General and cell-type specific mechanisms target TRPP2/PKD-2 to cilia

Development. 2006 Oct;133(19):3859-70. doi: 10.1242/dev.02555. Epub 2006 Aug 30.

Abstract

Ciliary localization of the transient receptor potential polycystin 2 channel (TRPP2/PKD-2) is evolutionarily conserved, but how TRPP2 is targeted to cilia is not known. In this study, we characterize the motility and localization of PKD-2, a TRPP2 homolog, in C. elegans sensory neurons. We demonstrate that GFP-tagged PKD-2 moves bidirectionally in the dendritic compartment. Furthermore, we show a requirement for different molecules in regulating the ciliary localization of PKD-2. PKD-2 is directed to moving dendritic particles by the UNC-101/adaptor protein 1 (AP-1) complex. When expressed in non-native neurons, PKD-2 remains in cell bodies and is not observed in dendrites or cilia, indicating that cell-type specific factors are required for directing PKD-2 to the dendrite. PKD-2 stabilization in cilia and cell bodies requires LOV-1, a functional partner and a TRPP1 homolog. In lov-1 mutants, PKD-2 is greatly reduced in cilia and forms abnormal aggregates in neuronal cell bodies. Intraflagellar transport (IFT) is not essential for PKD-2 dendritic motility or access to the cilium, but may regulate PKD-2 ciliary abundance. We propose that both general and cell-type-specific factors govern TRPP2/PKD-2 subcellular distribution by forming at least two steps involving somatodendritic and ciliary sorting decisions.

Publication types

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

MeSH terms

  • Adaptor Protein Complex 1 / metabolism
  • Animals
  • Caenorhabditis elegans / metabolism*
  • Caenorhabditis elegans / ultrastructure
  • Caenorhabditis elegans Proteins / analysis
  • Caenorhabditis elegans Proteins / genetics
  • Caenorhabditis elegans Proteins / metabolism*
  • Cilia / chemistry
  • Cilia / metabolism
  • Cilia / ultrastructure
  • Dendrites / chemistry
  • Dendrites / metabolism*
  • Dendrites / ultrastructure
  • Endoplasmic Reticulum / chemistry
  • Endoplasmic Reticulum / metabolism
  • Female
  • Flagella / chemistry
  • Flagella / metabolism
  • Green Fluorescent Proteins / analysis
  • Male
  • Neurons, Afferent / chemistry
  • Neurons, Afferent / metabolism*
  • Neurons, Afferent / ultrastructure
  • Protein Transport
  • TRPP Cation Channels / analysis
  • TRPP Cation Channels / metabolism*

Substances

  • Adaptor Protein Complex 1
  • Caenorhabditis elegans Proteins
  • LOV-1 protein, C elegans
  • TRPP Cation Channels
  • UNC-101 protein, C elegans
  • polycystic kidney disease 2 protein
  • Green Fluorescent Proteins