Weber Jost H, Vishnyakov Andrey, Hambach Kristina, Schultz Anita, Schultz Joachim E, Linder Jürgen U
Abteilung Pharmazeutische Biochemie, Fakultät für Chemie und Pharmazie, Universität Tübingen, Morgenstelle 8, 72076 Tübingen, Germany.
Cell Signal. 2004 Jan;16(1):115-25. doi: 10.1016/s0898-6568(03)00129-3.
In Paramecium, cAMP formation is stimulated by a potassium conductance, which is an intrinsic property of the adenylyl cyclase. We cloned a full-length cDNA and several gDNA fragments from Paramecium and Tetrahymena coding for adenylyl cyclases with a novel domain composition. A putative N-terminal ion channel domain contains a canonical S4 voltage-sensor and a canonical potassium pore-loop located C-terminally after the last transmembrane span on the cytoplasmic side. The adenylyl cyclase catalyst is C-terminally located. DNA microinjection of a green fluorescent protein (GFP)-tagged construct into the macronucleus of Paramecium resulted in ciliary localization of the expressed protein. An identical gene coding for an ion-channel adenylyl cyclase was cloned from the malaria parasite Plasmodium falciparum. Expression of the catalytic domain of the latter in Sf9 cells yielded an active homodimeric adenylyl cyclase. The occurrence of this highly unique subtype of adenylyl cyclase appears to be restricted to ciliates and apicomplexa.
在草履虫中，环磷酸腺苷（cAMP）的形成受到钾离子电导的刺激，这是腺苷酸环化酶的一种内在特性。我们从草履虫和四膜虫中克隆了一个全长cDNA和几个编码具有新型结构域组成的腺苷酸环化酶的基因组DNA片段。一个假定的N端离子通道结构域包含一个典型的S4电压感受器和一个位于细胞质侧最后一个跨膜区段之后C端的典型钾离子孔环。腺苷酸环化酶催化结构域位于C端。将绿色荧光蛋白（GFP）标记的构建体显微注射到草履虫的大核中，导致表达的蛋白定位于纤毛。从疟原虫恶性疟原虫中克隆出一个编码离子通道腺苷酸环化酶的相同基因。后者的催化结构域在Sf9细胞中的表达产生了一种活性同型二聚体腺苷酸环化酶。这种高度独特的腺苷酸环化酶亚型的出现似乎仅限于纤毛虫和顶复门寄生虫。
