The veA gene has been isolated by complementation of the veAI mutation. The nucleotide sequences of the cDNA as well as its genomic DNA were determined, showing that there is one open reading frame (ORF) possibly coding for a 573 amino acid polypeptide in the gene interrupted by two introns. No similarities in the amino acid sequence as well as in the nucleotide sequence were found to anyone currently available in GenBank and SWISS-Prot, respectively. It had four putative PEST regions that contain large amounts of proline (P), glutamic acid (E), serine (S), and threonine (T), and a nuclear localization signal, PKRARAC. The nucleotide sequence of the veAl mutant gene was also determined and was differed by one nucleotide from a wild type one. The mutant ORF seemed to have the 37th methionine codon of the wild type one as a new initiation codon. The expression of the gene started from just after 14 hours competence, peaked at 8 hr, and thereafter decreased, suggesting that it act at the early developmental stage. A null mutant of the gene constructed by replacing a part of its ORF with an argB gene never entered sexual development even under conditions where sexual development preferentially occurs. The induced expression of the gene in a veAl mutant resulted in the formation of sexual structures even in a submerged culture where wild type strains never form the sexual structures. These results indicated that the gene is an activator for sexual development, although it also can be a negative regulator for asexual development.
Fungal Genet. Newsl. 46 (Supl):
Full conference title:
Fungal Genetics Conference 20th
- Fungal Genetics Conference 20th (1999)