The Rho family of small GTPases coordinate actin cytoskeleton rearrangements that occur during cell migration. Among the proteins regulated by the Rho family GTPases are formins, which are involved in actin polymerization; the mammalian Diaphanous formins (mDia) are the best characterized subclass of formins. The activation dynamics of of mDia remain unclear because biosensors for studying these important actin-regulating molecules are lacking. Louis Hodgson, Ph.D., has received a 4-year, $1.5 million NIH grant to develop new fluorescent biosensor imaging tools for studying mDia paralogs 1 and 2. Dr. Hodgson plans to make these new mDia biosensors work together with his previously developed biosensors specific for the upstream regulators of mDia 1 and 2. He can then for the first time simultaneously observe the activities of the upstream regulator Rho GTPases and their downstream targets mDia1 and 2 in living cells. Dr. Hodgson is an associate professor of anatomy and structural biology and of the Gruss-Lipper Biophotonics Center at Einstein. (1 R01 GM132098-01)