Fig. 7: Proposed function of Spt5p in suppressing antisense transcription.
From: Spt5 orchestrates cryptic transcript suppression and transcriptional directionality
Spt5p enables proper transcriptional elongation by RNAPII and prevents antisense transcription within genes. H3K36me3 and H3K79me3 are highly enriched on genes exhibiting high-level transcription from the sense strand and low-level transcription from the antisense strand. In the absence of Spt5p, RNAPII encounters difficulties in progression and experiences premature termination. This causes rapid histone turnover and consequent removal of H3K36/79me3 and incorporation of acetylated histones, yielding a highly loosened DNA structure. The black arrows indicate the RNAPII signal observed in PRO-seq, with the signal intensity represented by the arrow size. The increased cryptic transcription within genes is indicated by orange arrows. RNAPII having the potential to complete mature elongation is depicted as a gray circle. Other colors are as follows: Spt5p (red), phosphate group (light blue), H3K36me3 / H3K79me3 (light pink), and histone acetylation (green).
