We are studying the actin cytoskeleton and are interested in its roles in generation of cell polarity, in cell migration, in phagocytosis and in many other processes. One family of proteins which we have described are the Nesprins. Nesprins exist in many isoforms. The largest nesprin-1 and Nesprin-2 isoforms have an F-actin binding site at their amino terminus, with which they interact with the cytoskeleton, and a single transmembrane domain at their carboxyl terminus (KASH-domain) which anchors them in the nuclear envelope (NE). At the NE they interact with the inner nuclear membrane protein SUN, with emerin and with lamins. Through these interactions a tight network is established which connects all these components with each other and provides a link (LINC) between the nucleus and the cytoplasm. Mutations in these proteins can lead to severe disease states such as muscular dystrophy or premature aging.

In this project we study the roles of nesprin-2 in the nucleus and its affects on the cytoskeleton. We also investigate mechanisms with which it contributes to disease states. we will search for binding partners using individual domains of nesprin-2 by carrying out pull down experiments employing cytosolic fractions and nucleoplasmic fractions, identify the proteins and confirm the interactions. This will reveal processes Nesprin-2 is involved in. We will use a Nesprin-2 Giant knockout mouse and Nesprin-2 deficient cell lines.