Non-catalytic component of the RNA exosome complex which has 3'->5' exoribonuclease activity and participates in a multitude of cellular RNA processing and degradation events (By similarity). In the nucleus, the RNA exosome complex is involved in proper maturation of stable RNA species such as rRNA, snRNA and snoRNA, in the elimination of RNA processing by-products and non-coding 'pervasive' transcripts such as antisense RNA species, and of mRNAs with processing defects, thereby limiting or excluding their export to the cytoplasm (By similarity). In the cytoplasm, the RNA exosome complex is involved in general mRNA turnover and specifically degrades inherently unstable mRNAs containing AU-rich elements (AREs) within their 3' untranslated regions, and in RNA surveillance pathways, preventing translation of aberrant mRNAs (By similarity). The catalytic inactive RNA exosome core complex of 9 subunits is proposed to play a pivotal role in the binding and presentation of RNA for ribonucleolysis, and to serve as a scaffold for the association with catalytic subunits and accessory proteins or complexes (By similarity). Required generally for normal embryonic and neuronal development (PubMed:32645003). Also plays a critical role in the maintenance of neuronal function in mature flies by controlling the levels of specific mRNAs such as the synaptic regulator Arc1 (PubMed:32645003). Component of the RNA exosome complex (PubMed:12490954). Specifically part of the catalytically inactive RNA exosome core complex (By similarity). RNAi-mediated knockdown in the whole body, neurons, glia or muscles is lethal (PubMed:32645003). RNAi-mediated knockdown in mushroom bodies affects the morphology of the alpha- and beta-lobes as well as ellipsoid bodies (PubMed:32645003). RNAi-mediated knockdown in the wing pouch results in severe wing development phenotypes and increase of miR-252-5p expression (PubMed:25892215). Belongs to the RRP40 family.