Ci: a complex transducer of the hedgehog signal

Trends Genet. 1999 Nov;15(11):458-62. doi: 10.1016/s0168-9525(99)01869-7.


Recent progress has unveiled Cubitus interruptus (Ci) as a complex transcription factor whose diverse activities as an activator and repressor are regulated by its proteolysis, localization and concentration. The principal role of Ci is to elaborate the developmental program directed by the morphogen Hedgehog (Hh), and it uses its various activities to target the expression of key downstream genes to different spatial domains. Here, we highlight recent advances in the Ci story, and discuss remaining questions whose resolution promise to help explain how morphogens like Hh signal their distant targets.

Publication types

  • Review

MeSH terms

  • Animals
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / physiology*
  • Drosophila Proteins*
  • Drosophila melanogaster / embryology*
  • Drosophila melanogaster / genetics
  • Gene Expression Regulation, Developmental*
  • Genes, Insect
  • Hedgehog Proteins
  • Insect Proteins / genetics
  • Insect Proteins / physiology*
  • Membrane Proteins / physiology
  • Morphogenesis
  • Phenotype
  • Proto-Oncogene Proteins / physiology
  • Receptors, Cell Surface
  • Signal Transduction / physiology*
  • Transcription Factors
  • Wings, Animal / embryology
  • Wnt1 Protein


  • DNA-Binding Proteins
  • Drosophila Proteins
  • Hedgehog Proteins
  • Insect Proteins
  • Membrane Proteins
  • Proto-Oncogene Proteins
  • Receptors, Cell Surface
  • Transcription Factors
  • Wnt1 Protein
  • ci protein, Drosophila
  • dpp protein, Drosophila
  • ptc protein, Drosophila
  • wg protein, Drosophila
  • hh protein, Drosophila