Dr. Hinshaw’s laboratory is interested in membrane and protein recycling within eukaryotic cells. The approach the Lab is taking is to examine the structure and function of proteins involved in these processes by transmission electron microscopy, including cyro-electron microscopy, and by biochemical methods. Presently, the Lab is examining a 100 kDa GTPase called dynamin, which is involved in the constriction and fission of clathrin-coated pits from plasma membrane during receptor-mediated endocytosis and during membrane retrieval in nerve terminals. Its research has shown that dynamin self-assembles into spirals and onto lipid bilayers forming dynamin decorated lipid tubes that undergo a large conformational change upon GTP addition resulting in membrane constriction. To further understand the mechanism of dynamin-induced membrane constriction, the Lab has solved the 3-dimensional structure of dynamin in the non-constricted and constricted states by high-resolution electron microscopy and image processing methods. This work suggests a GTP-induced conformational change within the dynamin oligomer is responsible for constriction. Additional dynamin family members have been implicated in numerous fundamental cellular processes, including other membrane fission events, anti-viral activity, cell plate formation and chloroplast biogenesis. The Lab is currently examining the effects of GTP on these proteins to determine if a common mechanism of action exists for all dynamin family members.