Vacuoles of diatoms

• Applicant: Professor Dr. Uwe Gallus Maier
• Subject Area: Plant Cell and Developmental Biology
• Term: from 2014 to 2018
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 258134917

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.

• DFG Programme: Research Grants