title: U6atac snRNA stem-loop interacts with U12 p65 RNA binding protein and is functionally interchangeable with the U12 apical stem-loop III.
abstract: Formation of catalytic core of the U12-dependent spliceosome involves U6atac and U12 interaction with the 5' splice site and branch site regions of a U12-dependent intron, respectively. Beyond the formation of intermolecular helix I region between U6atac and U12 snRNAs, several other regions within these RNA molecules are predicted to form stem-loop structures. Our previous work demonstrated that the 3' stem-loop region of U6atac snRNA contains a U12-dependent spliceosome-specific targeting activity. Here, we show a detailed structure-function analysis and requirement of a substructure of U6atac 3' stem-loop in U12-dependent in vivo splicing. We show that the C-terminal RNA recognition motif of p65, a U12 snRNA binding protein, also binds to the distal 3' stem-loop of U6atac. By using a binary splice site mutation suppressor assay we demonstrate that p65 protein-binding apical stem-loop of U12 snRNA can be replaced by this U6atac distal 3' stem-loop. Furthermore, we tested the compatibility of the U6atac 3' end from phylogenetically distant species in a human U6atac background, to establish the evolutionary relatedness of these structures and in vivo function. In summary, we demonstrate that RNA-RNA and RNA-protein interactions in the minor spliceosome are highly plastic as compared to the major spliceosome.
authors: Center for Gene Regulation in Health and Disease, Cleveland State University, Cleveland, OH 44115, USA.|Department of Biological Sciences, Cleveland State University, Cleveland, OH 44115, USA.
authors: Jagjit
authors: J
authors: Singh
authors: Center for Gene Regulation in Health and Disease, Cleveland State University, Cleveland, OH 44115, USA.|Department of Biological Sciences, Cleveland State University, Cleveland, OH 44115, USA.
authors: Kavleen
authors: K
authors: Sikand
authors: Department of Cellular Biochemistry, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany.
authors: Heike
authors: H
authors: Conrad
authors: Department of Cellular Biochemistry, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany.
authors: Cindy L
authors: CL
authors: Will
authors: Center for Gene Regulation in Health and Disease, Cleveland State University, Cleveland, OH 44115, USA.|Department of Biological Sciences, Cleveland State University, Cleveland, OH 44115, USA.
authors: Anton A
authors: AA
authors: Komar
authors: Center for Gene Regulation in Health and Disease, Cleveland State University, Cleveland, OH 44115, USA.|Department of Biological Sciences, Cleveland State University, Cleveland, OH 44115, USA.
authors: Girish C
authors: GC
authors: Shukla
mesh_terms: D000818:Animals; D001665:Binding Sites; D016466:CHO Cells; D020134:Catalytic Domain; D003412:Cricetulus; D019143:Evolution, Molecular; D006801:Humans; D008958:Models, Molecular; D009687:Nuclear Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D009690:Nucleic Acid Conformation; D010802:Phylogeny; D011485:Protein Binding; D012342:RNA, Small Nuclear / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D017381:Spliceosomes / Q000235:genetics / Q000378:metabolism
chemical_list: D009687:Nuclear Proteins; D012342:RNA, Small Nuclear; D016601:RNA-Binding Proteins; C498172:RNPC3 protein, human; C000627177:RNU6ATAC RNA, human; C096986:U12 small nuclear RNA