| Modification Notes |
Exonucleolytic degradation of the poly(A) tail often initiates the first step in the decay of eukaryotic mRNAs. Poly(A)-specific ribonuclease (PARN), a highly poly(A)-specific 3'-exoribonuclease, efficiently degrades mRNA poly(A) tails. PARN, which also may be designated deadenylating nuclease, may also be involved in nonsense-mediated mRNA decay, a critical process of selective degradation of mRNAs that contain premature stop codons, and in the degradation of inherently unstable mRNAs that contain au-rich elements (AREs) in their 3' untranslated regions. PARN, which can form a homodimer, interacts with KHSRP and can be found in a mRNA decay complex with RENT1, RENT2 and RENT3B.It localizes mainly to the nucleus (may be detected in the nucleolus), but may also localize to the cytoplasm. |