Developmental behaviour of zebrafish cellular nucleic acid binding protein (zCNBP)

LOMBARDO, V.; ARMAS, P.; WEINER A.; CALCATERRA, N. B.

Bariloche - Río Negro

Simposio; XXXIX Annual Meeting of the Argentine Society for Biochemistry and Molecular Biology (SAIB); XXXII Annual Meeting of the Biophysical Society of Argentina (SAB) - Bariloche Protein Symposium.; 2003

Sociedad Argentina de Investigación en Bioquímica y Biología Molecular (SAIB); Sociedad Argentina de Biofísica (SAB)

CNBP is widespread throughout the animal kingdom. This protein shows an striking sequence conservation and general structural organization which suggests it plays a fundamental biological role in different species throughout evolution. It was suggested involving in the developmental control expression of ribosomal proteins as well as in c-Myc regulation. We used the zebrafish Danio rerio as an animal model to study the CNBP behaviour during early development. We cloned and analysed zebrafish CNBP. zCNBP is a small protein which contains seven retroviral CCHC zinc finger motif, an RGG box and putative phosphorylation sites. Although its mRNA is detected in several adult tissues, we could observed a higher level of expression in ovary. We performed in vitro phosphorylation assays on GST-zCNBP in presence of zebrafish embryo extracts from different developmental stages. We observed that zCNBP is phosphorylated in vitro in a differential way depending on the embryo developmental stage used. Band-shift assays were performed to analyse the ability of proteins present in embryo extracts to bind single-stranded probes of ribosomal protein 5´UTR and c-Myc 5´UTR. All the stages analysed were able to bind per se both probes, but their binding capacity varied through early development. The same band-shift pattern was observed using GST-zCNBP instead embryo extracts. Taking together, CNBP might be a single-stranded nucleic-acid binding protein with differential behaviour during early development.