Functional dissection of Drosophila abdominal-B protein

Mech Dev. 1991 Aug;35(1):55-64. doi: 10.1016/0925-4773(91)90041-4.


The Abdominal-B gene is unique among homeotic Drosophila genes as it encodes two proteins m and r which confer different functions. The m protein corresponds to an r protein with a large N-terminal extension; the two proteins contain the same homeodomain. We have used a transient co-transfection assay, based on HeLa cells, to analyse the intrinsic function of m and r protein in activating transcription. We find two strong transcriptional activation domains in the common part of the two proteins. The m-specific exon contains additional transcriptional activation potential. Despite this, the m protein is a weaker transcriptional activator than the r protein. Apparently, there are inhibitory sequences in the m-specific exon which, in the embryo, may have a role in masking r function in the intact m protein.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Drosophila / genetics
  • Drosophila / physiology*
  • Drosophila Proteins*
  • Exons
  • Gene Expression Regulation / genetics
  • Gene Expression Regulation / physiology
  • Genes, Homeobox / genetics
  • Genes, Homeobox / physiology*
  • Homeodomain Proteins*
  • Insect Hormones / genetics
  • Insect Hormones / physiology*
  • Transcription, Genetic / genetics


  • Abd-B proteins, Drosophila
  • Drosophila Proteins
  • Homeodomain Proteins
  • Insect Hormones