title: The iStem, a long-range RNA secondary structure element required for efficient exon inclusion in the Drosophila Dscam pre-mRNA.
abstract: The Drosophila Dscam gene encodes 38,016 different proteins, due to alternative splicing of 95 of its 115 exons, that function in axon guidance and innate immunity. The alternative exons are organized into four clusters, and the exons within each cluster are spliced in a mutually exclusive manner. Here we describe an evolutionarily conserved RNA secondary structure we call the Inclusion Stem (iStem) that is required for efficient inclusion of all 12 variable exons in the exon 4 cluster. Although the iStem governs inclusion or exclusion of the entire exon 4 cluster, it does not play a significant role in determining which variable exon is selected. Thus, the iStem is a novel type of regulatory element that simultaneously controls the splicing of multiple alternative exons.
authors.affiliation: Department of Genetics and Developmental Biology, University of Connecticut Health Center, 263 Farmington Avenue, Farmington, CT 06030-3301, USA.
authors.forename: Jenny M
authors.initials: JM
authors.lastname: Kreahling
authors.forename: Brenton R
authors.initials: BR
authors.lastname: Graveley
mesh_terms: D000818:Animals; D001483:Base Sequence; D015815:Cell Adhesion Molecules; D002460:Cell Line; D029721:Drosophila Proteins / Q000235:genetics*; D004331:Drosophila melanogaster / Q000235:genetics*; D019143:Evolution, Molecular; D005091:Exons / Q000235:genetics*; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D009690:Nucleic Acid Conformation; D010802:Phylogeny; D012322:RNA Precursors / Q000737:chemistry* / Q000235:genetics; D012326:RNA Splicing / Q000235:genetics*; D012333:RNA, Messenger / Q000737:chemistry* / Q000235:genetics
chemical_list: D015815:Cell Adhesion Molecules; D029721:Drosophila Proteins; C491736:Dscam1 protein, Drosophila; D012322:RNA Precursors; D012333:RNA, Messenger