title: Inducible overproduction of the mouse c-myc protein in mammalian cells.
abstract: We have made Chinese hamster ovary (CHO) cell lines that contain up to 2000 copies of the coding region of the mouse c-myc gene fused to the promoter of the Drosophila gene (hsp70) encoding a Mr 70,000 heat shock protein. Incubation of these cells at 43 degrees C results in an estimated 100-fold induction of c-myc mRNA. Translation of this mRNA occurs when the cells are returned to 37 degrees C, and during the first 3 hr of recovery at 37 degrees C, the c-myc protein is one of the most abundantly synthesized proteins in the cells. The products of the induced c-myc gene are phosphoproteins of apparent Mr 64,000, 66,000, and 75,000. Induced cells die, suggesting that elevated levels of c-myc are cytotoxic. Amplification of genes placed under control of the Drosophila hsp70 promoter may provide a general method for inducibly over expressing proteins in mammalian cells.
mesh_terms: D000818:Animals; D002470:Cell Survival; D003001:Cloning, Molecular; D005784:Gene Amplification; D005786:Gene Expression Regulation; D005818:Genetic Engineering; D006360:Heat-Shock Proteins / Q000235:genetics; D051379:Mice; D011401:Promoter Regions, Genetic; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D012333:RNA, Messenger / Q000378:metabolism; D013696:Temperature
chemical_list: D006360:Heat-Shock Proteins; D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger