scholarly journals Regulation of Nitrogen Metabolism by GATA Zinc Finger Transcription Factors in Yarrowia lipolytica

mSphere ◽  
2017 ◽  
Vol 2 (1) ◽  
Author(s):  
Kyle R. Pomraning ◽  
Erin L. Bredeweg ◽  
Scott E. Baker
Keyword(s):  
Transcription Factor ◽  
Lipid Metabolism ◽  
Nitrogen Source ◽  
Lipid Accumulation ◽  
Catabolite Repression ◽  
Carbon Catabolite Repression ◽  
Oleaginous Yeast ◽  
Nitrogen Catabolite Repression ◽  
Content Type ◽  
Gata Transcription Factor

ABSTRACT Nitrogen source is commonly used to control lipid production in industrial fungi. Here we identified regulators of nitrogen catabolite repression in the oleaginous yeast Y. lipolytica to determine how the nitrogen source regulates lipid metabolism. We show that disruption of both activators and repressors of nitrogen catabolite repression leads to increased lipid accumulation via activation of carbon catabolite repression through an as yet uncharacterized method. Fungi accumulate lipids in a manner dependent on the quantity and quality of the nitrogen source on which they are growing. In the oleaginous yeast Yarrowia lipolytica, growth on a complex source of nitrogen enables rapid growth and limited accumulation of neutral lipids, while growth on a simple nitrogen source promotes lipid accumulation in large lipid droplets. Here we examined the roles of nitrogen catabolite repression and its regulation by GATA zinc finger transcription factors on lipid metabolism in Y. lipolytica. Deletion of the GATA transcription factor genes gzf3 and gzf2 resulted in nitrogen source-specific growth defects and greater accumulation of lipids when the cells were growing on a simple nitrogen source. Deletion of gzf1, which is most similar to activators of genes repressed by nitrogen catabolite repression in filamentous ascomycetes, did not affect growth on the nitrogen sources tested. We examined gene expression of wild-type and GATA transcription factor mutants on simple and complex nitrogen sources and found that expression of enzymes involved in malate metabolism, beta-oxidation, and ammonia utilization are strongly upregulated on a simple nitrogen source. Deletion of gzf3 results in overexpression of genes with GATAA sites in their promoters, suggesting that it acts as a repressor, while gzf2 is required for expression of ammonia utilization genes but does not grossly affect the transcription level of genes predicted to be controlled by nitrogen catabolite repression. Both GATA transcription factor mutants exhibit decreased expression of genes controlled by carbon catabolite repression via the repressor mig1, including genes for beta-oxidation, highlighting the complex interplay between regulation of carbon, nitrogen, and lipid metabolism. IMPORTANCE Nitrogen source is commonly used to control lipid production in industrial fungi. Here we identified regulators of nitrogen catabolite repression in the oleaginous yeast Y. lipolytica to determine how the nitrogen source regulates lipid metabolism. We show that disruption of both activators and repressors of nitrogen catabolite repression leads to increased lipid accumulation via activation of carbon catabolite repression through an as yet uncharacterized method.

scholarly journals Carbon Catabolite Repression in Filamentous Fungi Is Regulated by Phosphorylation of the Transcription Factor CreA

mBio ◽  
2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Leandro José de Assis ◽  
Lilian Pereira Silva ◽  
Ozgur Bayram ◽  
Paul Dowling ◽  
Olaf Kniemeyer ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Filamentous Fungi ◽  
Enzyme Activities ◽  
Catabolite Repression ◽  
Cellular Localization ◽  
Carbon Catabolite Repression ◽  
Plant Biomass ◽  
Protein Accumulation ◽  
Phosphorylation Sites ◽  
Content Type

