Serine/Arginine Rich Splicing Factor 9 (SRSF9)

Recombinant SRp30c produced in E. coli restored splicing to a cytosolic HeLa S100 extract deficient in SR factors, suggesting that SRp30c protein is involved in mRNA formation.Proximal spinal muscular atrophy (SMA) is caused by the homozygous loss of SMN1. SMN2, a nearly identical copy gene, is present in all SMA patients; however, this gene cannot provide protection from disease due to the aberrant splicing of a critical exon. SMN2-derived transcripts predominantly lack SMN exon 7 due to a single nonpolymorphic nucleotide difference (C in SMN1 vs T in SMN2). SRp30c did not directly associate with SMN exon 7; rather, its association with the exonic enhancer was mediated by a direct interaction with TRA2-beta. In the absence of the TRA2-beta binding site, SRp30c failed to associate with SMN exon 7.