Binds the poly(A) tail of mRNA. Unable to interact with the cap-binding complex and is therefore unlikely to be involved in translation initiation. Homodimer; Upon poly(A) binding, undergoes a dimer-monomer transition that removes the polyproline motif from the RNA recognition site and allows it to be replaced by the adenosine nucleotides of poly(A). Expressed both maternally and zygotically. Restricted to oogenesis, early embryogenesis and the adult ovary. Levels decrease after the onset of zygotic transcription (at protein level).