Calcium-signaling networks in olfactory receptor neurons.
The olfactory neuroepithelium represents a unique interface between the brain and the external environment. Olfactory function comprises a distinct set of molecular tasks: sensory signal transduction, cytoprotection and adult neurogenesis. A multitude of biochemical studies has revealed the central role of Ca(2+) signaling in the function of olfactory receptor neurons (ORNs). We set out to establish Ca(2+)-dependent signaling networks in ORN cilia by proteomic analysis. We subjected a ciliary membrane preparation to Ca(2+)/calmodulin-affinity chromatography using mild detergent conditions in order to maintain functional protein complexes involved in olfactory Ca(2+) signaling. Thus, calmodulin serves as a valuable tool to gain access to novel Ca(2+)-regulated protein complexes. Tandem mass spectrometry (nanoscale liquid-chromatography-electrospray injection) identified 123 distinct proteins. Ninety-seven proteins (79%) could be assigned to specific olfactory functions, including 32 to sensory signal transduction and 40 to cytoprotection. We point out novel perspectives for research on the Ca(2+)-signaling networks in the olfactory system of the rat.
D000818:Animals; D020013:Calcium Signaling / Q000502:physiology*; D002147:Calmodulin / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D019295:Computational Biology; D051379:Mice; D008822:Mice, Transgenic; D008959:Models, Neurological; D051842:Olfactory Marker Protein / Q000172:deficiency; D009831:Olfactory Mucosa / Q000166:cytology*; D018034:Olfactory Receptor Neurons / Q000378:metabolism*; D015290:Second Messenger Systems / Q000502:physiology*; D053719:Tandem Mass Spectrometry / Q000379:methods
D002147:Calmodulin; D051842:Olfactory Marker Protein; C497598:Omp protein, mouse