Zinc-dependent regulation of the Adh1 antisense transcript in fission yeast.
In yeast, Adh1 (alcohol dehydrogenase 1) is an abundant zinc-binding protein that is required for the conversion of acetaldehyde to ethanol. Through transcriptome profiling of the Schizosaccharomyces pombe genome, we identified a natural antisense transcript at the adh1 locus that is induced in response to zinc limitation. This antisense transcript (adh1AS) shows a reciprocal expression pattern to that of the adh1 mRNA partner. In this study, we show that increased expression of the adh1AS transcript in zinc-limited cells is necessary for the repression of adh1 gene expression and that the increased level of the adh1AS transcript in zinc-limited cells is a result of two mechanisms. At the transcriptional level, the adh1AS transcript is expressed at a high level in zinc-limited cells. In addition to this transcriptional control, adh1AS transcripts preferentially accumulate in zinc-limited cells when the adh1AS transcript is expressed from a constitutive promoter. This secondary mechanism requires the simultaneous expression of adh1. Our studies reveal how multiple mechanisms can synergistically control the ratio of sense to antisense transcripts and highlight a novel mechanism by which adh1 gene expression can be controlled by cellular zinc availability.
Ehrensberger KM, Mason C, Corkins ME, Anderson C, Dutrow N, Cairns BR, Dalley B, Milash B, Bird AJ