Molecular components and dynamics of the osmoregulatory system Paramecium tetraurelia

草履虫细胞具有一个渗透调节系统（ORS），其H+- atp酶产生一个质子梯度，反过来，通过化学渗透隔离，允许有节奏地排出水。这与一些离子（如Ca2+）的选择性挤出是平行的。ORS活性确实是维持Ca2+稳态的主要成分，并且它含有用于Ca2+微调的InsP3受体。除了一组复杂的H+- atp酶亚基（位于更外围的“装饰海绵体”中），我们在草草虫基因组计划的框架内发现了一组ORS特异性的SNAREs（主要在“光滑海绵体”中），我们可以通过几个热点定位snare特异性伴侣NSF到ORS。由于SNAREs被认为与特定的膜相互作用和融合有关，因此问题出现了，它们是否以及如何促进这种复杂细胞器的未知生物发生。SNAREs不仅可以介导ORS节律性搏动活动期间的膜相互作用，而且从理论上讲，SNAREs针还可以建立海海绵中平行管状结构的复杂分支。我们打算分析复杂的分子相互作用，包括阳离子交换器和水通道蛋白，参与草履虫的生物发生和ORS功能的表现。

Paramecium cells possess an osmoregulatory system (ORS) whose H+-ATPase produces a proton gradient which in turn, by chemiosmotic sequestration, allows the rhythmic expulsion of water. This is paralleled by the selective extrusion of some ions, e.g., Ca2+. ORS activity is indeed the dominating component to maintain Ca2+ hoemostasis and that it contains an InsP3 receptor for Ca2+ fine-tuning. In addition to a complex set of subunits of the H+-ATPase (located in the more peripheral ¿decorated spongiome¿) we found, within the frame of the Paramecium genome project, an ORS-specific set of SNAREs (mainly in the ¿smooth spongiome¿) and we could localize, with several hot spots, the SNARE-specific chaperone, NSF, to the ORS. Since SNAREs are considered relevant for specific membrane interactions and fusion the question arises whether and how they contribute to the as yet unknown biogenesis of this complex organelle. SNAREs may mediate not only membrane interactions during the rhythmic pulsation activities of the ORS, but SNARE-pins could theoretically also establish the complicated branching of parallel tubular structures in the spongiome. We intend to analyze the complex molecular interactions, incl. cation exchangers and aquaporins, involved in biogenesis and performance of the ORS function in Paramecium.