The implications of alternative splicing in the ENCODE protein complement

Proc Natl Acad Sci U S A. 2007 Mar 27;104(13):5495-500. doi: 10.1073/pnas.0700800104. Epub 2007 Mar 19.


Alternative premessenger RNA splicing enables genes to generate more than one gene product. Splicing events that occur within protein coding regions have the potential to alter the biological function of the expressed protein and even to create new protein functions. Alternative splicing has been suggested as one explanation for the discrepancy between the number of human genes and functional complexity. Here, we carry out a detailed study of the alternatively spliced gene products annotated in the ENCODE pilot project. We find that alternative splicing in human genes is more frequent than has commonly been suggested, and we demonstrate that many of the potential alternative gene products will have markedly different structure and function from their constitutively spliced counterparts. For the vast majority of these alternative isoforms, little evidence exists to suggest they have a role as functional proteins, and it seems unlikely that the spectrum of conventional enzymatic or structural functions can be substantially extended through alternative splicing.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alternative Splicing*
  • Databases, Genetic
  • Gene Expression Regulation
  • Genome, Human
  • Humans
  • Internet
  • Models, Molecular
  • Protein Conformation
  • Protein Isoforms
  • Protein Sorting Signals
  • Protein Structure, Tertiary
  • Proteins / chemistry
  • RNA Precursors*
  • RNA Splicing


  • Protein Isoforms
  • Protein Sorting Signals
  • Proteins
  • RNA Precursors