A histidine kinase PmHHK1 regulates polar growth, sporulation and cell wall composition in the dimorphic fungus Penicillium marneffei

P. brasiliensis is a thermally dimorphic fungus belonging to Paracoccidioides complex, causative of a systemic, endemic mycosis limited to Latin American countries. Signal transduction pathways related to important aspects as surviving, proliferation according to the biological niches are linked to the fungal pathogenicity in many species, but its elucidation in P. brasiliensis remains poorly explored. As Drk1, a hybrid histidine kinase, plays regulators functions in other dimorphic fungi species, mainly in dimorphism and virulence, here we investigated its importance in P. brasilensis. We, therefore generated the respective recombinant protein, anti-PbDrk1 polyclonal antibody and a silenced strain. The Drk1 protein shows a random distribution including cell wall location that change its pattern during osmotic stress condition; moreover the P. brasiliensis treatment with anti-PbDrk1 antibody, which does not modify the fungus’s viability, resulted in decreased virulence in G. mellonella model and reduced interaction with pneumocytes. Down-regulating PbDRK1 yielded phenotypic alterations such as yeast cells with more elongated morphology, virulence attenuation in G. mellonella infection model, lower amount of chitin content, increased resistance to osmotic and cell wall stresses, and also caspofungin, and finally increased sensitivity to itraconazole. These observations highlight the importance of PbDrk1 to P. brasiliensis virulence, stress adaptation, morphology, and cell wall organization, and therefore it an interesting target that could help develop new antifungals.

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Mechanisms of polar growth in the alphaproteobacterial order rhizobiales

10.32469/10355/79574 ◽

2019 ◽

Author(s):

◽

Michelle A. Williams

Keyword(s):

Gene Expression ◽

Cell Wall ◽

Cell Division ◽

Molecular Mechanisms ◽

Cell Wall Composition ◽

Wall Material ◽

Polar Growth ◽

Cell Wall Synthesis ◽

Type Vi Secretion System ◽

Atypical Form

All bacteria elongate and divide to faithfully reproduce their cell shape. Understanding the mechanisms that drive bacterial morphology requires an intimate knowledge of how the cell wall is synthesized. During cell division, most bacteria synthesize new cell wall at mid-cell and the mechanism underlying this process is highly conserved. In contrast, there is a high degree of diversity in bacterial growth patterning during elongation. Bacteria in the Rhizobiales exhibit an atypical form of unipolar elongation, and the molecular mechanisms of how new cell wall is synthesized during growth and division currently remains unexplored. Using microfluidics and fluorescent cell wall probes we first investigated whether polar growth is conserved in a morphologically complex bacterium, Prosthecomicrobium hirschii. We showed that P. hirschii has a dimorphic lifestyle and can switch between a long-stalked, non-motile form and a short-stalked, motile form. Furthermore, we found that all morphotypes of P. hirschii elongate using polar growth, suggesting the polar elongation is a widespread feature of bacteria in this order. Next, we used the rod-shaped bacterium Agrobacterium tumefaciens as a model to investigate the precise mechanisms that drive polar elongation. We characterized a comprehensive set of cell wall synthesis enzymes in A. tumefaciens and identified penicillin-binding protein 3a (PBP3a) and PBP3b as a synthetic lethal pair that function during cell division, and PBP1a as an essential enzyme required for polar growth and maintenance of rod shape. Compositional analysis of the PBP1a depletion, suggested that LD-transpeptidase (LDT) enzymes may play an important role in polar growth. We identified three LDTs that likely function in polar growth. We also observed subpolar localization of LDTs, suggesting bacteria in the Rhizobiales may insert or remodel cell wall material in a subpolar zone during growth. Finally, we used RNA-seq to explore changes in gene expression during PBP1a depletion, revealing that that loss of PBP1a induces a lifestyle switch which mimics the switch from a free-living bacterium into a plant-associated state. The change in lifestyle is characterized by increased exopolysaccharide production and Type VI Secretion System activity and a decrease in flagella-mediated motility. This finding indicates that bacteria have a mechanism to sense changes in cell wall composition or integrity due to the loss of PBP1a and respond through changes in gene expression that impact physiology and behavior. This finding opens the door to future studies on the link between changes in cell wall composition and complex bacterial behaviors and lifestyles. Overall, this research provides mechanistic insights about the roles of cell wall synthesis during cell growth and division in the A. tumefaciens, which are conserved in other Rhizobiales, including agriculturally and medically species such as Sinorhizobium and Brucella.

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Role of the yakA gene in morphogenesis and stress response in Penicillium marneffei

Microbiology ◽

10.1099/mic.0.080689-0 ◽

2014 ◽

Vol 160 (9) ◽

pp. 1929-1939 ◽

Cited By ~ 7

Author(s):

Sumanun Suwunnakorn ◽

Chester R. Cooper ◽

Aksarakorn Kummasook ◽

Nongnuch Vanittanakom

Keyword(s):

