The Effect of Spt5p on Transcriptional Directionality [PRO-seq]

SPT5 is a well-conserved factor which manipulates multiple stages of transcription including promoter-proximal pausing (PPP). Furthermore, recent studies have reported an unidentified increase of antisesne transcripts near promoters in SPT5 mutations. Here, we have identified Spt5p-restricted intragenic antisense transcripts which are in close relationship with sense transcription. The antisense highly-restricted genes have common properties: endogenously strong sense transcription and weak antisense transcription, which is also conserved in humans. We identified that Spt5p depletion reduce H3K36me3 and H3K79me3 and lead to histone hyperacetylation, which might be the intermediate stage to induce antisense transcription. We additionaly found possible termination factors that are involved in the antisense restriction with Spt5p. By unveiling the new role of SPT5 in finely balancing the transcription bidirections, we revealed that transcription machinery can determine the direction cotranscriptionally. PRO-seq and PRO-cap libraries were generated using Bur1p-IS strain presented by S. Bratowski's group (Chun et al., 2019) and several auxin-inducible degron (AID) strains. S. pombe is used for spike-in control. Two biological replicates are merged. Every libraries are normalized by spike-in.