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Valente S, Cometto A, Piombo E, Meloni GR, Ballester AR, González-Candelas L, Spadaro D. Elaborated regulation of griseofulvin biosynthesis in Penicillium griseofulvum and its role on conidiation and virulence. Int J Food Microbiol 2020; 328:108687. [PMID: 32474227 DOI: 10.1016/j.ijfoodmicro.2020.108687] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Revised: 05/14/2020] [Accepted: 05/23/2020] [Indexed: 10/24/2022]
Abstract
Penicilium griseofulvum, the causal agent of apple blue mold, is able to produce in vitro and on apple a broad spectrum of secondary metabolites (SM), including patulin, roquefortine C and griseofulvin. Among them, griseofulvin is known for its antifungal and antiproliferative activity, and has received interest in many sectors, from medicine to agriculture. The biosynthesis of SM is finely regulated by filamentous fungi and can involve global regulators and pathway specific regulators, which are usually encoded by genes present in the same gene cluster as the backbone gene and tailoring enzymes. In the griseofulvin gene cluster, two putative transcription factors were previously identified, encoded by genes gsfR1 and gsfR2, and their role has been investigated in the present work. Analysis of P. griseofulvum knockout mutants lacking either gene suggest that gsfR2 forms part of a different pathway and gsfR1 exhibits many spectra of action, acting as regulator of griseofulvin and patulin biosynthesis and influencing conidia production and virulence on apple. The analysis of gsfR1 promoter revealed that the regulation of griseofulvin biosynthesis is also controlled by global regulators in response to many environmental stimuli, such as carbon and nitrogen. The influence of carbon and nitrogen on griseofulvin production was further investigated and verified, revealing a complex network of response and confirming the central role of gsfR1 in many processes in P. griseofulvum.
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Affiliation(s)
- Silvia Valente
- Dept. Agricultural, Forest and Food Sciences (DISAFA), Università degli Studi di Torino, Largo Paolo Braccini 2, 10095 Grugliasco, Italy
| | - Agnese Cometto
- Dept. Agricultural, Forest and Food Sciences (DISAFA), Università degli Studi di Torino, Largo Paolo Braccini 2, 10095 Grugliasco, Italy
| | - Edoardo Piombo
- Dept. Agricultural, Forest and Food Sciences (DISAFA), Università degli Studi di Torino, Largo Paolo Braccini 2, 10095 Grugliasco, Italy
| | - Giovanna Roberta Meloni
- Dept. Agricultural, Forest and Food Sciences (DISAFA), Università degli Studi di Torino, Largo Paolo Braccini 2, 10095 Grugliasco, Italy
| | - Ana-Rosa Ballester
- IATA-CSIC - Instituto de Agroquímica y Tecnología de Alimentos, Calle Catedrático Agustín Escardino 7, Paterna 46980, Valencia, Spain
| | - Luis González-Candelas
- IATA-CSIC - Instituto de Agroquímica y Tecnología de Alimentos, Calle Catedrático Agustín Escardino 7, Paterna 46980, Valencia, Spain.
| | - Davide Spadaro
- Dept. Agricultural, Forest and Food Sciences (DISAFA), Università degli Studi di Torino, Largo Paolo Braccini 2, 10095 Grugliasco, Italy.
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2
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Wang ZQ, Meng FZ, Zhang MM, Yin LF, Yin WX, Lin Y, Hsiang T, Peng YL, Wang ZH, Luo CX. A Putative Zn 2Cys 6 Transcription Factor Is Associated With Isoprothiolane Resistance in Magnaporthe oryzae. Front Microbiol 2018; 9:2608. [PMID: 30429837 PMCID: PMC6220061 DOI: 10.3389/fmicb.2018.02608] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Accepted: 10/12/2018] [Indexed: 12/18/2022] Open
Abstract
Isoprothiolane (IPT), a systemic fungicide, has been applied to control rice blast since the 1970s. Although resistance to IPT has been observed, the mechanism of resistance still has not been fully elucidated. In this study, nucleotide polymorphisms were detected between two IPT-resistant mutants generated in the lab, and their parental wild type isolates using a whole-genome sequencing approach. In the genomes of the two resistant mutants, single point mutations were identified in a gene encoding a Zn2Cys6 transcription factor-like protein. Notably, either knocking out the gene or replacing the wild type allele with the mutant allele (R343W) in a wild type isolate resulted in resistance to IPT, indicating that the gene is associated with IPT resistance, and thus was designated as MoIRR (Magnaporthe oryzae isoprothiolane resistance related). Along with point mutations R343W in mutant 1a_mut, and R345C in 1c_mut, a 16 bp insertion in 6c_mut was also located in the Fungal_TF_MHR domain of MoIRR, revealing that this domain may be the core element for IPT resistance. In addition, IPT-resistant mutants and transformants showed cross-resistance with iprobenfos (IBP), which was consistent with previous observations. These results indicated that MoIRR is strongly connected to resistance to choline biosynthesis inhibitor (CBI), and further work should focus on investigating downstream effects of MoIRR.
