 80 (16) ◽  
pp. 5001-5011 ◽  
Author(s):  
D. H. Currie ◽  
A. M. Guss ◽  
C. D. Herring ◽  
R. J. Giannone ◽  
C. M. Johnson ◽  
...  
Keyword(s):  
Morphological Changes ◽  
Transmembrane Proteins ◽  
Liquid Chromatography Mass Spectrometry ◽  
Phosphotransferase System ◽  
Content Type ◽  
Thermoanaerobacterium Saccharolyticum ◽  
Conditional Expression ◽  
Hemicellulose Degradation ◽  
Associated Proteins

ABSTRACTThermoanaerobacterium saccharolyticum, a Gram-positive thermophilic anaerobic bacterium, grows robustly on insoluble hemicellulose, which requires a specialized suite of secreted and transmembrane proteins. We report here the characterization of proteins secreted by this organism. Cultures were grown on hemicellulose, glucose, xylose, starch, and xylan in pH-controlled bioreactors, and samples were analyzed via spotted microarrays and liquid chromatography-mass spectrometry. Key hydrolases and transporters employed byT. saccharolyticumfor growth on hemicellulose were, for the most part, hitherto uncharacterized and existed in two clusters (Tsac_1445throughTsac_1464for xylan/xylose andTsac_1344throughTsac_1349for starch). A phosphotransferase system subunit, Tsac_0032, also appeared to be exclusive to growth on glucose. Previously identified hydrolases that showed strong conditional expression changes included XynA (Tsac_1459), XynC (Tsac_0897), and a pullulanase, Apu (Tsac_1342). An omnipresent transcript and protein making up a large percentage of the overall secretome, Tsac_0361, was tentatively identified as the primary S-layer component inT. saccharolyticum, and deletion of theTsac_0361gene resulted in gross morphological changes to the cells. The view of hemicellulose degradation revealed here will be enabling for metabolic engineering efforts in biofuel-producing organisms that degrade cellulose well but lack the ability to catabolize C5sugars.

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