|
RhoC (Ras homolog gene family, member C) is a small (~21 kDa) signaling G protein (more specifically a GTPase), and is a member of the Rac subfamily of the family Rho family of GTPases. It is encoded by the gene RHOC.〔(【引用サイトリンク】 url = http://www.ncbi.nlm.nih.gov/sites/entrez?Db=gene&Cmd=ShowDetailView&TermToSearch=389 )〕 ==Mechanism and function== It is prenylated at its C-terminus, and localizes to the cytoplasm and plasma membrane. It is thought to be important in cell locomotion. It cycles between inactive GDP-bound and active GTP-bound states and function as molecular switches in signal transduction cascades. Rho proteins promote reorganization of the actin cytoskeleton and regulate cell shape and motility. RhoC can activate formins such as mDia1 and FMNL2 to remodel the cytoskeleton.〔Jaffe, Aron B, and Alan Hall. “Rho GTPases: Biochemistry and Biology.” Annual Review of Cell and Developmental Biology 21 (2005): 247–69. doi:10.1146/annurev.cellbio.21.020604.150721〕〔Vega, Francisco M, and Anne J Ridley. “Rho GTPases in Cancer Cell Biology.” FEBS Letters 582, no. 14 (June 18, 2008): 2093–2101. doi:10.1016/j.febslet.2008.04.039.〕 Overexpression of RhoC is associated with cell proliferation and causing tumors to become malignant.〔Horiuchi, Akiko, Tsutomu Imai, Cuiju Wang, Satoshi Ohira, Yuzhen Feng, Toshio Nikaido, and Ikuo Konishi. “Up-Regulation of Small GTPases, RhoA and RhoC, Is Associated with Tumor Progression in Ovarian Carcinoma.” Laboratory Investigation; a Journal of Technical Methods and Pathology 83, no. 6 (June 2003): 861–70.〕 It causes degradation and reconstruction of the Extracellular Matrix (ECM) which helps cells escape the tissue they are currently in. It enhances cell motility giving it the ability to become invasive.〔Ikoma, Tetsuro, Tomoyuki Takahashi, Satoshi Nagano, Yun-Mo Li, Yasushi Ohno, Kazuki Ando, Takako Fujiwara, Hisayoshi Fujiwara, and Ken-ichiro Kosai. “A Definitive Role of RhoC in Metastasis of Orthotopic Lung Cancer in Mice.” Clinical Cancer Research: An Official Journal of the American Association for Cancer Research 10, no. 3 (February 1, 2004): 1192–1200.〕 It has been found to have a direct relationship to advanced tumor stage and metastasis, with increases in stage being related to increases in RhoC expression.〔Zhao, Yang, Zhi-hong Zong, and Hui-mian Xu. “RhoC Expression Level Is Correlated with the Clinicopathological Characteristics of Ovarian Cancer and the Expression Levels of ROCK-I, VEGF, and MMP9.” Gynecologic Oncology 116, no. 3 (March 2010): 563–71. doi:10.1016/j.ygyno.2009.11.015.〕 RhoC-deficient mice can still develop tumors but these fail to metastasize, arguing that RhoC is essential for metastasis. It has also been found to enhance the creation of angiogenic factors such as VEGF, which is necessary for a tumor to become malignant.〔〔Srivastava, S, B Ramdass, S Nagarajan, M Rehman, G Mukherjee, and S Krishna. “Notch1 Regulates the Functional Contribution of RhoC to Cervical Carcinoma Progression.” British Journal of Cancer 102, no. 1 (January 5, 2010): 196–205. doi:10.1038/sj.bjc.6605451.〕 In a study by Vega,〔Vega, Francisco M, Gilbert Fruhwirth, Tony Ng, and Anne J Ridley. “RhoA and RhoC Have Distinct Roles in Migration and Invasion by Acting through Different Targets.” The Journal of Cell Biology 193, no. 4 (May 16, 2011): 655–65. doi:10.1083/jcb.201011038.〕 RhoC was knocked out which resulted in cells spreading out wide in all directions. When RhoC was disabled, the cell's abilities to move in a specific direction and migrate was impaired. It also reduced the cell's speed of movement, because it was difficult, and sometimes impossible, to polarize the cell. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「RhoC」の詳細全文を読む スポンサード リンク
|