# The RHO Family GTPases: Mechanisms of Regulation and Signaling
## 1 Introduction
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**RHO GTPases** & **Effector Proteins** & **Function** & **Functions and Effects** & **References** \\ \hline \multirow{4}{*}{RHOA} & ROCK I/II & Ser /Thr kinase & \begin{tabular}{c} Actin myosin contraction, \\ Stress fiber formation \\ \end{tabular} & [10,11] \\ \cline{2-5}  & Citron kinase & Ser /Thr kinase & Cytokinesis & [12] \\ \cline{2-5}  & MBS & Phosphatase subunit & MLC inactivation & [13] \\ \cline{2-5}  & DIA 1/2 & Formin-like proteins & Actin polymerization & [10] \\ \hline RHOB & Integrin \(\beta\)1 & Cell surface receptor & Cell adhesion and migration & [14] \\ \hline RHOC & FMNL3 & Formin like proteins & Migration, Invasion & [15] \\ \hline RHOH & Kaiso & Transcription factor & TCR activation & [16] \\ \cline{2-5}  & PAK1/2/3 * & Ser /Thr kinase & \begin{tabular}{c} JNK activation, Actin \\ filament stabilization \\ \end{tabular} & [17] \\ \cline{2-5}  & MLK 2/3 * & Ser /Thr kinase & JNK activation & [18,19] \\ \cline{2-5}  & WAVE & Scaffold & Actin organization & [20] \\ \cline{2-5}  & p70 56 kinase * & Ser /Thr kinase & Translation regulation & [21] \\ \cline{2-5}  & IQGAP1/2 * & Scaffold & Actin/cell-cell contacts & [22,23] \\ \cline{2-5}  & MEKK1/4 * & Ser /Thr kinase & JNK activation & [24] \\ \cline{2-5}  & POR1 & Scaffold & Actin organization & [25] \\ \cline{2-5}  & p67\({}^{\text{Phox*}}\) & Scaffold & ROS generation & [26] \\ \cline{2-5}  & PI3 kinase & Lipid kinase & PIP3 levels & [27] \\ \cline{2-5}  & DAG kinase & Lipid kinase & PA levels & [28,29] \\ \cline{2-5}  & PLC\(\beta\)2 * & Lipase & DAG and IP3 levels & [30] \\ \hline RAC1B & p120\({}^{\text{ctn}}\) & Catenin & Cellular transformation & [31] \\ \hline RAC2 & LFA-1 & Cell surface receptor & B cell adhesion & [32] \\ \hline RAC3 & GIT1 & ARF GAP and scaffold & \begin{tabular}{c} Regulation of cell adhesion \\ and differentiation \\ \end{tabular} & [33] \\ \hline RHOG & Kinectin & Kinesin receptor & \begin{tabular}{c} Microtubule dependent \\ transport \\ \end{tabular} & [34] \\ \hline \multirow{4}{*}{CDC42} & N-WASP & Scaffold & Actin organization & [35] \\ \cline{2-5}  & PAK4 & Ser/Thr kinase & Actin organization & [36] \\ \cline{2-5}  & MRC\(\kappa/\beta\) & Ser/Thr kinase & Actin organization & [37] \\ \hline TCL & GIT-PIX complex & Scaffold & \
\begin{tabular}{c} Stabilization of focal \\ adhesion \\ \end{tabular} & [38,39] \\ \hline RHOD & Plexin A1/B1 & Semaphorin co-receptor & Growth cone formation & [40] \\ \hline RIF & DIA 1/2 & Formin-like proteins & Actin organization & [40,41] \\ \hline \multirow{2}{*}{RND1} & \multirow{2}{*}{Stathmin2} & Neuronal growth &
\begin{tabular}{c} Microtubule \\ depolymerization, Neurite \\ extension \\ \end{tabular} & [42] \\ \cline{2-5}  & RND2 & Rapostlin & Formin-binding protein & Neurite branching & [43] \\ \cline{2-5}  & Socius & Scaffold & Loss of stress fibers & [44] \\ \cline{2-5}  & ROCKI & Ser/Thr kinase & Actomyosin contractility & [45,46] \\ \hline \hline \end{tabular}  
* Proteins shown with an asterisk are shared effectors for both RAC1 and CDC42.  
\end{table} 
Table 1: RHO GTPases, potential effectors and their functions in mammalian cells.