title: Determinants of plant U12-dependent intron splicing efficiency.
abstract: Factors affecting splicing of plant U12-dependent introns have been examined by extensive mutational analyses in an in vivo tobacco (Nicotiana tabacum) protoplast system using introns from three different Arabidopsis thaliana genes: CBP20, GSH2, and LD. The results provide evidence that splicing efficiency of plant U12 introns depends on a combination of factors, including UA content, exon bridging interactions between the U12 intron and flanking U2-dependent introns, and exon splicing enhancer sequences (ESEs). Unexpectedly, all three plant U12 introns required an adenosine at the upstream purine position in the branchpoint consensus UCCUURAUY. The exon upstream of the LD U12 intron is a major determinant of its higher level of splicing efficiency and potentially contains two ESE regions. These results suggest that in plants, U12 introns represent a level at which expression of their host genes can be regulated.
authors.affiliation: Department of Gene Expression, Adam Mickiewicz University, Poznan 60-371, Poland.
authors.forename: Dominika
authors.initials: D
authors.lastname: Lewandowska
authors.forename: Craig G
authors.initials: CG
authors.lastname: Simpson
authors.forename: Gillian P
authors.initials: GP
authors.lastname: Clark
authors.forename: Nikki S
authors.initials: NS
authors.lastname: Jennings
authors.forename: Maria
authors.initials: M
authors.lastname: Barciszewska-Pacak
authors.forename: Chiao-Feng
authors.initials: CF
authors.lastname: Lin
authors.forename: Wojciech
authors.initials: W
authors.lastname: Makalowski
authors.forename: John W S
authors.initials: JW
authors.lastname: Brown
authors.forename: Artur
authors.initials: A
authors.lastname: Jarmolowski
mesh_terms: D017360:Arabidopsis / Q000235:genetics*; D029681:Arabidopsis Proteins / Q000235:genetics*; D001483:Base Sequence; D007438:Introns / Q000235:genetics*; D012326:RNA Splicing / Q000235:genetics; D018749:RNA, Plant / Q000235:genetics; D016601:RNA-Binding Proteins / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D017411:Ribonucleoproteins, Small Nuclear / Q000235:genetics*; D014162:Transfection
chemical_list: D029681:Arabidopsis Proteins; D018749:RNA, Plant; D016601:RNA-Binding Proteins; D017411:Ribonucleoproteins, Small Nuclear; C552126:U11-U12 small nuclear ribonucleoprotein