The first deltex null mutant indicates tissue-specific deltex-dependent Notch signaling in Drosophila

Mol Genet Genomics. 2006 Mar;275(3):251-63. doi: 10.1007/s00438-005-0087-3. Epub 2006 Jan 5.


Notch (N) is a single-pass transmembrane receptor. The N signaling pathway is an evolutionarily conserved mechanism that controls various cell-specification processes. Drosophila Deltex (Dx), a RING-domain E3 ubiquitin ligase, binds to the N intracellular domain, promotes N's endocytic trafficking to late endosomes, and was proposed to activate Suppressor of Hairless [Su(H)]-independent N signaling. However, it has been difficult to evaluate the importance of dx, because no null mutant of a dx family gene has been available in any organism. Here, we report the first null mutant allele of Drosophila dx. We found that dx was involved only in the subsets of N signaling, but was not essential for it in any developmental context. A strong genetic interaction between dx and Su(H) suggested that dx might function in Su(H)-dependent N signaling. Our epistatic analyses suggested that dx functions downstream of the ligands and upstream of activated Su(H). We also uncovered a novel dx activity that suppressed N signaling downstream of N.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Base Sequence
  • DNA Primers
  • Drosophila
  • Drosophila Proteins / genetics*
  • Drosophila Proteins / metabolism*
  • Endocytosis
  • Membrane Proteins / genetics*
  • Mosaicism
  • Mutation*
  • Receptors, Notch / metabolism*
  • Signal Transduction*


  • DNA Primers
  • DX protein, Drosophila
  • Drosophila Proteins
  • Membrane Proteins
  • N protein, Drosophila
  • Receptors, Notch