Cytoplasmic poly(A) RNA polymerase that adds successive AMP monomers to the 3'-end of specific RNAs, forming a poly(A) tail. In contrast to the canonical nuclear poly(A) RNA polymerase, it only adds poly(A) to selected cytoplasmic mRNAs. Required for formation of long term memory. ATP + RNA(n) = diphosphate + RNA(n)-3'-adenine ribonucleotide Interacts with Fmr1 and eIF-4E. Found in neuronal cytoplasm, present in discrete neuronal particles associated with mRNA control, and in nuclear puncta. Expressed in the brain. Expressed in larvae, pupae and adults. Belongs to the DNA polymerase type-B-like family. GLD2 subfamily.