C-myc protein

The c-myc gene encodes a 49-kd protein that is highly concentrated in the nucleus of the cell. The concentration of c-myc protein normally varies appreciably with the metabolic state of the cell, increasing by more than an order of magnitude in cells just prior to chromosome duplication and cell division. 

In most human tumors associated with the c-myc gene, the concentration of c-myc protein is greatly amplified. Burkin s lymphoma, which we discussed earlier, is a notable exception. In this case the c-myc transcript is marginally, and in some cases not at all, increased by comparison... 

PHOSPHORYLA TWN chronic myelongenous leukemia-associated KIO BCR-ABL Drosophila Kr protein hepatitis B virus core and precore antigens human c-fos protein human c-myc protein human EGF receptor human epidermal growth factor receptor (tyrosine kinase domain) human immunodeficiency virus p24 human immunodeficiency virus tat protein human insulin receptor 6-subunit human insulin receptor - tyrosine kinase domain... 

B. Amati, T. D. Littlewood, G. I. Evan, and H. Land. The c-Myc protein induces cell cycle progression and apoptosis through dimerizatitxi with Max. EMBOJ, 12 (13), 5083—5087, 1993. 

This method has been used to estimate the concentration of c-myc protein in a number of normal and transformed cell lines (5,9) to monitor the increases in c-myc and c-fos expression that occur during mitogenic sdmula-tion of eukaryotic cells (5,6) to distinguish mitogenic pathways activated by different mitogens (10,11) and to analyze levels of c-myc expression in solid tumors of the head and neck (12) and breast (13). 

The absorbance of assay blanks (no added extract) should normally be in the range of 0.100-0.200. The c-myc ELISA can be calibrated with recombinant c-myc protein (5,15), but this is not likely to be available routinely. The assays are therefore best calibrated for determination of relative fos and myc values by preparation of a standard curve using different amounts of that extract known or suspected to contain the most fos or myc protein. Add appropriate buffer (extraction/dilution 1 9) to make all wells in the standard curve up to the same volume. Note that the relationship between A492 he amount of fos/ myc in the added extract is nonlinear. 

Spandidos D A., Field, J K, Agnatis, N J, Evan, G I, and Moore, J. P (1989) High levels of c-myc protein in human breast tumours determined by a sensitive ELISA technique. Anbcancer Res. 9, 821-826. 

The c-myc gene is the proto-oncogene of avian myelocytoma virus. It binds to DNA and is involved in transcription regulation. The gene product, p62, is located in the nucleus of transformed cells, and levels of c-myc correlate with the rate of cell division. The c-myc protein is essential for DNA replication and enhances mRNA transcription. Activation of the c-myc gene is associated with B- and T-ceH lymphoma, sarcomas, and endotheliomas. In leukemias and lymphomas, increased c-myc expression may be due to amplification or chromosomal translocation of the gene. In acute T-celi leukemias, there is an (8 14) (q24 qll) translocation that... 

R. E. (1986) Inducible overexpression of the mouse c-myc protein in mammalian cells. Proc. Natl. Acad. Sci. USA 83 5414—5418. 

Evan, G. I., and Hancock, D. C. (1985). Studies on the interaction of the human c-myc protein with cell nuclei p62 " as a member of a discrete subset of nuclear proteins. Cell (Cambridge, Mass.) 43, 253-261. 

Indirecte oncogenic herpesviruses EBV and KSHV. EBV. Some protein products of herpes viral genomic segments (EBV) encounter c-Myc proteins, form host cell and viral protein complexes, thus inducing immune reactions to host cell proteins via the phenomenon of molecular mimicry, so claim Niller et al [925, 926]. 

In an in vivo model of intestinal tumorigenesis in Apc mice, feeding of grape seed extract reduced the total number of intestinal polyps compared to control mice [116]. The findings paralleled with decreased cyclin D1 and c-Myc protein levels in the small intestine along with downregulation in expression of other important molecules such as COX-2, iNOS, and p-catenin and increased expression... 

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