Involved in surveillance of pre-rRNAs and pre-mRNAs, and the degradation of cryptic non-coding RNAs (ncRNA) derived from intergenic regions and the ribosomal DNA spacer heterochromatin. Binds RNA. Colocalizes with the nuclear exosome and ribosomes. Lethal in combination with the absence of either RRP6 or its cofactor RRP47. Weak but detectable stabilization of unspliced pre-mRNAs, and stronger stabilization is detected for mRNAs with defects in 3' cleavage and polyadenylation. Present with 1350 molecules/cell in log phase SD medium.