The Eukaryotic Cytoskeleton and Motor Proteins
The eukaryotic cytoskeleton is composed of three main types of filaments: (i) microfilaments (actin); (ii) microtubules; (iii) intermediate filaments. These filaments can be stable or dynamic, and are responsible not only for maintaining cell architecture but also for a plethora of cellular functions that interface with the membrane trafficking and signal transduction networks amongst others. Motor proteins use the filaments as tracks for the transport of intracellular cargo, be it multiprotein complexes or vesicles.
Trypanosomatids are a particularly interesting system for the study of the cytoskeleton for a number of reasons. Firstly, as the causative agents of several neglected tropical diseases (sleeping sickness, Chagas disease, Leishmaniasis) there is a need for new therapeutic strategies, and the cytoskeleton is essential to the viability of the cells. Study of the ways in which the cytoskeleton performs its many cellular functions will both add to biological knowledge and illuminate areas for possible drug development. Secondly, as descendants of an early-branching eukaryote they are likely to exhibit both conserved and novel features in their cytoskeleton (for instance, there are no intermediate filament proteins encoded in their genomes), making them an important reference in evolutionary cell biology studies, and a source of cytoskeletal diversity. Thirdly, like many parasites, they boast a streamlined cellular physiology, making them ideal model systems for a number of fundamental questions in eukaryotic biology.