On the role of the global regulator RlcA in red-light sensing in Aspergillus nidulans

Homeobox transcription factors are conserved in eukaryotes and act as multi-functional transcription factors in filamentous fungi. Previously, it was demonstrated that HbxB governs fungal development and spore viability in Aspergillus nidulans. Here, the role of HbxB in A. nidulans was further characterized. RNA-sequencing revealed that HbxB affects the transcriptomic levels of genes associated with trehalose biosynthesis and response to thermal, oxidative, and radiation stresses in asexual spores called conidia. A phenotypic analysis found that hbxB deletion mutant conidia were more sensitive to ultraviolet stress. The loss of hbxB increased the mRNA expression of genes associated with β-glucan degradation and decreased the amount of β-glucan in conidia. In addition, hbxB deletion affected the expression of the sterigmatocystin gene cluster and the amount of sterigmatocystin. Overall, these results indicated that HbxB is a key transcription factor regulating trehalose biosynthesis, stress tolerance, β-glucan degradation, and sterigmatocystin production in A.nidulans conidia.

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Studies on the Role of the are a Gene in the Regulation of Nitrogen Catabolism in Aspergillus nidulans

Australian Journal of Biological Sciences ◽

10.1071/bi9750301 ◽

1975 ◽

Vol 28 (3) ◽

pp. 301 ◽

Cited By ~ 84

Author(s):

MJ Hynes

Keyword(s):

Nitrogen Source ◽

Aspergillus Nidulans ◽

Carbon Sources ◽

Nitrogen Sources ◽

Selection Methods ◽

Growth Responses ◽

Dominance Relationships ◽

Regulatory Circuits ◽

Specific Activities

Mutants of Apergillus nidulanswith lesions in a gene, areA (formerly called amdT), have been isolated by a variety of different selection methods. The areA mutants show a range of pleiotropic growth responses to a number of compounds as sole nitrogen sources, but are normal in utilization of carbon sources. The levels of two amidase enzymes as well as urease have been investigated in the mutants and have been shown to be affected by this gene. Most of the areA mutants have much lower amidase-specific activities when grown in ammonium-containing medium, compared with mycelium incubated in medium la9king a nitrogen source. Some of the areA. mutants do not show derepression of urease upon relief of ammonium repression. The dominance relationships of areA alleles have been investigated in� heterozygous diploids, and these studies lend support to the proposal that areA codes for a positively acting regulatory product. One of the new areA alleles is partially dominant to areA + and areA102. This may be a result of negative complementation or indicate that areA has an additional negative reiuIatory function. Investigation.of various amdR; areA double mutants has led to the conclusion that amdR and areA participate in independent regulatory circuits in the control of acetamide utilizatiol1. Studies on an amdRc; areA.double mutant indicate that areA is involved in derepression of acetamidase upon relief of ammo.nium repression.

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Characterization of the Role of the FluG Protein in Asexual Development of Aspergillus nidulans

Genetics ◽

10.1093/genetics/158.3.1027 ◽

2001 ◽

Vol 158 (3) ◽

pp. 1027-1036 ◽

Cited By ~ 2

Author(s):

Cletus A D'Souza ◽

Bee Na Lee ◽

Thomas H Adams

Keyword(s):

Aspergillus Nidulans ◽

Negative Influence ◽

Asexual Development ◽

Wild Type ◽

Significant Similarity ◽

Developmental Defects ◽

Asexual Sporulation ◽

Type Strains

Abstract We showed previously that a ΔfluG mutation results in a block in Aspergillus nidulans asexual sporulation and that overexpression of fluG activates sporulation in liquid-submerged culture, a condition that does not normally support sporulation of wild-type strains. Here we demonstrate that the entire N-terminal region of FluG (∼400 amino acids) can be deleted without affecting sporulation, indicating that FluG activity resides in the C-terminal half of the protein, which bears significant similarity with GSI-type glutamine synthetases. While FluG has no apparent role in glutamine biosynthesis, we propose that it has an enzymatic role in sporulation factor production. We also describe the isolation of dominant suppressors of ΔfluG(dsg) that should identify components acting downstream of FluG and thereby define the function of FluG in sporulation. The dsgA1 mutation also suppresses the developmental defects resulting from ΔflbA and dominant activating fadA mutations, which both cause constitutive induction of the mycelial proliferation pathway. However, dsgA1 does not suppress the negative influence of these mutations on production of the aflatoxin precursor, sterigmatocystin, indicating that dsgA1 is specific for asexual development. Taken together, our studies define dsgA as a novel component of the asexual sporulation pathway.

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The role of VosA/VelB-activated developmental gene vadA in Aspergillus nidulans

PLoS ONE ◽

10.1371/journal.pone.0177099 ◽

2017 ◽

Vol 12 (5) ◽

pp. e0177099 ◽

Cited By ~ 11

Author(s):

Hee-Soo Park ◽

Mi-Kyung Lee ◽

Sun Chang Kim ◽

Jae-Hyuk Yu

Keyword(s):

Aspergillus Nidulans ◽

Developmental Gene

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YaeB, Expressed in Response to the Acidic pH in Macrophages, Promotes Intracellular Replication and Virulence of Salmonella Typhimurium

International Journal of Molecular Sciences ◽

10.3390/ijms20184339 ◽

2019 ◽

Vol 20 (18) ◽

pp. 4339 ◽

Cited By ~ 2

Author(s):

Huan Zhang ◽

Xiaorui Song ◽

Peisheng Wang ◽

Runxia Lv ◽

Shuangshuang Ma ◽

...

Keyword(s):

Salmonella Enterica Serovar Typhimurium ◽

Intracellular Pathogen ◽

Acidic Ph ◽

Intracellular Replication ◽

Global Regulator ◽

Serovar Typhimurium ◽

Survival And Growth ◽

Bacterial Replication ◽

Specific Transport System

Salmonella enterica serovar Typhimurium is a facultative intracellular pathogen that infects humans and animals. Survival and growth in host macrophages represents a crucial step for S. Typhimurium virulence. Many genes that are essential for S. Typhimurium proliferation in macrophages and associated with virulence are highly expressed during the intracellular lifecycle. yaeB, which encodes an RNA methyltransferase, is also upregulated during S. Typhimurium growth in macrophages. However, the involvement of YaeB in S. Typhimurium pathogenicity is still unclear. In this study, we investigated the role of YaeB in S. Typhimurium virulence. Deletion of yaeB significantly impaired S. Typhimurium growth in macrophages and virulence in mice. The effect of yaeB on pathogenicity was related to its activation of pstSCAB, a phosphate (Pi)-specific transport system that is verified here to be important for bacterial replication and virulence. Moreover, qRT-PCR data showed YaeB was induced by the acidic pH inside macrophages, and the acidic pH passed to YeaB through inhibiting global regulator histone-like nucleoid structuring (H-NS) which confirmed in this study can repress the expression of yaeB. Overall, these findings identified a new virulence regulatory network involving yaeB and provided valuable insights to the mechanisms through which acidic pH and low Pi regulate virulence.

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