Specificity of the inhibitory effects of Dad on TGF-beta family type I receptors, Thickveins, Saxophone, and Baboon in Drosophila

FEBS Lett. 2008 Jul 23;582(17):2496-500. doi: 10.1016/j.febslet.2008.05.052. Epub 2008 Jun 25.


In mammals, two inhibitory Smads (I-Smads), Smad6 and Smad7, play pivotal roles in negative regulation of TGF-beta family signaling. Smad7 ubiquitously inhibits TGF-beta family signaling, whereas Smad6 inhibits signaling from the ALK-3/6 subfamily in preference to that from the ALK-1/2 and ALK-4/5/7 subfamilies of TGF-beta family type I receptors. In Drosophila, only one I-Smad, Dad, has been identified. Here we examined inhibitory effects of Dad on type I receptors in Drosophila. Dad inhibited Saxophone (ALK-1/2 orthologue) and Thickveins (ALK-3/6 orthologue) but not Baboon (ALK-4/5/7 orthologue). The differential modes of action of I-Smads in mammals and Drosophila are discussed.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Activin Receptors / antagonists & inhibitors*
  • Activin Receptors / metabolism
  • Animals
  • DNA-Binding Proteins / metabolism
  • Drosophila Proteins / antagonists & inhibitors*
  • Drosophila Proteins / metabolism*
  • Drosophila melanogaster / metabolism*
  • Humans
  • Phosphorylation
  • Protein-Serine-Threonine Kinases / antagonists & inhibitors*
  • Protein-Serine-Threonine Kinases / metabolism
  • Receptors, Cell Surface / antagonists & inhibitors*
  • Receptors, Cell Surface / metabolism
  • Receptors, Transforming Growth Factor beta / antagonists & inhibitors*
  • Receptors, Transforming Growth Factor beta / metabolism
  • Smad4 Protein / metabolism
  • Transcription Factors / metabolism


  • DNA-Binding Proteins
  • Dad protein, Drosophila
  • Drosophila Proteins
  • MAD protein, Drosophila
  • Med protein, Drosophila
  • Receptors, Cell Surface
  • Receptors, Transforming Growth Factor beta
  • Smad4 Protein
  • Transcription Factors
  • sax protein, Drosophila
  • tkv protein, Drosophila
  • Protein-Serine-Threonine Kinases
  • Activin Receptors
  • Babo protein, Drosophila