Activation of c-src neuron-specific splicing by an unusual RNA element in vivo and in vitro.
A conserved positive-acting RNA sequence was found to be required for the neuron-specific splicing of the mouse c-src N1 exon. The sequence lies in the intron between exons N1 and 4, close to the N1 donor site. Normally, only the neural-specific splicing of exon N1 required this sequence. When the intron downstream of N1 was shortened, splicing at the constitutive exon 4 acceptor also became dependent on the activating sequence. The neuronal and nonneuronal patterns of src splicing were reconstituted in vitro. HeLa cell extracts spliced exon 4 to exon 3, skipping exon N1. Weri-1 retinoblastoma cell extracts spliced exon 4 to exon N1 as well as to exon 3. Both patterns of splicing were dependent on the activating sequence. A 123 nt RNA containing just the activating sequence specifically inhibited both patterns of src splicing, indicating that factors bound to the activator were required for its effects.
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Whitehead Institute for Biomedical Research, Nine Cambridge Center, Massachusetts 02142.
D000818:Animals; D001483:Base Sequence; D002457:Cell Extracts; D005091:Exons / Q000235:genetics; D016391:Genes, src / Q000235:genetics*; D007438:Introns / Q000235:genetics; D051379:Mice; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D009474:Neurons / Q000378:metabolism*; D009838:Oligodeoxyribonucleotides / Q000235:genetics; D016133:Polymerase Chain Reaction; D012326:RNA Splicing / Q000235:genetics*; D014407:Tumor Cells, Cultured
D002457:Cell Extracts; D009838:Oligodeoxyribonucleotides