Promoter sequences regulated by the calcineurin-activated transcription factor Crz1 in the yeast ENA1 gene

Abstract.

In Saccharomyces cerevisiae the transcription of the ENA1 gene is modulated by multiple transduction pathways that respond to osmotic, ionic and nutrient stresses. We have investigated the molecular mechanisms involved in ENA1 induction by the calcium-calcineurin-activated transcription factor Crz1/Tcn1. We found in the ENA1 promoter a calcium-responsive, Crz1-dependent upstream activating region (UAS _ENA1 ) located between –713 bp and –826 bp relative to the translation start. This region contains two separate control elements: the upstream element (5′-GAATGGCTG-3′) between –813 and –821 binds Crz1p with lower affinity and mostly contributes to basal ENA1 expression, whereas the downstream element (5′-GGGTGGCTG-3′) between –727 and –719 binds Crz1p with higher affinity and is a major determinant of the induction response to calcium.