ABSTRACT Filamentous fungi of the genus Aspergillus are of particular interest for biotechnological applications due to their natural capacity to secrete carbohydrate-active enzymes (CAZy) that target plant biomass. The presence of easily metabolizable sugars such as glucose, whose concentrations increase during plant biomass hydrolysis, results in the repression of CAZy-encoding genes in a process known as carbon catabolite repression (CCR), which is undesired for the purpose of large-scale enzyme production. To date, the C2H2 transcription factor CreA has been described as the major CC repressor in Aspergillus spp., although little is known about the role of posttranslational modifications in this process. In this work, phosphorylation sites were identified by mass spectrometry on Aspergillus nidulans CreA, and subsequently, the previously identified but uncharacterized site S262, the characterized site S319, and the newly identified sites S268 and T308 were chosen to be mutated to nonphosphorylatable residues before their effect on CCR was investigated. Sites S262, S268, and T308 are important for CreA protein accumulation and cellular localization, DNA binding, and repression of enzyme activities. In agreement with a previous study, site S319 was not important for several here-tested phenotypes but is key for CreA degradation and induction of enzyme activities. All sites were shown to be important for glycogen and trehalose metabolism. This study highlights the importance of CreA phosphorylation sites for the regulation of CCR. These sites are interesting targets for biotechnological strain engineering without the need to delete essential genes, which could result in undesired side effects. IMPORTANCE In filamentous fungi, the transcription factor CreA controls carbohydrate metabolism through the regulation of genes encoding enzymes required for the use of alternative carbon sources. In this work, phosphorylation sites were identified on Aspergillus nidulans CreA, and subsequently, the two newly identified sites S268 and T308, the previously identified but uncharacterized site S262, and the previously characterized site S319 were chosen to be mutated to nonphosphorylatable residues before their effect on CCR was characterized. Sites S262, S268, and T308 are important for CreA protein accumulation and cellular localization, DNA binding, and repression of enzyme activities. In agreement with a previous study, site S319 is not important for several here-tested phenotypes but is key for CreA degradation and induction of enzyme activities. This work characterized novel CreA phosphorylation sites under carbon catabolite-repressing conditions and showed that they are crucial for CreA protein turnover, control of carbohydrate utilization, and biotechnologically relevant enzyme production.

scholarly journals Snf1 Is a Regulator of Lipid Accumulation in Yarrowia lipolytica

2013 ◽  
Vol 79 (23) ◽  
pp. 7360-7370 ◽  
Author(s):  
John Seip ◽  
Raymond Jackson ◽  
Hongxian He ◽  
Quinn Zhu ◽  
Seung-Pyo Hong
Keyword(s):  
Yarrowia Lipolytica ◽  
Lipid Accumulation ◽  
Oleaginous Yeast ◽  
De Novo ◽  
Lipid Synthesis ◽  
Omega 3 ◽  
Wild Type ◽  
Content Type ◽  
Reverse Transcription Pcr ◽  
Dry Cell Weight

ABSTRACTIn the oleaginous yeastYarrowia lipolytica,de novolipid synthesis and accumulation are induced under conditions of nitrogen limitation (or a high carbon-to-nitrogen ratio). The regulatory pathway responsible for this induction has not been identified. Here we report that the SNF1 pathway plays a key role in the transition from the growth phase to the oleaginous phase inY. lipolytica. Strains with aY. lipolyticasnf1(Ylsnf1) deletion accumulated fatty acids constitutively at levels up to 2.6-fold higher than those of the wild type. When introduced into aY. lipolyticastrain engineered to produce omega-3 eicosapentaenoic acid (EPA),Ylsnf1deletion led to a 52% increase in EPA titers (7.6% of dry cell weight) over the control. Other components of theY. lipolyticaSNF1 pathway were also identified, and their function in limiting fatty acid accumulation is suggested by gene deletion analyses. Deletion of the gene encoding YlSnf4, YlGal83, or YlSak1 significantly increased lipid accumulation in both growth and oleaginous phases compared to the wild type. Furthermore, microarray and quantitative reverse transcription-PCR (qRT-PCR) analyses of theYlsnf1mutant identified significantly differentially expressed genes duringde novolipid synthesis and accumulation inY. lipolytica. Gene ontology analysis found that these genes were highly enriched with genes involved in lipid metabolism. This work presents a new role for Snf1/AMP-activated protein kinase (AMPK) pathways in lipid accumulation in this oleaginous yeast.

