Structure and function of a novel blue-light sensor molecule (photoactivated adenylyl cyclase)

新型蓝光传感器分子（光激活腺苷酸环化酶）的结构和功能

• 批准号: 12045265
• 负责人: WATANABE Masakatu
• 金额: $ 8.19万
• 依托单位: Okazaki National Research Institutes
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research on Priority Areas
• 财政年份: 2000
• 资助国家: 日本
• 起止时间: 2000 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-12045265/
• 关键词: blue-light receptor; flavoprotein; FAD; photoactivated adenylyl cyclase; cAMP; PAC; Euglena gracilis; photomovement; フラビンタンパク質; アデニル酸シクラーゼ; 青色光; 光センサー; フラビン; 光センサー分子; サイクリックAMP

Euglena gracilis, a unicellular flagellate, shows abrupt changes in its swimming direction in response to a sudden increase or decrease in incident light intensity (i.e.step-up or step-down photophobic responses), rsulting in photoavoidance or photoaccumlation, respectively.In addition, it shows positive and negative phototaxis (movement toward or away from the light source, respectively).In 2002, Iseki et al (Nature 415, 1047-1051) identified a flavoprotein in the photosensory organelle of Euglena as a photoreceptor for the step-up photophobic response.The flavoprotein, named photoactivated adenylyl cyclase (PAC), shows an apparent molecular mass of 400 kDa and seems to be a heterotetramer of α-and β-subunits.The subunits are similar to each other and contain two FAD-binding domains (BLUF domain) each followed by an adenylyl cyclase catalytic domain.PAC exhibits adenylyl cyclase activity, which is drastically elevated by blue-light irradiation. Recently, we found that suppression of gene expression of PAC by RNAi impaired not only the step-up photophobic response but also positive and negative phototaxis, which implies that PAC or its similar molecules are involved in phototactic orientation of Euglena (Ntefidou, et al. Plant Physiol. 133, 1517-21).

纤细裸藻是一种单细胞鞭毛虫，当入射光强度突然增加或减少时，其游动方向会发生突变（即步升或步降的避光反应），分别导致避光或避光，此外，它还表现出正趋光性和负趋光性（分别朝向或远离光源的运动）。（Nature 415，1047-1051）鉴定了眼虫的感光细胞器中的黄素蛋白，其作为用于逐步增加的嫌光反应的光感受器。光活化腺苷酸环化酶（PAC）的表观分子量约为400 kDa，是由α-和β-亚基组成的异源四聚体，亚基结构相似，含有两个FAD结合结构域（BLUF结构域），每个结构域后接一个腺苷酸环化酶催化结构域，PAC具有腺苷酸环化酶活性，蓝光照射可显著提高PAC的活性。最近，我们发现，通过RNAi抑制PAC的基因表达不仅损害了逐步升高的嫌光反应，而且损害了正趋光性和负趋光性，这意味着PAC或其类似分子参与了眼虫的趋光定向（Ntefidou，et al. Plant Physiol.133，1517-21）。

项目成果

M.Ohmori et al.: "Regulation of CAMP-mediated photosignaling by a phytochrome in the cyanobacterium Anabaena cylindrica"Photochem.Photobiol.. 75. 675-679 (2002)

M.Ohmori 等：“圆柱鱼腥藻中光敏色素对 CAMP 介导的光信号的调节”Photochem.Photobiol.. 75. 675-679 (2002)

Iseki M.: "A blue-light-activated adenylyl cyclase mediates photoavoidance in Euglena gracilis"Nature. 415. 1047-51 (2002)

Iseki M.：“蓝光激活的腺苷酸环化酶介导眼虫的避光作用”《自然》。

伊関峰生 ら: "一人二役の光センサータンパク質:光活性化アデニル酸シクラーゼ"細胞工学. 21. 514-515 (2002)

Mineo Iseki 等人：“具有双重作用的光传感器蛋白：光激活腺苷酸环化酶”《细胞工程》21. 514-515 (2002)。

Ohmori M, Terauchi K, Okamoto S, Watanabe M: "Regulation of cAMP-mediated photosignaling by a phytochrome in the cyanobacterium Anabaena cylindrica"Photochem.Photobiol.. 75. 675-679 (2002)

Ohmori M、Terauchi K、Okamoto S、Watanabe M：“圆柱鱼腥藻中光敏色素对 cAMP 介导的光信号的调节”Photochem.Photobiol.. 75. 675-679 (2002)

M.Ntefidou et al.: "Photoactivated adenylyl cyclase (PAC) controls phototaxis in the flagellate Euglena gracilis."Plant Physiol.. 133. 1517-1521 (2003)

M.Ntefidou 等人：“光激活腺苷酸环化酶 (PAC) 控制鞭毛虫眼虫的趋光性。”植物生理学 133. 1517-1521 (2003)