The Molecular MakeUp of a Living Cell's
Cytoskeleton and the Relationships between
Mechanical Properties and Biological Function
Jill Trewhella
Los Alamos National Laboratory
Chemical Science and Technology Division, MS G758
(505) 667-2031
(505) 667-0110 FAX
The cytoskeleton is a network of filamentous biomolecular structures that provide a matrix which supports and controls transport communication between all of the cellular components in higher organisms. There are three principal filamentous components that make up the cytoskeleton: actin filaments, microtubules, and intermediate filaments. Each of these components has distinctive chemical and mechanical properties that are required for their different biological functions. They operate in networks cooperatively with each other, as well as with several hundred accessory proteins. The relationships between the mechanical properties conferred by these filamentous networks on the cells cytoplasm (which is the volume between a cell's nucleus and its outer plasma membrane) and the biological functions of controlled transport, sub-cellular organization, shape, mechanical strength, flexibility, and motility are not well understood. The subunit structures are relatively well characterized and there is a broad biotechnology foundation that provides the capability to modulate their detailed chemistry. A full description of even a simplified model system containing one or more of these filamentous networks that relates the molecular level interactions with the bulk mechanical properties could aid the biologist in understanding the underlying structure/property/function relationships. At the same time it could provide the material scientist with the components for designing novel materials (e.g. reinforced fibrous materials) in which mechanical properties such as strength, fluidity/viscosity, durability could be controlled by manipulating the chemical interactions with the fundamental subunits..