Involved in histone mRNA 3'-end processing (By similarity). Involved in the cytoplasmic polyadenylation element (CPE)-mediated polyadenylation of maternal mRNAs in maturing oocytes. Serves as a scaffold upon which cytoplasmic polyadenylation regulatory factors are assembled. Identification in a complex with cpsf2, cpsf73, cpsf160 and sympk. Interacts with cpeb1, cpsf2 and papd4. Cajal bodies (CBs). The HEAT repeats have been determined based on 3D-structure analysis of the D.melanogaster ortholog and are not detected by sequence-based prediction programs. Belongs to the Symplekin family.