ANO2 is the cilial calcium-activated chloride channel that may mediate olfactory amplification.
For vertebrate olfactory signal transduction, a calcium-activated chloride conductance serves as a major amplification step. However, the molecular identity of the olfactory calcium-activated chloride channel (CaCC) is unknown. Here we report a proteomic screen for cilial membrane proteins of mouse olfactory sensory neurons (OSNs) that identified all the known olfactory transduction components as well as Anoctamin 2 (ANO2). Ano2 transcripts were expressed specifically in OSNs in the olfactory epithelium, and ANO2::EGFP fusion protein localized to the OSN cilia when expressed in vivo using an adenoviral vector. Patch-clamp analysis revealed that ANO2, when expressed in HEK-293 cells, forms a CaCC and exhibits channel properties closely resembling the native olfactory CaCC. Considering these findings together, we propose that ANO2 constitutes the olfactory calcium-activated chloride channel.
Stephan
Aaron B
AB
Department of Biology, The Johns Hopkins University School of Medicine, Baltimore, MD 21218, USA.
Shum
Eleen Y
EY
Hirsh
Sarah
S
Cygnar
Katherine D
KD
Reisert
Johannes
J
Zhao
Haiqing
H
D000818:Animals; D000075368:Anoctamins; D002460:Cell Line; D018118:Chloride Channels / Q000378:metabolism*; D002923:Cilia / Q000378:metabolism; D006801:Humans; D008565:Membrane Proteins / Q000378:metabolism*; D051379:Mice; D018034:Olfactory Receptor Neurons / Q000378:metabolism; D018408:Patch-Clamp Techniques; D040901:Proteomics; D015398:Signal Transduction / Q000502:physiology*; D012903:Smell / Q000502:physiology*
C532161:ANO2 protein, mouse; D000075368:Anoctamins; D018118:Chloride Channels; D008565:Membrane Proteins