Regulation of tissue-specific P-element pre-mRNA splicing requires the RNA-binding protein PSI.
Binding of a multiprotein complex to a 5' exon inhibitory element appears to repress splicing of the Drosophila P-element third intron (IVS3) in the soma. We have purified 97- and 50-kD proteins that interact specifically with the inhibitory element using RNA affinity chromatography. Antibodies specific for the 97-kD protein relieve inhibition of IVS3 splicing in somatic extracts, providing direct evidence that inhibition requires this protein, P-element somatic inhibitor (PSI). We identify the 50-kD protein as hrp48, a protein similar to the mammalian splicing factor hnRNP A1, and show that hrp48 recognizes specific nucleotides in a pseudo-5' splice site within the inhibitory element. The results indicate that PSI is an alternative splicing factor that regulates tissue-specific splicing, probably through interactions with generally expressed factors such as hrp48.
Department of Molecular and Cell Biology, University of California, Berkeley 94720.
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D017398:Alternative Splicing; D000818:Animals; D001483:Base Sequence; D002846:Chromatography, Affinity; D004251:DNA Transposable Elements; D004330:Drosophila / Q000235:genetics / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D005091:Exons; D015870:Gene Expression; D005786:Gene Expression Regulation; D006367:HeLa Cells; D000076245:Heterogeneous Nuclear Ribonucleoprotein A1; D034481:Heterogeneous-Nuclear Ribonucleoprotein Group A-B; D034441:Heterogeneous-Nuclear Ribonucleoproteins; D006801:Humans; D007438:Introns; D008322:Mammals; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009838:Oligodeoxyribonucleotides; D012322:RNA Precursors / Q000378:metabolism*; D012326:RNA Splicing; D016601:RNA-Binding Proteins / Q000378:metabolism*; D012261:Ribonucleoproteins / Q000235:genetics
D004251:DNA Transposable Elements; D000076245:Heterogeneous Nuclear Ribonucleoprotein A1; D034481:Heterogeneous-Nuclear Ribonucleoprotein Group A-B; D034441:Heterogeneous-Nuclear Ribonucleoproteins; D009838:Oligodeoxyribonucleotides; D012322:RNA Precursors; D016601:RNA-Binding Proteins; D012261:Ribonucleoproteins