A polar mechanism coordinates different regions of alternative splicing within a single gene.
Alternative splicing plays a key role in generating protein diversity. Transfections with minigenes revealed coordination between two distant, alternatively spliced exons in the same gene. Mutations that either inhibit or stimulate inclusion of the upstream alternative exon deeply affect inclusion of the downstream one. However, similar mutations at the downstream alternative exon have little effect on the upstream one. This polar effect is promoter specific and is enhanced by inhibition of transcriptional elongation. Consistently, cells from mutant mice with either constitutive or null inclusion of a fibronectin alternative exon revealed coordination with a second alternative splicing region, located far downstream. Using allele-specific RT-PCR, we demonstrate that this coordination occurs in cis and is also affected by transcriptional elongation rates. Bioinformatics supports the generality of these findings, indicating that 25% of human genes contain multiple alternative splicing regions and identifying several genes with nonrandom distribution of mRNA isoforms at two alternative regions.
Fededa
Juan P
JP
Laboratorio de Fisiología y Biología Molecular, Departamento de Fisiología, Biología Molecular y Celular, IFIBYNE-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Buenos Aires, Argentina.
Petrillo
Ezequiel
E
Gelfand
Mikhail S
MS
Neverov
Alexei D
AD
Kadener
Sebastián
S
Nogués
Guadalupe
G
Pelisch
Federico
F
Baralle
Francisco E
FE
Muro
Andrés F
AF
Kornblihtt
Alberto R
AR
D000483:Alleles; D000510:Alpha-Globulins / Q000235:genetics; D017398:Alternative Splicing; D000818:Animals; D000957:Antigens, Viral, Tumor / Q000235:genetics; D019556:COS Cells; D045744:Cell Line, Tumor; D002522:Chlorocebus aethiops; D019295:Computational Biology; D004268:DNA-Binding Proteins / Q000235:genetics; D004004:Dichlororibofuranosylbenzimidazole / Q000494:pharmacology; D005091:Exons / Q000235:genetics; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism; D005353:Fibronectins / Q000235:genetics; D005796:Genes / Q000235:genetics*; D006801:Humans; D051379:Mice; D018345:Mice, Knockout; D008957:Models, Genetic; D009687:Nuclear Proteins / Q000235:genetics; D011401:Promoter Regions, Genetic / Q000235:genetics; D020033:Protein Isoforms / Q000235:genetics; D012319:RNA Polymerase II / Q000037:antagonists & inhibitors / Q000378:metabolism; D012326:RNA Splicing; D016601:RNA-Binding Proteins / Q000235:genetics; D000068103:Serine-Arginine Splicing Factors; D014157:Transcription Factors / Q000235:genetics; D014162:Transfection
D000510:Alpha-Globulins; D000957:Antigens, Viral, Tumor; D004268:DNA-Binding Proteins; D005353:Fibronectins; D009687:Nuclear Proteins; D020033:Protein Isoforms; D016601:RNA-Binding Proteins; D014157:Transcription Factors; D000068103:Serine-Arginine Splicing Factors; D004004:Dichlororibofuranosylbenzimidazole; D012319:RNA Polymerase II