Glucose does not activate the plasma-membrane-bound H+-ATPase but affects pmaA transcript abundance in Aspergillus nidulans

The addition of glucose to starved cells of Aspergillus nidulans increased the abundance of the pmaA transcript only transiently (15 min) and to a ver y low degree (1.3-fold), but strongly decreased its abundance during furthe r incubation. this down-regulation was CreA (carbon catabolite repressor pr otein)-dependent. Glucose failed to stimulate the plasma membrane (PM)-ATPa se activity of A. nidulans, whereas under the same experimental conditions the activity of the enzyme from Saccharomyces cerevisiae was enhanced four- fold within 5-10 min following glucose addition. Glucose stimulated the PM- ATPase of Neurospora crassa only 1.3-fold. Sequence comparison of the C-ter minal end of the PM-ATPase from S. cerevisiae, N. crassa, A. nidulans, Fusa rium sporotrichoides and Penicillium simplicissimum showed that the two reg ulatory sites necessary for glucose stimulation in S. cerevisiae are conser ved in N. crassa dnf F. sporotrichoides but not in A. nidulans and P. simpl icissimum, and their presence therefore does not correlate with glucose sti mulation. We conclude that, in contrast to S. cerevisiae, which has become a paradigm of fungal glucose metabolism, glucose does not up-regulate the a ctivity of the plasma membrane ATPase in the filamentous fungi examined.