Regulation of maltose transport in Saccharomyces cerevisae

Citation
Thc. Brondijk et al., Regulation of maltose transport in Saccharomyces cerevisae, ARCH MICROB, 176(1-2), 2001, pp. 96-105
Citations number
24
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Microbiology
Journal title
ARCHIVES OF MICROBIOLOGY
ISSN journal
0302-8933 → ACNP
Volume
176
Issue
1-2
Year of publication
2001
Pages
96 - 105
Database
ISI
SICI code
0302-8933(200107)176:1-2<96:ROMTIS>2.0.ZU;2-3
Abstract
Solute transport in Saccharomyces cerevisiae can be regulated through mecha nisms such as trans-inhibition and/or catabolite inactivation by nitrogen o r carbon sources. Studies in hybrid membranes of S. cerevisiae suggested th at the maltose transport system Mal61p is fully reversible and capable of c atalyzing both influx and efflux transport. This conclusion has now been co nfirmed by studies in a S. cerevisiae strain lacking the maltase enzyme. Wh ole cells of this strain, wherein the orientation of the maltose transporte r is fully preserved, catalyze fully reversible maltose transport. Cataboli te inactivation of the maltose transporter Mal61p was studied in the presen ce and absence of maltose metabolism and by the use of different glucose an alogues. Catabolite inactivation of Mal61p could be triggered by maltose, p rovided the sugar was metabolized, and the rate of inactivation correlated with the rate of maltose influx. We also show that 2-deoxyglucose, unlike 6 -deoxyglucose, can trigger catabolite inactivation of the maltose transport er. This suggests a role for early glycolytic intermediates in catabolite i nactivation of the Mal61 protein. However, there was no correlation between intracellular glucose-6-phosphate or ATP levels and the rate of catabolite inactivation of Mal61p. On the basis of their identification in cell extra cts, we speculate that (dideoxy)-trehalose and/or (deoxy)-trehalose-6-phosp hate trigger catabolite inactivation of the maltose transporter.