Type 3 inositol 1,4,5-trisphosphate receptor is dispensable for sensory activation of the mammalian vomeronasal organ
Signal transduction in sensory neurons of the mammalian vomeronasal organ (VNO) involves the opening of the canonical transient receptor potential channel Trpc2, a Ca(2+)-permeable cation channel that is activated by diacylglycerol and inhibited by Ca(2+)-calmodulin. There has been a long-standing d...
Autores principales: | , , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Nature Publishing Group UK
2017
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5579292/ https://www.ncbi.nlm.nih.gov/pubmed/28860523 http://dx.doi.org/10.1038/s41598-017-09638-8 |
Sumario: | Signal transduction in sensory neurons of the mammalian vomeronasal organ (VNO) involves the opening of the canonical transient receptor potential channel Trpc2, a Ca(2+)-permeable cation channel that is activated by diacylglycerol and inhibited by Ca(2+)-calmodulin. There has been a long-standing debate about the extent to which the second messenger inositol 1,4,5-trisphosphate (InsP(3)) and type 3 InsP(3) receptor (InsP(3)R3) are involved in the opening of Trpc2 channels and in sensory activation of the VNO. To address this question, we investigated VNO function of mice carrying a knockout mutation in the Itpr3 locus causing a loss of InsP(3)R3. We established a new method to monitor Ca(2+) in the endoplasmic reticulum of vomeronasal sensory neurons (VSNs) by employing the GFP-aequorin protein sensor erGAP2. We also performed simultaneous InsP(3) photorelease and Ca(2+) monitoring experiments, and analysed Ca(2+) dynamics, sensory currents, and action potential or field potential responses in InsP(3)R3-deficient VSNs. Disruption of Itpr3 abolished or minimized the Ca(2+) transients evoked by photoactivated InsP(3), but there was virtually no effect on sensory activation of VSNs. Therefore, InsP(3)R3 is dispensable for primary chemoelectrical transduction in mouse VNO. We conclude that InsP(3)R3 is not required for gating of Trpc2 in VSNs. |
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