Involved in the 3'-end formation of mRNA precursors (pre-mRNA) by the addition of a poly(A) tail of 200-250 nt to the upstream cleavage product (PubMed:10481015). Stimulates poly(A) polymerase (PAPOLA) conferring processivity on the poly(A) tail elongation reaction and controls also the poly(A) tail length (By similarity). Increases the affinity of poly(A) polymerase for RNA (By similarity). Binds to poly(A) and to poly(G) with high affinity (PubMed:10481015). May protect the poly(A) tail from degradation (By similarity). Plays a role in the positive regulation of alpha-1,3 fucosylation, possibly by cooperating with swm which regulates nuclear export of fucosyltransferase FucTA (PubMed:21203496). Interacts with ZC3H3. Shuttles between the nucleus and the cytoplasm but predominantly found in the nucleus. Mostly found in the nucleus in the germarium. From egg chamber formation onwards, expressed in both the nuclei and cytoplasm of nurse cells and the oocyte. At stage 10, abundant in the nuclei of nurse cells, oocyte and follicle cells and in the cytoplasm of nurse cells. Uniformly distributed in the cytoplasm of early embryos then progressively localizes to nuclei during the pre-blastoderm and syncytial blastoderm stages. After cellularization, localizes mainly to the nucleus and remains nuclear in later embryonic and larval stages. During mitosis, expression levels are reduced in prophase nuclei and expression is localized to the cytoplasm during metaphase. Localizes to nuclear speckles. Expressed ubiquitously in all transcriptionally active cells. Expressed both maternally and zygotically. Expressed in all developmental stages; egg, embryo, larva, pupa and in both adult males and females. The RRM domain is essential for specific adenine bases recognition in the poly(A) tail but not sufficient for poly(A) binding. RNAi-mediated knockdown results in reduced alpha-1,3-fucosylation of chp.