Factors involved in the regulation of the Schizosaccharomyces pombe malic enzyme gene.

Transcription of the Schizosaccharomyces pombe malic enzyme gene, mae2, is induced when cells are grown on high glucose concentrations or under nonaerated conditions. Two cis-acting elements in the mae2 promoter, upstream activator sequences UAS1 and UAS2, are required for basal expression, whilst three negative-acting, upstream repressor sequences are involved in general derepression of mae2. Both the Pka1 and Sty1 signal transduction pathways are involved in the induced expression of mae2 under fermentative conditions. Expression of mae2 seems to be regulated in response to the carbon source, lack of oxygen and osmotic stress conditions, probably to assist in maintaining the intracellular redox balance.