Hostname: page-component-5db6c4db9b-mcx2m Total loading time: 0 Render date: 2023-03-25T11:06:02.034Z Has data issue: true Feature Flags: { "useRatesEcommerce": false } hasContentIssue true

Functions of SR proteins in the U12-dependent AT-AC pre-mRNA splicing pathway

Published online by Cambridge University Press:  07 March 2001

Cold Spring Harbor Laboratory, Cold Spring Harbor, New York 11724-2208, USA
Cold Spring Harbor Laboratory, Cold Spring Harbor, New York 11724-2208, USA
Get access


SR proteins play critical roles in the major pre-mRNA splicing pathway. A second pathway processes U12-dependent AT-AC introns. We demonstrate, by biochemical complementation, the requirement for SR proteins in splicing of AT-AC introns. Whereas SR proteins were sufficient to activate splicing of a P120 AT-AC intron, splicing of a sodium channel AT-AC intron required an additional nuclear fraction. Individual recombinant SR proteins promoted splicing of both substrates, but displayed marked preferences. SR proteins supported basal AT-AC splicing, and also splicing stimulation via a downstream enhancer or conventional 5′ splice site. Analysis of chimeric transcripts revealed that information dispersed throughout exons and introns dictates SR protein specificity and the requirement for the additional nuclear fraction. Thus, SR proteins function in both major and minor splicing pathways, and in coordinating the activities of both spliceosomes via exon definition. These results suggest that despite the substantial differences in intron consensus sequences and in four of the five snRNPs in each spliceosome, at least some of the interactions involving SR proteins are conserved between the two pathways.

Research Article
RNA , Volume 7 , Issue 3 , March 2001 , pp. 471 - 482
© 2001 RNA Society

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)