Splicing regulatory element (SRE) are ''cis''-acting sequences in

pre-mRNA A primary transcript is the single-stranded ribonucleic acid (RNA) product synthesized by transcription of DNA, and processed to yield various mature RNA products such as mRNAs, tRNAs, and rRNAs. The primary transcripts designated to be mRNAs a ...

, which either enhance or silence (suppress) the splicing of introns, or in general regulates the constitutive or alternative splicing of this pre-mRNA. SREs recruit ''trans''-acting

splicing factor A splicing factor is a protein involved in the removal of introns from strings of messenger RNA, so that the exons can bind together; the process takes place in particles known as spliceosomes. Genes are progressively switched off as we age, and sp ...

s to activate or suppress the splice site recognition or

spliceosome A spliceosome is a large ribonucleoprotein (RNP) complex found primarily within the nucleus of eukaryotic cells. The spliceosome is assembled from small nuclear RNAs (snRNA) and numerous proteins. Small nuclear RNA (snRNA) molecules bind to specifi ...

assembly. The "context dependence" of SREs is categorized into at least two studied groups: (a) the location-dependent activity of SREs: the activity varies with the relative positions of SREs in pre-mRNA; (b) the gene-dependent activity of SREs: the SRE activity observed in one gene is lost when the SRE is moved to another gene. SREs are: :present in

exon An exon is any part of a gene that will form a part of the final mature RNA produced by that gene after introns have been removed by RNA splicing. The term ''exon'' refers to both the DNA sequence within a gene and to the corresponding sequen ...

exonic splicing enhancer In molecular biology, an exonic splicing enhancer (ESE) is a DNA sequence motif consisting of 6 bases within an exon that directs, or enhances, accurate splicing of heterogeneous nuclear RNA ( hnRNA) or pre-mRNA into messenger RNA (mRNA). Intr ...

s (ESEs),

exonic splicing silencer An exonic splicing silencer (ESS) is a short region (usually 4-18 nucleotides) of an exon and is a cis-regulatory element. A set of 103 hexanucleotides known as FAS-hex3 has been shown to be abundant in ESS regions. ESSs inhibit or silence splicing ...

s (ESSs) :present in

intron An intron is any nucleotide sequence within a gene that is not expressed or operative in the final RNA product. The word ''intron'' is derived from the term ''intragenic region'', i.e. a region inside a gene."The notion of the cistron .e., gene. ...

s: intronic splicing enhancers (ISEs), intronic splicing silencers (ISSs).

References

{{Reflist, 35em Spliceosome RNA splicing