The essential Aspergillus nidulans gene pmaA encodes an homologue of fungal plasma membrane H+-ATPases

pmaA, an Aspergillus nidulans gene encoding a P-ATPase, has been cloned by heterologous hybridization with the yeast PMA1 gene, The putative 990-resid ue PmaA polypeptide shows 50% identity to Saccharomyces cerevisiae and Neur ospora crassa plasma membrane H+-ATPases and weak (19-26%) identity to othe r yeast P-type cation-translocating ATPases. PmaA contains all catalytic do mains characterizing H+-ATPases. pmaA transcript levels are not regulated b y PacC, the transcription factor mediating pH regulation, and were not sign ificantly affected by an extreme creA(d) mutation resulting in carbon catab olite derepression, Deletion of pmaA causes lethality, but a single copy of the gene is sufficient to support normal growth rate in pmaA hemizygous di ploids, even under acidic growth conditions, As compared to other fungal H-ATPases, PmaA presents three insertions, 39, 7, and 16 residues long, in t he conserved central region of the protein. Two of these insertions are pre dicted to be located in extracellular loops and might be of diagnostic valu e for the identification of Aspergillus species. Their absence from most ma mmalian P-type ATPases may have implications for antifungal therapy. (C) 19 98 Academy Press.