Identification of a Novel Base J Binding Protein Complex Involved in RNA Polymerase II Transcription Termination in Trypanosomes

Rudo Kieft; Yang Zhang; Alexandre P. Marand; Jose Dagoberto Moran; Robert Bridger; Lance Wells; Robert J. Schmitz; Robert Sabatini

337 brucei and ablation results in similar growth defects as seen in PJW/PP1 complex (60) (Fig 3B) . Table) . 364 The location of the genes with >3-fold upregulation was mapped (Fig 4A and S5 ). Interestingly, these 365 genes were closely located at regions flanking PTUs or subtelomeric regions, suggesting a role of 366 PNUTS in genome-wide transcription, specifically at transcription initiation and termination sites, as well 367 as subtelomeres. The PTU flanking regions represent transcription termination sites (TTS) and 368 transcription start sites (TSS) within the so-called convergent strand switch region (cSSR) and divergent 369 strand switch region (dSSR), respectively. We have previously shown that base J is localized within the 370 cSSRs and dSSRs flanking PTUs and involved in Pol II termination. Therefore, we wanted to first confirm 371 the association with J at termination sites with changes in gene expression we observed in the PNUTS The copyright holder for this preprint (which was not peer-reviewed) is the author/funder. It . https://doi.org/10.1101/753004 doi: bioRxiv preprint 408 borders of PTUs, including downstream of normal transcription termination sites at the 3'-end. To take a 409 closer look at the increased level of transcripts at these sites, and determine whether they are due to 410 transcriptional readthrough, forward and reverse reads mapping to 5kb flanking and within cSSRs were 411 counted and RPKM values were generated. As shown in Fig 4B,