TY - JOUR T1 - Characterization of new RNA polymerase III and RNA polymerase II transcriptional promoters in the Bovine Leukemia Virus genome JF - bioRxiv DO - 10.1101/043034 SP - 043034 AU - Benoit Van Driessche AU - Anthony Rodari AU - Nadège Delacourt AU - Sylvain Fauquenoy AU - Caroline Vanhulle AU - Arsène Burny AU - Olivier Rohr AU - Carine Van Lint Y1 - 2016/01/01 UR - http://biorxiv.org/content/early/2016/03/09/043034.abstract N2 - Bovine leukemia virus latency is a viral strategy used to escape from the host immune system and contribute to tumor development. However, a highly expressed BLV micro-RNA cluster has been reported, suggesting that the BLV silencing is not complete. Here, we demonstrate the in vivo recruitment of RNA polymerase III to the BLV miRNA cluster both in BLV-latently infected cell lines and in ovine BLV-infected primary cells, through a canonical type 2 RNAPIII promoter. Moreover, by RPC6-knockdown, we showed, for the first time, a direct functional link between RNAPIII transcription and BLV miRNAs expression. Furthermore, both the tumor‐ and the quiescent-related isoforms of RPC7 subunits were recruited to the miRNA cluster. We showed that the BLV miRNA cluster was enriched in positive epigenetic marks. Interestingly, we demonstrated the in vivo recruitment of RNAPII at the 3’LTR/host genomic junction, associated with positive epigenetic marks. Functionally, we showed that the BLV LTR exhibited a strong antisense promoter activity and provided evidence for a collision between RNAPIII and RNAPII convergent transcriptions. Our results provide new insights into alternative ways used by BLV to counteract silencing of the viral 5’LTR promoter. ER -