Cell adhesion and Rho small GTPases.
The Rho small GTPases, Cdc42, Rac1 and Rho, are implicated in regulation of integrin-mediated cell-substratum adhesion and cadherin-mediated cell-cell adhesion. Identification and characterization of effectors of these GTPases have provided insights into their modes of action. Rho-kinase, an effector of Rho, regulates integrin-mediated cell-substratum adhesion (focal adhesion) by regulating the phosphorylation state of myosin light chain (MLC): it directly phosphorylates MLC and also inactivates myosin phosphatase. IQGAP1, an effector of Cdc42 and Rac1, regulates cadherin-mediated cell-cell adhesion by interacting with (beta)-catenin and dissociating (alpha)-catenin from the cadherin-catenins complex. Activated Cdc42 and Rac1 inhibit IQGAP1, thereby stabilizing the cadherin-catenins complex. Cdc42/Rac1 and IQGAP1 thus appear to constitute a switch that regulates cadherin-mediated cell-cell adhesion.
Fukata
M
M
Division of Signal Transduction, Nara Institute of Science and Technology, Ikoma 630-0101, Japan.
Nakagawa
M
M
Kuroda
S
S
Kaibuchi
K
K
D015820:Cadherins / Q000378:metabolism; D002448:Cell Adhesion / Q000502:physiology*; D019281:Dimerization; D020558:GTP Phosphohydrolases / Q000502:physiology*; D010766:Phosphorylation; D014443:Tyrosine / Q000378:metabolism
D015820:Cadherins; D014443:Tyrosine; D020558:GTP Phosphohydrolases