Function
Rho GTPase of higher vertebrates include RhoA, RhoB, RhoC, RhoD and RhoE. These 3 proteins share 85% sequence identity. RhoA is the more extensively studied among these three. RhoA regulates a signal transduction phosphorylation pathway linking plasma membrane receptors to the assembly of focal adhesions and actin stress fibers. Rho GTPase operates as a switch cycling between the active GTP-bound form and the inactive GDP-bound one. A number of proteins have been identified as targets of RhoA[1]. Mitochondrial Rho GTPase (Miro) have tandem GTP-binding domains separated by a linker region containing calcium-binding EF hand motifs indicating a role in mitochondrial homeostasis and apoptosis[2].
Disease
Mutations in RhoA were identified in diffuse gastric cancer[3].
Relevance
RhoA is thought to be important in mediating vasoconstriction in the penis[4].
Structural highlights
The transition state complex of RhoA and RhoGAP contains GDP, AlF4 and Mg+2 ion[5].
- ↑ Sepp KJ, Auld VJ. RhoA and Rac1 GTPases mediate the dynamic rearrangement of actin in peripheral glia. Development. 2003 May;130(9):1825-35. PMID:12642488
- ↑ Fransson A, Ruusala A, Aspenstrom P. Atypical Rho GTPases have roles in mitochondrial homeostasis and apoptosis. J Biol Chem. 2003 Feb 21;278(8):6495-502. Epub 2002 Dec 12. PMID:12482879 doi:https://dx.doi.org/10.1074/jbc.M208609200
- ↑ Zhou J, Hayakawa Y, Wang TC, Bass AJ. RhoA mutations identified in diffuse gastric cancer. Cancer Cell. 2014 Jul 14;26(1):9-11. doi: 10.1016/j.ccr.2014.06.022. PMID:25026207 doi:https://dx.doi.org/10.1016/j.ccr.2014.06.022
- ↑ Jin L, Burnett AL. RhoA/Rho-kinase in erectile tissue: mechanisms of disease and therapeutic insights. Clin Sci (Lond). 2006 Feb;110(2):153-65. PMID:16411892 doi:https://dx.doi.org/10.1042/CS20050255
- ↑ Rittinger K, Walker PA, Eccleston JF, Smerdon SJ, Gamblin SJ. Structure at 1.65 A of RhoA and its GTPase-activating protein in complex with a transition-state analogue. Nature. 1997 Oct 16;389(6652):758-62. PMID:9338791 doi:10.1038/39651