scholarly journals Ethanolamine Utilization and Bacterial Microcompartment Formation Are Subject to Carbon Catabolite Repression

2019 ◽  
Vol 201 (10) ◽  
Author(s):  
Karan Gautam Kaval ◽  
Margo Gebbie ◽  
Jonathan R. Goodson ◽  
Melissa R. Cruz ◽  
Wade C. Winkler ◽  
...  
Keyword(s):  
Gene Expression ◽  
Enterococcus Faecalis ◽  
Small Rna ◽  
Catabolite Repression ◽  
Carbon Catabolite Repression ◽  
Bioinformatics Analysis ◽  
Maximum Efficiency ◽  
Gi Tract ◽  
Content Type ◽  
Regulatory Factors

ABSTRACT Ethanolamine (EA) is a compound prevalent in the gastrointestinal (GI) tract that can be used as a carbon, nitrogen, and/or energy source. Enterococcus faecalis, a GI commensal and opportunistic pathogen, contains approximately 20 ethanolamine utilization (eut) genes encoding the necessary regulatory, enzymatic, and structural proteins for this process. Here, using a chemically defined medium, two regulatory factors that affect EA utilization were examined. First, the functional consequences of loss of the small RNA (sRNA) EutX on the efficacy of EA utilization were investigated. One effect observed, as loss of this negative regulator causes an increase in eut gene expression, was a concomitant increase in the number of catabolic bacterial microcompartments (BMCs) formed. However, despite this increase, the growth of the strain was repressed, suggesting that the overall efficacy of EA utilization was negatively affected. Second, utilizing a deletion mutant and a complement, carbon catabolite control protein A (CcpA) was shown to be responsible for the repression of EA utilization in the presence of glucose. A predicted cre site in one of the three EA-inducible promoters, PeutS, was identified as the target of CcpA. However, CcpA was shown to affect the activation of all the promoters indirectly through the two-component system EutV and EutW, whose genes are under the control of the PeutS promoter. Moreover, a bioinformatics analysis of bacteria predicted to contain CcpA and cre sites revealed that a preponderance of BMC-containing operons are likely regulated by carbon catabolite repression (CCR). IMPORTANCE Ethanolamine (EA) is a compound commonly found in the gastrointestinal (GI) tract that can affect the behavior of human pathogens that can sense and utilize it, such as Enterococcus faecalis and Salmonella. Therefore, it is important to understand how the genes that govern EA utilization are regulated. In this work, we investigated two regulatory factors that control this process. One factor, a small RNA (sRNA), is shown to be important for generating the right levels of gene expression for maximum efficiency. The second factor, a transcriptional repressor, is important for preventing expression when other preferred sources of energy are available. Furthermore, a global bioinformatics analysis revealed that this second mechanism of transcriptional regulation likely operates on similar genes in related bacteria.

scholarly journals TORC1 Regulates Developmental Responses to Nitrogen Stress via Regulation of the GATA Transcription Factor Gaf1

mBio ◽  
2015 ◽  
Vol 6 (4) ◽  
Author(s):  
Dana Laor ◽  
Adiel Cohen ◽  
Martin Kupiec ◽  
Ronit Weisman
Keyword(s):  
Transcription Factor ◽  
Sexual Development ◽  
Nitrogen Availability ◽  
Stress Conditions ◽  
Nitrogen Stress ◽  
Content Type ◽  
Downstream Target ◽  
Gata Transcription Factor ◽  
Novel Target ◽  
Developmental Responses

