Alternative titles; symbols
HGNC Approved Gene Symbol: RHOB
Cytogenetic location: 2p24.1 Genomic coordinates (GRCh38): 2:20,447,074-20,449,440 (from NCBI)
A family of RAS proteins, originally designated RHO proteins, were identified and isolated from protein products expressed in the marine snail, Aplysia (Madaule and Axel, 1985). In humans, the products of these genes, called ARH (Aplysia ras-related homologs), display striking homology to the products of the classic RAS genes. Madaule and Axel (1985) identified 3 classes of ARH genes, designated H6, H9 (RHOC; 165380), and H12 (RHOA; 165390). Chardin et al. (1988) reported the complete H6 coding sequence and renamed the gene RhoB. The predicted protein is 196 amino acids long.
Ridley and Hall (1992) showed that Rho stimulates actin stress fiber production and the formation of focal adhesions when it is microinjected into serum-starved Swiss 3T3 cells. Addition of serum or growth factors such as PDGF also induced actin reorganization and stress fibers, but when Rho was inhibited focal adhesion and stress fiber assembly were impaired.
The actin cytoskeleton undergoes extensive remodeling during cell morphogenesis and motility. The small guanosine triphosphatase Rho regulates such remodeling. In their Figure 3C, Maekawa et al. (1999) diagrammed proposed signaling pathways for Rho-induced remodeling of the actin cytoskeleton. They demonstrated that LIM kinase (see 601329) is phosphorylated and activated by ROCK (601702), a downstream effector of Rho, and that LIM kinase, in turn, phosphorylates cofilin (601442).
Sandilands et al. (2004) found that RhoB colocalized with active Src (190090) in the cytoplasm of mouse embryonic fibroblasts, and they presented evidence that RhoB is a component of 'outside-in' signaling pathways that coordinate Src activation with translocation to transmembrane receptors.
By a combination of Southern analysis of somatic cell hybrid panels and in situ hybridization, Cannizzaro et al. (1990) mapped the genes RHOB to 2pter-p12, ARH12 (RHOA) to 3p21, and ARH9 (RHOC) to 5q31-qter.
Cannizzaro, L. A., Madaule, P., Hecht, F., Axel, R., Croce, C. M., Huebner, K. Chromosome localization of human ARH genes, a ras-related gene family. Genomics 6: 197-203, 1990. [PubMed: 2407642] [Full Text: https://doi.org/10.1016/0888-7543(90)90557-b]
Chardin, P., Madaule, P., Tavitian, A. Coding sequence of human rho cDNAs clone 6 and clone 9. Nucleic Acids Res. 16: 2717 only, 1988. [PubMed: 3283705] [Full Text: https://doi.org/10.1093/nar/16.6.2717]
Madaule, P., Axel, R. A novel ras-related gene family. Cell 41: 31-40, 1985. [PubMed: 3888408] [Full Text: https://doi.org/10.1016/0092-8674(85)90058-3]
Maekawa, M., Ishizaki, T., Boku, S., Watanabe, N., Fujita, A., Iwamatsu, A., Obinata, T., Ohashi, K., Mizuno, K., Narumiya, S. Signaling from Rho to the actin cytoskeleton through protein kinases ROCK and LIM-kinase. Science 285: 895-898, 1999. [PubMed: 10436159] [Full Text: https://doi.org/10.1126/science.285.5429.895]
Ridley, A. J., Hall, A. The small GTP-binding protein rho regulates the assembly of focal adhesions and actin stress fibers in response to growth factors. Cell 70: 389-399, 1992. [PubMed: 1643657] [Full Text: https://doi.org/10.1016/0092-8674(92)90163-7]
Sandilands, E., Cans, C., Fincham, V. J., Brunton, V. G., Mellor, H., Prendergast, G. C., Norman, J. C., Superti-Furga, G., Frame, M. C. RhoB and actin polymerization coordinate Src activation with endosome-mediated delivery to the membrane. Dev. Cell 7: 855-869, 2004. [PubMed: 15572128] [Full Text: https://doi.org/10.1016/j.devcel.2004.09.019]