. . . . . . . . "Component of the TRAMP (TRF4) complex which has a poly(A) RNA polymerase activity and is involved in a post-transcriptional quality control mechanism limiting inappropriate expression of genetic information. Polyadenylation is required for the degradative activity of the exosome on several of its nuclear RNA substrates like cryptic transcripts generated by RNA polymerase II and III, or hypomethylated pre-tRNAi-Met. Both complexes polyadenylate RNA processing and degradation intermediates of snRNAs, snoRNAs and mRNAs that accumulate in strains lacking a functional exosome. AIR2 also inhibits the methylation of NPL3 mediated by HMT1 through its interaction with HMT1." .