Abstract
Summary Exon definition is a mechanism whereby splice sites are selected initially via interactions between splicing factors across an exon, prior to spliceosome assembly and intron removal. It occurs in the splicing of vertebrate pre-mRNAs and, recently, evidence for exon definition and the role of exon sequences has been obtained in plant intron splicing. Here we demonstrate that interactions between plant introns influence splicing efficiency and that these interactions are consistent with an exon definition process. The splicing efficiency of a UA-poor, inefficiently spliced intron (wheat amylase) increases 3.5- to 4.4-fold when placed in tandem with a UA-rich, well spliced, intron (legumin). Enhanced splicing is also observed with partial pea legumin intron sequences. However, mutation of splice sites in the partial UA-rich intron sequences abolished the enhanced splicing effect such that intact splice sites at the 5′ and 3′ ends of the exon were required, thus pointing to exon definition. This was further supported by reducing the size of the intervening exon or replacing with a UA-rich sequence which leads to loss of splicing of the UA-poor intron. Finally, the results support UA-rich sequences functioning early in the splicing process in plants.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.