Vacuoles of diatoms

对动物、酵母和陆地植物的溶酶体和液泡进行了深入的研究。在这些研究过程中，人们清楚地发现，这些隔室不仅具有裂解活性，而且有助于许多细胞功能。从细胞生物学的角度来看，这些隔室的产生和分子向液泡和溶酶体的运输是重要的问题，这些问题在最先进的方法中得到了深入的研究。最近的进展显示了模型之间在分子和功能上的主要差异，表明了对不同生物的研究在这一主题中的重要性。在拟议的项目中，我们想要研究硅藻中的液泡状结构。这些生物体属于一个超群，即嗜铬细胞，这是关于液泡的，只进行了初步的研究。我们的初步工作支持这一观点，即这些单细胞生物体中存在两种不同的液泡样结构，它们被认为至少具有储存脂质和多糖的功能。但是，没有描述其他功能。我们用GFP与潜在的液泡膜蛋白融合的初步靶向实验表明，不同的结构可以被标记；其中之一确实是光和电子显微镜结合技术所显示的空泡样结构之一。此外，我们还建立了几个隔室特异的标记，这将有助于研究空泡样结构的靶向机制。这些机制将用组合的方法来研究，其中膜蛋白针对硅藻的两种不同的液泡状结构的靶向信号被研究。此外，我们还想探讨其中一种液泡状结构的起源。我们希望从我们的工作中不仅能对硅藻的两种不同的液泡状结构进行分子表征，而且还能在分子可及模型系统中对细胞内蛋白质跨不同、基本特征的隔室靶向的机制有新的见解。所有这些发现都将从进化的角度进行平行研究，目的是为硅藻的进化提供新的方面。从长远来看，我们的工作可能会通过为重组蛋白质或纤维提供新的储存室来影响生物技术的应用。

Lysosomes and vacuoles of animals, yeast and land plants are intensively studied. In the course of these studies it became clear that these compartments have more than lytic activities and contribute to many cellular functions. From a cell biological view, the generation of these compartments and trafficking of molecules to vacuoles and lysosomes represent important issues, which are intensively studied in state-of-the-art approaches. Recent progress showed major molecular and functional differences between the models, indicating the importance of research on different organisms in this topic. In the proposed project we would like to investigate vacuolar-like structures in diatoms. These organisms belong to a supergroup, the chromalveolates, which is in respect to vacuoles only rudimentary studied. Our preliminary work supports the view that two different vacuolar-like structures are present in these unicellular organisms, which are supposed to have at least functions in storage of lipids and glycans. However, other functions are not described. Our initial targeting experiments with GFP fused to potential vacuolar membrane proteins showed that different structures can be labeled; one of these is indeed one of the vacuolar-like structures as showed by the combination of light and electron microscopically techniques. In addition we have established several compartment-specific markers, which will be indicative to study targeting mechanisms to vacuolar-like structures. These mechanisms will be studied in a combinatorial approach, in which the targeting signals of membrane proteins directed to the two different vacuolar-like structures of diatoms are studied. In addition we would like to investigate the origin of one of the vacuolar like structures. We expect from our work not only a molecular characterization of the two different vacuolar-like structures of a diatom, but also new insights into the mechanisms of intracellular protein targeting across the different, rudimentary characterized compartments in a molecular accessible chromalveolate model system. All of the findings will be studied in parallel in an evolutionary view with the aim to provide new aspects of the evolution of diatoms. Perspectively, our work might influence biotechnological applications by providing new storage compartments for recombinant proteins or fibers.