A CYCLIC NUCLEOTIDE-GATED CONDUCTANCE IN OLFACTORY RECEPTOR CILIA
A CYCLIC NUCLEOTIDE-GATED CONDUCTANCE IN OLFACTORY RECEPTOR CILIA
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DOI：
10.1038/325442a0
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发表时间：
1987-01-29
期刊：
影响因子：
64.8
通讯作者：
GOLD, GH
中科院分区：
文献类型：
--
作者：
NAKAMURA, T;GOLD, GH
嗅觉传导被认为是通过气味物质与嗅觉受体细胞纤毛中的特异性受体蛋白结合而启动的（综述见参考文献1 -3）。气味结合可以启动膜去极化的机制是未知的，但最近发现的气味刺激的腺苷酸环化酶在纯化的嗅纤毛4，5表明，环AMP可能作为细胞内的信使嗅觉转导。如果是这样，那么在纤毛质膜中可能存在由cAMP控制的电导。在这里，我们报告说，切除补丁的睫状体质膜，从解离的受体细胞，含有直接由cAMP门控的电导。这种电导类似于介导视杆和视锥外节光转导的环GMP门控电导6，7，但不同之处在于它被cAMP和cGMP激活。我们的数据提供了一个机械的基础，通过它的气味刺激环核苷酸浓度的增加可能会导致膜电导的增加，因此，膜去极化。这些数据表明，嗅觉和视觉转导机制之间的显着相似性，并表明相当大的保护的感觉转导机制。
Olfactory transduction is thought to be initiated by the binding of odorants to specific receptor proteins in the cilia of olfactory receptor cells (reviewed in refs1–3). The mechanism by which odorant binding could initiate membrane depolarization is unknown, but the recent discovery of an odorant-stimulated adenylate cyclase in purified olfactory cilia4,5suggests that cyclic AMP may serve as an intracellular messenger for olfactory transduction. If so, then there might be a conductance in the ciliary plasma membrane which is controlled by cAMP. Here we report that excised patches of ciliary plasma membrane, obtained from dissociated receptor cells, contain a conductance which is gated directly by cAMP. This conductance resembles the cyclic GMP-gated conductance that mediates phototransduction in rod and cone outer segments6,7, but differs in that it is activated by both cAMP and cGMP. Our data provide a mechanistic basis by which an odorant-stimulated increase in cyclic nucleotide concentration could lead to an increase in membrane conductance and therefore, to membrane depolarization. These data suggest a remarkable similarity between the mechanisms of olfactory and visual transduction and indicate considerable conservation of sensory transduction mechanisms.