ABSTRACT The TOR (target of rapamycin [sirolimus]) is a universally conserved kinase that couples nutrient availability to cell growth. TOR complex 1 (TORC1) in Schizosaccharomyces pombe positively regulates growth in response to nitrogen availability while suppressing cellular responses to nitrogen stress. Here we report the identification of the GATA transcription factor Gaf1 as a positive regulator of the nitrogen stress-induced gene isp7 +, via three canonical GATA motifs. We show that under nitrogen-rich conditions, TORC1 positively regulates the phosphorylation and cytoplasmic retention of Gaf1 via the PP2A-like phosphatase Ppe1. Under nitrogen stress conditions when TORC1 is inactivated, Gaf1 becomes dephosphorylated and enters the nucleus. Gaf1 was recently shown to negatively regulate the transcription induction of ste11 +, a major regulator of sexual development. Our findings support a model of a two-faceted role of Gaf1 during nitrogen stress. Gaf1 positively regulates genes that are induced early in the response to nitrogen stress, while inhibiting later responses, such as sexual development. Taking these results together, we identify Gaf1 as a novel target for TORC1 signaling and a step-like mechanism to modulate the nitrogen stress response. IMPORTANCE TOR complex 1 (TORC1) is an evolutionary conserved protein complex that positively regulates growth and proliferation, while inhibiting starvation responses. In fission yeast, the activity of TORC1 is downregulated in response to nitrogen starvation, and cells reprogram their transcriptional profile and prepare for sexual development. We identify Gaf1, a GATA-like transcription factor that regulates transcription and sexual development in response to starvation, as a downstream target for TORC1 signaling. Under nitrogen-rich conditions, TORC1 positively regulates the phosphorylation and cytoplasmic retention of Gaf1 via the PP2A-like phosphatase Ppe1. Under nitrogen stress conditions when TORC1 is inactivated, Gaf1 becomes dephosphorylated and enters the nucleus. Budding yeast TORC1 regulates GATA transcription factors via the phosphatase Sit4, a structural homologue of Ppe1. Thus, the TORC1-GATA transcription module appears to be conserved in evolution and may also be found in higher eukaryotes.

scholarly journals Regulation ofAspergillus nidulansCreA-Mediated Catabolite Repression by the F-Box Proteins Fbx23 and Fbx47

mBio ◽  
2018 ◽  
Vol 9 (3) ◽  
Author(s):  
Leandro José de Assis ◽  
Mevlut Ulas ◽  
Laure Nicolas Annick Ries ◽  
Nadia Ali Mohamed El Ramli ◽  
Ozlem Sarikaya-Bayram ◽  
...  
Keyword(s):  
Carbon Source ◽  
Aspergillus Nidulans ◽  
Ubiquitin Ligase ◽  
Catabolite Repression ◽  
Carbon Catabolite Repression ◽  
26S Proteasome ◽  
Xylanase Production ◽  
Content Type ◽  
Regulatory Pathways ◽  
Ubiquitin Ligase Complex

ABSTRACTThe attachment of one or more ubiquitin molecules by SCF (Skp–Cullin–F-box) complexes to protein substrates targets them for subsequent degradation by the 26S proteasome, allowing the control of numerous cellular processes. Glucose-mediated signaling and subsequent carbon catabolite repression (CCR) are processes relying on the functional regulation of target proteins, ultimately controlling the utilization of this carbon source. In the filamentous fungusAspergillus nidulans, CCR is mediated by the transcription factor CreA, which modulates the expression of genes encoding biotechnologically relevant enzymes. Although CreA-mediated repression of target genes has been extensively studied, less is known about the regulatory pathways governing CCR and this work aimed at further unravelling these events. The Fbx23 F-box protein was identified as being involved in CCR and the Δfbx23mutant presented impaired xylanase production under repressing (glucose) and derepressing (xylan) conditions. Mass spectrometry showed that Fbx23 is part of an SCF ubiquitin ligase complex that is bridged via the GskA protein kinase to the CreA-SsnF-RcoA repressor complex, resulting in the degradation of the latter under derepressing conditions. Upon the addition of glucose, CreA dissociates from the ubiquitin ligase complex and is transported into the nucleus. Furthermore, casein kinase is important for CreA function during glucose signaling, although the exact role of phosphorylation in CCR remains to be determined. In summary, this study unraveled novel mechanistic details underlying CreA-mediated CCR and provided a solid basis for studying additional factors involved in carbon source utilization which could prove useful for biotechnological applications.IMPORTANCEThe production of biofuels from plant biomass has gained interest in recent years as an environmentally friendly alternative to production from petroleum-based energy sources. Filamentous fungi, which naturally thrive on decaying plant matter, are of particular interest for this process due to their ability to secrete enzymes required for the deconstruction of lignocellulosic material. A major drawback in fungal hydrolytic enzyme production is the repression of the corresponding genes in the presence of glucose, a process known as carbon catabolite repression (CCR). This report provides previously unknown mechanistic insights into CCR through elucidating part of the protein-protein interaction regulatory system that governs the CreA transcriptional regulator in the reference organismAspergillus nidulansin the presence of glucose and the biotechnologically relevant plant polysaccharide xylan.

