Molecular identification and functional analysis of a caffeine receptor on the plasma membrane.

质膜上咖啡因受体的分子鉴定和功能分析。

• 批准号: 18390067
• 负责人: KUBO Yoshihiro
• 金额: $ 9.93万
• 依托单位: National Institute for Physiological Sciences
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2006
• 资助国家: 日本
• 起止时间: 2006 至 2007
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-18390067/
• 关键词: Physiology; Neuroscience; Biomolecule; Protein; Signal transduction

Caffeine has various well-characterized pharmacological effects mediated e.g. via ryanodine receptor stimulation and phosphodiesterase inhibition. However, it was recently reported that application of caffeine to STC-1 mouse gastrointestinal endocrine cells induces a rapid increase in intracellular Ca^<2+> (Ca^<2+>; ) that is suppressed by inhibition of phospholipase C. This suggests a novel pharmacological action for caffeine. We observed that caffeine-induced increases in Ca^<2+>i in fura-2-loaded STC-1 cells were dependent on extracellular Ca^<2+> and were suppressed by TRP (Transient Receptor Potential) channel blockers. In addition, Ca^<2+>i imaging and electrophysiological analyses showed that mouse TRPA1 channels were activated by mM concentrations of caffeine in heterologous expression systems such as HEK293T cells and Xenopus oocytes. These responses to caffeine were confirmed in acutely dissociated dorsal root ganglion sensory neurons from wild-type (WT) mice, which are known to express TRPA1, but were not seen in neurons from TRPA1 knock-out (KO) mice. Expression of TRPA1 protein was detected immunohistochemically in nerve fibers and bundles in the mouse tongue. Moreover, WT mice, but not KO mice, showed a remarkable aversion to caffeine-containing water in two-bottle preference tests. Finally, we observed that the activity of human TRPA1 channels is suppressed by caffeine, in clear contrast to the mouse channels. Our findings demonstrated caffeine activates a Ca^<2+>-permeable TRPA1 channel in mouse but suppresses the activity of the human orthologue. We also showed that mouse TRPA1 channels expressed in sensory neurons cause an aversion to drinking caffeine-containing water, suggesting they mediate the perception of caffeine.

咖啡因具有多种明显的药理作用，例如：通过兰尼碱受体刺激和磷酸二酯酶抑制。然而，最近有报道称，对STC-1小鼠胃肠道内分泌细胞施用咖啡因会诱导细胞内Ca^2+(Ca^2+;)快速增加，而这种增加被磷脂酶C的抑制所抑制。这表明咖啡因的新药理作用。我们观察到，在负载fura-2的STC-1细胞中，咖啡因诱导的Ca ^ 2+ i 增加依赖于细胞外Ca ^ 2+ ，并且被TRP（瞬时受体电位）通道阻断剂抑制。此外，Ca 2+ 成像和电生理学分析表明，在异源表达系统例如HEK293T细胞和非洲爪蟾卵母细胞中，小鼠TRPA1通道被mM浓度的咖啡因激活。这些对咖啡因的反应在野生型 (WT) 小鼠的急性分离背根神经节感觉神经元中得到证实，这些神经元已知表达 TRPA1，但在 TRPA1 敲除 (KO) 小鼠的神经元中没有观察到。免疫组化检测小鼠舌神经纤维和神经束中 TRPA1 蛋白的表达。此外，在两瓶偏好测试中，WT 小鼠（而非 KO 小鼠）表现出对含咖啡因水的显着厌恶。最后，我们观察到人类 TRPA1 通道的活性被咖啡因抑制，这与小鼠通道形成鲜明对比。我们的研究结果表明，咖啡因激活小鼠体内的Ca^2+-可渗透的TRPA1通道，但抑制人类直系同源物的活性。我们还发现，在感觉神经元中表达的小鼠 TRPA1 通道会导致人们厌恶饮用含咖啡因的水，这表明它们介导了对咖啡因的感知。

项目成果

TRPA1チャネルはカフェインにより活性化される

TRPA1 通道被咖啡因激活

• 发表时间: 2008
• 作者: 長友 克広;久保 義弘
• 通讯作者: 久保 義弘

Activation of TRPA1 channel by caffeine

咖啡因激活 TRPA1 通道

• 发表时间: 2008
• 作者: 長友 克広;久保 義弘;Nagatomo K and Kubo Y
• 通讯作者: Nagatomo K and Kubo Y

Alternative splicing of RGS8 gene changes the binding property to the M1 muscarinic receptor to confer receptor type-specific Go regulation.

RGS8 基因的选择性剪接改变了与 M1 毒蕈碱受体的结合特性，从而赋予受体类型特异性 Go 调节。

• 发表时间: 2006
• 期刊: Journal of Neurochemistry 99
• 作者: Itoh;M.;Nagatomo;K.;Kubo;Y.;Saitoh;O.
• 通讯作者: O.

Coupling profile of the metabotropic glutamate receptor 1□is regulated by the C-terminal domain.

代谢型谷氨酸受体1□的偶联特征由C端结构域调节。

• 发表时间: 2007
• 期刊: Molecular and Cellular Neuroscience 34
• 作者: Tateyama M;Kubo Y
• 通讯作者: Kubo Y

The motor protein prestin is a bullet-shaped molecule with inner cavities

• DOI: 10.1074/jbc.m702681200
• 发表时间: 2008-01-11
• 期刊: JOURNAL OF BIOLOGICAL CHEMISTRY
• 影响因子: 4.8
• 作者: Mio, Kazuhiro;Kubo, Yoshihiro;Sato, Chikara
• 通讯作者: Sato, Chikara