TGF-beta-upregulated Lnc-Nr6a1 acts as a reservoir of miR-181 and mediates assembly of a glycolytic complex [RNA-seq]

Long noncoding RNAs (lncRNAs) have emerged as key regulators in a wide range of biological processes. The involvement of lncRNAs in epithelial-to-mesenchymal transition (EMT) has been well stablished; however, the role as immediate-early regulators is still unclear. Here, we identified a mouse miRNA-host gene lncRNA (lnc-Nr6a1) early upregulated during EMT. We show that this lncRNA is processed giving rise to abundant polyadenylated isoforms, lnc-Nr6a1 and lnc-Nr6a1-2, and a longer non-polyadenylated microprocessor-driven lnc-pri-miRNAS containing clustered pre-miRNA-181a2 and pre-miRNA-181b2 hairpins. Ectopic expression of lnc-Nr6a1-1/2 isoforms enhance cell migration and invasive capacity of the cells, whereas the expression of isoforms and miR-181a2/b2 confers anoikis resistance. Lnc-Nr6a1 gene deletion results in cells with lower adhesion capacity and reduced glycolytic metabolism which are restored by lnc-Nr6a1-1 isoform expression. We perform identification of direct RNA interacting proteins (iDRIP) to identify proteins interacting directly with lnc-Nr6a1-1 isoform. We define a network of interacting proteins, including glycolytic enzymes, desmosome proteins and chaperone proteins and we demonstrated that lnc-Nr6a1-1 isoform directly binds and acts as a scaffold molecule for the assembly of ENO1, ALDOA, GAPDH, PKM glycolytic enzymes along with LDHA, supporting substrate canneling for efficient glycolysis. Our results unveil a role of lnc-Nr6a1 as a multifunctional lncRNA acting as a backbone for multiprotein complexes formation and as a primary microRNAs reservoir. Transcriptome profiles of NMuMG mouse glandular epithelial cells treated with TGFβ1 at 2h and control cells were generated by deep sequencing, in duplicates, using Illumina NextSeq 500 Mid Output.