Why three Rho proteins? RhoA, RhoB, RhoC, and cell motility

Exp Cell Res. 2004 Nov 15;301(1):43-9. doi: 10.1016/j.yexcr.2004.08.012.


Higher vertebrates have 3 Rho GTPases, RhoA, RhoB, and RhoC, which share 85% amino acid sequence identity. Here, we compare and contrast the roles of RhoA, B, and C in the regulation of the cytoskeleton and cell motility. Despite their similarity, some regulators and effectors show preferential interaction with RhoA, B, or C, and the three proteins show differences in function in cells. RhoA plays a key role in the regulation of actomyosin contractility. RhoB, which is localized primarily on endosomes, has been shown to regulate cytokine trafficking and cell survival, while RhoC may be more important in cell locomotion. In cancer cells, the expression and activity of RhoA, B, and C is altered in different ways. Together, this evidence suggests that although the 3 isoforms of Rho are structurally highly homologous, they have different cellular functions.

Publication types

  • Review

MeSH terms

  • Actomyosin / metabolism
  • Animals
  • Cell Movement / physiology*
  • Cell Survival
  • Humans
  • Protein Transport
  • rho GTP-Binding Proteins / metabolism*
  • rhoA GTP-Binding Protein / metabolism*
  • rhoB GTP-Binding Protein / metabolism*
  • rhoC GTP-Binding Protein


  • Actomyosin
  • RHOC protein, human
  • rho GTP-Binding Proteins
  • rhoA GTP-Binding Protein
  • rhoB GTP-Binding Protein
  • rhoC GTP-Binding Protein