Cytoskeleton remodeling Regulation of actin cytoskeleton by Rho GTPases
Regulation of actin cytoskeleton by Rho GTPases Ras homolog gene family, member A ( RhoA ) downstream effector Rho-associated,coiled-coil containing protein kinase ( ROCK ) directly phosphorylates LIM domainkinases 1 and 2 ( LIMK1 and LIMK2 ) that in turn phosphorylatesCofilin. Cofilin exhibits Actin -depolymerizing activity followedby reorganization of the Actin cytoskeleton . The activated ROCK also subsequently phosphorylates and inactivates the Myosinlight chain phosphatase ( MLCP )  that attenuates Myosin lightchains ( MELC ) (myosin light chains) and Myosin light chain regulatory (MRLC ) phosphorylation . Ras-related C3 botulinum toxin substrate 1 ( Rac1 ) downstream effector P21protein-activated kinase 1 ( PAK1 ) directly phosphorylates LIMK1 , inhibits MLCK , activates MRLC and ARP2 actin-related protein 2 and 3 ( Arp2/3 ) complex .Arp2/3 complex nucleates new Actin filaments from the sides of preexistingfilaments. . Also, WAS protein family member 1 ( WAVE ) plays acritical role downstream of Rac in that it regulates the Actin cytoskeletonrequired for membrane ruffling. WAVE share function as an inducer of Actinreorganization through profiling . Cell division cycle 42 ( CDC42 ) initiates Wiskott-Aldrich syndrome (WASP )/ Arp2/3 nucleation of Actin . Recruitment offactors, including Profilin, by WASP stimulates cellular Actin-based motility .