Adapter protein that plays a central role in localization of transcripts in the oocyte and in young embryos (PubMed:9118812). Maintains RNA targets in a repressed state by promoting their deadenylation and protects deadenylated mRNAs from further degradation (PubMed:21937713). Binds to and recruits eIF-4E to the 3'-UTR of some mRNA targets which prevents interaction between eIF4E1 and eIF4G (PubMed:14685270, PubMed:15465908, PubMed:21081899). This may contribute to translational repression but does not appear to be necessary for it to occur (PubMed:21081899). Can promote translational repression independently of deadenylation and eIF4E1 binding (PubMed:21937713). Required for correct localization of eIF4E1 in the developing oocyte (PubMed:15465908). Required for translational repression of oskar (osk) mRNA (PubMed:14691132, PubMed:14723848). Also required for the translational repression of nanos (nos) mRNA (PubMed:21081899). Promotes the accumulation of the germ plasm components osk, vas and stau at the posterior pole of the oocyte and is required for germ cell development (PubMed:22454519, PubMed:17277377). Represses orb positive autoregulatory activity which prevents premature activation of orb and ensures its accumulation specifically in the developing oocyte (PubMed:22164257). In 0-1 hour embryos, forms a complex with me31B, cup, tral and pAbp which binds to various mRNAs including maternal mRNAs, and downregulates their expression during the maternal-to-zygotic transition (PubMed:28875934).