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Affiliation(s)
- Zuo-Qian Wang
- Department of Plant Pathology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Fan-Zhu Meng
- Department of Plant Pathology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Ming-Ming Zhang
- Department of Plant Pathology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Liang-Fen Yin
- Department of Plant Pathology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
- The Key Lab of Crop Disease Monitoring & Safety Control in Hubei Province, Huazhong Agricultural University, Wuhan, China
| | - Wei-Xiao Yin
- Department of Plant Pathology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
- The Key Lab of Crop Disease Monitoring & Safety Control in Hubei Province, Huazhong Agricultural University, Wuhan, China
| | - Yang Lin
- Department of Plant Pathology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
- The Key Lab of Crop Disease Monitoring & Safety Control in Hubei Province, Huazhong Agricultural University, Wuhan, China
| | - Tom Hsiang
- School of Environmental Sciences, University of Guelph, Guelph, ON, Canada
| | - You-Liang Peng
- Department of Plant Pathology, College of Plant Protection, China Agricultural University, Beijing, China
| | - Zong-Hua Wang
- College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Chao-Xi Luo
- Department of Plant Pathology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
- The Key Lab of Crop Disease Monitoring & Safety Control in Hubei Province, Huazhong Agricultural University, Wuhan, China
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3
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Chang PK, Ehrlich KC. Genome-wide analysis of the Zn(II)2Cys6 zinc cluster-encoding gene family in Aspergillus flavus. Appl Microbiol Biotechnol 2013; 97:4289-300. [DOI: 10.1007/s00253-013-4865-2] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2013] [Revised: 03/13/2013] [Accepted: 03/18/2013] [Indexed: 12/16/2022]
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4
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Suzuki Y, Murray SL, Wong KH, Davis MA, Hynes MJ. Reprogramming of carbon metabolism by the transcriptional activators AcuK and AcuM in Aspergillus nidulans. Mol Microbiol 2012; 84:942-64. [DOI: 10.1111/j.1365-2958.2012.08067.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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5
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Developing Aspergillus as a host for heterologous expression. Biotechnol Adv 2009; 27:53-75. [DOI: 10.1016/j.biotechadv.2008.09.001] [Citation(s) in RCA: 204] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2008] [Revised: 09/04/2008] [Accepted: 09/07/2008] [Indexed: 12/11/2022]
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6
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Caruso ML, Litzka O, Martic G, Lottspeich F, Brakhage AA. Novel basic-region helix-loop-helix transcription factor (AnBH1) of Aspergillus nidulans counteracts the CCAAT-binding complex AnCF in the promoter of a penicillin biosynthesis gene. J Mol Biol 2002; 323:425-39. [PMID: 12381299 DOI: 10.1016/s0022-2836(02)00965-8] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Cis-acting CCAAT elements are found frequently in eukaryotic promoter regions. Many of the genes containing such elements in their promoters are regulated by a conserved multimeric CCAAT-binding complex. In the fungus Emericella (Aspergillus) nidulans, this complex was designated AnCF (A.nidulans CCAAT-binding factor). AnCF regulates several genes, including the penicillin biosynthesis genes ipnA and aatA. Since it is estimated that the CCAAT-binding complex regulates more than 200 genes, an important question concerns the regulation mechanism that allows so many genes to be regulated by a single complex in a gene-specific manner. One of the answers to this question appears to lie in the interaction of AnCF with other transcription factors. Here, a novel transcription factor designated AnBH1 was isolated. The corresponding anbH1 gene was cloned and found to be located on chromosome IV. The deduced AnBH1 protein belongs to the family of basic-region helix-loop-helix (bHLH) transcription factors. AnBH1 binds in vitro as a homodimer to an, not previously described, asymmetric E-box within the aatA promoter that overlaps with the AnCF-binding site. This is the first report demonstrating that the CCAAT-binding complex and a bHLH transcription factor bind to overlapping sites. Since deletion of anbH1 appears to be lethal, the anbH1 gene was replaced by a regulatable alcAp-anbH1 gene fusion. The analysis of aatAp-lacZ expression in such a strain indicated that AnBH1 acts as a repressor of aatA gene expression and therefore counteracts the positive action of AnCF.
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Affiliation(s)
- Maria Louise Caruso
- Institut für Mikrobiologie, Universität Hannover, Schneiderberg 50, 30167 Hannover, Germany
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7
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MacCabe AP, Orejas M, Tamayo EN, Villanueva A, Ramón D. Improving extracellular production of food-use enzymes from Aspergillus nidulans. J Biotechnol 2002; 96:43-54. [PMID: 12142142 DOI: 10.1016/s0168-1656(02)00036-6] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Filamentous fungi, and particularly those of the genus Aspergillus, are major producers of enzymatic activities that have important applications in the food and beverage industries. Prior to the availability of transformation systems improvement of industrial production strains was largely restricted to the strategy of mutagenesis, screening and selection. Aspergillus nidulans is a genetically amenable filamentous fungus the ease of handling and analysis of which has led to its use as a model system for the investigation of eukaryotic gene regulation. Although not used industrially it is able to produce a wide variety of extracellular enzymatic activities. As a consequence of half a century of study a considerable resource of characterised mutants has been generated in conjunction with extensive genetic and molecular information on various gene regulatory systems in this micro-organism. Investigation of xylanase gene regulation in A. nidulans as a model for the production of food-use extracellular enzymes suggests strategies by which production of these enzymes in industrially useful species may be improved.
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Affiliation(s)
- A P MacCabe
- Instituto de Agroquímica y Tecnología de Alimentos (CSIC), Apartado de Correos 73, 46100, Valencia, Burjassot, Spain.
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8
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Li D, Sirakova T, Rogers L, Ettinger WF, Kolattukudy PE. Regulation of constitutively expressed and induced cutinase genes by different zinc finger transcription factors in Fusarium solani f. sp. pisi (Nectria haematococca). J Biol Chem 2002; 277:7905-12. [PMID: 11756444 DOI: 10.1074/jbc.m108799200] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Cutin monomers, generated by the low levels of constitutively expressed cutinase, induce high levels of cutinase that can help pathogenic fungi to penetrate into the host through the cuticle whose major structural polymer is cutin. We cloned three highly homologous cutinase genes, cut1, cut2, and cut3, from Fusarium solani f. pisi (Nectria haematococca). Amino acid sequence deduced from the nucleotide sequence of cut1 and cut2/3 matched with that of the peptides from cutinase 1 and cutinase 2, respectively, isolated from F. solani pisi grown on cutin as the sole carbon source. Induction of beta-glucuronidase gene fused to the promoters of the cutinases integrated into F. solani pisi genome indicates that cut2 is constitutively expressed and induced under starvation, whereas cut1 is highly induced by cutin monomers. A palindrome binding protein (PBP) previously cloned binds only to palindrome 1 of cut1 promoter but not palindrome 1 of cut2/3 which contains two base substitutions. PBP is thought to interfere with the binding of CTF1 alpha, the transcription factor involved in induction, to cut1 promoter and thus keep cut1 gene repressed until induced by cutin monomers. Because PBP cannot bind palindrome 1 of cut2, this gene is not repressed. CTF1 alpha does not transactivate cut2 promoter. A new Cys(6)Zn(2) motif-containing transcription factor, CTF1 beta, that binds palindrome 2 was cloned and sequenced. In yeast, CTF1 beta transactivates cut2 promoter but not cut1 promoter unless its palindrome 1 is mutated, unlike CTF1 alpha which transactivates cut1. Thus, CTF1 beta is involved in the constitutive expression of cut2 that causes production of low levels of cutin monomers that strongly induce cut1 using CTF1 alpha as the transcription factor.
