scholarly journals The regulatory gene areA mediating nitrogen metabolite repression in Aspergillus nidulans. Mutations affecting specificity of gene activation alter a loop residue of a putative zinc finger.

1990 ◽  
Vol 9 (5) ◽  
pp. 1355-1364 ◽  
Author(s):  
B. Kudla ◽  
M.X. Caddick ◽  
T. Langdon ◽  
N.M. Martinez-Rossi ◽  
C.F. Bennett ◽  
...  
Keyword(s):  
Aspergillus Nidulans ◽  
Zinc Finger ◽  
Regulatory Gene ◽  
Gene Activation ◽  
Nitrogen Metabolite Repression ◽  
Putative Zinc Finger ◽  
Loop Residue

scholarly journals nirA, the pathway-specific regulatory gene of nitrate assimilation in Aspergillus nidulans, encodes a putative GAL4-type zinc finger protein and contains four introns in highly conserved regions.

1991 ◽  
Vol 11 (11) ◽  
pp. 5746-5755 ◽  
Author(s):  
G Burger ◽  
J Strauss ◽  
C Scazzocchio ◽  
B F Lang
Keyword(s):  
Amino Acids ◽  
Aspergillus Nidulans ◽  
Zinc Finger ◽  
Zinc Finger Protein ◽  
Regulatory Gene ◽  
Wild Type ◽  
Transcript Levels ◽  
Amino Terminal ◽  
Nitrate And Nitrite ◽  
Acidic Region

The nucleotide sequence of nirA, mediating nitrate induction in Aspergillus nidulans, has been determined. Alignment of the cDNA and the genomic DNA sequence indicates that the gene contains four introns and encodes a protein of 892 amino acids. The deduced NIRA protein displays all characteristics of a transcriptional activator. A putative double-stranded DNA-binding domain in the amino-terminal part comprises six cysteine residues, characteristic for the GAL4 family of zinc finger proteins. An amino-terminal highly acidic region and two proline-rich regions are also present. The nucleotide sequences of two mutations were determined after they were mapped by transformation with overlapping DNA fragments, amplified by the polymerase chain reaction. nirA87, a mutation conferring noninducibility by nitrate and nitrite, has a -1 frameshift at triplet 340, which eliminates 549 C-terminal amino acids from the polypeptide. Under the assumption that the truncated polypeptide is stable, it comprises the zinc finger domain and the acidic region, which seem not sufficient for transcriptional activation. nirAd-106, an allele conferring nitrogen metabolite derepression of nitrate and nitrite reductase activity, includes two transitions, changing a glutamic acid to a lysine and a valine to an alanine, situated between a basic and a proline-rich region of the protein. Northern (RNA) analysis of the wild type and of constitutive (nirAc) and derepressed (nirAd) mutants show that the nirA transcript does not vary between these strains, being in all cases constitutively expressed. On the other hand, transcript levels of structural genes (niaD and niiA) do vary, being highly inducible in the wild type but constitutively expressed in the nirAc mutant. The nirAd mutant appears phenotypically derepressed, because the niaD and niiA transcript levels are overinduced in the presence of nitrate but are still partially repressed in the presence of ammonium.

nit-2, the major nitrogen regulatory gene of Neurospora crassa, encodes a protein with a putative zinc finger DNA-binding domain

1990 ◽  
Vol 10 (3) ◽  
pp. 1056-1065
Author(s):  
Y H Fu ◽  
G A Marzluf
Keyword(s):  
Nucleotide Sequence ◽  
Dna Binding ◽  
Neurospora Crassa ◽  
Zinc Finger ◽  
Regulatory Gene ◽  
Amino Acid Residues ◽  
Loss Of Function ◽  
Catabolic Enzymes ◽  
Regulatory Circuit ◽  
Putative Zinc Finger

The nitrogen regulatory circuit of Neurospora crassa consists of a set of unlinked structural genes which specify various nitrogen catabolic enzymes plus control genes and metabolic effectors which regulate their expression. The positive-acting nit-2 regulatory gene is required to turn on the expression of the nitrogen catabolic enzymes during conditions of nitrogen limitation. The complete nucleotide sequence of the nit-2 gene was determined. The nit-2 mRNA is 4.3 kilobases long and has a long nontranslated sequence at both its 5' and 3' ends. The nit-2 gene nucleotide sequence can be translated to yield a protein containing 1,036 amino acid residues with a molecular weight of approximately 110,000. Deletion analyses demonstrated that approximately 21% of the NIT2 protein at its carboxy terminus can be removed without loss of function. The nit-2 protein contains a single putative Cys2/Cys2 zinc finger domain which appears to function in DNA binding and which has striking homology to a mammalian trans-acting factor, GF-1.

