physarum actinin previously isolated [ hatano , s. , & owaribe , k. ( 1976 ) in cell motility ( goldman , r. , pollard , t. , & rosenbaum , j. , eds . ) vol . 3 , book b , p 499 , cold spring harbor laboratory , cold spring harbor , ny ] was found to be a 1:1 complex of actin and fragmin which is a regulatory factor in the formation of actin filaments .
C0007608
cell
C0001271
actin