Regulation of tissue-specific P-element pre-mRNA splicing requires the RNA-binding protein PSI

• Published in: Genes & development Vol. 8; no. 14; pp. 1713 - 1725
• Main Authors: Siebel, C W, Kanaar, R, Rio, D C
• Format: Journal Article
• Language: English
• Published: United States 15.07.1994
• Subjects: Alternative Splicing; Animals; Base Sequence; Chromatography, Affinity; DNA Transposable Elements; Drosophila; Drosophila - genetics; Drosophila - metabolism; Electrophoresis, Polyacrylamide Gel; Exons; Gene Expression; Gene Expression Regulation; HeLa Cells; Heterogeneous Nuclear Ribonucleoprotein A1; Heterogeneous-Nuclear Ribonucleoprotein Group A-B; Heterogeneous-Nuclear Ribonucleoproteins; Humans; Introns; Mammals; Molecular Sequence Data; Molecular Weight; Oligodeoxyribonucleotides; Ribonucleoproteins - genetics; RNA Precursors - metabolism; RNA Splicing; RNA-Binding Proteins - metabolism
• ISSN: 0890-9369; 1549-5477
• DOI: 10.1101/gad.8.14.1713

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.