The present invention provides genomic and cDNA encoding human cytoplasmic polyadenylation element binding protein, expression vectors comprising human cytoplasmic polyadenylation element binding protein cDNA and host cells that contain the expression vectors. Also provided are recombinant human cytoplasmic polyadenylation element binding protein and polypeptides derived thereof. In addition, the present invention reports that the human Mos 3′ untranslated region (3′ UTR) contains a functional cytoplasmic polyadenylation element (CPE), interacts with the human CPEB1 protein and directs maturation-dependent cytoplasmic polyadenylation of the endogenous Mos mRNA.