Integrator restraints paraspeckles assembly by promoting the 3’-end processing of the polyadenylated lncRNA NEAT1_1

ABSTRACT: Alternative 3’-end RNA processing provides an important source of transcriptome diversification, which impacts various biological processes and the etiology of diseases, including cancer. Here, we focused on a transcript isoform switch that leads to the readthrough expression of the long noncoding RNA NEAT1_2, at the expense of the shorter polyadenylated transcript NEAT1_1. Expression of NEAT1_2 is required for the formation of paraspeckles (PS), nuclear bodies that protect cancer cells from oncogene-induced replication stress and chemotherapy. Searching for proteins that interact with endogenous NEAT1 by RNA Affinity Purification coupled to mass spectrometry (RAP-MS), we identified factors involved in the 3’-end processing of polyadenylated (pA+) RNA as well as several components of the Integrator complex, known to process the 3’-ends of RNAs lacking polyadenylation sites. Unexpectedly, genetic perturbation experiments established that Integrator restraints NEAT1_2 expression, and thereby PS assembly, by promoting the 3’-end processing of pA+ NEAT1_1. Consistently, low expression levels of several Integrator subunits correlated with poorer prognosis of cancer patients exposed to chemotherapeutics. Our study identifies Integrator as a key regulator of PS biogenesis and highlights a previously unrecognized ability of the complex to process pA+ RNA. The data also establish a link between Integrator, cancer biology and chemosensitivity, which may be exploited therapeutically.

INSTRUMENT(S): Q Exactive

ORGANISM(S): Homo Sapiens (human)

TISSUE(S): Breast Epithelium, Breast Adenocarcinoma Cell Line

DISEASE(S): Breast Cancer

SUBMITTER: Impens Francis  

LAB HEAD: Jean-Christophe Marine

PROVIDER: PXD015158 | Pride | 2020-10-14

REPOSITORIES: Pride