Finding molecular targets for the nucleic acid chaperone CNBP.

ARMAS, P.; RUZZI, L.R.; CALCATERRA, N.B.

San Miguel de Tucumán, Tucumán, Argentina.

Congreso; XLV Annual Meeting of the Argentine Society for Biochemestry and Molecular Biology Research.; 2009

Argentine Society for Biochemestry and Molecular Biology Research.

Cellular nucleic acid binding protein (CNBP) is a conserved single-stranded nucleic acid binding protein required for vertebrates craniofacial development. CNBP acts as a nucleic acid chaperone, rearranging the secondary structure of its targets. Recently, our group demonstrated that CNBP promotes the formation of G-quadruplexes, stable nucleic acid structures described as novel elements for gene expression regulation. However, the consensus sequence of CNBP targets has not been elucidated yet. The main goal of this work was to gain knowledge about the common features among CNBP molecular targets in order to identify putative genes regulated by this protein. Therefore, we performed a “Systematic Evolution of Ligands by Exponential Enrichment” (SELEX) using zebrafish CNBP and a single-stranded nucleic acid library degenerated in 16 nucleotides. Sequences obtained with this procedure have been analyzed and compared with previous reported targets in order to establish a consensus sequence. On the other hand, we performed a genome-wide screening for zebrafish CNBP binding sites using “inverse monohybrid” strategy on a genomic zebrafish library cloned in yeast. The screening provided the identity of putative target genes that may be controlled by CNBP. These results will help to better understand how CNBP performs its essential biological function in embryonic development.