Transcription of the Hsp30, Hsp70, and Hsp90 heat shock protein genes is modulated by the PalA protein in response to acid pH-sensing in the fungus Aspergillus nidulans

Freitas, Janana S.; Silva, Emiliana M.; Leal, Juliana; Gras, Diana E.; Martinez-Rossi, Nilce M.; Santos, Lucilene Delazari dos; Palma, Mário Sérgio; Rossi, Antônio

doi:10.1007/s12192-011-0267-5

Cited by 28 publications

(27 citation statements)

References 36 publications

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“…Furthermore, A. fumigatus appears to downregulate genes involved in carbohydrate metabolism at high temperatures in a way that is linked to the upregulation of heat shock proteins, thereby enhancing the speed, efficiency and efficacy of heat shock response (Do et al, 2009). Studies on A. nidulans have identified PalA, a protein, which induces an efficient increase in the production of protein stabilization at extreme pH values (Freitas et al, 2011).…”

Section: Hydrophobic Stressorsmentioning

confidence: 99%

Ecology of aspergillosis: insights into the pathogenic potency of Aspergillus fumigatus and some other Aspergillus species

Paulussen

Hallsworth

Álvarez‐Pérez

et al. 2016

Microbial Biotechnology

278

175

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SummaryFungi of the genus Aspergillus are widespread in the environment. Some Aspergillus species, most commonly Aspergillus fumigatus, may lead to a variety of allergic reactions and life‐threatening systemic infections in humans. Invasive aspergillosis occurs primarily in patients with severe immunodeficiency, and has dramatically increased in recent years. There are several factors at play that contribute to aspergillosis, including both fungus and host‐related factors such as strain virulence and host pulmonary structure/immune status, respectively. The environmental tenacity of Aspergilllus, its dominance in diverse microbial communities/habitats, and its ability to navigate the ecophysiological and biophysical challenges of host infection are attributable, in large part, to a robust stress‐tolerance biology and exceptional capacity to generate cell‐available energy. Aspects of its stress metabolism, ecology, interactions with diverse animal hosts, clinical presentations and treatment regimens have been well‐studied over the past years. Here, we synthesize these findings in relation to the way in which some Aspergillus species have become successful opportunistic pathogens of human‐ and other animal hosts. We focus on the biophysical capabilities of Aspergillus pathogens, key aspects of their ecophysiology and the flexibility to undergo a sexual cycle or form cryptic species. Additionally, recent advances in diagnosis of the disease are discussed as well as implications in relation to questions that have yet to be resolved.

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Section: Hydrophobic Stressorsmentioning

confidence: 99%

Ecology of aspergillosis: insights into the pathogenic potency of Aspergillus fumigatus and some other Aspergillus species

Paulussen

Hallsworth

Álvarez‐Pérez

et al. 2016

Microbial Biotechnology

278

175

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“…The PacC signal transduction pathway is involved in the hyphal response under both acidic and alkaline growth conditions. PacC is a Zn-finger transcription factor that is activated through protein-protein interactions in a conserved signaling cascade composed of six pal genes (palA, palB, palC, palF, palH, and palI) (45) and Vps32 (46). PacC controls the expression of many functional genes at pH 5.0, including gelA (45), a member of the Gas family of proteins, in A. niger.…”

Section: Discussionmentioning

confidence: 99%

P gas , a Low-pH-Induced Promoter, as a Tool for Dynamic Control of Gene Expression for Metabolic Engineering of Aspergillus niger

