Regulation of apoptosis by ΔNP63 during Xenopus laevis development

CELESTE TRÍBULO; MANUEL J. AYBAR; SARA S. SÁNCHEZ

Mar del Plata

Congreso; XLIII Reunión Anual Sociedad Argentina de Investigación Bioquímica y Biología Molecular; 2007

SAIB (Sociedad Argentina de Investigación Bioquímica y Biología Molecular

The p63 gene is a transcription factor and in mammals has two promoters that generate two types of protein isoforms, TAp63 and ANp63. The TA isoforms contain a transcription activation domainand are able to induce apoptosis. The AN isoforms lack the transactivation domain and can function as “dominant negative” proteins having an anti-apoptotic role. Although the p63 sequencesare conserved among organisms, in Xenopus, only the orthologue of mammalian Anp63y has been cloned and its role in development and apoptosis remains unknown. We analyzed the participation of ANp63 regulating apoptosis in Xenopus embryos. First, we analyzed the expression pattern of ANp63 using whole mount in situ hybridization. The main expression of ANp63 is located in theepidermis and also is detected as a defined line in the limit between neural folds and epidermis. Then, we proceeded to overexpress ANp63 in whole embryos and in animal caps to determine whether ANp63 was able to modify apoptosis. In both experiments, the TUNEL analysis showed that ANp63 produced a decrease of apoptosis. Finally, we analyzed whether ANp63 was able to regulate the transcription of caspase 2, 3 and 9, and Bcl2. Our results suggest that ANp63 is acting as an antiapoptotic factor during the development of Xenopus laevis regulating the transcriptions ofsome apoptotic and anti-apoptotic factors.