Structure and Expression of Zebrafish Cellular Nucleic Acid Binding Protein (CNBP).

ARMAS, P.; CACHERO S.; CALCATERRA, N. B.

Villa Carlos Paz, Córdoba, Argentina.

Congreso; XXXVII Reunión anual de la Sociedad Argentina de Investigación en Bioquímica y Biología Molecular.; 2001

Sociedad Argentina de Investigación en Bioquímica y Biología Molecular.

Ribosomal protein mRNAs (rp-mRNAs) translation is regulated during early development according to the needs of translational machinery of the embryo cells. Although the regulation is clear, the mechanism and way of signalling are unknown. It has been shown that CNBP specifically binds 5’UTR-rp-mRNAs, possibly inhibiting their translation. The biological role of CNBP has not been addressed, but its structure and expression pattern show several items of interest. Due to the advantages of Zebrafish Danio rerio in the study of developmental processes we analyzed the Zebrafish CNBP amino acid sequence deduced from an EST expressed in embryos and liver. This analysis showed the existence of several Zn-fingers and other motifs probably involved in RNA and protein binding. We confirmed the presence of putative phosphorylation sites and the correlation with the b isoform. The homology analysis showed that it is more than 82% similar to CNBP from other vertebrates and approximately 50% similar to CNBP-like sequences from insects and inferior eukaryotes. The expression of CNBP mRNA was confirmed by specific RT-PCR on whole-fish-total RNA. We also analyzed the pattern of CNBP expression in Zebrafish embryos by Western blot of total soluble proteins and compared it to expression in other organisms. These results confirm the expression of Zebrafish CNBP and allow the use of this model for functional studies in rp-mRNA translation regulation during early development.