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Affiliation(s)
- Daoxin Li
- Department of Biochemistry, The Ohio State University, Columbus, Ohio 43210, USA
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Steidl S, Hynes MJ, Brakhage AA. The Aspergillus nidulans multimeric CCAAT binding complex AnCF is negatively autoregulated via its hapB subunit gene. J Mol Biol 2001; 306:643-53. [PMID: 11243777 DOI: 10.1006/jmbi.2001.4412] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Cis-acting CCAAT elements are frequently found in eukaryotic promoter regions. Many of them are bound by conserved multimeric complexes. In the fungus Aspergillus nidulans the respective complex was designated AnCF (A. nidulans CCAAT binding factor). AnCF is composed of at least three subunits designated HapB, HapC and HapE. Here, we show that the promoter regions of the hapB genes in both A. nidulans and Aspergillus oryzae contain two inversely oriented, conserved CCAAT boxes (box alpha and box beta). Electrophoretic mobility shift assays (EMSAs) using both nuclear extracts and the purified, reconstituted AnCF complex indicated that AnCF binding in vitro to these boxes occurs in a non-mutually exclusive manner. Western and Northern blot analyses showed that steady-state levels of HapB protein as well as hapB mRNA were elevated in hapC and hapE deletion mutants, suggesting a repressing effect of AnCF on hapB expression. Consistently, in a hapB deletion background the hapB-lacZ expression level was elevated compared with the expression in the wild-type. This was further supported by overexpression of hapB using an inducible alcA-hapB construct. Induction of alcA-hapB expression strongly repressed the expression of a hapB-lacZ gene fusion. However, mutagenesis of box beta led to a fivefold reduced expression of a hapB-lacZ gene fusion compared with the expression derived from a wild-type hapB-lacZ fusion. These results indicate that (i) box beta is an important positive cis-acting element in hapB regulation, (ii) AnCF does not represent the corresponding positive trans-acting factor and (iii) that AnCF is involved in repression of hapB.
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Affiliation(s)
- S Steidl
- Institut für Mikrobiologie und Genetik, Technische Universität Darmstadt, Schnittspahnstrasse 10, Darmstadt, D-64287, Germany
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10
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Aspergillus nidulans as a model organism for the study of the expression of genes encoding enzymes of relevance in the food industry. ACTA ACUST UNITED AC 2001. [DOI: 10.1016/s1874-5334(01)80011-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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11
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Metabolic Regulation in Fungi. ACTA ACUST UNITED AC 2001. [DOI: 10.1016/s1874-5334(01)80005-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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12
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Tsuji G, Kenmochi Y, Takano Y, Sweigard J, Farrall L, Furusawa I, Horino O, Kubo Y. Novel fungal transcriptional activators, Cmr1p of Colletotrichum lagenarium and pig1p of Magnaporthe grisea, contain Cys2His2 zinc finger and Zn(II)2Cys6 binuclear cluster DNA-binding motifs and regulate transcription of melanin biosynthesis genes in a developmentally specific manner. Mol Microbiol 2000; 38:940-54. [PMID: 11123670 DOI: 10.1046/j.1365-2958.2000.02181.x] [Citation(s) in RCA: 123] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Colletotrichum lagenarium and Magnaporthe grisea are plant pathogenic fungi that produce melanin during the appressorial differentiation stage of conidial germination and during the late stationary phase of mycelial growth. Here, we report the identification of genes for two unique transcription factors, CMR1 (Colletotrichum melanin regulation) and PIG1 (pigment of Magnaporthe), that are involved in melanin biosynthesis. Both Cmr1p and Pig1p contain two distinct DNA-binding motifs, a Cys2His2 zinc finger motif and a Zn(II)2Cys6 binuclear cluster motif. The presence of both these motifs in a single transcriptional regulatory protein is unique among known eukaryotic transcription factors. Deletion of CMR1 in C. lagenarium caused a defect in mycelial melanization, but not in appressorial melanization. Also, cmr1Delta mutants do not express the melanin biosynthetic structural genes SCD1 and THR1 during mycelial melanization, although the expression of these two genes was not affected during appressorial melanization.
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Affiliation(s)
- G Tsuji
- Laboratory of Plant Pathology, Faculty of Agriculture, Kyoto Prefectural University, Kyoto 606-8522, Japan
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13
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Small AJ, Hynes MJ, Davis MA. The TamA protein fused to a DNA-binding domain can recruit AreA, the major nitrogen regulatory protein, to activate gene expression in Aspergillus nidulans. Genetics 1999; 153:95-105. [PMID: 10471703 PMCID: PMC1460753 DOI: 10.1093/genetics/153.1.95] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The areA gene of Aspergillus nidulans encodes a GATA zinc finger transcription factor that activates the expression of a large number of genes subject to nitrogen metabolite repression. The amount and activity of the AreA protein under different nitrogen conditions is modulated by transcriptional, post-transcriptional, and post-translational controls. One of these controls of AreA activity has been proposed to involve the NmrA protein interacting with the DNA-binding domain and the extreme C terminus of AreA to inhibit DNA binding under nitrogen sufficient conditions. In contrast, mutational evidence suggests that the tamA gene has a positive role together with areA in regulating the expression of genes subject to nitrogen metabolite repression. This gene was identified by the selection of mutants resistant to toxic nitrogen source analogues, and a number of nitrogen metabolic activities have been shown to be reduced in these mutants. To investigate the role of this gene we have used constructs encoding the TamA protein fused to the DNA-binding domain of either the FacB or the AmdR regulatory proteins. These hybrid proteins have been shown to activate expression of the genes of acetate or GABA utilization, respectively, as well as the amdS gene. Strong activation was shown to require the AreA protein but was not dependent on AreA binding to DNA. The homologous areA gene of A. oryzae and nit-2 gene of Neurospora crassa can substitute for A. nidulans areA in this interaction. We have shown that the same C-terminal region of AreA and NIT-2 that is involved in the interaction with NmrA is required for the TamA-AreA interaction. However, it is unlikely that TamA requires the same residues as NmrA within the GATA DNA-binding domain of AreA.
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Affiliation(s)
- A J Small
- Department of Genetics, University of Melbourne, Parkville, Victoria 3052, Australia
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14
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Hutchings H, Stahmann KP, Roels S, Espeso EA, Timberlake WE, Arst HN, Tilburn J. The multiply-regulated gabA gene encoding the GABA permease of Aspergillus nidulans: a score of exons. Mol Microbiol 1999; 32:557-68. [PMID: 10320578 DOI: 10.1046/j.1365-2958.1999.01371.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We describe the cloning, sequence and expression of gabA, encoding the gamma-amino-n-butyrate (GABA) permease of the fungus Aspergillus nidulans. Sequence changes were determined for three up-promoter (gabI ) and six gabA loss-of-function mutations. The predicted protein contains 517 residues and shows 30.3% overall identity with a putative GABA permease of Arabidopsis thaliana, 29.6% identity with the yeast choline transporter and 23.4% identity with the yeast UGA4 GABA permease. Structural predictions favour 11-12 transmembrane domains. Comparison of the genomic and cDNA sequences shows the presence of 19 introns, an unusually large number of introns for, we believe, any fungal gene. In agreement with the wealth of genetic data available, transcript level analyses demonstrate that gabA is subject to carbon catabolite and nitrogen metabolite repression, omega-amino acid induction and regulation in response to ambient pH (being acid-expressed). In agreement with this, we report consensus binding sites 5' to the coding region, six each for CreA and AREA and one for PacC, the transcription factors mediating carbon catabolite and nitrogen metabolite repression and response to ambient pH respectively.
