Evidence for a linear search in bimolecular 3′ splice site AG selection
AUTOR(ES)
Chen, Shuyan
FONTE
The National Academy of Sciences
RESUMO
In most eukaryotic introns the 3′ splice site is defined by a surprisingly short AG consensus found a variable distance downstream of the branch site. Exactly how the spliceosome determines which AG to use, however, is not well understood. Previously we showed that when the branch site and 3′ splice site AG are supplied by separate RNA molecules, there is a strong preference for use of the 5′-most AG in the 3′ splice site-containing RNA. Here we show that this apparent 5′→3′ directionality holds even when this RNA contains four tandem repeats of a 6-nt sequence containing AG. Exactly the same pattern of 3′ splice site choice was observed when the same tandem repeats were incorporated into a full-length splicing substrate. When the 3′ splice site AG is supplied by a separate RNA, that RNA must be linear with an unobstructed 5′ end. Similarly, the branch-containing RNA must be truncated immediately 3′ to the polypyrimidine tract. A model is presented that incorporates these observations and reconciles previously proposed mechanisms for 3′ splice site selection.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=15375Documentos Relacionados
- 3' splice site selection in dicot plant nuclei is position dependent.
- Splicing in Caenorhabditis elegans does not require an AG at the 3' splice acceptor site.
- Scanning and competition between AGs are involved in 3' splice site selection in mammalian introns.
- Genes of nuclear encoded mitochondrial proteins: evidence for a variant of the 3' splice-site consensus sequence.
- Evidence for a HeLa cell splicing activity that is necessary for activation of a regulated adenovirus 3' splice site.
