Distinct actions and cooperative roles of ROCK and mDia in Rho small G protein-induced reorganization of the actin cytoskeleton in Madin-Darby canine kidney cells. Mol Biol Cell 1999 Aug;10(8):2481-91
Date
08/06/1999Pubmed ID
10436006Pubmed Central ID
PMC25478DOI
10.1091/mbc.10.8.2481Scopus ID
2-s2.0-0032784388 (requires institutional sign-in at Scopus site) 138 CitationsAbstract
Rho, a member of the Rho small G protein family, regulates the formation of stress fibers and focal adhesions in various types of cultured cells. We investigated here the actions of ROCK and mDia, both of which have been identified to be putative downstream target molecules of Rho, in Madin-Darby canine kidney cells. The dominant active mutant of RhoA induced the formation of parallel stress fibers and focal adhesions, whereas the dominant active mutant of ROCK induced the formation of stellate stress fibers and focal adhesions, and the dominant active mutant of mDia induced the weak formation of parallel stress fibers without affecting the formation of focal adhesions. In the presence of C3 ADP-ribosyltransferase for Rho, the dominant active mutant of ROCK induced the formation of stellate stress fibers and focal adhesions, whereas the dominant active mutant of mDia induced only the diffuse localization of actin filaments. These results indicate that ROCK and mDia show distinct actions in reorganization of the actin cytoskeleton. The dominant negative mutant of either ROCK or mDia inhibited the formation of stress fibers and focal adhesions, indicating that both ROCK and mDia are necessary for the formation of stress fibers and focal adhesions. Moreover, inactivation and reactivation of both ROCK and mDia were necessary for the 12-O-tetradecanoylphorbol-13-acetate-induced disassembly and reassembly, respectively, of stress fibers and focal adhesions. The morphologies of stress fibers and focal adhesions in the cells expressing both the dominant active mutants of ROCK and mDia were not identical to those induced by the dominant active mutant of Rho. These results indicate that at least ROCK and mDia cooperatively act as downstream target molecules of Rho in the Rho-induced reorganization of the actin cytoskeleton.
Author List
Nakano K, Takaishi K, Kodama A, Mammoto A, Shiozaki H, Monden M, Takai YAuthor
Akiko Mammoto MD, PhD Associate Professor in the Pediatrics department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
ADP Ribose TransferasesActins
Animals
Carrier Proteins
Cells, Cultured
Cytoskeleton
Dogs
GTP-Binding Proteins
Genes, Dominant
Intracellular Signaling Peptides and Proteins
Kidney
Mutation
Tetradecanoylphorbol Acetate
rho-Associated Kinases
rhoA GTP-Binding Protein