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Affiliation(s)
- H Hutchings
- Department of Infectious Diseases, Imperial College School of Medicine at Hammersmith Hospital, Ducane Road, London W12 ONN, UK
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15
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Ehrlich KC, Montalbano BG, Cary JW. Binding of the C6-zinc cluster protein, AFLR, to the promoters of aflatoxin pathway biosynthesis genes in Aspergillus parasiticus. Gene 1999; 230:249-57. [PMID: 10216264 DOI: 10.1016/s0378-1119(99)00075-x] [Citation(s) in RCA: 132] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
AFLR is a Zn2Cys6-type sequence-specific DNA-binding protein that is thought to be necessary for expression of most of the genes in the aflatoxin pathway gene cluster in Aspergillus parasiticus and A. flavus, and the sterigmatocystin gene cluster in A. nidulans. However, it was not known whether AFLR bound to the promoter regions of each of the genes in the cluster. Recently, A. nidulans AFLR was shown to bind to the motif 5'-TCGN5CGA-3'. In the present study, we examined the binding of AFLR to promoter regions of 11 genes in the A. parasiticus cluster. Based on electrophoretic mobility shift assays, the genes nor1, pksA, adhA, norA, ver1, omtA, ordA, and, vbs, had at least one 5'-TCGN5CGA-3' binding site within 200bp of the translation start site, and pksA and ver1 had an additional binding site further upstream. Although the promoter region of avnA lacked this motif, AFLR bound weakly to the sequence 5'-TCGCAGCCCGG-3' at -110bp. One region in the promoter of the divergently transcribed genes aflR/aflJ bound weakly to AFLR even though it contained a site with at most only 7bp of the 5'-TCGN5CGA-3' motif. This partial site may be recognized by a monomeric form of AFLR. Based on a comparison of 16 possible sites, the preferred binding sequence was 5'-TCGSWNNSCGR-3'.
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Affiliation(s)
- K C Ehrlich
- Southern Regional Research Center, USDA, PO Box 19687, New Orleans, LA 70179, USA.
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16
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Fernandes M, Keller NP, Adams TH. Sequence-specific binding by Aspergillus nidulans AflR, a C6 zinc cluster protein regulating mycotoxin biosynthesis. Mol Microbiol 1998; 28:1355-65. [PMID: 9680223 DOI: 10.1046/j.1365-2958.1998.00907.x] [Citation(s) in RCA: 163] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The Aspergillus nidulans aflR gene is found within a 60 kb gene cluster that includes approximately 24 other genes that putatively function in the production of the aflatoxin-related mycotoxin sterigmatocystin. Previous work showed that AflR is a C6 zinc binuclear cluster protein that is conserved across Aspergillus spp. and functions as a pathway-specific transcription factor in activating expression of other cluster genes. In this report, we demonstrate that A. nidulans AflR (AnAflR) is a 45kDa protein that binds to the palindromic sequence 5'-TCG(N5)CGA-3' found in the promoter regions of several aflatoxin and sterigmatocystin cluster genes (stc genes). The in vivo relevance of this AnAflR binding site was assessed by examining the contribution of the three TCG(N5)CGA elements in the 1.1 kb promoter region of stcU using gene fusions with the bacterial uidA gene encoding beta-glucuronidase (GUS). By mutating one, two or all three of the AnAflR-binding elements and examining GUS activity in wild-type aflR or delta aflR A. nidulans strains, we found that stc gene activation required both AnAflR and at least one TCG(N5)CGA AflR binding site.
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Affiliation(s)
- M Fernandes
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station 77843, USA
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17
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Todd RB, Andrianopoulos A. Evolution of a fungal regulatory gene family: the Zn(II)2Cys6 binuclear cluster DNA binding motif. Fungal Genet Biol 1997; 21:388-405. [PMID: 9290251 DOI: 10.1006/fgbi.1997.0993] [Citation(s) in RCA: 206] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The coevolution of DNA binding proteins and their cognate binding sites is essential for the maintenance of function. As a result, comparison of DNA binding proteins of unknown function in one species with characterized DNA binding proteins in another can identify potential targets and functions. The Zn(II)2Cys6 (or C6 zinc) binuclear cluster DNA binding domain has thus far been identified exclusively in fungal proteins, generally transcriptional regulators, and there are more than 80 known or predicted proteins which contain this motif, the best characterized of which are GAL4, PPR1, LEU3, HAP1, LAC9, and PUT3. Here we review all known proteins containing the Zn(II)2Cys6 motif, along with their function, DNA binding, dimerization, and zinc(II) coordination properties and DNA binding sites. In addition, we have identified all of the Zn(II)2Cys6 motif-containing proteins in the sequence databases, including a large number with unknown function from the completed Saccharomyces cerevisiae and ongoing Schizosaccharomyces pombe genome projects, and examined the phylogenetic relationships of all the Zn(II)2Cys6 motifs from these proteins. Based on these relationships, we have assigned potential functions to a number of these unknown proteins.
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Affiliation(s)
- R B Todd
- Department of Genetics, University of Melbourne, Parkville, Victoria, Australia
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18
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Li D, Kolattukudy PE. Cloning of cutinase transcription factor 1, a transactivating protein containing Cys6Zn2 binuclear cluster DNA-binding motif. J Biol Chem 1997; 272:12462-7. [PMID: 9139694 DOI: 10.1074/jbc.272.19.12462] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Hydroxy fatty acids from plant cutin were shown previously to induce the expression of the cutinase gene via a palindromic sequence located at -159 base pairs of the cutinase gene in Fusarium solani f. sp. pisi (Nectria hematococca mating type VI). Of the two overlapping palindromes in this sequence, palindrome 2 was found to be essential for the inducibility of cutinase by hydroxy fatty acids. Screening of a phage expression library with the concatenated palindrome 2 as probe detected a distinct cDNA clone encoding a polypeptide designated cutinase transcription factor 1alpha (CTF1alpha) with a calculated molecular weight of 101,109. This protein contains a Cys6Zn2 binuclear cluster motif sharing homology to the Cys6Zn2 binuclear cluster DNA-binding domains of transcription factors from Saccharomyces cerevisiae, S. carlsbergensis, Kluyveromyces lactis, Neurospora crassa, Aspergillus nidulans, and A. flavus. CTF1alpha, expressed in Escherichia coli, showed specific binding to the palindrome 2 DNA fragment but not to palindrome 1 or mutant palindrome 2 DNA fragments, suggesting specific binding of CTF1alpha to palindrome 2. When CTF1alpha was expressed as a fusion protein with the nuclear localization sequence of SV40 in yeast, it transactivated the native cutinase promoter fused to the chloramphenicol acetyl transferase (cat) gene. Mutation of palindrome 2 but not palindrome 1 abolished this transactivation. Thus, CTF1alpha positively acts in vivo by binding selectively to palindrome 2 of the cutinase gene promoter.
