Regulation of LIM homeodomain activity in vivo: a tetramer of dLDB and apterous confers activity and capacity for regulation by dLMO

Mol Cell. 1999 Aug;4(2):267-73. doi: 10.1016/s1097-2765(00)80374-3.


Dorsal-ventral axis formation in the Drosophila wing depends on the activity of the LIM homeodomain transcription factor Apterous and its cofactor, dLDB/Chip. We present evidence that Apterous activity depends on the formation of a LIM homeodomain dimer bridged by a dimer of cofactor. We show that Apterous activity levels are regulated in vivo by dLMO, an antagonist of homodimer formation. Making use of a constitutively active form of Apterous and dominant-negative forms of Apterous and dLDB/Chip, we show that the normal function of dLMO is to downregulate Apterous activity and that the dLMO mutant phenotype is due to excess Apterous activity. These findings may point to a general mechanism for regulation of LIM homeodomain protein activity.

MeSH terms

  • Animals
  • Body Patterning
  • Cloning, Molecular
  • Dimerization
  • Drosophila / genetics*
  • Drosophila / growth & development*
  • Drosophila Proteins*
  • Homeodomain Proteins / genetics
  • Homeodomain Proteins / metabolism*
  • Insect Proteins / metabolism
  • LIM-Homeodomain Proteins
  • Macromolecular Substances
  • Nuclear Proteins / chemistry
  • Nuclear Proteins / genetics
  • Nuclear Proteins / metabolism*
  • Polymerase Chain Reaction
  • Recombinant Proteins / metabolism
  • Transcription Factors / chemistry
  • Transcription Factors / genetics
  • Transcription Factors / metabolism*
  • Wings, Animal / growth & development*


  • Bx protein, Drosophila
  • Chi protein, Drosophila
  • Drosophila Proteins
  • Homeodomain Proteins
  • Insect Proteins
  • LIM-Homeodomain Proteins
  • Macromolecular Substances
  • Nuclear Proteins
  • Recombinant Proteins
  • Transcription Factors
  • ap protein, Drosophila