Overlapping positive and negative GATA factor binding sites mediate inducible DAL7 gene expression in Saccharomyces cerevisiae

Allantoin pathway gene expression in Saccharomyces cerevisiae responds to t wo different environmental stimuli. The expression of these genes is induce d in the presence of allantoin or its degradative metabolites and repressed when a good nitrogen source (e.g. asparagine or glutamine) is provided. Th ree types of cis-acting sites and trans acting factors are required for all antoin pathway gene transcription as follows: (i) UAS(NTR) element associat ed with the transcriptional activators Gln3p and Gat1p, (ii) URSGATA elemen t associated with the repressor Dal80p, and (iii) UISALL element associated with the Dal82 and Dal81 proteins required for inducer-dependent transcrip tion. Most of the work leading to the above conclusions has employed induce r-independent allantoin pathway genes (e.g, DAL5 and DAL3), The purpose of this work is to extend our understanding of these elements and their roles to inducible allantoin pathway genes using the DAL7 (encoding malate syntha se) as a model. We show that eight distinct cis-acting sites participate in the process as follows: a newly identified GC-rich element, two UAS(NTR), two UISALL, arid three URSGATA elements. The two GATA-containing UAS(GATA) elements are coincident with two of the three GATA sequences that make up t he URSGATA elements. The remaining URSGATA GATA sequence, however, is not a UAS(NTR) element but appears to function only in repression. The data prov ide insights into how these cis- and trans-acting factors function together to accomplish the regulated expression of the DAL7 gene that is observed i n vivo.