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Affiliation(s)
- D Li
- Neurobiotechnology Center, Ohio State University, Columbus, Ohio 43210, USA
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19
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20
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Papagiannopoulos P, Andrianopoulos A, Sharp JA, Davis MA, Hynes MJ. The hapC gene of Aspergillus nidulans is involved in the expression of CCAAT-containing promoters. MOLECULAR & GENERAL GENETICS : MGG 1996; 251:412-21. [PMID: 8709944 DOI: 10.1007/bf02172369] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The 5' regulatory region of the amdS gene of Aspergillus nidulans, which encodes an acetamidase required for growth on acetamide as a carbon and nitrogen source, contains a CCAAT sequence which is required for setting the basal level of amdS expression. Mobility shift studies have identified a factor in A. nidulans nuclear extracts which binds to this CCAAT sequence. In Saccharomyces cerevisiae the HAP3 gene encodes one component of a multisubunit complex that binds CCAAT sequences. A search of the EMBL and SwissProt databases has revealed an A. nidulans sequence with significant homology to the HAP3 gene adjacent to the previously cloned regulatory gene amdR. Sequencing of the remainder of this region has confirmed the presence of a gene, designated hapC, with extensive homology to HAP3. The predicted amino acid sequence of HapC shows extensive identity to HAP3 in the central conserved domain, but shows little conservation in the flanking sequences. A haploid carrying a hapC deletion has been created and is viable, but grows poorly on all media tested. This null mutant grows especially slowly on acetamide as a sole carbon and nitrogen source, indicating that hapC plays a role in amdS expression. In agreement with this notion, it has been shown that the hapC deletion results in reduced levels of expression of an amdS::lacZ reporter gene and this effect is particularly evident under conditions of carbon limitation. Nuclear extracts prepared from the hapC deletion mutant show no CCAAT binding activity to the amdS or gatA promoters, indicating that hapC may encode a component of the complex binding at this sequence.
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Affiliation(s)
- P Papagiannopoulos
- Department of Genetics, University of Melbourne, Parkville, Victoria, Australia
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21
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Akiyama M, Nakashima H. Molecular cloning of the acr-2 gene which controls acriflavine sensitivity in Neurospora crassa. BIOCHIMICA ET BIOPHYSICA ACTA 1996; 1307:187-92. [PMID: 8679704 DOI: 10.1016/0167-4781(96)00042-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The acr-2 gene of Neurospora crassa was cloned by complementation of the wild-type strain by DNA from an acriflavine-resistant strain, acr-2. The transcript of the acr-2 gene is 2.3 kb long and contains two leader open reading frames (ORFs) that precede the acr-2 coding region and, if translated, they would generate sequences of 23 and 43 amino acid residues, respectively. The predicted ACR-2 protein contains 595 amino acids that include a putative Zn(II)Cys6 binuclear domain that is followed by a rather long serine/threonine-rich region near the amino-terminus. The acr-2 mutation, which confers acriflavine resistance, substitutes the amino acid residue at position 303 of the encoded protein from asparagine to lysine. Progeny that were hypersensitive to acriflavine were obtained by disruption of the acr-2 gene by repeat induced point mutation (RIP). The level of expression of the acr-2 gene is significantly higher in the acr-2 strain than in the wild-type strain. These results indicate that the acr-2 gene controls acriflavine sensitivity in N. crassa.
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Affiliation(s)
- M Akiyama
- Department of Biology, Faculty of Science, Okayama University, Japan
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22
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Davis MA, Small AJ, Kourambas S, Hynes MJ. The tamA gene of Aspergillus nidulans contains a putative zinc cluster motif which is not required for gene function. J Bacteriol 1996; 178:3406-9. [PMID: 8655534 PMCID: PMC178106 DOI: 10.1128/jb.178.11.3406-3409.1996] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Expression of many nitrogen catabolic enzymes is controlled by nitrogen metabolite repression in Aspergillus nidulans. Although the phenotypes of tamA mutants have implicated this gene in nitrogen regulation, its function is unknown. We have cloned the tamA gene by complementation of a new tamA allele. The tamA sequence shares significant homology with the UGA35/DAL81/DURL gene of Saccharomyces cerevisiae. In vitro mutagenesis of sequences encoding a putative zinc cluster DNA binding domain indicated that this motif is not required for in vivo TamA function.
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Affiliation(s)
- M A Davis
- Department of Genetics, The University of Melbourne, Parkville, Australia
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23
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Arst Jr. HN. Nitrogen metabolite repression inAspergillus nidulans: an historical perspective. ACTA ACUST UNITED AC 1995. [DOI: 10.1139/b95-238] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The paper of Arst and Cove (Mol. Gen. Genet. 126: 111 – 141, 1973) on "Nitrogen metabolite repression in Aspergillus nidulans" has influenced studies and perceptions of gene regulation in filamentous fungi during the past 21 years. Here I attempt to appraise the contributions of that paper and assess its role in further developments. Nitrogen metabolite repression, carbon catabolite repression, pathway-specific and integrated induction, as-acting regulatory mutations, a useful class of growth inhibitors, and a homologous Neurospora crassa gene are all discussed. Key words: Aspergillus nidulans, carbon catabolite repression, nitrogen metabolite repression.
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24
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Lints R, Davis MA, Hynes MJ. The positively acting amdA gene of Aspergillus nidulans encodes a protein with two C2H2 zinc-finger motifs. Mol Microbiol 1995; 15:965-75. [PMID: 7596297 DOI: 10.1111/j.1365-2958.1995.tb02365.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Semi-dominant mutations in the amdA gene lead to elevated expression of the gene encoding acetamidase, amdS. These mutations also cause constitutive expression of the acetate-inducible gene, aciA. In the amdS 5' regulatory region, two cis-acting mutations, amdl66 and amdl666, have been isolated which specifically affect amdA activation of amdS. These mutations are a duplication and a triplication of an 18 bp GA-rich sequence, thought to define the amdA site of action within the amdS promoter region. Similar GA-rich sequences have also been found in the 5' region of aciA. This paper describes the cloning and initial functional characterization of the amdA gene and two of its mutant alleles. The wild-type amdA gene has been cloned by a chromosome walk from genes gatA and alcC on linkage group VII and localized by complementation of an amdA loss-of-function mutation. Transcriptional analysis reveals that the gene is expressed constitutively at low levels under growth conditions which affect expression of amdS and aciA. The gene is predicted to encode an 880-amino-acid protein which contains two C2H2 zinc fingers, a nuclear localization sequence and two transcriptional activation domains. The amdA7 semi-dominant gain-of-function mutation results in a glycine to aspartate substitution which would increase the acidity of one of these regions. Analysis of in vitro generated mutations in the 5' region of amdS using an amdS::lacZ reporter has been used to localize the site of action of AmdA. The C2H2 zinc-finger motifs identified in the protein are similar to those found in the carbon catabolite repressor protein, CreA, which also regulates amdS and recognizes sequences which overlap with the proposed site of action for AmdA.
