SR protein-mediated inhibition of CFTR exon 9 inclusion: molecular characterization of the intronic splicing silencer.
The intronic splicing silencer (ISS) of CFTR exon 9 promotes exclusion of this exon from the mature mRNA. This negative influence has important consequences with regards to human pathologic events, as lack of exon 9 correlates well with the occurrence of monosymptomatic and full forms of CF disease. We have previously shown that the ISS element interacts with members of the SR protein family. In this work, we now provide the identification of SF2/ASF and SRp40 as the specific SR proteins binding to this element and map their precise binding sites in IVS9. We have also performed a functional analysis of the ISS element using a variety of unrelated SR-binding sequences and different splicing systems. Our results suggest that SR proteins mediate CFTR exon 9 exclusion by providing a 'decoy' sequence in the vicinity of its suboptimal donor site. The results of this study give an insight on intron 'exonization' mechanisms and provide useful indications for the development of novel therapeutic strategies aimed at the recovery of exon inclusion.
Buratti
Emanuele
E
International Centre for Genetic Engineering and Biotechnology (ICGEB) 34012 Trieste, Italy.
Stuani
Cristiana
C
De Prato
Greta
G
Baralle
Francisco E
FE
D001483:Base Sequence; D001665:Binding Sites; D045744:Cell Line, Tumor; D019005:Cystic Fibrosis Transmembrane Conductance Regulator / Q000235:genetics* / Q000378:metabolism; D005091:Exons; D006367:HeLa Cells; D006801:Humans; D007438:Introns; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000378:metabolism*; D016376:Oligonucleotides, Antisense; D012326:RNA Splicing; D016601:RNA-Binding Proteins / Q000378:metabolism*; D038621:Regulatory Sequences, Ribonucleic Acid; D000068103:Serine-Arginine Splicing Factors
D009687:Nuclear Proteins; D016376:Oligonucleotides, Antisense; D016601:RNA-Binding Proteins; D038621:Regulatory Sequences, Ribonucleic Acid; D019005:Cystic Fibrosis Transmembrane Conductance Regulator; D000068103:Serine-Arginine Splicing Factors