Mechanism of photoactivation of photoactivated adenylyl cyclase (PAC), a novel blue-light receptor, and mechanism of photocontrol of cellular functions.

新型蓝光受体光激活腺苷酸环化酶（PAC）的光激活机制以及细胞功能的光控制机制。

• 批准号: 15207006
• 负责人: WATANABE Masakatsu
• 金额: $ 31.28万
• 依托单位: The Graduate University for Advanced Studies (2004-2006)Okazaki National Research Institutes (2003)
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (A)
• 财政年份: 2003
• 资助国家: 日本
• 起止时间: 2003 至 2006
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-15207006/
• 关键词: blue-light sensor; photoactivated enzyme; cAMP; Euglena; photobehavior; PAC; flavin; 光運動反応; 光センサー分子; 青色光反応; フラビン蛋白質; 光活性化アデニル酸シクラーゼ; 青色光受容体; FAD

Photoactivated adenylyl cyclase (PAC) (Iseki et al. 2002 Nature) is a blue-light sensor protein responsible for photoavoidance behavior in a eukaryotic unicellular flagellate alga Euglena gracilis. It is composed of flavin-binding, light sensing domains and adenylyl cyclase catalytic domains so that it produces cAMP, a versatile intracellular second messenger, in response to blue-light irradiation.By molecular phylogenetic analyses of homologues fo PAC in various euglenoids, it was suggested that PAC was introduced into Euglena almost concomitantly with the secondary symbiotic introduction of its chroloplasts (Koumura et al. 2004 Photochem Photobiol Sci).By analyses of the photoactivation kinetics of purified PAC from Euglena, action spectrum and responsively to repeated short pulse irradiations were determined as well as intracellular cAMP concentration time courses. These results were in accordance with the corresponding in vivo photobehavior characteristics (Yoshikawa et al. 2005 Ph … More otochem Photobiol Sci).By analyses of the photochemical cycle kinetics of a flavin-binding domain heterologously expressed in E. coil, threshold light flounce rate, quantum efficiency as well as half life of dark recovery ware determined which were in general similarity to other members of the so-called BLUF family of flavin-binding domains, mostly of prokaryotic origins (Ito et al. 2005 Photochem Photobiol Sci).The unique distinguishing feature of PAC to act as a light sensor having intrinsic effector function of adenylyl cyclase provide promising possibilities to be used as a tool to photomanipulate various cAMP-dependent biological functions including neural and reproductive processes if it is successfully expressed functionally in heterologous systems (Iseki et al. 2002 Nature). This possibility was in fact realized by successful functional expression of PAC in frog oocytes, human cultured cells as well as in fly brains, particularly in which grooming behavior of the fly individual was specifically photosuppressed by external light irradiation (Schroeder-Lang 2007 Nature Methods). Less

光活化的腺酰环化酶(PAC)(Iseki等人)。2002自然)是一种蓝光感受器蛋白，负责真核单细胞鞭毛藻Euglena gracilis的光回避行为。PAC由黄素结合区、光敏结构域和腺苷环化酶催化结构域组成，在蓝光照射下产生一种多功能的细胞内第二信使cAMP。通过对不同类型优节藻中PAC同源物的分子系统发育分析，表明PAC几乎与其有色体的次生共生引入到裸藻中(KouMura等人)。2004 PhotoChem Photobiol Sci)。通过对Euglena纯化的PAC的光活化动力学分析，测定了作用光谱和对重复短脉冲照射的响应以及细胞内cAMP浓度的时间过程。这些结果与相应的体内光行为特征是一致的(Yoshikawa等人。2005年Ph…通过对异源表达的黄素结合结构域的光化学循环动力学的分析，确定了黄素结合结构域的阈值光闪烁速率、量子效率以及暗恢复的半衰期，它们与所谓的黄素结合结构域的BLUF家族的其他成员总体上相似，主要来自原核(Ito等人)。2005年PhotoChem Photobiol Sci)。PAC作为具有腺酰环化酶内在效应功能的光传感器的独特区别特征，如果它在异源系统中成功地功能性表达，就有可能被用作光操纵包括神经和生殖过程在内的各种cAMP依赖的生物学功能的工具(Iseki等人)。2002《自然》)。事实上，这种可能性是通过在青蛙卵母细胞、人类培养细胞以及苍蝇大脑中成功表达PAC来实现的，特别是在苍蝇个体的梳理行为因外部光照射而受到光抑制的情况下(Schroeder-Lang 2007自然方法)。较少

项目成果

Koumura, Yoshiko: "The origin of photoactivated adenylyl cyclase (PAC), the Euglena blue-light receptor : phylogenetic analysis of orthologues of PAC subunits from several euglenoids and trypanosome-type adenylyl cyclases from Euglena gracilis."Photochemi

Koumura、Yoshiko：“光激活腺苷酸环化酶 (PAC)（眼虫蓝光受体）的起源：来自几种眼虫类的 PAC 亚基和来自细小眼虫的锥虫型腺苷酸环化酶的系统发育分析。”Photochemi

Flavins -Photochemistry and Photobiology

黄素-光化学和光生物学

• 发表时间: 2006
• 作者: Silva;E.
• 通讯作者: E.

ミドリムシの光運動反応を観察する

观察眼虫的光动反应

• 发表时间: 2004
• 期刊: 遺伝 58・6
• 作者: 伊関峰生;渡辺正勝
• 通讯作者: 渡辺正勝

Handbook of Photosensory Receptors (共著)

光感感受器手册（合著者）

• 发表时间: 2005
• 作者: Watanabe;M.;Iseki;M.
• 通讯作者: M.

Ntefidou, Maria: "Photoactivated adenylyl cyclase controls phototaxis in the flagellate Euglena gracilis."Plant Physiology. 133(4). 1517-1521 (2003)

Ntefidou，Maria：“光激活腺苷酸环化酶控制鞭毛眼虫的趋光性。”植物生理学。