Regulation of apoptosis by delta NP63 during Xenopus laevis development

TRIBULO C.; AYBAR M.J.; SÁNCHEZ S.S.

Mar del Plata, Buenos Aires, Argentina

Congreso; XLIII Anual Meeting Sociedad Argentina de Investigacion en Bioquímica y Biología Molecular; 2007

Sociedad Argentina de Investigacion en Bioquímica y Biología Molecular

The p63 gene is a transcription factor and in marnmals has two promoters that generate two types of protein isoforms, TAp63 and deltaNp63. The TA isoforms contain a transcription activation domain and are able to induce apoptosis. The delta N isoforms lack the transactivation domain and can function as "dominant negative", proteins having an anti-apoptotic role. Although the p63 sequences are conserved among organisms, in Xenopus, only the orthologue of marnmalian delta Np63y has been cloned and its role in development and apoptosis remains unknown. We analyzed the participation of p63 regulating apoptosis in Xenopus embryos. First, we analyzed the expression pattem of delta Np63 using whole mount in situ hybridization. The main expression of delta Np63 is located in the epidermis and also is detected as a defined line in the limit between neural folds and epidermis. Then, we proceeded to overexpress delta Np63 in whole embryos and in animal caps to determine whether delta Np63 was able to modify apoptosis. In both experiments, the TUNEL analysis showed that mp63 produced a decrease of apoptosis. Finally, we analyzed whether mp63 was able to regulate the transcription of caspase 2, 3 and 9, and Bc1 2. Our results suggest that delta Np63 is acting as an antiapoptotic factor during the development of Xenopus laevis regulating the transcriptions of some apoptotic and anti -apoptotic factors.