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Affiliation(s)
- R Lints
- Department of Genetics, University of Melbourne, Parkville, Victoria, Australia
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25
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Mulder W, Scholten IH, de Boer RW, Grivell LA. Sequence of the HAP3 transcription factor of Kluyveromyces lactis predicts the presence of a novel 4-cysteine zinc-finger motif. MOLECULAR & GENERAL GENETICS : MGG 1994; 245:96-106. [PMID: 7845362 DOI: 10.1007/bf00279755] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The Kluyveromyces lactis homologue of the Saccharomyces cerevisiae HAP3 gene was isolated by functional complementation of the respiratory-deficient phenotype of the S. cerevisiae hap3::HIS4 strain SHY40. The KlHAP3 gene encodes a protein of 205 amino acids, of which the central B-domain of 90 residues is highly homologous to HAP3 counterparts of S. cerevisiae and higher eukaryotes. The protein contains a novel 4-cysteine zinc-finger motif and we propose by analogy that all other homologous HAP3 proteins contain the same motif, with the position containing the third cysteine being occupied by a serine residue. In contrast to the situation in S. cerevisiae, disruption of the KlHAP3 gene in K. lactis does not result in a respiratory-deficient phenotype and the growth of the null strain is indistinguishable from wild type. There is also no effect on the expression of the carbon source-regulated KlCYC1 gene, suggesting either a different role for the HAP2/3/4 complex, or the existence of a different mechanism of carbon source regulation. Sequence verification of the S. cerevisiae HAP3 locus reveals that, just as in K. lactis, a long open reading frame (ORF) is present upstream of the HAP3 gene. These highly homologous ORFs are predicted to have at least eight membrane-spanning fragments, but do not show significant homology to any known sequence present in databases. The ScORFX gene is transcribed in the opposite direction to ScHAP3, but, in contrast to an earlier report by Hahn et al. (1988), the transcripts of the two genes do not overlap. The model proposed by these authors, in which the ScHAP3 gene is regulated by an anti-sense non-coding mRNA, is therefore not correct.
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Affiliation(s)
- W Mulder
- Section for Molecular Biology, Institute for Molecular Cell Biology, Biocentrum Amsterdam, The Netherlands
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26
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Delaveau T, Delahodde A, Carvajal E, Subik J, Jacq C. PDR3, a new yeast regulatory gene, is homologous to PDR1 and controls the multidrug resistance phenomenon. MOLECULAR & GENERAL GENETICS : MGG 1994; 244:501-11. [PMID: 8078477 DOI: 10.1007/bf00583901] [Citation(s) in RCA: 159] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The Saccharomyces cerevisiae PDR3 gene, located near the centromere of chromosome II, has been completely sequenced and characterised. Mutations pdr3-1 and pdr3-2, which confer resistance to several antibiotics can be complemented by a wild-type allele of the PDR3 gene. The sequence of the wild-type PDR3 gene revealed the presence of a long open reading frame capable of encoding a 976-amino acid protein. The protein contains a single Zn(II)2Cys6 binuclear-type zinc finger homologous to the DNA-binding motifs of other transcriptional activators from lower eukaryotes. Evidence that the PDR3 protein is a transcriptional activator was provided by demonstrating that DNA-bound LexA-PDR3 fusion proteins stimulate expression of a nearby promoter containing LexA binding sites. The use of LexA-PDR3 fusions revealed that the protein contains two activation domains, one localised near the N-terminal, cysteine-rich domain and the other localised at the C-terminus. The salient feature of the PDR3 protein is its similarity to the protein coded by PDR1, a gene responsible for pleiotropic drug resistance. The two proteins show 36% amino acid identity over their entire length and their zinc finger DNA-binding domains are highly conserved. The fact that the absence of both PDR1 and PDR3 (simultaneous disruption of the two genes) enhances multidrug sensitivity strongly suggests that the two transcriptional factors have closely related functions.
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Affiliation(s)
- T Delaveau
- Laboratoire de Génétique Moléculaire, CNRS URA 1302, Paris, France
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27
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Endo H, Kajiwara S, Tsunoka O, Shishido K. A novel cDNA, priBc, encoding a protein with a Zn(II)2Cys6 zinc cluster DNA-binding motif, derived from the basidiomycete Lentinus edodes. Gene X 1994; 139:117-21. [PMID: 8112580 DOI: 10.1016/0378-1119(94)90533-9] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
A cDNA clone (designated priBc) was isolated from a primordial cDNA library of the basidiomycete, Lentinus edodes (Le). The priBc clone consisted of 2628 bp encoding 565 amino acids. As was expected, the priB transcript was abundant in primordia, while preprimordial mycelia and mature fruiting bodies contained lower levels of this Le transcript. The deduced PRIB protein (64 kDa) contained a 'Zn(II)2Cys6 zinc cluster' DNA-binding motif. PRIB was produced in Escherichia coli using the bacteriophage T7 expression system. Southwestern blot analysis revealed that PRIB binds to the DNA fragment containing the upstream region of priB.
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Affiliation(s)
- H Endo
- Department of Life Sciences, Tokyo Institute of Technology, Yokohama, Japan
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28
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Davis MA, Kelly JM, Hynes MJ. Fungal catabolic gene regulation: molecular genetic analysis of the amdS gene of Aspergillus nidulans. Genetica 1993; 90:133-45. [PMID: 8119589 DOI: 10.1007/bf01435035] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Aspergillus nidulans is an excellent experimental organism for the study of gene regulation. Genetic and molecular analyses of trans-acting and cis-acting mutations have revealed a complex pattern of regulation involving multiple independent controls. Expression of the amdS gene is regulated by the facB and amdA genes which encode positively acting regulatory proteins mediating a major and a minor form of acetate induction respectively. The product of the amdR gene mediates omega amino acid induction of amdS. The binding sites for each of these proteins have been localised through amdS cis-acting mutations which specifically affect the interaction with the regulatory protein. The global controls of nitrogen metabolite repression and carbon catabolite repression regulate the expression of many catabolic genes, including amdS. Nitrogen control is exerted through the positively acting areA gene product and carbon control is dependent on the creA gene product. Each of the characterized regulatory genes encodes a DNA-binding protein which recognises particular sequences in the amdS promoter to activate or repress gene expression. In addition, there is evidence for other genetically uncharacterized proteins, including a CCAAT-binding complex, which interact with the 5' region of the amdS gene.