Cell Wall ◽

Stress Response ◽

Penicillium Marneffei ◽

Cell Wall Integrity ◽

South East Asia ◽

Wild Type ◽

Phase Growth ◽

Dimorphic Fungus ◽

Heat Stress Response

Penicillium marneffei is a thermally dimorphic fungus and a highly significant pathogen of immunocompromised individuals living in or having travelled in south-east Asia. At 25 °C, P. marneffei grows filamentously. Under the appropriate conditions, these filaments (hyphae) produce conidiophores bearing chains of conidia. Yet, when incubated at 37 °C, or upon infecting host tissue, P. marneffei grows as a yeast that divides by binary fission. Previously, an Agrobacterium-mediated transformation system was used to randomly mutagenize P. marneffei, resulting in the isolation of a mutant defective in normal patterns of morphogenesis and conidiogenesis. The interrupted gene was identified as yakA. In the current study, we demonstrate that the yakA mutant produced fewer conidia at 25 °C than the wild-type and a complemented strain. In addition, disruption of the yakA gene resulted in early conidial germination and perturbation of cell wall integrity. The yakA mutant exhibited abnormal chitin distribution while growing at 25 °C, but not at 37 °C. Interestingly, at both temperatures, the yakA mutant possessed increased chitin content, which was accompanied by amplified transcription of two chitin synthase genes, chsB and chsG. Moreover, the expression of yakA was induced during post-exponential-phase growth as well as by heat shock. Thus, yakA is required for normal patterns of development, cell wall integrity, chitin deposition, appropriate chs expression and heat stress response in P. marneffei.

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Internode structure and cell wall composition in maturing tillers of switchgrass (Panicum virgatum. L)

Bioresource Technology ◽

10.1016/j.biortech.2006.10.020 ◽

2007 ◽

Vol 98 (16) ◽

pp. 2985-2992 ◽

Cited By ~ 49

Author(s):

Gautam Sarath ◽

Lisa M. Baird ◽

Kenneth P. Vogel ◽

Robert B. Mitchell

Keyword(s):

Cell Wall ◽

Panicum Virgatum ◽

Cell Wall Composition ◽

Panicum Virgatum L

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CO2 enrichment leads to altered cell wall composition in plants of Pfaffia glomerata (Spreng.) Pedersen (Amaranthaceae)

Plant Cell Tissue and Organ Culture (PCTOC) ◽

10.1007/s11240-021-02031-4 ◽

2021 ◽

Author(s):

Eliza Louback ◽

Diego Silva Batista ◽

Tiago Augusto Rodrigues Pereira ◽

Talita Cristina Mamedes-Rodrigues ◽

Tatiane Dulcineia Silva ◽

...

Keyword(s):

Cell Wall ◽

Co2 Enrichment ◽

Cell Wall Composition ◽

Pfaffia Glomerata ◽

Altered Cell

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Correction to: Assessing the impacts of cell wall composition on the optimum stage for “Uradome” in moso bamboo

Journal of Wood Science ◽

10.1186/s10086-021-01983-7 ◽

2021 ◽

Vol 67 (1) ◽

Author(s):

Yuka Furusawa ◽

Tatsuya Ashitani

Keyword(s):

Cell Wall ◽

Cell Wall Composition ◽

Moso Bamboo

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Maize Stover and Cob Cell Wall Composition and Ethanol Potential as Affected by Nitrogen Fertilization

BioEnergy Research ◽

10.1007/s12155-015-9595-0 ◽

2015 ◽

Vol 8 (3) ◽

pp. 1352-1361 ◽

Cited By ~ 3

Author(s):

Aaron J. Sindelar ◽

Craig C. Sheaffer ◽

John A. Lamb ◽

Hans-Joachim G. Jung ◽

Carl J. Rosen

Keyword(s):

Cell Wall ◽

Nitrogen Fertilization ◽

Cell Wall Composition ◽

Maize Stover

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Molecular analysis of the Penicillium marneffei glyceraldehyde-3-phosphate dehydrogenase-encoding gene (gpdA) and differential expression of gpdA and the isocitrate lyase-encoding gene (acuD) upon internalization by murine macrophages

Journal of Medical Microbiology ◽

10.1099/jmm.0.2008/002832-0 ◽

2008 ◽

Vol 57 (11) ◽

pp. 1322-1328 ◽

Cited By ~ 15

Author(s):

Sophit Thirach ◽

Chester R. Cooper ◽

Nongnuch Vanittanakom

Keyword(s):

Differential Expression ◽

Isocitrate Lyase ◽

Glyoxylate Cycle ◽

Evolutionary Relationship ◽

Amino Acid Sequences ◽

Penicillium Marneffei ◽

Macrophage Infection ◽

Dimorphic Fungus ◽

Isolation And Characterization ◽

Encoding Gene

Penicillium marneffei is an intracellular dimorphic fungus that can cause a fatal disseminated disease in human immunodeficiency virus-infected patients. The factors that affect the pathogenicity of this fungus remain unclear. Here, we report the isolation and characterization of the gpdA cDNA and genomic clones encoding glyceraldehyde-3-phosphate dehydrogenase (GAPDH) in P. marneffei. Phylogenetic analysis of GAPDH amino acid sequences demonstrated the evolutionary relationship of P. marneffei to other fungi, including the intracellular pathogen Ajellomyces capsulatus. To assess the central importance of phagocytic cells in defence against P. marneffei infection, we used Northern blotting to investigate the response of the isocitrate lyase-encoding gene (acuD) and gpdA to nutrient deprivation inside macrophages. The results revealed that after macrophage internalization, the gene involved in the glyoxylate cycle, acuD, showed higher expression levels as early as 2 h from the start of co-incubation, and the differential expression could be observed again at 8 h after infection. In contrast, the expression of gpdA was downregulated in the yeast phase, as well as during macrophage infection after 2, 4 and 8 h of infection. The induction of P. marneffei acuD was shown to be coordinated with the downregulation of the glycolytic gpdA gene, implying that the cytoplasmic environment of macrophages is deficient in glucose and the glyoxylate pathway could be used by this pathogen to allow subsistence on two-carbon compounds within the host cell following its intracellular persistence.

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