Figure 1.

nc-tgp1 transcription increases H3K36me3 levels over the tgp1⁺ promoter. (A) Schematic representation of the tgp1⁺ locus, including the nc-tgp1 lncRNA gene located immediately upstream. In phosphate-rich conditions (+PO₄) the tgp1⁺ gene is repressed by nc-tgp1 transcription into the tgp1⁺ promoter. In contrast, reduced nc-tgp1 transcription, in response to phosphate starvation (−PO₄) or following deletion of the nc-tgp1 promoter (1343Δ), permits tgp1⁺ induction (34). Primer pairs spaced over the tgp1⁺ locus are displayed below. (B and C) RT-qPCR analysis of tgp1⁺ mRNA levels (primer pair 1) and upstream nc-tgp1 lncRNA levels (primer pair 5) in wild-type cells grown in the presence or absence of phosphate, as well as in phosphate-replete1343Δ cells. (D) ChIP-qPCR analysis of the Ser2P form of elongating RNAPII over the tgp1⁺ locus in response to changes in phosphate availability/nc-tgp1 transcription. (E) ChIP-qPCR analysis of H3K36me3 over the tgp1⁺ locus in response to changes in phosphate availability/nc-tgp1 transcription. Error bars represent standard deviation resulting from at least three independent experiments.