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Affiliation(s)
- M A Davis
- Department of Genetics, University of Melbourne, Parkville, Australia
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29
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Verdoes JC, Punt PJ, Schrickx JM, van Verseveld HW, Stouthamer AH, van den Hondel CA. Glucoamylase overexpression in Aspergillus niger: molecular genetic analysis of strains containing multiple copies of the glaA gene. Transgenic Res 1993; 2:84-92. [PMID: 8513339 DOI: 10.1007/bf01969381] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
A strategy, based on the usage of the amdS selection marker and a cosmid vector containing four copies of the glucoamylase gene (glaA), was developed to obtain glucoamylase (GLA)-overproducing A. niger strains. With this strategy, fungal strains carrying up to 200 copies of the glaA gene could be isolated at a relatively high frequency. In each transformant analysed, integration occurred in a single chromosome. A significant increase in the extracellular GLA production was observed in most of the transformants carrying multiple copies of the glaA gene. Further analysis showed that the amount of GLA that is produced was not proportional to the number of glaA copies in these transformants. However, the level of GLA production clearly correlated with the amount of glaA mRNA produced in these transformants. From these results it is concluded that GLA production is limited at the level of transcription.
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Affiliation(s)
- J C Verdoes
- Department of Molecular Genetics and Gene-Technology, TNO Medical Biological Laboratory, Rijswijk, Netherlands
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30
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Chang YC, Timberlake WE. Identification of Aspergillus brlA response elements (BREs) by genetic selection in yeast. Genetics 1993; 133:29-38. [PMID: 8417986 PMCID: PMC1205295 DOI: 10.1093/genetics/133.1.29] [Citation(s) in RCA: 114] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
The brlA gene of Aspergillus nidulans plays a central role in controlling conidiophore development. To test the hypothesis that brlA encodes a transcriptional regulator and to identify sites of interaction for the BrlA polypeptide, we expressed brlA in Saccharomyces cerevisiae (yeast) strains containing Aspergillus DNA sequences inserted upstream of a minimal yeast promoter fused to the Escherichia coli lacZ gene. Initially, a DNA fragment from the promoter region of the developmentally regulated rodA gene was tested and shown to mediate brlA-dependent transcriptional activation. Two additional DNA fragments were selected from an Aspergillus genomic library by their ability to respond to brlA in yeast. These fragments contained multiple copies of a sequence motif present in the rodA fragment, which we propose to be sites for BrlA interaction and designate brlA response elements (BREs). DNA fragments containing BREs upstream of a minimal Aspergillus promoter were capable of conferring developmental regulation in Aspergillus. Deletion of BREs from the upstream region of rodA greatly decreased its developmental induction. Multiple copies of a synthetic oligonucleotide with the consensus sequence identified among the BREs mediated brlA-dependent transcriptional activation in yeast. The results show that a primary activity of brlA is transcriptional activation and tentatively identify sites of interaction for the BrlA polypeptide.
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Affiliation(s)
- Y C Chang
- Department of Genetics, University of Georgia, Athens 30602-7223
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31
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Wang XW, Hynes MJ, Davis MA. Structural and functional analysis of the amdR regulatory gene of Aspergillus oryzae. Gene 1992; 122:147-54. [PMID: 1452021 DOI: 10.1016/0378-1119(92)90042-n] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
We have isolated the Aspergillus oryzae homologue of the amdR regulatory gene of Aspergillus nidulans by cross hybridization. Sequence analysis and functional studies have shown that the amdR genes are highly conserved and functionally interchangeable between the two species. The homology between the two genes extends throughout most of the coding sequences, including sequences encoding the DNA-binding domain and putative activation domains. Two regions of nonconserved sequence were also identified. Studies using various amdS::lacZ fusion constructs indicate that the A. oryzae gene product binds similar sequences and responds to inducer in a similar manner to the A. nidulans protein. Inactivation of the A. oryzae gene results in the inability to grow on gamma-amino-butyric acid (GABA) as a carbon and/or nitrogen source indicating that GABA utilization is amdR-dependent in A. oryzae as it is in A. nidulans.
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Affiliation(s)
- X W Wang
- Molecular and Evolutionary Systematics Group, Research School of Biological Sciences, Australian National University, Canberra
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32
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Mayorga ME, Timberlake WE. The developmentally regulated Aspergillus nidulans wA gene encodes a polypeptide homologous to polyketide and fatty acid synthases. MOLECULAR & GENERAL GENETICS : MGG 1992; 235:205-12. [PMID: 1465094 DOI: 10.1007/bf00279362] [Citation(s) in RCA: 138] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The Aspergillus nidulans wA gene is required for synthesis of a green pigment present in the walls of mature asexual spores (conidia); wA mutants produce colorless (white) conidia. We determined the transcriptional structure and DNA sequence of the wA gene. wA consists of 5 exons separated by short (40-60 bp) introns. The processed transcript has the potential to encode a protein consisting of 1986 amino acid residues. The predicted WA polypeptide showed extensive sequence similarities with bacterial and fungal polyketide synthases and vertebrate fatty acid synthases, particularly within conserved active sites. Properties of the yellow conidial wall pigment intermediate suggest that it is a polyketide rather than a fatty acid. It is therefore likely that wA encodes all or part of a polyketide synthase involved in the formation of this pigment intermediate.
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Affiliation(s)
- M E Mayorga
- Department of Genetics, University of Georgia, Athens 30602
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33
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Punt PJ, Kramer C, Kuyvenhoven A, Pouwels PH, van den Hondel CA. An upstream activating sequence from the Aspergillus nidulans gpdA gene. Gene 1992; 120:67-73. [PMID: 1398125 DOI: 10.1016/0378-1119(92)90010-m] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Introduction of a previously identified promoter element of the Aspergillus nidulans gpdA gene (encoding glyceraldehyde-3-phosphate dehydrogenase), the so-called gpd box, into the upstream region of the highly regulated A. nidulans amdS gene (encoding acetamidase), significantly increased (up to 30-fold) the expression of the lacZ reporter gene fused to these expression signals. This increase was dependent on the orientation of the gpd box and on the site of introduction into the amdS upstream region. The presence of additional gpdA sequences which flank the gpd box reduced or even extinguished positive effects of the gpd box. omega-Amino acid and carbon catabolite regulation of the amdS promoter were retained after introduction of the gpd box, indicating that the gpd box does not abolish interactions of the regulatory proteins, AmdR and CreA, with the amdS transcription control sequences. Based on the results, it is suggested that the gpd box comprises at least two separate activities: one being orientation dependent, but relatively independent of position of the gpd box in the upstream region, and the other is only functional near other sites of transcriptional control. Most likely, both activities are not involved in regulation of the amdS promoter.
