Sano M, Kitajima S, Mizutani A
Arch Biochem Biophys. 1983 Feb 1;220(2):333-9. doi: 10.1016/0003-9861(83)90421-6.
Detergent-dispersed adenylate cyclase from rat cerebrum was detected in two components, one sensitive to Ca2+ and calmodulin and another sensitive to fluoride or guanyl-5'-yl imidodiphosphate (Gpp(NH)p). The enzyme activity of both components was markedly augmented by forskolin assayed in the presence or absence of other enzyme activators (e.g., NaF, Gpp(NH)p, calmodulin). The catalytic subunit fraction in which G/F protein was totally lacking was also activated by forskolin. During 1-35 days of postnatal development, the basal adenylate cyclase activities in either cerebrum and cerebellum particulate preparations progressively increased. While the fluoride sensitivity of the cerebrum and cerebellum enzyme increased during postnatal development, the responsiveness to forskolin remained unaltered. There was no enhancement of soluble adenylate cyclase (from rat testis) by forskolin under the assay conditions in which there was a marked stimulatory action on the particulate enzyme. The results seen with the solubilized enzyme, with either Lubrol PX or cholate, indicate that the effects of forskolin on the cyclase do not require either G/F protein or calmodulin and the results of our study of brain enzymes support this view. Data on soluble testis cyclase (a poor or absent response to forskolin by this enzyme) imply that it lacks a protein (other than the catalytic unit) which could confer greater stimulation. The present results do not rule out an alternative explanation that forskolin stimulates adenylate cyclase by a direct interaction with the catalytic subunit, if the catalytic proteins do differ widely in various species of cells and their response to this diterpene.
大鼠大脑中经去污剂分散的腺苷酸环化酶可分为两个组分，一个对Ca2+和钙调蛋白敏感，另一个对氟化物或鸟苷-5'-亚基亚氨二磷酸（Gpp(NH)p）敏感。在有或没有其他酶激活剂（如NaF、Gpp(NH)p、钙调蛋白）存在的情况下进行检测，两种组分的酶活性均被福斯可林显著增强。完全缺乏G/F蛋白的催化亚基部分也被福斯可林激活。在出生后1至35天的发育过程中，大脑和小脑颗粒制剂中的基础腺苷酸环化酶活性逐渐增加。虽然大脑和小脑酶对氟化物的敏感性在出生后发育过程中增加，但对福斯可林的反应性保持不变。在对颗粒酶有显著刺激作用的检测条件下，福斯可林对可溶性腺苷酸环化酶（来自大鼠睾丸）没有增强作用。用Lubrol PX或胆酸盐溶解酶所得到的结果表明，福斯可林对环化酶的作用不需要G/F蛋白或钙调蛋白，我们对脑酶的研究结果支持这一观点。关于可溶性睾丸环化酶的数据（该酶对福斯可林反应不佳或无反应）表明，它缺乏一种能带来更大刺激作用的蛋白质（催化亚基除外）。如果催化蛋白在不同种类的细胞中确实存在很大差异以及它们对这种二萜的反应不同，那么目前的结果并不排除另一种解释，即福斯可林通过与催化亚基直接相互作用来刺激腺苷酸环化酶。
