An RNA electrophoretic mobility shift and mutational analysis of rnp-4f 5'-UTR intron splicing regulatory proteins in Drosophila reveals a novel new role for a dADAR protein isoform.

Alternative splicing greatly enhances the diversity of proteins encoded by eukaryotic genomes, and is also important in gene expression control. In contrast to the great depth of knowledge as to molecular mechanisms in the splicing pathway itself, relatively little is known about the regulatory events behind this process. The 5'-UTR and 3'-UTR in pre-mRNAs play a variety of roles in controlling eukaryotic gene expression, including translational modulation, and nearly 4000 of the roughly 14,000 protein coding genes in Drosophila contain introns of unknown functional significance in their 5'-UTR.