PT - JOURNAL ARTICLE AU - Tichon, Ailone AU - Gil, Noa AU - Lubelsky, Yoav AU - Havkin Solomon, Tal AU - Lemze, Doron AU - Itzkovitz, Shalev AU - Stern-Ginossar, Noam AU - Ulitsky, Igor TI - A conserved abundant cytoplasmic long noncoding RNA modulates repression by Pumilio proteins in human cells AID - 10.1101/033423 DP - 2016 Jan 01 TA - bioRxiv PG - 033423 4099 - http://biorxiv.org/content/early/2016/03/21/033423.short 4100 - http://biorxiv.org/content/early/2016/03/21/033423.full AB - Thousands of long noncoding RNA (lncRNA) genes are encoded in the human genome, and hundreds of them are evolutionary conserved, but their functions and modes of action remain largely obscure. Particularly enigmatic lncRNAs are those that are exported to the cytoplasm, including NORAD – an abundant and highly conserved cytoplasmic lncRNA. Most of the sequence of NORAD is comprised of repetitive units that together contain at least 17 functional binding sites for the two Pumilio homologs in mammals. Through binding to PUM1 and PUM2, NORAD modulates the mRNA levels of their targets, which are enriched for genes involved in chromosome segregation during cell division. Our results suggest that some cytoplasmic lncRNAs function by modulating the activities of RNA binding proteins, an activity which positions them at key junctions of cellular signaling pathways.