Partially Deadenylated mRNA Complex mature mRNA (eukaryotic, capped and deadenylated) Deadenylation of mRNA by PARN Authored: May, B, 2009-07-22 EC Number: 3.1.13.4 Edited: May, B, 2009-07-22 Pubmed10882133 Pubmed11283721 Pubmed1355481 Pubmed14749774 Pubmed15475613 Pubmed16141059 Pubmed17052452 Pubmed17245413 Pubmed19239894 Pubmed9099687 Reactome Database ID Release 43429992 Reactome, http://www.reactome.org ReactomeREACT_20662 Reviewed: Wilusz, J, 2009-09-17 The PARN exoribonuclease hydrolyzes adenosine residues at the 3' ends of polyadenylated mRNA, shortening the poly(A) tail from about 80 adenosine residues to about 10-15 residues and yielding adenosine 5'-monophosphate. PARN interacts simultaneously with the poly(A) tail and with the 7-methylguanosine cap of the mRNA, therefore it is believed that PARN displaces the eIF4F cap-binding complex. The trigger for deadenylation by PARN is unknown. PARN is also part of a complex that regulates poly(A) tail length and hence translation in developing oocytes. eIF4A