RT Journal Article
SR Electronic
T1 Characterization of new RNA polymerase III and RNA polymerase II transcriptional promoters in the Bovine Leukemia Virus genome
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 043034
DO 10.1101/043034
A1 Benoit Van Driessche
A1 Anthony Rodari
A1 Nadège Delacourt
A1 Sylvain Fauquenoy
A1 Caroline Vanhulle
A1 Arsène Burny
A1 Olivier Rohr
A1 Carine Van Lint
YR 2016
UL http://biorxiv.org/content/early/2016/03/09/043034.abstract
AB 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.