Rabconnectin-3 is a functional regulator of mammalian Notch signaling

J Biol Chem. 2010 Nov 5;285(45):34757-64. doi: 10.1074/jbc.M110.158634. Epub 2010 Sep 1.

Abstract

The Notch signaling pathway is important for cell fate decisions in embryonic development and adult life. Defining the functional importance of the Notch pathway in these contexts requires the elucidation of essential signal transduction components that have not been fully characterized. Here, we show that Rabconnectin-3B is required for the Notch pathway in mammalian cells. siRNA-mediated silencing of Rabconnectin-3B in mammalian cells attenuated Notch signaling and disrupted the activation and nuclear accumulation of the Notch target Hes1. Rabconnectin-3B knockdown also disrupted V-ATPase activity in mammalian cells, consistent with previous observations in Drosophila. Pharmacological inhibition of the V-ATPase complex significantly reduced Notch signaling in mammalian cells. Finally, Rabconnectin-3B knockdown phenocopied functional disruption of Notch signaling during osteoclast differentiation. Collectively, these findings define an important role for Rabconnectin-3 and V-ATPase activity in the Notch signaling pathway in mammalian cells.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adaptor Proteins, Signal Transducing / genetics
  • Adaptor Proteins, Signal Transducing / metabolism*
  • Animals
  • Basic Helix-Loop-Helix Transcription Factors / genetics
  • Basic Helix-Loop-Helix Transcription Factors / metabolism
  • Cell Differentiation / physiology*
  • Cell Line, Tumor
  • Drosophila melanogaster
  • Gene Knockdown Techniques
  • Homeodomain Proteins / genetics
  • Homeodomain Proteins / metabolism
  • Humans
  • Mice
  • Nerve Tissue Proteins / genetics
  • Nerve Tissue Proteins / metabolism*
  • Osteoclasts / metabolism*
  • RNA, Small Interfering / genetics
  • Receptors, Notch / genetics
  • Receptors, Notch / metabolism*
  • Signal Transduction / physiology*
  • Transcription Factor HES-1
  • Vacuolar Proton-Translocating ATPases / genetics
  • Vacuolar Proton-Translocating ATPases / metabolism

Substances

  • Adaptor Proteins, Signal Transducing
  • Basic Helix-Loop-Helix Transcription Factors
  • DMXL2 protein, human
  • Hes1 protein, mouse
  • Homeodomain Proteins
  • Nerve Tissue Proteins
  • RNA, Small Interfering
  • Receptors, Notch
  • Transcription Factor HES-1
  • HES1 protein, human
  • Vacuolar Proton-Translocating ATPases