INTERACTION OF ALPHA-ACTININ WITH CELLULAR TITIN

Cellular titin (c-titin) colocalizes,vith myosin II in cytoskeletal st ructures containing actin in vivo and organizes highly ordered myosin bipolar filament arrays in the absence of actin in vitro. We report he re that the actin-binding protein a-actinin associates with coassembli es of c-titin and myosin through direct interaction with c-titin. Thes e results support the possibility that interaction between the myosin- associated protein c-titin and the actin-associated protein alpha-acti nin organizes and stabilizes actin-myosin II cytoskeletal structures i n vivo.