The Aspergillus nidulans abaA gene encodes a transcriptional activator that acts as a genetic switch to control development.

Abstract

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.

Determination of a transcriptional regulator-like gene involved in biosynthesis of elsinochrome phytotoxin by the citrus scab fungus, Elsinoë fawcettii

“…In addition, examination of upstream sequences revealed the presence of consensus MRAGGGR motifs in the promoter regions of TSF1, which are presumably involved in binding the conidiation-specific Bristle (BRLA)-like transcriptional activator in A. nidulans . The consensus CATTCY motif (Y5pyrimidine) that is recognized by the ABAA transcriptional activator (Andrianopoulos & Timberlake, 1994), is also found in the RDT1, OXR1, EfPKS1 and ECT1 gene promoters (Table 2). ABAA is activated by BRLA and is involved in conidiphore development of A. nidulans (Andrianopoulos & Timberlake, 1994).…”

“…The consensus CATTCY motif (Y5pyrimidine) that is recognized by the ABAA transcriptional activator (Andrianopoulos & Timberlake, 1994), is also found in the RDT1, OXR1, EfPKS1 and ECT1 gene promoters (Table 2). ABAA is activated by BRLA and is involved in conidiphore development of A. nidulans (Andrianopoulos & Timberlake, 1994). To provide a regulatory framework for better understanding the elsinochrome biosynthesis and conidial formation in E. fawcettii, a hypothetical model describing intertwined regulatory controls via TSF1 is proposed (Fig.…”

Comparative genomics of MAP kinase and calcium–calcineurin signalling components in plant and human pathogenic fungi

“…However, in our survey we failed to detect clear Tec1 orthologues in S. pombe and the filamentous ascomycetes F. graminearum, M. grisea and N. crassa. Interestingly, the human pathogen A. fumigatus contains a Tec1 orthologue that is highly similar to A. nidulans AbaA, a transcription factor with an ATTS DNA-binding motif required for conidiophore development (Andrianopoulos and Timberlake, 1994). The role of Tec1 in virulence of A. fumigatus has not been explored so far.…”

Insights into transcription enhancer factor 1 (TEF-1) activity from the solution structure of the TEA domain

“…The only Caenorhabditis elegans TEF homolog, egl-44, regulates differentiation of touch-sensitive cells and egg-laying motor neurons (16)(17)(18). The less conserved orthologs of Saccharomyces cerevisiae and Aspergillus nidulans, namely TEC1, regulate hyphal development (filamentous growth) (19,20). Development of virulence in systemic candidiasis in mouse models also depends on Candida albicans TEC1 activity (21).…”