Molecular studies of drosophila cup protein and its putative mouse homologue clast4 during female germ-line development. Analysis of the embryonic phenotype caused by a hypomorphic mutation of the tale gene prep1 (pknox1)
- Autores: J. Carlos Villaescusa
- Directores de la Tesis: Francesco Blasi (dir. tes.), Riaz Farookhi (codir. tes.)
- Lectura: En la Universitat Autònoma de Barcelona ( España ) en 2007
- Idioma: español
- Tribunal Calificador de la Tesis: Purificacion Muñoz Canoves (presid.), Maria Plana i Coll (secret.), Anna Bigas Terricabras (voc.), Fátima Gebauer (voc.), Gemma Marfany i Nadal (voc.)
- Materias:
- Texto completo no disponible (Saber más ...)
- Resumen
This thesis is composed of two different parts. The aim of the first part was to study the role of Cup protein in the control of translation initiation during Drosophila oogenesis, and to identify a possible mouse homolog. We focused our work on the role of Cup during ovary development through its interaction with eIF4E. The resulting data shows that Cup colocalizes with eIF4E to the posterior cytoplasm of developing oocytes and is required for the correct accumulation and localization of eIF4E within the oocyte. We also demonstrate that Cup and eIF4E interact genetically to control ovary development and growth. Our results demonstrate that the interaction between eIF4E and Cup is essential to achieve the correct level of translational activity required for the normal development of Drosophila ovary.
A search of the protein database for a mouse homologue of the Drosophila Cup protein identified the product of the Clast4 gene. We performed a yeast two-hybrid screen in order to identify specific interactors of Clast4, and we isolated the product of eIF4E gene. We also show that Clast4 mRNA and protein are highly expressed within the cytoplasm of growing oocytes. The Clast4 protein is stable during this developmental window and post-translationally modified by phosphorylation upon oocyte meiotic maturation. Moreover, we demonstrate that Clast4 and eIF4E directly interact by a canonical and functional eIF4E-binding motif.
In summary, our results suggest that Cup functionally interacts with eIF4E, pointing to a crucial role for Cup in the control of translation initiation during oogenesis in Drosophila. Clast4, similar to Drosophila Cup, may act at the translational level during murine female germ-line development.
The aim of the second part was to study the role of Prep1 protein in vivo during embryo development. Due to the early embryonic death of the Prep1 null mutant mice, we have analyzed a hypomorphic mutant mouse (Prep1i/i), which produces between 3 to 10
