Moonlighting proteins: old proteins learning new tricks

Trends Genet. 2003 Aug;19(8):415-7. doi: 10.1016/S0168-9525(03)00167-7.


Recently, several laboratories identifying proteins involved in the complex processes of replication, transcription and tumor suppression found that the 'new' protein they discovered had another, previously identified, function. A single protein with multiple functions might seem surprising, but there are actually many cases of proteins that 'moonlight', or have more than one role in an organism. As well as adding to the number and types of proteins that are known to moonlight, these new examples add to our understanding of the potential importance of moonlighting proteins.

MeSH terms

  • Animals
  • Cysteine Endopeptidases / genetics*
  • Cysteine Endopeptidases / metabolism
  • DNA Replication / genetics
  • DNA Replication / physiology
  • Drosophila / genetics
  • Drosophila / metabolism
  • Drosophila Proteins / genetics*
  • Drosophila Proteins / metabolism
  • Multienzyme Complexes / genetics*
  • Multienzyme Complexes / metabolism
  • Proteasome Endopeptidase Complex
  • RNA Processing, Post-Transcriptional / genetics
  • RNA Processing, Post-Transcriptional / physiology
  • Saccharomyces cerevisiae / genetics
  • Saccharomyces cerevisiae / metabolism
  • Tumor Suppressor Proteins / genetics*
  • Tumor Suppressor Proteins / metabolism


  • Drosophila Proteins
  • Multienzyme Complexes
  • Tumor Suppressor Proteins
  • crn protein, Drosophila
  • Cysteine Endopeptidases
  • Proteasome Endopeptidase Complex