Sequence and expression of GLN3, a positive nitrogen regulatory gene of Saccharomyces cerevisiae encoding a protein with a putative zinc finger DNA-binding domain

1991 ◽  
Vol 11 (12) ◽  
pp. 6216-6228 ◽  
Author(s):  
P L Minehart ◽  
B Magasanik
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Zinc Finger ◽  
Regulatory Gene ◽  
Null Alleles ◽  
Gene Encoding ◽  
Reading Frame ◽  
Activation Of Transcription ◽  
Initiation Of Translation ◽  
Putative Zinc Finger ◽  
Activation Sequence

The GLN3 gene of Saccharomyces cerevisiae is required for the activation of transcription of a number of genes in response to the replacement of glutamine by glutamate as source of nitrogen. We cloned the GLN3 gene and constructed null alleles by gene disruption. GLN3 is not essential for growth, but increased copies of GLN3 lead to a drastic decrease in growth rate. The complete nucleotide sequence of the GLN3 gene was determined, revealing one open reading frame encoding a polypeptide of 730 amino acids, with a molecular weight of approximately 80,000. The GLN3 protein contains a single putative Cys2/Cys2 zinc finger which has homology to the Neurospora crassa NIT2 protein, the Aspergillus nidulans AREA protein, and the erythroid-specific transcription factor GATA-1. Immunoprecipitation experiments indicated that the GLN3 protein binds the nitrogen upstream activation sequence of GLN1, the gene encoding glutamine synthetase. Neither control of transcription nor control of initiation of translation of GLN3 is important for regulation in response to glutamine availability.

scholarly journals Sequence and expression of GLN3, a positive nitrogen regulatory gene of Saccharomyces cerevisiae encoding a protein with a putative zinc finger DNA-binding domain.

1991 ◽  
Vol 11 (12) ◽  
pp. 6216-6228 ◽  
Author(s):  
P L Minehart ◽  
B Magasanik
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Zinc Finger ◽  
Regulatory Gene ◽  
Null Alleles ◽  
Gene Encoding ◽  
Reading Frame ◽  
Activation Of Transcription ◽  
Initiation Of Translation ◽  
Putative Zinc Finger ◽  
Activation Sequence

The GLN3 gene of Saccharomyces cerevisiae is required for the activation of transcription of a number of genes in response to the replacement of glutamine by glutamate as source of nitrogen. We cloned the GLN3 gene and constructed null alleles by gene disruption. GLN3 is not essential for growth, but increased copies of GLN3 lead to a drastic decrease in growth rate. The complete nucleotide sequence of the GLN3 gene was determined, revealing one open reading frame encoding a polypeptide of 730 amino acids, with a molecular weight of approximately 80,000. The GLN3 protein contains a single putative Cys2/Cys2 zinc finger which has homology to the Neurospora crassa NIT2 protein, the Aspergillus nidulans AREA protein, and the erythroid-specific transcription factor GATA-1. Immunoprecipitation experiments indicated that the GLN3 protein binds the nitrogen upstream activation sequence of GLN1, the gene encoding glutamine synthetase. Neither control of transcription nor control of initiation of translation of GLN3 is important for regulation in response to glutamine availability.

Identification of the sites of action for regulatory genes controlling the amdS gene of Aspergillus nidulans

1988 ◽  
Vol 8 (6) ◽  
pp. 2589-2596
Author(s):  
M J Hynes ◽  
C M Corrick ◽  
J M Kelly ◽  
T G Littlejohn
Keyword(s):  
Aspergillus Nidulans ◽  
Gene Product ◽  
Regulatory Gene ◽  
Gene Activation ◽  
Base Change ◽  
Product Introduction ◽  
Base Pairs ◽  
Cis Acting ◽  
Amds Gene ◽  
Sites Of Action

The amdS gene of Aspergillus nidulans, which encodes an acetamidase enzyme, is positively regulated by the trans-acting genes amdR, facB, amdA, and areA. Sequence changes in several cis-acting mutations in the 5' region of the gene which specifically affect amdS regulation were determined. The amdI9 mutation, which results in increased facB-dependent acetate induction, is due to a single-base change at base pair -210 relative to the start point of translation. The amdI93 mutation, which abolishes amdR-dependent omega-amino acid induction, is a deletion of base pairs -181 to -151. The amdI66 mutation, which causes increased gene activation in strains carrying amdA regulatory gene mutations, is a duplication of base pairs -107 to -90. Transformation of A. nidulans can generate transformants containing multiple integrated copies of plasmid sequences. When these plasmids carry a potential binding site for a regulatory gene product, growth on substrates whose catabolism requires genes activated by that regulatory gene can be reduced, apparently because of titration of the regulatory gene product. Introduction of 5' amdS sequences via cotransformation into strains of various genotypes was used to localize sequences apparently involved in binding of the products of the amdR, amdA, and facB genes. The position of these sequences is in agreement with the positions of the specific cis-acting mutations. Consistent with these results, a transformant of A. nidulans derived from a plasmid deleted for sequences upstream from -111 was found to have lost amdR- and facB-mediated control but was still regulated by the amdA gene. In addition, amdS expression in this transformant was still dependent on the areA gene.

scholarly journals nit-2, the major nitrogen regulatory gene of Neurospora crassa, encodes a protein with a putative zinc finger DNA-binding domain.

