Placenta-specific zinc-finger RNA-binding protein that destabilizes cytoplasmic AU-rich element (ARE)-containing mRNA transcripts by promoting their poly(A) tail removal or deadenylation, and hence provide a mechanism for attenuating protein synthesis (PubMed:15814898, PubMed:26952984). Binds to the 3'-UTR ARE of placental target mRNAs, such as TNF, HBEGF and LIPG (PubMed:15814898, PubMed:18367448, PubMed:26952984). Involved in placental expression of many genes important for normal placental physiology (PubMed:26952984). Localizes exlusively in the cytoplasm (PubMed:18367448, PubMed:15814898). Not detected in the nucleus despite the presence of a nuclear localization signal (NLS) in the zinc finger regions; a C-terminal alanine-rich repeat domain is able to override the activity of the nuclear localization signal and prevent import into the nucleus (PubMed:18367448, PubMed:26493225). Expressed in placenta and extraembryonic tissues (at protein level). Not detected in embryos and fetus (PubMed:15814898, PubMed:26952984). Expressed in placenta at 14.5 dpc. Expressed in the single layer of endodermal epithelial cells of the visceral yolk sac at 15.5 dpc (PubMed:26952984). Expressed in syncytiotrophoblast and trophoblast giant cells of the labyrinth region of the placenta at 17.5 dpc (PubMed:15814898, PubMed:26952984) (at protein level). Expressed specifically in extraembryonic structures, in placenta from 9.5 to 18.5 and yolk sac/amnion from 12.5 to 18.5 (PubMed:15814898, PubMed:26952984). Expressed in the labyrinthine layer of the trophoblastic placenta at 10.5, 12.5 and 14.5 dpc (PubMed:15814898). Expressed in syncytiotrophoblast and trophoblast giant cells, less in spongiotrophoblast cells, and not detected in maternal decidua or in allantois at 17.5 dpc (PubMed:26952984). Contains long series of C-terminal alanine-rich repeats that serve to maintain the protein in the cytoplasm. Mice are viable and fertile, without apparent morphological or histological abnormalities in the placenta, but display a decrease in the numbers of surviving offspring. Display an abnormal accumulation of placental 3'UTR ARE-containing mRNAs. Exhibit also a decrease in ARE-containing mRNA decay in differentiated trophoblast stem cells. Rodent-specific retrogene derived apparently from its related family member ZFP36L2 mRNA (PubMed:15814898, PubMed:26493225).