ADP-ribosylation of filamentous actin induces its depolymerization : the role of ADP-ribosylation in cytoskeletal reorganization

Actin, a major constituent in all eukaryotic cells, is one of the most important components of cytoskeletal architecture, and is involved in a numerous cellular processes including phagocytosis, cell locomotion, and maintenance of cell shape. These functions depend on the capacity of actin to polymerize and depolymerize. We previously reported that chicken arginine-specific ADP-ribosyltransferase ADP-ribosylated globular (G-) and filamentous (F-) actins, and that the modification of G-actin inhibited its capacity to polymerize i,1 vitro and in situ, suggesting the involvement of ADP-ribosylation in regulation of the cytoskeletal organization in vivo. In the present study, we demonstrated that ADP-ribosylation of F-actin resulted in the depolymerization of the actin. Thus, ADP-ribosylation may have a role to shift G-F actin equilibrium toward the G-actin through the modification of both G- and F-actins, and participate in the regulation ofcytoskeletal reorganization.