The actin cytoskeleton plays an essential role in multiple cellular functions, including cytokinesis, vesicular trafficking, and the maintenance of cell shape and polarity. To accomplish these functions, the cytoskeleton undergoes constant remodeling into various forms of structural and functional networks, such as lamellipodia, filopodia, stress fibers and focal adhesions. Remodeling of the cytoskeleton of eukaryotic cells is a tightly regulated process, involving hundreds of actin-binding and signaling proteins. Additionally, many bacterial pathogens highjack the eukaryotic actin cytoskeleton during invasion. The main focus of the research in our lab is to understand the molecular basis for how protein-protein interaction networks bring together cytoskeleton scaffolding, nucleation, elongation, and signaling proteins to accomplish specific cellular functions. We are also interested in understanding the function of BAR domain-containing proteins, which are emerging as a critical linkage between signaling, the cytoskeleton and cellular membranes. Our lab is finally deeply invested in understanding the role of cytoskeleton dynamics in muscle cells, particularly the differentiated vascular smooth muscle cell. Our primary research tool is structural biology, including cryo-EM and X-ray crystallography. The atomic snapshots resulting from these structural methods provide a wealth of knowledge, but lack information about the function, dynamics and energetic aspects of protein-protein recognition. To obtain this kind of information we use a host of other approaches, including bio-informatics, biophysical and biochemical methods and collaborative cellular studies.