Yamamoto H, Tachibana A, Saikawa W, Nagano M, Matsumura K, Fusetani N
Fusetani Biofouling Project, ERATO, Research Development Corporation of Japan, Yokohama, Japan.
J Exp Zool. 1998 Jan 1;280(1):8-17.
During our study on signal transduction systems involved in larval settlement and metamorphosis of the barnacle Balanus amphitrite, we could detect calmodulin, a major intracellular calcium-binding protein, in both cyprids and adult barnacles using immunoblot technique. In order to examine roles of calmodulin in larval settlement and metamorphosis, we examined the effects of calmodulin inhibitors involved in phosphodiesterase (PDE), myosin light chain kinase (MLCK), calmodulin kinase II (CaM-II) on cyprids. Calcium-calmodulin-dependent PDE inhibitors inhibited larval attachment and metamorphosis in a dose-dependent manner. In contrast, cyclic AMP (cAMP)-dependent PDE inhibitors promoted larval attachment and metamorphosis, while cyclic GMP (cGMP)-dependent PDE inhibitors did not show such effect. Thus, PDE activity may depend on cAMP rather than calmodulin or cGMP in promotion of larval attachment and metamorphosis. Moreover, calmodium inhibitors involved in MLCK or CaM-II inhibited larval behaviors for attachment and metamorphosis. These results suggest that calmodulin, which is present in both adult barnacles and cyprids, may be involved in enzyme reactions such as MLCK or CaM-II rather than PDE in B. amphitrite cyprids.
在我们对藤壶白脊藤壶幼虫附着和变态所涉及的信号转导系统的研究中，我们使用免疫印迹技术在无节幼虫和成年藤壶中均检测到了钙调蛋白，一种主要的细胞内钙结合蛋白。为了研究钙调蛋白在幼虫附着和变态中的作用，我们检测了参与磷酸二酯酶（PDE）、肌球蛋白轻链激酶（MLCK）、钙调蛋白激酶II（CaM-II）的钙调蛋白抑制剂对无节幼虫的影响。钙-钙调蛋白依赖性磷酸二酯酶抑制剂以剂量依赖性方式抑制幼虫附着和变态。相反，环磷酸腺苷（cAMP）依赖性磷酸二酯酶抑制剂促进幼虫附着和变态，而环磷酸鸟苷（cGMP）依赖性磷酸二酯酶抑制剂则未显示出这种作用。因此，在促进幼虫附着和变态方面，磷酸二酯酶活性可能依赖于cAMP而非钙调蛋白或cGMP。此外，参与肌球蛋白轻链激酶或钙调蛋白激酶II的钙调蛋白抑制剂抑制幼虫的附着和变态行为。这些结果表明，在成年藤壶和无节幼虫中均存在的钙调蛋白，可能参与白脊藤壶无节幼虫中诸如肌球蛋白轻链激酶或钙调蛋白激酶II等酶反应，而非磷酸二酯酶反应。
