Identification of RNA binding sequences of Drosophila SR protein DX16.

Dxl6 is a member of the Drosophila melanogaster SR protein family, a group of nuclear proteins that are both essential splicing factors and specific splicing regulators. To get more insight of Dx16 function, we generated the monoclonal antibody against Dx16 and determined its expression pattern and subcellular location. It is mainly expressed in the nucleus of CNS in Drosophila embryos. In order to investigate the RNA-binding specificity of Dxl6, Dxl6-binding RNAs were identified by SELEX screen by using recombinant Dxl6 N-terminus protein as the target. These RNAs contained a consensus motif. Some pre-mRNAs from the corresponding genes showed splicing defects in the Dxl6-P-element insertional mutant fly. These results indicate that Dxl6 has unique functions in the removal of some introns during development.