Neuroblastoma RAS Viral Oncogene Homolog (NRAS)

NRAS is a member of the RAS gene family. It is mapped on chromosome 1, and it is activated in HL60, a promyelocytic leukemia line. The order of nearby genes is as follows: cen--CD2--NGFB--NRAS--tel. The mammalian ras gene family consists of the harvey and kirsten ras genes (c-Hras1 and c-Kras2), an inactive pseudogene of each (c-Hras2 and c-Kras1) and the N-ras gene. They differ significantly only in the C-terminal 40 amino acids. These ras genes have GTP/GDP binding and GTPase activity, and their normal function may be as G-like regulatory proteins involved in the normal control of cell growth. Mutations which change amino acid residues 12, 13 or 61 activate the potential of N-ras to transform cultured cells and are implicated in a variety of human tumors. The N-ras gene specifies two main transcripts of 2Kb and 4.3Kb.