Exonic splicing enhancer

Faiibrother WG, Yeh RF, Sharp PA, Bulge CB (2002) Predictive identification of exonic splicing enhancers in human genes. Science 297 1007-1013 Fisher CW, Fisher CR, Chuang JL, Lau KS, Chuang DT et al (1993) Occurrence of a 2-bp (AT) deletion allele and a nonsense (G-to-T) mutant allele at the E2 (DBT) locus of six patients with maple syrup urine disease multiple-exon skipping as a secondary effect of the mutations. Am J Hum Genet 52 414-424... 

Kondo S, Yamcunoto N, Murakami T, Okumura M, Mayeda A et al (2004) Tra2 beta, SF2/ASF and SRp30c modulate the function of an exonic splicing enhancer in exon 10 of tau pre-mRNA. Genes Cells 9 121-130... 

Smith PJ, Zhang C, Wang J, Chew SL, Zhang MQ et al (2006) An increased specificity score matrix for the prediction of SF2/ASF-specific exonic splicing enhancers. Hum Mol Genet 15 2490-2508... 

Splicing is facilitated by splicosomes that consist of more than 100 proteins and five small nuclear (sn) RNAs (snRNAs). Certain regulatory proteins called splicing regulator (SR) proteins bind to a particular nucleotide sequence in the exon called the exon splicing enhancer (ESE) and recruit splicosomes. The exon may contain an exon splicing suppressor (ESS) sequence, which prevents the splicosome from splicing. 

Figure 5. Model for /mns-spUdng in COT pre-mRNAs. The exons are represented by boxes, the introns by lines. The exonic splicing enhancers (ESE) are represented in exon 2 in thicker lines. The 3 acceptor site of intron I reacts with the S donor sites of introns 2 or 3 of other molecules of pre-mRNA (rrans-splicing). The organization of the mRNAs is shown at the right.

COT, Carnitine Octanoyltransferase. RT-PCR, reverse transcriptase-polymerase chain reaction. ESE, exonic splicing enhancer. PL, plasmid polylinker region. 

Naturally, a whole cornucopia of accessory factors regulates splicing and splice site selection [18]. In addition to cis-elements within the RNA, several families of RNA factors control which alternative splicing path is chosen. Well-studied examples include serine-rich (SR) proteins and heterologous nuclear ribonuclear particles (hnRNPs) [19, 20]. SR proteins bind to exonic splicing enhancers (ESEs) or intronic splicing enhancers (ISEs) and aid in recruiting the spliceosome itself. 

Sun, Q., Mayeda, A., Hampson, R.K., Krainer, A.R. Rottman, E.M. (1993) Genes Dev. 7, 2598-2608. General splicing factor SF2/ASF promotes alternative splicing by binding to an exonic splicing enhancer. 

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