scholarly journals The Formaldehyde Dehydrogenase SsFdh1 Is Regulated by and Functionally Cooperates with the GATA Transcription Factor SsNsd1 in Sclerotinia sclerotiorum

mSystems ◽  
2019 ◽  
Vol 4 (5) ◽  
Author(s):  
Genglin Zhu ◽  
Gang Yu ◽  
Xianghui Zhang ◽  
Jinliang Liu ◽  
Yanhua Zhang ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Zinc Finger ◽  
Sclerotinia Sclerotiorum ◽  
Promoter Region ◽  
Nuclear Translocation ◽  
Effective Control ◽  
Formaldehyde Dehydrogenase ◽  
Content Type ◽  
Gata Transcription Factor ◽  
Gata Box

ABSTRACT GATA transcription factors (TFs) are common eukaryotic regulators, and glutathione-dependent formaldehyde dehydrogenases (GD-FDH) are ubiquitous enzymes with formaldehyde detoxification activity. In this study, the formaldehyde dehydrogenase Sclerotinia sclerotiorum Fdh1 (SsFdh1) was first characterized as an interacting partner of a GATA TF, SsNsd1, in S. sclerotiorum. Genetic analysis reveals that SsFdh1 functions in formaldehyde detoxification, nitrogen metabolism, sclerotium development, and pathogenicity. Both SsNsd1 and SsFdh1 harbor typical zinc finger motifs with conserved cysteine residues. SsNsd1 regulates SsFdh1 in two distinct manners. SsNsd1 directly binds to GATA-box DNA in the promoter region of Ssfdh1; SsNsd1 associates with SsFdh1 through disulfide bonds formed by conserved Cys residues. The SsNsd1-SsFdh1 interaction and nuclear translocation were found to prevent efficient binding of SsNsd1 to GATA-box DNA. Site-directed point mutation of these Cys residues influences the SsNsd1-SsFdh1 interaction and SsNsd1 DNA binding capacity. SsFdh1 is regulated by and functions jointly with the SsNsd1 factor, providing new insights into the complex transcriptional regulatory mechanisms of GATA factors. IMPORTANCE S. sclerotiorum is a pathogenic fungus with sclerotium and infection cushion development, making S. sclerotiorum one of the most challenging agricultural pathogens with no effective control method. We identified important sclerotium and compound appressorium formation determinants, SsNsd1 and SsFdh1, and investigated their regulatory mechanism at the molecular level. SsNsd1 and SsFdh1 are zinc finger motif-containing proteins and associate with each other in the nucleus. On other hand, SsNsd1, as a GATA transcription factor, directly binds to GATA-box DNA in the promoter region of Ssfdh1. The SsNsd1-SsFdh1 interaction and nuclear translocation were found to prevent efficient binding of SsNsd1 to GATA-box DNA. Our results provide insights into the role of the GATA transcription factor and its regulation of formaldehyde dehydrogenase in stress resistance, fungal sclerotium and compound appressorium development, and pathogenicity.

scholarly journals Global Expression Analysis of the Yeast Lachancea (Saccharomyces) kluyveri Reveals NewURCGenes Involved in Pyrimidine Catabolism

