Intraflagellar transport is required for the vectorial movement of TRPV channels in the ciliary membrane.
The membranes of all eukaryotic motile (9 + 2) and immotile primary (9 + 0) cilia harbor channels and receptors involved in sensory transduction (reviewed by). These membrane proteins are transported from the cytoplasm onto the ciliary membrane by vesicles targeted for exocytosis at a point adjacent to the ciliary basal body. Here, we use time-lapse fluorescence microscopy to demonstrate that select GFP-tagged sensory receptors undergo rapid vectorial transport along the entire length of the cilia of Caenorhabditis elegans sensory neurons. Transient receptor potential vanilloid (TRPV) channels OSM-9 and OCR-2 move in ciliary membranes at rates comparable to the intraflagellar transport (IFT) machinery located between the membrane and the underlying axonemal microtubules. OSM-9 motility is disrupted in certain IFT mutant backgrounds. Surprisingly, motility of transient receptor potential polycystin (TRPP) channel PKD-2 (polycystic kidney disease-2), a mechano-receptor, was not detected. Our study demonstrates that IFT, previously shown to be necessary for transport of axonemal components, is also involved in the motility of TRPV membrane protein movement along cilia of C. elegans sensory cells.
Qin
Hongmin
H
Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, Connecticut 06511, USA.
Burnette
Dylan T
DT
Bae
Young-Kyung
YK
Forscher
Paul
P
Barr
Maureen M
MM
Rosenbaum
Joel L
JL
D000818:Animals; D001692:Biological Transport / Q000502:physiology; D017173:Caenorhabditis elegans / Q000502:physiology*; D029742:Caenorhabditis elegans Proteins / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism*; D002923:Cilia / Q000378:metabolism*; D049452:Green Fluorescent Proteins; D007473:Ion Channels / Q000378:metabolism*; D008565:Membrane Proteins / Q000378:metabolism; D008856:Microscopy, Fluorescence; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D009475:Neurons, Afferent / Q000378:metabolism* / Q000502:physiology; D050396:TRPP Cation Channels; D050916:TRPV Cation Channels; D050051:Transient Receptor Potential Channels / Q000378:metabolism*
D029742:Caenorhabditis elegans Proteins; D049452:Green Fluorescent Proteins; D007473:Ion Channels; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; D050396:TRPP Cation Channels; D050916:TRPV Cation Channels; D050051:Transient Receptor Potential Channels; C464590:OCR-2 protein, C elegans; C108820:OSM-9 protein, C elegans