Yin

Shin

et al. 2017

Appl Environ Microbiol

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The dynamic control of gene expression is important for adjusting fluxes in order to obtain desired products and achieve appropriate cell growth, particularly when the synthesis of a desired product drains metabolites required for cell growth. For dynamic gene expression, a promoter responsive to a particular environmental stressor is vital. Here, we report a low-pH-inducible promoter, Pgas, which promotes minimal gene expression at pH values above 5.0 but functions efficiently at low pHs, such as pH 2.0. First, we performed a transcriptional analysis of Aspergillus niger, an excellent platform for the production of organic acids, and we found that the promoter Pgas may act efficiently at low pH. Then, a gene for synthetic green fluorescent protein (sGFP) was successfully expressed by Pgas at pH 2.0, verifying the results of the transcriptional analysis. Next, Pgas was used to express the cis-aconitate decarboxylase (cad) gene of Aspergillus terreus in A. niger, allowing the production of itaconic acid at a titer of 4.92 g/liter. Finally, we found that Pgas strength was independent of acid type and acid ion concentration, showing dependence on pH only. IMPORTANCE The promoter Pgas can be used for the dynamic control of gene expression in A. niger for metabolic engineering to produce organic acids. This promoter may also be a candidate tool for genetic engineering.KEYWORDS Aspergillus niger, low-pH-inducible promoter, itaconic acid, dynamic gene expression, metabolic engineering A spergillus niger is an excellent cell factory for the production of organic acids (1). The rational engineering of A. niger has attracted increasing attention, and great achievements have been made in this area (2, 3). Nevertheless, because heterologous pathways are controlled by constitutive promoters, e.g., the promoter of the glyceraldehyde-3-phosphate dehydrogenase gene (gpdA), most of this research has focused on static metabolic engineering; that is, the gene expression level is set without sensing changes in the pathway output or cellular environment (4). One disadvantage of static control is related to the trade-off between growth and the production of a desired compound; suboptimal productivity is obtained because these pathways can drain metabolites required for biomass synthesis (5). Metabolic engineering approaches are being developed to tackle this problem via a dynamic control system to compensate for changing conditions (6). In this system, the cell modulates its metabolic pathways dynamically to adjust fluxes such that the required metabolic intermediates are delivered at the appropriate levels and times to optimize growth (7).

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“…To date, little is known about functions of these molecular chaperones in filamentous fungi. In Aspergillus nidulans and Aspergillus terreus, Hsp70 orthologous were found to be associated with extracellular pH changes or amphotericin B resistance (Freitas et al, 2011;Blatzer et al, 2015). However, the definite proteins folded by Hsp70s have remained elusive in both yeasts and filamentous fungi (Peisker et al, 2010;Willmund et al, 2013).…”

Section: Introductionmentioning

confidence: 99%

The FgSsb‐FgZuo‐FgSsz complex regulates multiple stress responses and mycotoxin production via folding the soluble SNARE Vam7 and β2‐tubulin in Fusarium graminearum

Liu

Wang

Huang

et al. 2017

Environmental Microbiology

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Hsp70 proteins play important roles in protein folding in the budding yeast, but their functions in pathogenic fungi are largely unknown. Here, we found that Fusarium graminearum Hsp70 proteins FgSsb, FgSsz and their cochaperone FgZuo formed a complex. This complex was required for microtubule morphology, vacuole fusion and endocytosis. More importantly, the β2-tubulin FgTub2 and SNARE protein FgVam7 were identified as targeting proteins of this complex. We further found that the complex FgSsb-FgZuo-FgSsz controlled sensitivity of F. graminearum to the antimicrotubule drug carbendazim and cold stress via regulating the folding of FgTub2. Moreover, this complex assisted the folding of FgVam7, subsequently modulated vacuole fusion and responses to heavy metal, osmotic and oxidative stresses. In addition, the deletion of this complex led to dramatically decreased deoxynivalenol biosynthesis. This study uncovers a novel regulating mechanism of Hsp70 in multiple stress responses in a filamentous fungus.

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Transcription of the Hsp30, Hsp70, and Hsp90 heat shock protein genes is modulated by the PalA protein in response to acid pH-sensing in the fungus Aspergillus nidulans

Cited by 28 publications

References 36 publications

Ecology of aspergillosis: insights into the pathogenic potency of Aspergillus fumigatus and some other Aspergillus species

Ecology of aspergillosis: insights into the pathogenic potency of Aspergillus fumigatus and some other Aspergillus species

P gas , a Low-pH-Induced Promoter, as a Tool for Dynamic Control of Gene Expression for Metabolic Engineering of Aspergillus niger

The FgSsb‐FgZuo‐FgSsz complex regulates multiple stress responses and mycotoxin production via folding the soluble SNARE Vam7 and β2‐tubulin in Fusarium graminearum

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