RESUMO
SR proteins play important roles in regulating alternative pre-mRNA splicing. As a newly discovered neural and reproductive tissue specific SR protein, SRp38 regulates the alternative splicing of several genes important for neural function, such as GluR-B, Trk-C and NCAML1. It also acts as a splicing inhibitor during mitosis or stress response in order to prevent wrong splicing. The expression of SRp38 in mouse retina was investigated by Western blot and immunohistochemistry (IHC) analyses. The result shows that the expression of SRp38 proteins in mouse retina is region-specific, with extensive distribution in the outer and inner plexiform layers, inner nuclear layer and ganglion cell layer, but no expression in outer nuclear layer. Double staining of isolated retina cells with anti-SRp38 and anti-Trk-C antibodies showed that SRp38 is localized in the dendrites, somata and axon terminals of rod-bipolar cells. By transient co-transmission of over-expressed SRp38 plasmid and RT-PCR analyses, the further results showed that overexpressed SRp38 could promote the splicing of the Flip isoform of GluR-B minegene in R28 cells. The result suggests that SRp38 may play important roles in the retinal function, possibly via regulating the neural-specific alternative splicing of genes as GluR-B.