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Splicing of Pre-mRNA

  1. Yu-Shiou Lu,
  2. Woan-Yuh Tarn

Published Online: 15 SEP 2010

DOI: 10.1002/9780470015902.a0005037.pub2



How to Cite

Lu, Y.-S. and Tarn, W.-Y. 2010. Splicing of Pre-mRNA. eLS. .

Author Information

  1. Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan

Publication History

  1. Published Online: 15 SEP 2010

This is not the most recent version of the article. View current version (16 FEB 2015)


Eukaryotic messenger ribonucleic acids (mRNAs) are initially transcribed as intron-containing precursor mRNAs (pre-mRNAs). Removal of introns from each pre-mRNA by splicing occurs concurrently with ligation of the two flanking exons to generate a mature mRNA. Pre-mRNA splicing is catalysed by the spliceosome, a large ribonucleoprotein complex containing five small nuclear RNAs and numerous protein factors. In higher eukaryotes, alternative splicing provides a mechanism to generate multiple mRNA isoforms from a single gene. Alternative splicing not only increases proteome diversity but also regulates the level of gene expression posttranscriptionally. Moreover, alternative splicing has a substantial impact on regulation of many physiological processes such as cell differentiation and development. Defects in pre-mRNA splicing underlie a considerable number of genetic diseases and cancers.

Key Concepts:

  • In most eukaryotic pre-mRNAs, the coding sequences (exons) are interrupted by stretches of noncoding sequences (introns).

  • The spliceosome uses a two-step transesterification reaction to remove introns and join exons of pre-mRNAs.

  • The snRNAs and spliceosomal protein Prp8 are implicated in the key catalytic steps of splicing.

  • Alternative splicing extends proteome diversity and regulates gene expression levels.

  • Alternative splicing is determined by interplays between trans-acting factors and cis-elements of pre-mRNAs.

  • Alteration of cis-elements and aberrant control of trans-acting factors lead to diseases.


  • pre-mRNA splicing;
  • spliceosome;
  • alternative splicing;
  • snRNA;
  • RNA-binding protein