Cofilin phosphorylation and actin cytoskeletal dynamics regulated by Rho- and Cdc42-activated LIM-kinase 2

Citation
T. Sumi et al., Cofilin phosphorylation and actin cytoskeletal dynamics regulated by Rho- and Cdc42-activated LIM-kinase 2, J CELL BIOL, 147(7), 1999, pp. 1519-1532
Citations number
58
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Cell & Developmental Biology
Journal title
JOURNAL OF CELL BIOLOGY
ISSN journal
0021-9525 → ACNP
Volume
147
Issue
7
Year of publication
1999
Pages
1519 - 1532
Database
ISI
SICI code
0021-9525(199912)147:7<1519:CPAACD>2.0.ZU;2-S
Abstract
The rapid turnover of actin filaments and the tertiary meshwork formation a re regulated by a variety of actin-binding proteins. Protein phosphorylatio n of cofilin, an actin-binding protein that depolymerizes actin filaments, suppresses its function. Thus, cofilin is a terminal effector of signaling cascades that evokes actin cytoskeletal rearrangement. When wild-type LIMK2 and kinase-dead LIMK2 (LIMK2/KD) were respectively expressed in cells, LIM K2, but not LIMK2/KD, phosphorylated cofilin and induced formation of stres s fibers and focal complexes. LIMK2 activity toward cofilin phosphorylation was stimulated by coexpression of activated Rho and Cdc42, but not Rac. Im portantly, expression of activated Rho and Cdc42, respectively, induced str ess fibers and filopodia, whereas both Rho-induced stress fibers and Cdc42- induced filopodia were abrogated by the coexpression of LIMK2/KD. In contra st, the coexpression of LIMK2/KD with the activated Rac did not affect Rac- induced lamellipodia formation. These results indicate that LIMK2 plays a c rucial role both in Rho- and Cdc42-induced actin cytoskeletal reorganizatio n, at least in part by inhibiting the functions of cofilin. Together with r ecent findings that LIMK1 participates in Rac-induced lamellipodia formatio n, LIMK1 and LIMK2 function under control of distinct Rho subfamily GTPases and are essential regulators in the Rho subfamilies-induced actin cytoskel etal reorganization.