Present address: Institute for Genome Sciences and Policy, Department of Biology, Duke University, Durham, NC 27708, USA.
Identification of an intronic splicing regulatory element involved in auto-regulation of alternative splicing of SCL33 pre-mRNA
Article first published online: 29 OCT 2012
© 2012 The Authors. The Plant Journal © 2012 Blackwell Publishing Ltd
The Plant Journal
Volume 72, Issue 6, pages 935–946, December 2012
How to Cite
Thomas, J., Palusa, S. G., Prasad, K. V.S.K., Ali, G. S., Surabhi, G.-K., Ben-Hur, A., Abdel-Ghany, S. E. and Reddy, A. S.N. (2012), Identification of an intronic splicing regulatory element involved in auto-regulation of alternative splicing of SCL33 pre-mRNA. The Plant Journal, 72: 935–946. doi: 10.1111/tpj.12004
- Issue published online: 6 DEC 2012
- Article first published online: 29 OCT 2012
- Accepted manuscript online: 22 AUG 2012 11:16AM EST
- Received 21 March 2012; Revised 11 August 2012; Accepted 20 August 2012; published online 29 October 2012.
- Arabidopsis thaliana ;
- alternative splicing;
- pre-mRNA splicing;
- splicing regulatory elements;
- SR proteins;
In Arabidopsis, pre-mRNAs of serine/arginine-rich (SR) proteins undergo extensive alternative splicing (AS). However, little is known about the cis-elements and trans-acting proteins involved in regulating AS. Using a splicing reporter (GFP–intron–GFP), consisting of the GFP coding sequence interrupted by an alternatively spliced intron of SCL33, we investigated whether cis-elements within this intron are sufficient for AS, and which SR proteins are necessary for regulated AS. Expression of the splicing reporter in protoplasts faithfully produced all splice variants from the intron, suggesting that cis-elements required for AS reside within the intron. To determine which SR proteins are responsible for AS, the splicing pattern of the GFP–intron–GFP reporter was investigated in protoplasts of three single and three double mutants of SR genes. These analyses revealed that SCL33 and a closely related paralog, SCL30a, are functionally redundant in generating specific splice variants from this intron. Furthermore, SCL33 protein bound to a conserved sequence in this intron, indicating auto-regulation of AS. Mutations in four GAAG repeats within the conserved region impaired generation of the same splice variants that are affected in the scl33 scl30a double mutant. In conclusion, we have identified the first intronic cis-element involved in AS of a plant SR gene, and elucidated a mechanism for auto-regulation of AS of this intron.