Required for exosome-dependent processing of pre-rRNA and small nucleolar RNA (snRNA) precursors. Involved in processing of 35S pre-rRNA at the A0, A1 and A2 sites. Required for activity of RRP6 in 7S pre-rRNA processing. Also has a role in 3'-processing of U4 and U5 small nuclear RNAs (snRNAs). Acts as a mRNA export factor. Mediates mRNA degradation upon UV irradiation. Maintains genome integrity where it is involved in both non-homologous end joining (NHEJ) and homologous recombination pathway repair of double strand DNA breaks. During NHEJ, required for joining 3'-overhanging ends. Also involved in telomere length regulation and maintenance. Associated with nuclear form of the RNA exosome complex. Interacts with RRP4, RRP6, RRP45 and RRP46. Belongs to the C1D family.