Integrative Structural Biology Approach to Intermediate Filaments

Our research focuses on the three-dimensional structure of intermediate filaments (IF). IFs alongside with microtubules and actin microfilaments form filamentous system of the eukaryotic cytoskeleton. There are six different types of IFs that function in different cells. Their main role is to provide reinforcement to the cell to withstand external stress and strain. The number of diseases associated with mutations in IF genes is constantly growing. At the same time, the structural organization of IFs remains a major unresolved problem. Its solution is essential for developing treatment strategies. We will apply the bottom-up approach to trace how filamentous system is formed from IF dimers that are elementary building blocks of the network system. Recent crystallographic studies of the dimer fragments have provided an almost complete picture of IF dimer. However, these data are not enough for a valid computational modeling of the assembly mechanism. Experimental data on higher levels of IF architecture can provide necessary restraints for computational modeling. In order to obtain these data, our project includes recombinant protein isolation, crystallization, X-ray crystallographic studies as well as additional biophysical and biochemical experiments.