Alternative splicing (AS) might produce multiple mature mRNA isoforms from one single gene, contributing essentially to protein diversity [1, 2]. AS also has a pivotal role in many biological processes, such as cell proliferation, differentiation and death. It is believed that AS is also involved in the regulation of gene expression via nonsense-mediated decay and via selective inclusion of protein domains in final gene products [3].
There is growing evidence that cis-regulatory motifs in combination with other factors such as splicing sites, exon size, etc play an important role in the regulation of alternative splicing [1]. Often, cis-regulatory motifs are degenerate short sequences on pre-mRNAs, acting as the binding sites for trans-regulatory factors or pairing to form loop structure [4]. According to the locations and functions, they are categorized as exonic splicing enhancer/silencer (ESE/ESS) and intronic splicing enhancer/silencer (ISE/ISS).
1. Ladd AN, Cooper TA. Finding signals that regulate alternative splicing in the post-genomic era. Genome Biol 2002, 3(11):reviews0008.
2. Matlin AJ, Clark F, Smith CW. Understanding alternative splicing: towards a cellular code. Nat Rev Mol Cell Biol 2005, 6(5):386-398.
3. Dunker AK. Intrinsically Disordered Proteins: An Update. Bioinformatics and Bioengineering, 2007 BIBE 2007 Proceedings of the 7th IEEE International Conference 2007, pp 49-58.
4. Miriami E, Margalit H, Sperling R. Conserved sequence elements associated with exon skipping. Nucleic Acids Res 2003, 31(7):1974-1983.