2013 ◽  
Vol 13 (1) ◽  
pp. 31-42 ◽  
Author(s):  
Anna Andersson Rasmussen ◽  
Dineshkumar Kandasamy ◽  
Halfdan Beck ◽  
Seth D. Crosby ◽  
Olof Björnberg ◽  
...  
Keyword(s):  
Expression Pattern ◽  
Catabolite Repression ◽  
Nitrogen Sources ◽  
Global Changes ◽  
Nitrogen Catabolite Repression ◽  
Content Type ◽  
Double Deletion ◽  
Pyrimidine Catabolism ◽  
Saccharomyces Kluyveri ◽  
Similar Expression Pattern

ABSTRACTPyrimidines are important nucleic acid precursors which are constantly synthesized, degraded, and rebuilt in the cell. Four degradation pathways, two of which are found in eukaryotes, have been described. One of them, theURCpathway, has been initially discovered in our laboratory in the yeastLachancea kluyveri. Here, we present the global changes in gene expression inL. kluyveriin response to different nitrogen sources, including uracil, uridine, dihydrouracil, and ammonia. The expression pattern of the knownURCgenes,URC1-6, helped to identify nine putative novelURCgenes with a similar expression pattern. The microarray analysis provided evidence that both theURCandPYDgenes are under nitrogen catabolite repression inL. kluyveriand are induced by uracil or dihydrouracil, respectively. We determined the function ofURC8, which was found to catalyze the reduction of malonate semialdehyde to 3-hydroxypropionate, the final degradation product of the pathway. The other eight genes studied were all putative permeases. Our analysis of double deletion strains showed that theL. kluyveriFui1p protein transported uridine, just like its homolog inSaccharomyces cerevisiae, but we demonstrated that is was not the only uridine transporter inL. kluyveri. We also showed that theL. kluyverihomologs ofDUR3andFUR4do not have the same function that they have inS. cerevisiae, where they transport urea and uracil, respectively. InL. kluyveri, both of these deletion strains grew normally on uracil and urea.

scholarly journals Put3 Positively Regulates Proline Utilization in Candida albicans

mSphere ◽  
2017 ◽  
Vol 2 (6) ◽  
Author(s):  
Walters Aji Tebung ◽  
Raha Parvizi Omran ◽  
Debra L. Fulton ◽  
Joachim Morschhäuser ◽  
Malcolm Whiteway
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Transcription Factor ◽  
Candida Albicans ◽  
Nitrogen Source ◽  
Opportunistic Pathogen ◽  
Baker's Yeast ◽  
Null Mutant ◽  
Multiple Sources ◽  
Content Type ◽  
Proline Catabolism

ABSTRACT Candida albicans poses a significant threat to the lives of immunocompromised people. Historically, knowledge has been drawn from studies on Saccharomyces cerevisiae to understand the pathogen, and many Candida albicans genes are named after their S. cerevisiae orthologs. Direct studies on the pathogen have, however, revealed differences in the roles of some orthologous proteins in the two yeasts. We show that the Put3 transcription factor allows the pathogen to completely degrade proline to usable nitrogen and carbon by evading regulatory restrictions imposed on its S. cerevisiae ortholog, which mandates conditional use of proline only as a nitrogen source in the baker’s yeast. The ability of Candida albicans to freely obtain nutrients from multiple sources may help it thrive as a commensal and opportunistic pathogen. The zinc cluster transcription factor Put3 was initially characterized in Saccharomyces cerevisiae as the transcriptional activator of PUT1 and PUT2, two genes acting early in the proline assimilation pathway. We have used phenotypic studies, transcription profiling, and chromatin immunoprecipitation with microarray technology (ChIP-chip) to establish that unlike S. cerevisiae, which only uses proline as a nitrogen source, Candida albicans can use proline as a nitrogen source, a carbon source, or a source of both nitrogen and carbon. However, a C. albicans put3 null mutant cannot grow on proline, suggesting that as in S. cerevisiae, C. albicans Put3 (CaPut3) is required for proline catabolism, and because the C. albicans put3 null mutant grew efficiently on glutamate as the sole carbon or nitrogen source, it appears that CaPut3 also regulates the early genes of the pathway. CaPut3 showed direct binding to the CaPUT1 promoter, and both PUT1 and PUT2 were upregulated in response to proline addition in a Put3-dependent manner, as well as in a C. albicans strain expressing a hyperactive Put3. CaPut3 directs proline degradation even in the presence of a good nitrogen source such as ammonia, which contrasts with S. cerevisiae Put3 (ScPut3)-regulated proline catabolism, which only occurs in the absence of a rich nitrogen source. Thus, while overall proline regulatory circuitry differs between S. cerevisiae and C. albicans, the specific role of Put3 appears fundamentally conserved. IMPORTANCE Candida albicans poses a significant threat to the lives of immunocompromised people. Historically, knowledge has been drawn from studies on Saccharomyces cerevisiae to understand the pathogen, and many Candida albicans genes are named after their S. cerevisiae orthologs. Direct studies on the pathogen have, however, revealed differences in the roles of some orthologous proteins in the two yeasts. We show that the Put3 transcription factor allows the pathogen to completely degrade proline to usable nitrogen and carbon by evading regulatory restrictions imposed on its S. cerevisiae ortholog, which mandates conditional use of proline only as a nitrogen source in the baker’s yeast. The ability of Candida albicans to freely obtain nutrients from multiple sources may help it thrive as a commensal and opportunistic pathogen.

