The RhoC gene contains 6 exons and 5 introns. It was predicted to span over approximately 6.3 kb of the genomic DNA with mRNA size approximately 1116 bp. This gene is related to a gene originally identified in the marine snail, Aplysia. After the original cloning of Rho gene in Aplysia californica, then several genes in mammal been identified and divided into several subfamily, among them is (RhoA, RhoB and RhoC isoforms). In 1993, human ARH9 (RhoC), was reexamined and showed that it was present in choromosome 1. Human cDNA of RhoC proteins were isolated from the complete H9Rho (clone 9) coding sequence. Other group isolated RhoC from adult retina library.

Three alternative transcripts encoding the same protein have been identified for RhoC gene.

The primary protein sequences of Rho-subfamily (RhoA, B and C) are about 85% identical, with most divergence close to the C-terminus. The sequence divergence among RhoA, B and C is found in the insert loop, a helix between amino acids 123 and 137. The RhoC consists of 193 amino acids corresponding to a molecular weight of 22 kDa. RhoC protein consists of GTPase binding domain in the N-terminal. In C-terminal consists of geranylgeranyl group and carboxyl methylation extension. RhoC contains the sequence motif of GTP-binding proteins, bind to GDP and GTP with high affinity and are involved in cycle between in-active, GDP-bound and active, GTP-bound states. RhoC displays about 30% amino acids identity with Ras proteins which mainly clustered in four highly homologues internal region corresponding to the GTP binding site.

The RhoC proteins are over-expressed in bladder carcinoma, breast carcinoma, and in the squamous cell carcinoma of the head and neck. At mRNA level, RhoC are over-expressed in adenocarcinoma of the ovary, pancreatic cancer and hepatocellular carcinoma.

Mainly in the cytoplasm, there is a small fraction localized in the plasma membrane of the Rat-2 fibroblast cells and associated with undefined perinuclear structures.

The Rho proteins are involved in multiple processes, such as organization of the cytoskeletal components, cell division or intracellular trafficking. Role of RhoC also been observed in limb development. The RhoC protein has been connected to cancer development. It is up-regulated in malignant pancreatic ductal carcinoma, inflammatory breast cancer tumors and highly metastatic melanoma. Ectopic over-expression of this gene increases the tumorigenic and metastasis properties of tumor progenitor cell. RhoC also induces the expression of angiogenic factors in human mammary epithelial cells, by facilitating the vascularization of tumors in which it is expressed.

At least there are five homologues of RhoC sequences with pair-wise similarity from 80-100% at the amino acids level. Among them in dog (Canis lupus familiaris), rat (Rattus norvergicus), mouse (Mus musculus), zebrafish (Danio rerio), and chicken (Gallus gallus).

Not found in Homo sapiens

Not found in Homo sapiens