Molecular characterization of the murine neural retina leucine zipper gene, Nrl.

The NRL gene (D14S46E) is expressed in cells of human retina and encodes a putative DNA-binding protein of the leucine zipper family. Here we describe the analysis of the murine homolog of the NRL gene, Nrl. Various cDNAs resulting from alternate polyadenylation are characterized. The deduced polypeptide sequence is highly conserved between mouse and human, with an identical basic motif and leucine zipper domain. The nucleotide sequences in the 5' and 3'-untranslated regions also show significant homology. The 3'-untranslated region contains a polymorphic AGG-trinucleotide repeat. The murine Nrl gene consists of three exons; of these, the first is untranslated. The 5'-upstream promoter region has no canonical TATA box, but contains consensus binding site sequences for several DNA-binding proteins. Analysis of RNA from adult mouse tissues confirms the retina-specific expression of Nrl. This study provides the basis for dissecting the cis-regulatory elements involved in the retina-specific expression and for the development of an experimental model to investigate the function or any diseases associated with this gene in humans.