Membrane proteins fulfill innumerous key functions in all living cells and account for ~30 percent of most proteomes. Two thirds of all known drugs on the market target membrane proteins, thus highlighting their critical importance in human health. In spite of their importance, less than a dozen atomic structures of human polytopic membrane proteins are reported. Clearly, there is an immense need for more structural information on human membranes proteins, and membrane proteins in general to understand their function and molecular mechanisms.

The Fotiadis laboratory focuses on the function, structure and supramolecular organization of membrane proteins. To this aim, biochemical and biophysical approaches as well as high-resolution microscopy and crystallography techniques are used.

During the years a strong focus was put on the structure and organization of membrane proteins in their native environment, the lipid bilayer. This is studied best by electron and atomic force microscopy of proteoliposomes, 2D crystals and native membranes. Finally, high-resolution structures are determined by X-ray crystallography of 3D crystals of detergent-solubilized membrane proteins.

The subject and title of Dimitrios Fotiadis’ Ph.D. thesis was the “Biochemical and structural analyses of membrane proteins in plants and animals” (2000, University of Basel).

During his postdoc in the group of Prof. Andreas Engel at the Biozentrum of the University of Basel, Dimitrios Fotiadis unsettled the dogma that the light receptor protein rhodopsin functions as a monomer in the retina by direct visualization of rhodopsin dimers and higher oligomers in native disk membranes using electron and particularly atomic force microscopy (Fotiadis et al. Nature (2003), 421, 127-128 and Fotiadis et al. Nature (2003), 426, 31). This discovery led to a reconsideration of how the first steps in vision work (Fotiadis et al. Curr. Opin. Struct. Biol. (2006), 252-259). Furthermore, these results from electron and atomic force microscopy on the oligomeric state of rhodopsin were corroborated by biochemical and biophysical methods in Basel and during Dimitrios Fotiadis’ scientific stay in Kris Palczewski’s laboratory (University of Washington, Seattle, USA). Importantly, rhodopsin is just one example of a G-protein-coupled receptor (GPCR) of which more than a thousand exist in the human body.

It now seems likely that most of these GPCR receptors also function as paired molecules. This has implications for our health and for the development and screening of new drugs (Fotiadis et al. Curr. Opin. Struct. Biol. (2006), 252-259).

In 2004 Dimitrios Fotiadis got involvement in the ‘European Genomics Initiative on Disorders of Plasma Membrane Amino Acid Transporters (EUGINDAT)’ a Specific Targeted Research Project of the 6th European Community Framework Program. Since then his laboratory focuses on the function and structure of channel and transport proteins.

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