Related RAS Viral Oncogene Homolog (RRAS)

RRAS protein has an amino-terminal extension of 26 residues compared with HRAS p21 and shares 55% sequence identity with it. The cloned mouse Rras cDNA encodes a predicted protein sharing 94.5% sequence identity with the human protein. Rras was primarily expressed in vascular smooth muscle cells in small arterioles and major arteries and in endothelial cells of lung capillaries. Lower Rras levels were found in smooth muscle cells of veins, renal glomeruli, and venous endothelium of spleen. In smooth muscle cells, Rras was distributed along the plasma membrane. Downregulation of RRAS activity by the plexin B1/RND1 complex was essential for the SEMA4D-induced growth cone collapse in hippocampal neurons.