Molecular cloning of the uaY regulatory gene of Aspergillus nidulans reveals a favoured region for DNA insertions

1991 ◽  
Vol 230 (3) ◽  
pp. 369-375 ◽  
Author(s):  
Teresa Suárez ◽  
Nathalie Oestreicher ◽  
Miguel Angel Peñalva ◽  
Claudio Scazzocchio
1994 ◽  
Vol 14 (4) ◽  
pp. 2503-2515
Author(s):  
A Andrianopoulos ◽  
W E Timberlake

The Aspergillus nidulans abaA gene encodes a protein containing an ATTS DNA-binding motif and is required for the terminal stages of conidiophore development. Results from gel mobility shift and protection, missing-contact, and interference footprint assays showed that AbaA binds to the sequence 5'-CATTCY-3', where Y is a pyrimidine, making both major- and minor-groove contacts. Multiple AbaA binding sites are present in the cis-acting regulatory regions of several developmentally controlled structural genes as well as those of the upstream regulatory gene brlA, the downstream regulatory gene wetA, and abaA itself. These cis-acting regulatory regions confer AbaA-dependent transcriptional activation in a heterologous Saccharomyces cerevisiae gene expression system. From these observations, we propose that the AbaA transcription factor establishes a novel set of feedback regulatory loops responsible for determination of conidiophore development.


Genetics ◽  
1995 ◽  
Vol 139 (2) ◽  
pp. 537-547 ◽  
Author(s):  
J F Marhoul ◽  
T H Adams

Abstract Overexpression of several Aspergillus nidulans developmental regulatory genes has been shown to cause growth inhibition and development at inappropriate times. We set out to identify previously unknown developmental regulators by constructing a nutritionally inducible A. nidulans expression library containing small, random genomic DNA fragments inserted next to the alcA promoter [alcA(p)] in an A. nidulans transformation vector. Among 20,000 transformants containing random alcA(p) genomic DNA fusion constructs, we identified 66 distinct mutant strains in which alcA(p) induction resulted in growth inhibition as well as causing other detectable phenotypic changes. These growth inhibited mutants were divided into 52 FIG (Forced expression Inhibition of Growth) and 14 FAB (Forced expression Activation of brlA) mutants based on whether or not alcA(p) induction resulted in accumulation of mRNA for the developmental regulatory gene brlA. In four FAB mutants, alcA(p) induction not only activated brlA expression but also caused hyphae to differentiate into reduced conidiophores that produced viable spores from the tips as is observed after alcA(p)::brlA induction. Sequence analyses of the DNA fragments under alcA(p) control in three of these four sporulating strains showed that in two cases developmental activation resulted from overexpression of previously uncharacterized genes, whereas in the third strain, the alcA(p) was fused to brlA. The potential uses for this strategy in identifying genes whose overexpression results in specific phenotypic changes like developmental induction are discussed.


1999 ◽  
Vol 27 (1) ◽  
pp. 55-66 ◽  
Author(s):  
James D Joseph ◽  
Joseph Heitman ◽  
Anthony R Means

1983 ◽  
Vol 217 (1208) ◽  
pp. 243-264 ◽  

There is a single major alcohol dehydrogenase (ADH) and a single major aldehyde dehydrogenase (AldDH) in Aspergillus nidulans . Both ADH and AldDH are induced by ethanol and by acetaldehyde and both are subject to carbon catabolite repression. ADH and AldDH are necessary for the utilization of ethanol and of threonine, indicating that both compounds are utilized via acetaldehyde. ADH and AldDH each give a single major activity band on gel electrophoresis. Sodium dodecyl sulphate polyacrylamide gel electrophoresis of cell extracts shows at least two similar ADH polypeptides of approximate relative molecular mass (r. m. m.) 41000 and two similar AldDH polypeptides of approximate r. m. m. 57000. The in vitro translation of mRNA from induced, carbon derepressed wild-type cells gives up to three ADH polypeptides in the r. m. m. range 39000-43000 and an AldDH polypeptide of approximate r. m. m. 57000. The mRNA from uninduced, carbon repressed wild-type cells does not direct the synthesis of the ADH and AldDH polypeptides. This indicates that the regulation of ADH and AldDH is at the level of transcription and/or post-transcriptional modification. The probable explanation of the multiple ADH polypeptides is post-transcriptional modification of the mRNA. Allyl alcohol mutants were made by using diepoxyoctane and γ-rays as mutagens. There are two classes, alcA and alcR . Neither class can utilize ethanol or threonine as a carbon source. The alcA mutants lack normal ADH and are recessive. Of the 47 alcA mutants examined 39 do not make the ADH polypeptides while eight do so. Therefore alcA is the structural gene for ADH. The two alcA mutants tested do not make functional mRNA for ADH. The alcR mutants lack both ADH and AldDH and are recessive. No alcR mutants make the ADH or the AldDH polypeptides. The three alcR mutants tested do not make functional ADH or AldDH mRNA. The mutant alcR 125 is a nonsense mutant, which establishes that alcR codes for a protein. The alcA and alcR genes are adjacent on chromosome VII and a preliminary fine-structure map of the alcA gene has been made. Three mutants that cannot utilize ethanol or threonine and have ADH, but lack AldDH, define a gene AldA on chromosome VIII. The aldA 23 mutant makes the AldDH polypeptides, the other two aldA mutants do not. Therefore aldA is probably the structural gene for AldDH. Our current hypothesis is that alcA and aldA are the structural genes for ADH and AldDH respectively and alcR is a transacting regulatory gene coding for a protein whose function is necessary for the expression of the alcA and aldA genes.


Gene ◽  
1988 ◽  
Vol 73 (2) ◽  
pp. 385-396 ◽  
Author(s):  
Béatrice Felenbok ◽  
Daria Sequeval ◽  
Martine Mathieu ◽  
Susan Sibley ◽  
David I. Gwynne ◽  
...  

1994 ◽  
Vol 14 (4) ◽  
pp. 2503-2515 ◽  
Author(s):  
A Andrianopoulos ◽  
W E Timberlake

The Aspergillus nidulans abaA gene encodes a protein containing an ATTS DNA-binding motif and is required for the terminal stages of conidiophore development. Results from gel mobility shift and protection, missing-contact, and interference footprint assays showed that AbaA binds to the sequence 5'-CATTCY-3', where Y is a pyrimidine, making both major- and minor-groove contacts. Multiple AbaA binding sites are present in the cis-acting regulatory regions of several developmentally controlled structural genes as well as those of the upstream regulatory gene brlA, the downstream regulatory gene wetA, and abaA itself. These cis-acting regulatory regions confer AbaA-dependent transcriptional activation in a heterologous Saccharomyces cerevisiae gene expression system. From these observations, we propose that the AbaA transcription factor establishes a novel set of feedback regulatory loops responsible for determination of conidiophore development.


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