Serine/arginine-rich protein-dependent suppression of exon skipping by exonic splicing enhancers.
The 5' and 3' splice sites within an intron can, in principle, be joined to those within any other intron during pre-mRNA splicing. However, exons are joined in a strict 5' to 3' linear order in constitutively spliced pre-mRNAs. Thus, specific mechanisms must exist to prevent the random joining of exons. Here we report that insertion of exon sequences into an intron can inhibit splicing to the downstream 3' splice site and that this inhibition is independent of intron size. The exon sequences required for splicing inhibition were found to be exonic enhancer elements, and their inhibitory activity requires the binding of serine/arginine-rich splicing factors. We conclude that exonic enhancers can act as barriers to prevent exon skipping and thereby may play a key role in ensuring the correct 5' to 3' linear order of exons in spliced mRNA.
Ibrahim
El Chérif
EC
Department of Cell Biology, Harvard Medical School, 240 Longwood Avenue, Boston, MA 02115, USA.
Schaal
Thomas D
TD
Hertel
Klemens J
KJ
Reed
Robin
R
Maniatis
Tom
T
D000818:Animals; D004742:Enhancer Elements, Genetic; D005091:Exons; D005260:Female; D006367:HeLa Cells; D006801:Humans; D066298:In Vitro Techniques; D007438:Introns; D007700:Kinetics; D009687:Nuclear Proteins / Q000235:genetics* / Q000378:metabolism*; D009865:Oocytes / Q000378:metabolism; D010750:Phosphoproteins / Q000235:genetics* / Q000378:metabolism*; D012319:RNA Polymerase II / Q000378:metabolism; D012326:RNA Splicing; D016601:RNA-Binding Proteins; D000068103:Serine-Arginine Splicing Factors; D013489:Suppression, Genetic; D014982:Xenopus laevis
D009687:Nuclear Proteins; D010750:Phosphoproteins; D016601:RNA-Binding Proteins; D000068103:Serine-Arginine Splicing Factors; D012319:RNA Polymerase II