PAPOLA (poly(A) polymerase alpha) is a nuclear polymerase that synthesizes the 3'-poly(A) tail on mRNA molecules, a critical step in mRNA maturation and stability 1. Beyond tail synthesis, PAPOLA also participates in the endonucleolytic cleavage reaction required at polyadenylation sites, acquiring specificity through interactions with cleavage and polyadenylation specificity factor (CPSF) [UniProt]. The enzyme possesses poly(A) RNA polymerase activity and binds ATP, magnesium, and manganese ions, enabling catalytic function in the nucleus and cytoplasm. PAPOLA functions redundantly with related tailing enzymes TENT2 and PAPOLG to adenylate unadenylated RNAs arising from premature transcription termination 1. These adenylated transcripts are subsequently targeted for degradation through the nuclear Poly(A) tail eXosome Targeting (PAXT) pathway or exported for cytoplasmic degradation, preventing accumulation of aberrant transcripts that would otherwise impair translation and cell viability 1. Thus, PAPOLA serves as a safeguard mechanism protecting cells from products of pervasive transcription, playing an essential role in post-transcriptional quality control.