Integrator enforces the fidelity of transcriptional termination at protein-coding genes

Integrator regulates the 3’-end processing and termination of multiple classes of noncoding RNAs. Depletion of INTS11, the catalytic subunit of Integrator, or ectopic expression of its catalytic dead enzyme impairs the 3’-end processing and termination of a set of protein coding transcripts termed Integrator-regulated termination (IRT) genes. This defect is manifested by increased RNA polymerase II (RNAPII) readthrough and occupancy of serine-2 phosphorylated RNAPII, de-novo trimethylation of lysine 36 on histone H3, and a compensatory elevation of the cleavage and polyadenylation (CPA) complex in the downstream regions. 3’-RNA-sequnecing reveals that proximal polyadenylation site usage relies on the endonuclease activity of INTS11. The DNA sequence encompassing the transcription end sites of IRT genes feature downstream polyadenylation motifs and an enrichment of GC content that permits the formation of secondary structures within the 3’UTR. Taken together, this study identifies a subset of protein-coding transcripts whose 3’-end processing requires the Integrator complex. ChIP-seq of CPSF73, CSTF64 and H3K36me2 in INTS11-depleted HeLa shINTS11 cells in duplicates. eCLIP in HeLa shINTS11 cells in duplicates. 3' mRNA-Seq in HeLa WT shINTS11 and E203Q shINTS11 cells in duplicates.