NRAS is an enzyme that in humans is encoded by the NRASgene. It was discovered by a small team of researchers led by Robin Weiss at the Institute of Cancer Research in London.[1][2] It was the third RAS gene to be discovered, and was named NRAS, for its initial identification in human neuroblastoma cells.
The N-ras proto-oncogene 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 (HRAS and KRAS), 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.
The N-ras gene specifies two main transcripts of 2Kb and 4.3Kb. The difference between the two transcripts is a simple extension through the termination site of the 2Kb transcript. The N-ras gene consists of seven exons (-I, I, II, III, IV, V, VI). The smaller 2Kb transcript contains the VIa exon, and the larger 4.3Kb transcript contains the VIb exon which is just a longer form of the VIa exon. Both transcripts encode identical proteins as they differ only the 3' untranslated region.[3]
Mutations
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[3] e.g. melanoma.
As a drug target
Binimetinib (MEK162) has had a phase III clinical trial for NRAS Q61 mutant melanoma.[4]
References
↑Marshall CJ, Hall A, Weiss RA (September 1982). "A transforming gene present in human sarcoma cell lines". Nature. 299 (5879): 171–3. doi:10.1038/299171a0. PMID6287287.
McCormick F (1996). "Ras-related proteins in signal transduction and growth control". Mol. Reprod. Dev. 42 (4): 500–6. doi:10.1002/mrd.1080420419. PMID8607982.
van Elsas A, Scheibenbogen C, van der Minne C, et al. (1998). "UV-induced N-ras mutations are T-cell targets in human melanoma". Melanoma Res. 7 Suppl 2: S107–13. doi:10.1097/00008390-199708001-00017. PMID9578425.
Yuasa Y, Kamiyama T, Kato M, et al. (1990). "Transforming genes from familial adenomatous polyposis patient cells detected by a tumorigenicity assay". Oncogene. 5 (4): 589–96. PMID1970154.
Hancock JF, Magee AI, Childs JE, Marshall CJ (1989). "All ras proteins are polyisoprenylated but only some are palmitoylated". Cell. 57 (7): 1167–77. doi:10.1016/0092-8674(89)90054-8. PMID2661017.
Nitta N, Ochiai M, Nagao M, Sugimura T (1987). "Amino-acid substitution at codon 13 of the N-ras oncogene in rectal cancer in a Japanese patient". Jpn. J. Cancer Res. 78 (1): 21–6. PMID3102434.
Raybaud F, Noguchi T, Marics I, et al. (1988). "Detection of a low frequency of activated ras genes in human melanomas using a tumorigenicity assay". Cancer Res. 48 (4): 950–3. PMID3276402.
Hirai H, Kobayashi Y, Mano H, et al. (1987). "A point mutation at codon 13 of the N-ras oncogene in myelodysplastic syndrome". Nature. 327 (6121): 430–2. doi:10.1038/327430a0. PMID3295562.
Taparowsky E, Shimizu K, Goldfarb M, Wigler M (1983). "Structure and activation of the human N-ras gene". Cell. 34 (2): 581–6. doi:10.1016/0092-8674(83)90390-2. PMID6616621.
Mitchell EL, Jones D, White GR, et al. (1995). "Determination of the gene order of the three loci CD2, NGFB, and NRAS at human chromosome band 1p13 and refinement of their localisation at the subband level by fluorescence in situ hybridisation". Cytogenet. Cell Genet. 70 (3–4): 183–5. doi:10.1159/000134028. PMID7789166.
Kodaki T, Woscholski R, Hallberg B, et al. (1995). "The activation of phosphatidylinositol 3-kinase by Ras". Curr. Biol. 4 (9): 798–806. doi:10.1016/S0960-9822(00)00177-9. PMID7820549.
1plj: CRYSTALLOGRAPHIC STUDIES ON P21H-RAS USING SYNCHROTRON LAUE METHOD: IMPROVEMENT OF CRYSTAL QUALITY AND MONITORING OF THE GTPASE REACTION AT DIFFERENT TIME POINTS
1plk: CRYSTALLOGRAPHIC STUDIES ON P21H-RAS USING SYNCHROTRON LAUE METHOD: IMPROVEMENT OF CRYSTAL QUALITY AND MONITORING OF THE GTPASE REACTION AT DIFFERENT TIME POINTS
1pll: CRYSTALLOGRAPHIC STUDIES ON P21H-RAS USING SYNCHROTRON LAUE METHOD: IMPROVEMENT OF CRYSTAL QUALITY AND MONITORING OF THE GTPASE REACTION AT DIFFERENT TIME POINTS
5p21: REFINED CRYSTAL STRUCTURE OF THE TRIPHOSPHATE CONFORMATION OF H-RAS P21 AT 1.35 ANGSTROMS RESOLUTION: IMPLICATIONS FOR THE MECHANISM OF GTP HYDROLYSIS