Control of poly(A) polymerase level is essential to cytoplasmic polyadenylation and early development in Drosophila

AUTOR(ES)

Juge, François

FONTE

Oxford University Press

RESUMO

Poly(A) polymerase (PAP) has a role in two processes, polyadenylation of mRNA precursors in the nucleus and translational control of certain mRNAs by cytoplasmic elongation of their poly(A) tails, particularly during early development. It was found recently that at least three different PAP genes exist in mammals, encoding several PAP isoforms. The in vivo specificity of function of each PAP isoform currently is unknown. Here, we analyse PAP function in Drosophila. We show that a single PAP isoform exists in Drosophila that is encoded by the hiiragi gene. This single Drosophila PAP is active in specific polyadenylation in vitro and is involved in both nuclear and cytoplasmic polyadenylation in vivo. Therefore, the same PAP can be responsible for both processes. In addition, in vivo overexpression of PAP does not affect poly(A) tail length during nuclear polyadenylation, but leads to a dramatic elongation of poly(A) tails and a loss of specificity during cytoplasmic polyadenylation, resulting in embryonic lethality. This demonstrates that regulation of the PAP level is essential for controlled cytoplasmic polyadenylation and early development.

Documentos Relacionados

• The enzyme that adds poly(A) to mRNAs is a classical poly(A) polymerase.
• Poly(A) Tail Length Is Controlled by the Nuclear Poly(A)-binding Protein Regulating the Interaction between Poly(A) Polymerase and the Cleavage and Polyadenylation Specificity Factor*
• Maturation-specific polyadenylation and translational control: diversity of cytoplasmic polyadenylation elements, influence of poly(A) tail size, and formation of stable polyadenylation complexes.
• Polyadenylation of maternal mRNA during oocyte maturation: poly(A) addition in vitro requires a regulated RNA binding activity and a poly(A) polymerase.
• Role of poly(A) polymerase in the cleavage and polyadenylation of mRNA precursor.