Poly(A)-specific ribonuclease

Exonucleolytic degradation of the poly(A) tail is often the first step in the decay of eukaryotic mRNAs. The amino acid sequence of poly(A)-specific ribonuclease shows homology to the RNase D family of 3'-exonucleases. The protein appears to be localized in both the nucleus and the cytoplasm. It is not stably associated with polysomes or ribosomal subunits.^[6] Hereditary mutations in PARN lead to the bone marrow failure disease dyskeratosis congenita which is caused by defective telomerase RNA processing and degradation in patients.^{[7][8][9][10][11][12][13]}