Two interdependent TRPV channel subunits, inactive and Nanchung, mediate hearing in Drosophila.
Hearing in Drosophila depends on the transduction of antennal vibration into receptor potentials by ciliated sensory neurons in Johnston's organ, the antennal chordotonal organ. We previously found that a Drosophila protein in the vanilloid receptor subfamily (TRPV) channel subunit, Nanchung (NAN), is localized to the chordotonal cilia and required to generate sound-evoked potentials (Kim et al., 2003). Here, we show that the only other Drosophila TRPV protein is mutated in the behavioral mutant inactive (iav). The IAV protein forms a hypotonically activated channel when expressed in cultured cells; in flies, it is specifically expressed in the chordotonal neurons, localized to their cilia and required for hearing. IAV and NAN are each undetectable in cilia of mutants lacking the other protein, indicating that they both contribute to a heteromultimeric transduction channel in vivo. A functional green fluorescence protein-IAV fusion protein shows that the channel is restricted to the proximal cilium, constraining models for channel activation.
Gong
Zhefeng
Z
Biology Department, University of Virginia, Charlottesville, Virginia 22904, USA.
Son
Wonseok
W
Chung
Yun Doo
YD
Kim
Janghwan
J
Shin
Dong Wook
DW
McClung
Colleen A
CA
Lee
Yong
Y
Lee
Hye Won
HW
Chang
Deok-Jin
DJ
Kaang
Bong-Kiun
BK
Cho
Hawon
H
Oh
Uhtaek
U
Hirsh
Jay
J
Kernan
Maurice J
MJ
Kim
Changsoo
C
D000818:Animals; D015220:Calcium Channels / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D002460:Cell Line; D002874:Chromosome Mapping; D002923:Cilia / Q000378:metabolism; D006224:Cricetinae; D003433:Crosses, Genetic; D004330:Drosophila / Q000235:genetics / Q000502:physiology*; D029721:Drosophila Proteins / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D005260:Female; D006309:Hearing / Q000235:genetics / Q000502:physiology*; D006311:Hearing Disorders / Q000235:genetics; D007473:Ion Channels / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D008297:Male; D016296:Mutagenesis; D009154:Mutation; D009475:Neurons, Afferent / Q000378:metabolism / Q000648:ultrastructure; D018408:Patch-Clamp Techniques; D021122:Protein Subunits / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology; D011955:Receptors, Drug / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D050051:Transient Receptor Potential Channels
D015220:Calcium Channels; D029721:Drosophila Proteins; C494780:IAV protein, Drosophila; D007473:Ion Channels; C476010:Nan protein, Drosophila; D021122:Protein Subunits; D011955:Receptors, Drug; D050051:Transient Receptor Potential Channels