A pseudoexon is a potential exon in intronic regions of pre‐mRNA that is not normally spliced into mature mRNA. It contains sequences similar to 5′ and 3′ splice‐site consensus sequences, but is not recognized by the cellular splicing machinery.

Keywords: intron–exon; pseudoexon; exon inactivation; splicing; silencer

Figure 1.

Distribution of conserved splice sites of real introns in six organisms. In these logo graphs, the information content ranges from zero to two. Zero signifies no conservation (all four nucleotides have equal probability of use) and two indicates the maximum degree of conservation (one nucleotide is present).

Figure 2.

Example of a pseudoexon, formed in intron 6 between exons 6 and 7 (open boxes) of the human gene encoding the growth‐hormone receptor (GHR): the pseudoexon sequence (6ψ) is located between the bar signs (‘|’) and is indicated in bold. Underlined letters indicate the base that when mutated activates the pseudoexon, which leads to pathological insensitivity to growth hormone. The mRNAs for both normal and mutant genes are shown above the genes (thick lines indicate exons in mature mRNAs).



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Further Reading

Burge CB, Tuschl T and Sharp PA (1999) Splicing of precursors to mRNAs by the spliceosomes. In: Gesteland RF and Cech TR, Atkins JF (eds.) The RNA World, 2nd edn. pp. 525–560. Cold Spring Harbor, NY: Cold Spring Harbor Laboratory Press.

Stephens RM and Schneider TD (1992) Features of spliceosome evolution and function inferred from an analysis of the information at human splice sites. Journal of Molecular Biology 228: 1124–1136.

Web Links

GenBank Database. This is a sequence database run by National Center for Biotechnology Information, National Institutes of Health, USA. It collected all publicly available DNA sequences

Deleted in azoospermia (DAZ). LocusID: 1617. LocusLink:

Growth hormone receptor (GHR). LocusID: 2690. LocusLink:

Glycophorin B (GYPB). LocusID: 2994. LocusLink:

Hypoxanthine phosphoribosyltransferase 1 (HPRT1). LocusID: 3251. LocusLink:

Deleted in azoospermia (DAZ). MIM number: 400003. OMIM:‐post/Omim/dispmim?400003

Glycophorin B (GYPB). MIM number: 111740. OMIM:‐post/Omim/dispmim?111740

Growth hormone receptor (GHR). MIM number: OMIM:‐post/Omim/dispmim?600946

Hypoxanthine phosphoribosyltransferase 1 (HPRT1). MIM number: 30800. OMIM:‐post/Omim/dispmim?308000

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How to Cite close
Long, Manyuan(Jul 2006) Pseudoexons. In: eLS. John Wiley & Sons Ltd, Chichester. [doi: 10.1038/npg.els.0005089]