Rho GTPases and their effector proteins

TLDR

Rho GTPases are molecular switches that regulate essential cellular processes such as actin dynamics, gene transcription, cell‑cycle progression, and cell adhesion, yet among the ~30 identified effector proteins it remains unclear which mediate the diverse biological effects. This review examines how Rho GTPases physically interact with and regulate multiple effector proteins, and how specific effectors drive distinct cellular responses. The review focuses on the three best‑characterized mammalian Rho GTPases—Rho, Rac, and Cdc42—while also highlighting insights from genetic studies in lower eukaryotes. Recent work has linked Rho GTPases to filamentous actin assembly, establishing biochemical connections that advance understanding of cytoskeletal regulation.

Abstract

Rho GTPases are molecular switches that regulate many essential cellular processes, including actin dynamics, gene transcription, cell-cycle progression and cell adhesion. About 30 potential effector proteins have been identified that interact with members of the Rho family, but it is still unclear which of these are responsible for the diverse biological effects of Rho GTPases. This review will discuss how Rho GTPases physically interact with, and regulate the activity of, multiple effector proteins and how specific effector proteins contribute to cellular responses. To date most progress has been made in the cytoskeleton field, and several biochemical links have now been established between GTPases and the assembly of filamentous actin. The main focus of this review will be Rho, Rac and Cdc42, the three best characterized mammalian Rho GTPases, though the genetic analysis of Rho GTPases in lower eukaryotes is making increasingly important contributions to this field.