Activation and desensitization of the olfactory cAMP-gated transduction channel: identification of functional modules

Olfactory receptor neurons respond to odor stimulation with a receptor potential that results from the successive activation of cyclic AMP (cAMP)-gated, Ca2+-permeable channels and Ca2+-activated chloride channels. The cAMP-gated channels open at micromolar concentrations of their ligand and are sub...

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Main Authors: Waldeck, Clemens zu (Author) , Vocke, Kerstin (Author) , Ungerer, Nicole (Author) , Frings, Stephan (Author) , Möhrlen, Frank (Author)
Format: Article (Journal)
Language:English
Published: October 12, 2009
In: The journal of general physiology
Year: 2009, Volume: 134, Issue: 5, Pages: 397-408
ISSN:1540-7748
DOI:10.1085/jgp.200910296
Online Access:Verlag, kostenfrei, Volltext: http://dx.doi.org/10.1085/jgp.200910296
Verlag, kostenfrei, Volltext: http://jgp.rupress.org/content/134/5/397
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Author Notes:Clemens Waldeck, Kerstin Vocke, Nicole Ungerer, Stephan Frings and Frank Möhrlen
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Summary:Olfactory receptor neurons respond to odor stimulation with a receptor potential that results from the successive activation of cyclic AMP (cAMP)-gated, Ca2+-permeable channels and Ca2+-activated chloride channels. The cAMP-gated channels open at micromolar concentrations of their ligand and are subject to a Ca2+-dependent feedback inhibition by calmodulin. Attempts to understand the operation of these channels have been hampered by the fact that the channel protein is composed of three different subunits, CNGA2, CNGA4, and CNGB1b. Here, we explore the individual role that each subunit plays in the gating process. Using site-directed mutagenesis and patch clamp analysis, we identify three functional modules that govern channel operation: a module that opens the channel, a module that stabilizes the open state at low cAMP concentrations, and a module that mediates rapid Ca2+-dependent feedback inhibition. Each subunit could be assigned to one of these functions that, together, define the gating logic of the olfactory transduction channel.
Item Description:Gesehen am 05.05.2017
Physical Description:Online Resource
ISSN:1540-7748
DOI:10.1085/jgp.200910296