GSE110775
Genome-wide screening of NEAT1 regulators reveals mito-paraspeckle communication
The long non-coding RNA NEAT1 (nuclear enriched abundant transcript 1) nucleates the formation of paraspeckles, which constitute a type of nuclear body that has multiple roles in gene expression. How the NEAT1 gene itself is regulated and how paraspeckles communicate with other cell compartments remains poorly understood. Here we identify regulators of NEAT1 transcription using an endogenous NEAT1 promoter-driven EGFP reporter in human cells coupled with genome-wide RNAi screens. In addition to transcription factors and chromatin modulators, the screens unexpectedly yielded gene candidates involved in mitochondrial functions as essential regulators of NEAT1 expression and paraspeckle formation. Mitochondrial defects altered NEAT1 transcription via ATF2 and subsequently uncoupled 3' end processing of NEAT1_1 from its long isoform to favour NEAT1_2 production, which is key for generating elongated paraspeckles that have different features from the regular, globular bodies. Correspondingly, NEAT1 depletion has profound effects on mitochondrial dynamics and function by altering sequestration of mRNAs of mitochondrial genes enriched in paraspeckles. Overall, our data provided a rich resource for understanding NEAT1 and paraspeckle regulation, and revealed an unexpected crosstalk between cytoplasmic organelles and nuclear bodies.  Overall design: Examination of differential expressed genes between wild type and NEAT1 KO by poly(A)+ RNA-Seq and identifying RNAs that interact with NEAT1 by NEAT1 CHART (capture hybridization analysis of RNA targets) assays followed by RNA-sequencing (CHART RNA-seq) from HeLa cells.