Comparative Study on Molecular Mechanism of Photoreception in the Retina and Pineal Gland

视网膜与松果体感光分子机制的比较研究

• 批准号: 05454027
• 负责人: FUKADA Yoshitaka
• 金额: $ 3.84万
• 依托单位: The University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (B)
• 财政年份: 1993
• 资助国家: 日本
• 起止时间: 1993 至 1995
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-05454027/
• 关键词: Rod; Cone; Pineal Gland; Photon-Signal Transduction; Photoreceptor Protein; Pinopsin; G-Protein; Transducin; 光情報伝達; ロドプシン; 脂肪酸修飾; 慨日リズム; 脂質修飾; メチル化

Many vertebrates have several types of photoreceptive cells ; rods and cones in the retina, and pinealocytes in the pineal gland. It is important to understand the difference in molecular mechanism responsible for the diverged cellular functions ; that is, rods for scotopic vision, cones for color vision, and pinealocytes for circadian regulation of biological clock. This project aimed at comparative studies on the photon-signal transduction processes in the three types of photoreceptive cells, particularly at the structures and functions of photoreceptive pigments and signal-transducing G-proteins in the cells.[Rod] To identify the physiological roles of lipid modifications of transducin alpha-and betagamma-subunits (Talpha and Tbetagamma), we studied the mechanism of the subunit interaction and the membrane association. It ws clearly shown that the isoprenyl and methyl groups of Tgamma regulate the efficiency of photon-signal transduction by affecting 1) Talpha-Tbetagamma coupling th … More rough direct contact with alpha-subunit, and 2) the interaction between transducin and cellular membranes. Monoclonal antibodies recognizing the structure of the N-terminal fatty acid of Talpha stained almost all of the rod outer segments in a bovine retina, suggesting that a single rod cell contains the four isoforms of Talpha modified with four kinds of fatty acids. The target of recoverin was shown to be rhodopsin kinase. The complex of calcium-recoverin-rhodopsin kinase was stabilized by the membrane association, by which the kinase activity was effectively inhibited.[Cone] Comparative studies on cone and rod photoreceptive pigments by low temperature spectroscopy, laser flash photolysis, and circular dichroism showed that the life times of the active intermediates of cone pigments are much faster than that of rhodopsin. This clearly indicates that the molecular property of cone pigment is one of the major determinants for physiological photoresponse of cones. Photochemical reactions of chimeric mutants composed of rod-and cone-type pigments demonstrated that the structures of helices 1 through 3 determines the life time of the active intermediate of photoreceptive pigments.[Pinealocytes] Little is known about the photon-signal transduction process in a photosensitive pineal gland. We found opsin-like immunoreaction in the gland by immunohistochemistry. Then we isolated the cDNA encoding a pineal specific opsin-like protein. Reconstitution experiment with 11-cis-retinal revealed its blue-light sensitivity, and thus we named it "pinopsin" after pineal opsin. This is the first demonstration of an opsin expressed in non-retinal tissues. Less

许多脊椎动物具有几种类型的感光细胞。视网膜中的棒和锥，松果体中的松果体。重要的是要了解导致分歧分散细胞功能的分子机制的差异。也就是说，用于Scotopic Vision的杆，彩色视觉锥和生物钟调节的松果体。该项目旨在对三种类型的光感受性细胞中光子信号转导过程进行比较研究，尤其是在细胞中光感受性色素的结构和功能和信号转移的G蛋白的结构和功能。亚基相互作用和膜关联。 WS清楚地表明，Tgamma的异丙基和甲基通过影响光子信号转导的效率1）talpha-tbetagamma耦合……与α-亚基的直接直接直接接触，以及2）2）2）在跨多核素和细胞膜之间的相互作用。单克隆抗体识别Talpha的N末端脂肪酸的结构几乎染色了牛视网膜中的所有棒外部片段，这表明一个单杆细胞包含四种用四种脂肪酸修饰的Talpha的同工型。恢复素的靶标被证明是视紫红质激酶。通过膜缔合稳定了钙回生蛋白 - 偶像激酶的复合物，通过低温光谱，激光光谱，激光闪光照射分析和圆形二色症对锥形和棒光感应性色素进行了对锥形和杆光感受性色素的比较研究表明，与活性Interemiment cone cone cone cone cone cone cone cone cone cone cone cone cone cone cone cone cone cone cone cone cone相比。这清楚地表明，锥色素的分子特性是锥体物理光响应的主要决定剂之一。由棒状锥形颜料组成的嵌合突变体的光化学反应表明，螺旋的结构1至3的结构决定了光感受器色素的活性中间体的寿命。[松果细胞]关于光敏感性松果腺中光 - 信号转移过程的知识很少。我们通过免疫组织化学在腺体中发现了蛋白蛋白样的免疫反应。然后，我们分离了编码松果体特异性Opsin样蛋白的cDNA。对11盘视网膜的重组实验揭示了其蓝光灵敏度，因此我们在松果蛋白之后将其命名为“ Pineopsin”。这是在非视网膜组织中表达的Opsin的第一次演示。较少的

项目成果

Yoshinori Shichida: "Nanosecond laser photolysis of iodopsin,a chicken red-sensitive cone visual pigment." Biochemistry. 32. 10832-10838 (1993)

Yoshinori Shichida：“碘紫红质的纳秒激光光解，碘紫红质是一种鸡红色敏感的视锥视觉色素。”

Y.Shichida, H.Imai, y.Imamoto, Y.Fukada and T.Yoshizawa: "Is chicken green-sensitive cone visual pigment a rhodopsin-like pigment? A comparative study of the molecular properties between chicken green and rhodopsin." Biochemistry. 33. 9040-9044 (1994)

Y.Shichida、H.Imai、y.Imamoto、Y.Fukada 和 T.Yoshizawa：“鸡绿敏感视锥视色素是视紫红质样色素吗？鸡绿和视紫红质分子特性的比较研究”。

T.Okano and Y.Fukada: "Brain is the third eye." Newton. 15. 102-107 (1995)

T.Okano 和 Y.Fukada：“大脑是第三只眼。”

T.Okano and Y.Fukada: "Brain photoreceptor pinopsin and biological clock." Biological Science News. 278. 14-16 (1995)

T.Okano 和 Y.Fukada：“大脑光感受器 pinopsin 和生物钟。”

Y.Shichida, T.Okada, H.Kandori, Y.Fukada and T.Yoshizawa: "Nanosecond laser photolysis of iodopsin, a chicken red-sensitive cone visual pigment." Biochemistry. 32. 10832-10838 (1993)

Y.Shichida、T.Okada、H.Kandori、Y.Fukada 和 T.Yoshizawa：“碘紫红质的纳秒激光光解，碘紫红质是一种鸡红色敏感的视锥视色素。”