title: Control of poly(A) polymerase level is essential to cytoplasmic polyadenylation and early development in Drosophila.
abstract: 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.
authors.affiliation: Génétique du Développement de la Drosophile, Institut de Génétique Humaine, 141 rue de la Cardonille, 34396 Montpellier Cedex 5, France.
authors.forename: François
authors.initials: F
authors.lastname: Juge
authors.forename: Sophie
authors.initials: S
authors.lastname: Zaessinger
authors.forename: Claudia
authors.initials: C
authors.lastname: Temme
authors.forename: Elmar
authors.initials: E
authors.lastname: Wahle
authors.forename: Martine
authors.initials: M
authors.lastname: Simonelig
mesh_terms: D000818:Animals; D002467:Cell Nucleus / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism*; D004330:Drosophila / Q000196:embryology / Q000502:physiology*; D029721:Drosophila Proteins / Q000378:metabolism; D020869:Gene Expression Profiling; D026723:Polyadenylation / Q000502:physiology*; D011062:Polynucleotide Adenylyltransferase / Q000235:genetics / Q000378:metabolism*; D012322:RNA Precursors / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000378:metabolism
chemical_list: D029721:Drosophila Proteins; D012322:RNA Precursors; D016601:RNA-Binding Proteins; C089932:orb protein, Drosophila; D011062:Polynucleotide Adenylyltransferase; C426563:hrg protein, Drosophila