Masuda Shinji, Ono Taka-aki
Laboratory for Photo-Biology (1), RIKEN Photodynamics Research Center, The Institute of Physical and Chemical Research, 519-1399 Aramaki, Aoba, Sendai 980-0845, Japan.
FEBS Lett. 2004 Nov 5;577(1-2):255-8. doi: 10.1016/j.febslet.2004.09.086.
We report herein the biochemical properties of an adenylyl cyclase, Cya1, from the cyanobacterium Synechocystis sp. PCC 6803. Heterologously expressed Cya1 catalyzed cyclic AMP formation with a Km for ATP of approximately 2.2 microM at pH 7.5. Although cellular Cya1 activity is increased by blue light illumination [Terauchi and Ohmori, Mol. Microbiol. 52 (2004) 303], purified Cya1 did not contain any chromophores, and the activity was light-insensitive. This suggests that an unknown blue light-responsive factor interacts with the N-terminal regulatory domain of Cya1 to control its adenylyl cyclase activity. Finally, our results show that the sensor of blue light using FAD (BLUF) protein, Slr1694, does not appear to be involved in the regulation of Cya1-mediated cAMP signal transduction in this bacterium.
我们在此报告来自蓝藻集胞藻PCC 6803的腺苷酸环化酶Cya1的生化特性。异源表达的Cya1在pH 7.5时催化生成环化AMP，对ATP的Km约为2.2微摩尔。尽管蓝光照射可增加细胞Cya1活性[Terauchi和Ohmori，《分子微生物学》52 (2004) 303]，但纯化的Cya1不含任何发色团，且活性对光不敏感。这表明一种未知的蓝光响应因子与Cya1的N端调节结构域相互作用，以控制其腺苷酸环化酶活性。最后，我们的结果表明，使用黄素腺嘌呤二核苷酸的蓝光传感器（BLUF）蛋白Slr1694似乎不参与该细菌中Cya1介导的环化AMP信号转导的调节。
