Crystallographic Studies of Vimentin and Lamin A

Publication date: 2013-12-05

Author:

Chernyatina, Anastasia

Abstract:

Together with microtubules and actin microfilaments, ̴11 nm wide intermediate filaments (IFs) form a dynamic filament network required for all eukaryotes. IFs are critically involved into division, motility and other cellular processes, but at present it is the least structurally characterized system of the three filament networks. Structures of all IF proteins are similar: central coiled-coil ‘rod’ domain of several alfa-helical segments of conserved secondary structure and size is flanked by nonhelical end domains of variable length, sequence and chemical characteristics. Understanding the structure of the IFs is critical to describing the assembly of the polymers and possible interactions with other proteins, as well as the effect of inherited mutations. In the current work we studied a structure of vimentin a major IF protein in mesenchymal cells, 53 kDa in size. For structures determination we use crystallographic approach. Due to difficulties of whole IF crystallization, we use ‘divide-and-conquer’ technique, solving structures of different fragments and then merging them. Currently we have only structures of vimentin fragments which do not cover all its length. Critically absent is the structure of predicted linker regions. We plan to solve the rest unknown part of vimentin, to interpolate these data on all IF structures, to predict and prove possible regions involved in lateral IFs oligomer formation.