1990 ◽  
Vol 10 (3) ◽  
pp. 1056-1065 ◽  
Author(s):  
Y H Fu ◽  
G A Marzluf
Keyword(s):  
Nucleotide Sequence ◽  
Dna Binding ◽  
Neurospora Crassa ◽  
Zinc Finger ◽  
Regulatory Gene ◽  
Amino Acid Residues ◽  
Loss Of Function ◽  
Catabolic Enzymes ◽  
Regulatory Circuit ◽  
Putative Zinc Finger

The nitrogen regulatory circuit of Neurospora crassa consists of a set of unlinked structural genes which specify various nitrogen catabolic enzymes plus control genes and metabolic effectors which regulate their expression. The positive-acting nit-2 regulatory gene is required to turn on the expression of the nitrogen catabolic enzymes during conditions of nitrogen limitation. The complete nucleotide sequence of the nit-2 gene was determined. The nit-2 mRNA is 4.3 kilobases long and has a long nontranslated sequence at both its 5' and 3' ends. The nit-2 gene nucleotide sequence can be translated to yield a protein containing 1,036 amino acid residues with a molecular weight of approximately 110,000. Deletion analyses demonstrated that approximately 21% of the NIT2 protein at its carboxy terminus can be removed without loss of function. The nit-2 protein contains a single putative Cys2/Cys2 zinc finger domain which appears to function in DNA binding and which has striking homology to a mammalian trans-acting factor, GF-1.

scholarly journals Cloning of the regulatory gene areA mediating nitrogen metabolite repression in Aspergillus nidulans.

1986 ◽  
Vol 5 (5) ◽  
pp. 1087-1090 ◽  
Author(s):  
M.X. Caddick ◽  
H.N. Arst ◽  
L.H. Taylor ◽  
R.I. Johnson ◽  
A.G. Brownlee
Keyword(s):  
Aspergillus Nidulans ◽  
Regulatory Gene ◽  
Nitrogen Metabolite Repression

scholarly journals Identification of the sites of action for regulatory genes controlling the amdS gene of Aspergillus nidulans.

1988 ◽  
Vol 8 (6) ◽  
pp. 2589-2596 ◽  
Author(s):  
M J Hynes ◽  
C M Corrick ◽  
J M Kelly ◽  
T G Littlejohn
Keyword(s):  
Aspergillus Nidulans ◽  
Gene Product ◽  
Regulatory Gene ◽  
Gene Activation ◽  
Base Change ◽  
Product Introduction ◽  
Base Pairs ◽  
Cis Acting ◽  
Amds Gene ◽  
Sites Of Action

The amdS gene of Aspergillus nidulans, which encodes an acetamidase enzyme, is positively regulated by the trans-acting genes amdR, facB, amdA, and areA. Sequence changes in several cis-acting mutations in the 5' region of the gene which specifically affect amdS regulation were determined. The amdI9 mutation, which results in increased facB-dependent acetate induction, is due to a single-base change at base pair -210 relative to the start point of translation. The amdI93 mutation, which abolishes amdR-dependent omega-amino acid induction, is a deletion of base pairs -181 to -151. The amdI66 mutation, which causes increased gene activation in strains carrying amdA regulatory gene mutations, is a duplication of base pairs -107 to -90. Transformation of A. nidulans can generate transformants containing multiple integrated copies of plasmid sequences. When these plasmids carry a potential binding site for a regulatory gene product, growth on substrates whose catabolism requires genes activated by that regulatory gene can be reduced, apparently because of titration of the regulatory gene product. Introduction of 5' amdS sequences via cotransformation into strains of various genotypes was used to localize sequences apparently involved in binding of the products of the amdR, amdA, and facB genes. The position of these sequences is in agreement with the positions of the specific cis-acting mutations. Consistent with these results, a transformant of A. nidulans derived from a plasmid deleted for sequences upstream from -111 was found to have lost amdR- and facB-mediated control but was still regulated by the amdA gene. In addition, amdS expression in this transformant was still dependent on the areA gene.

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