In response to the signaling polyketide DIF-1 DimB directly activates transcription of the ecmB gene in pstB cells; a subset of the prestalk cells that are the precursors of the basal disc. We show that the promoter of pspA, a prespore-specific gene, also contains a DimB binding site. Mutation of this site causes ectopic expression in the prestalk region and ChIP analysis shows that DIF-1 induces binding of DimB to the pspA promoter. DIF-1 represses pspA gene expression in a suspension cell assay but this repression is abrogated in a dimB null strain. These results suggest a coupled control mechanism, whereby the same DIF-DimB signaling pathway that directly activates ecmB gene expression directly represses pspA gene expression.
Nunez-Corcuera, B., Birch, J. L., Yamada, Y., & Williams, J. G. (2012). Transcriptional repression by a bZIP protein regulates Dictyostelium prespore differentiation. PLoS ONE, 7(1). https://doi.org/10.1371/journal.pone.0029895