3'-exoribonuclease that has a preference for poly(A) tails of mRNAs, thereby efficiently degrading poly(A) tails (PubMed:27515512). Exonucleolytic degradation of the poly(A) tail is often the first step in the decay of eukaryotic mRNAs and is also used to silence certain maternal mRNAs translationally during oocyte maturation and early embryonic development (PubMed:27515512). May act as a regulator of multipotency in embryonic stem cells (PubMed:27515512). Is a critical factor for proper spermatogenesis, involved in pre-piRNAs processing to generate mature piRNAs (By similarity). Exonucleolytic cleavage of poly(A) to 5'-AMP. Localizes mainly in the endoplasmic reticulum. Specifically expressed in embryonic stem cells (PubMed:27515512). Highly expressed in testis (PubMed:26919431, PubMed:27515512). Expressed during early embryo development and fades during differentiation. Down-regulated in differentiated cells, due to methylation of its promoter by the methyltransferase DNMT3B. Belongs to the CAF1 family. Preliminary results in vitro suggested that Pnldc1 might act as an exonuclease that specifically cleaves precursor piRNAs (pre-piRNAs) at their 3' ends (PubMed:26919431). These results however require additional experimental evidences: another report showed that the protein mainly localizes to the endoplasmic reticulum and preferentially acts on poly(A) tails (PubMed:27515512).