scholarly journals Fungal Morphology, Iron Homeostasis, and Lipid Metabolism Regulated by a GATA Transcription Factor in Blastomyces dermatitidis

2015 ◽  
Vol 11 (6) ◽  
pp. e1004959 ◽  
Author(s):  
Amber J. Marty ◽  
Aimee T. Broman ◽  
Robert Zarnowski ◽  
Teigan G. Dwyer ◽  
Laura M. Bond ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Lipid Metabolism ◽  
Iron Homeostasis ◽  
Blastomyces Dermatitidis ◽  
Fungal Morphology ◽  
Gata Transcription Factor

scholarly journals Multiple Nuclear Localization Signals Mediate Nuclear Localization of the GATA Transcription Factor AreA

2014 ◽  
Vol 13 (4) ◽  
pp. 527-538 ◽  
Author(s):  
Cameron C. Hunter ◽  
Kendra S. Siebert ◽  
Damien J. Downes ◽  
Koon Ho Wong ◽  
Sara D. Kreutzberger ◽  
...  
Keyword(s):  
Gene Expression ◽  
Transcription Factor ◽  
Dna Binding ◽  
Nuclear Localization ◽  
Fluorescent Protein ◽  
Nitrogen Sources ◽  
Nuclear Accumulation ◽  
Content Type ◽  
Nuclear Localization Signals ◽  
Gata Transcription Factor

ABSTRACTTheAspergillus nidulansGATA transcription factor AreA activates transcription of nitrogen metabolic genes in response to nitrogen limitation and is known to accumulate in the nucleus during nitrogen starvation. Sequence analysis of AreA revealed multiple nuclear localization signals (NLSs), five putative classical NLSs conserved in fungal AreA orthologs but not in theSaccharomyces cerevisiaefunctional orthologs Gln3p and Gat1p, and one putative noncanonical RRX33RXR bipartite NLS within the DNA-binding domain. In order to identify the functional NLSs in AreA, we constructedareAmutants with mutations in individual putative NLSs or combinations of putative NLSs and strains expressing green fluorescent protein (GFP)-AreA NLS fusion genes. Deletion of all five classical NLSs individually or collectively did not affect utilization of nitrogen sources or AreA-dependent gene expression and did not prevent AreA nuclear localization. Mutation of the bipartite NLS conferred the inability to utilize alternative nitrogen sources and abolished AreA-dependent gene expression likely due to effects on DNA binding but did not prevent AreA nuclear localization. Mutation of all six NLSs simultaneously prevented AreA nuclear accumulation. The bipartite NLS alone strongly directed GFP to the nucleus, whereas the classical NLSs collaborated to direct GFP to the nucleus. Therefore, AreA contains multiple conserved NLSs, which show redundancy and together function to mediate nuclear import. The noncanonical bipartite NLS is conserved in GATA factors fromAspergillus, yeast, and mammals, indicating an ancient origin.

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