All cells use dynamic assembly of protein polymers to create a multicomponent cytoskeleton network which controls cell shape, movement, growth, and differentiated cell functions. The actin cytoskeleton is comprised of filaments which are polarized in nature, such that they have a fast (barbed) and a slow (pointed) end.  Regulated assembly and disassembly of actin subunits (monomers) at filament ends directly controls cell movement and morphogenesis, and is integrally linked to differentiated cell processes such as muscle contaction. Our lab is interested in the regulation of dynamic actin assembly and its consequences for cell structure, function and disease pathogenesis.  We utilize a variety of approaches from biochemical analyses of actin polymerization, to quantitative and live-cell fluorescence microscopy of single cells, to physiological and developmental studies of transgenic mice.  Our focus has been on the regulation of actin filament pointed end dynamics by tropomodulin, cofilin, and tropomyosin.