title: U1-independent pre-mRNA splicing contributes to the regulation of alternative splicing.
abstract: U1 snRNP plays a crucial role in the 5' splice site recognition during splicing. Here we report the first example of naturally occurring U1-independent U2-type splicing in humans. The U1 components were not included in the pre-spliceosomal E complex formed on the human F1gamma (hF1gamma) intron 9 in vitro. Moreover, hF1gamma intron 9 was efficiently spliced even in U1-disrupted Xenopus oocytes as well as in U1-inactivated HeLa nuclear extracts. Finally, hF1gamma exon 9 skipping induced by an alternative splicing regulator Fox-1 was impaired when intron 9 was changed to the U1-dependent one. Our results suggest that U1-independent splicing contributes to the regulation of alternative splicing of a class of pre-mRNAs.
authors.affiliation: Department of Biology, Graduate School of Science, Kobe University, Nadaku, Kobe, Japan.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Fukumura
authors.forename: Ichiro
authors.initials: I
authors.lastname: Taniguchi
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Sakamoto
authors.forename: Mutsuhito
authors.initials: M
authors.lastname: Ohno
authors.forename: Kunio
authors.initials: K
authors.lastname: Inoue
mesh_terms: D017398:Alternative Splicing; D000818:Animals; D005091:Exons; D006367:HeLa Cells; D006801:Humans; D006180:Proton-Translocating ATPases / Q000235:genetics; D012322:RNA Precursors / Q000378:metabolism*; D022821:RNA Splice Sites; D012333:RNA, Messenger / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000378:metabolism; D017412:Ribonucleoprotein, U1 Small Nuclear / Q000378:metabolism*; D017381:Spliceosomes / Q000378:metabolism*; D014981:Xenopus
chemical_list: D012322:RNA Precursors; D022821:RNA Splice Sites; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D017412:Ribonucleoprotein, U1 Small Nuclear; C444660:gamma subunit, F(1) ATPase; D006180:Proton-Translocating ATPases