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Affiliation(s)
- P J Punt
- Department of Molecular Genetics and Gene-Technology, Medical Biological Laboratory TNO, Rijswijk, The Netherlands
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34
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Littlejohn TG, Hynes MJ. Analysis of the site of action of the amdR product for regulation of the amdS gene of Aspergillus nidulans. MOLECULAR & GENERAL GENETICS : MGG 1992; 235:81-8. [PMID: 1435733 DOI: 10.1007/bf00286184] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The amdR gene of Aspergillus nidulans regulates a number of structural genes in response to omega amino acid inducers. The site of action of the amdR product on expression of the amdS gene was investigated by studying the effects of changes in the 5' region of amdS, generated in vitro, on the induction, and on responses of an amdS-lacZ fusion gene to an amdRc allele. A sequence was identified that is sufficient for amdR regulation and that shows identity with sequences involved in amdR regulation of the gatA and lam genes. This sequence includes a CCAAT sequence and it was shown that this sequence is an important element in setting the basal level of amdS expression.
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Affiliation(s)
- T G Littlejohn
- Department of Genetics, University of Melbourne, Parkville, Victoria, Australia
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35
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Parsons LM, Davis MA, Hynes MJ. Identification of functional regions of the positively acting regulatory gene amdR from Aspergillus nidulans. Mol Microbiol 1992; 6:2999-3007. [PMID: 1479891 DOI: 10.1111/j.1365-2958.1992.tb01758.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The amdR (intA) regulatory gene of Aspergillus nidulans encodes a 765-amino-acid polypeptide which determines the omega-amino acid induction of at least five structural genes. The AmdR polypeptide contains a potential Zn(II)2Cys6 DNA-binding motif which has been shown to be present in the N-terminal region of a large number of fungal activator proteins. In vitro mutagenesis of the fourth cysteine of this motif abolishes AmdR function as shown by loss of complementation of an amdR- mutation and by the AmdR- phenotype of a mutant gene replacement strain. Studies using constructs in which the proposed AmdR DNA-binding motif is replaced with that from another activator, FacB, shows that induction is independent of DNA-binding specificity and that sequences in the C-terminal region of AmdR are activation domains. Sequencing of several amdR mutant alleles which affect activation and/or induction, together with studies of deletion constructs indicate that changes in the conformation of the protein determines its activity and that this is modulated by inducers.
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Affiliation(s)
- L M Parsons
- Department of Genetics, University of Melbourne, Parkville, Victoria, Australia
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36
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Kües U, Casselton LA. Molecular and functional analysis of the A mating type genes of Coprinus cinereus. GENETIC ENGINEERING 1992; 14:251-68. [PMID: 1368279 DOI: 10.1007/978-1-4615-3424-2_14] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/25/2023]
Affiliation(s)
- U Kües
- Department of Plant Sciences, University of Oxford, UK
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37
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Marmorstein R, Carey M, Ptashne M, Harrison SC. DNA recognition by GAL4: structure of a protein-DNA complex. Nature 1992; 356:408-14. [PMID: 1557122 DOI: 10.1038/356408a0] [Citation(s) in RCA: 496] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
A specific DNA complex of the 65-residue, N-terminal fragment of the yeast transcriptional activator, GAL4, has been analysed at 2.7 A resolution by X-ray crystallography. The protein binds as a dimer to a symmetrical 17-base-pair sequence. A small, Zn(2+)-containing domain recognizes a conserved CCG triplet at each end of the site through direct contacts with the major groove. A short coiled-coil dimerization element imposes 2-fold symmetry. A segment of extended polypeptide chain links the metal-binding module to the dimerization element and specifies the length of the site. The relatively open structure of the complex would allow another protein to bind coordinately with GAL4.
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Affiliation(s)
- R Marmorstein
- Harvard University, Department of Biochemistry and Molecular Biology, Cambridge, Massachusetts
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Kulmburg P, Prangé T, Mathieu M, Sequeval D, Scazzocchio C, Felenbok B. Correct intron splicing generates a new type of a putative zinc-binding domain in a transcriptional activator of Aspergillus nidulans. FEBS Lett 1991; 280:11-6. [PMID: 2053973 DOI: 10.1016/0014-5793(91)80193-7] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
alcR is the pathway-specific transcriptional activator of the ethanol regulon in the filamentous fungus, Aspergillus nidulans. The deduced amino acid sequence of a cDNA clone, including the 5' part of the alcR-mRNA, shows that a putative Zn-binding domain of the all-cysteine class, exemplified by GAL4 is present. This structure presents some striking features. At variance with other structures of this class, the binding domain is strongly asymmetrical. Model building indicates that the zinc-binding motif of alcR could adopt an helix-turn-helix structure. We propose that the DNA-binding motif of alcR could participate in two types of DNA-binding structures: the zinc-cluster and the helix-turn-helix.
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Affiliation(s)
- P Kulmburg
- Institut de Génétique et Microbiologie, Centre Universitaire Paris-Sud, Orsay, France
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The pleiotropic UGA35(DURL) regulatory gene of Saccharomyces cerevisiae: cloning, sequence and identity with the DAL81 gene. Gene X 1991; 97:163-71. [PMID: 1999281 DOI: 10.1016/0378-1119(91)90048-g] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The UGA35 gene of Saccharomyces cerevisiae (also called DURL) encodes a positive regulator of the expression of structural genes involved in 4-aminobutyric acid (GABA) and urea catabolisms. The UGA35 gene has been cloned by complementation of function and identified by chromosomal gene replacement. The sequence of this regulatory gene and its flanking regions has been established. Our data reveal an open reading frame of 2892 nt, corresponding to 964 amino acids (aa). The deduced UGA35 aa sequence shares several similarities with that of other regulatory proteins, suggesting that the UGA35 gene encodes a DNA-binding transcriptional activator. We also show that UGA35 and the DAL81 regulatory gene controlling allantoin and urea catabolisms are one and the same gene. This means that the same factor is required for specific induction of three distinct catabolic pathways, namely those involved in GABA, urea and allantoin utilization as nitrogen sources.
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