Drosophila Nedd4 regulates endocytosis of Notch and suppresses its ligand-independent activation

Tadashi Sakata, Hiromi Sakaguchi, Leo Tsuda, Atsushi Higashitani, Toshiro Aigaki, Kenji Matsuno, Shigeo Hayashi

Research output: Contribution to journalArticlepeer-review

141 Citations (Scopus)

Abstract

Background: Ligand-induced proteolytic cleavage and internalization of the plasma membrane receptor Notch leads to its activation. Ligand-independent, steady-state internalization of Notch, however, does not lead to activation. The mechanism by which downstream effectors discriminate between these bipartite modes of Notch internalization is not understood. Nedd4 is a HECT domain-containing E3 ubiquitin ligase that targets transmembrane receptors containing the PPSY motif for endocytosis. Deltex is a positive Notch signaling regulator that encodes a putative ubiquitin ligase of the ring finger type. Results: We used the Drosophila system to show that Notch is ubiquitinated and destabilized by Nedd4 in a manner requiring the PPSY motif in the Notch intracellular domain. Loss of Nedd4 function dominantly suppresses the Notch and Deltex mutant phenotypes, and its hyperactivation attenuates Notch activity. In tissue culture cells, the dominant-negative form of Nedd4 blocks steady-state Notch internalization and activates Notch signaling independently of ligand binding. This effect was further potentiated by Deltex. Nedd4 destines Deltex for degradation in a Notch-dependent manner. Conclusions: Nedd4 antagonizes Notch signaling by promoting degradation of Notch and Deltex. This Nedd4 function may be important for protecting unstimulated cells from sporadic activation of Notch signaling.

Original languageEnglish
Pages (from-to)2228-2236
Number of pages9
JournalCurrent Biology
Volume14
Issue number24
DOIs
Publication statusPublished - 2004 Dec 29

ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)
  • Agricultural and Biological Sciences(all)

Fingerprint Dive into the research topics of 'Drosophila Nedd4 regulates endocytosis of Notch and suppresses its ligand-independent activation'. Together they form a unique fingerprint.

Cite this