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. 1985 Dec;5(12):3525–3531. doi: 10.1128/mcb.5.12.3525

Coordinate expression of amplified metallothionein I and II genes in cadmium-resistant Chinese hamster cells.

J K Griffith
PMCID: PMC369183  PMID: 3837847

Abstract

Recombinant DNA probes complementary to Chinese hamster metallothionein (MT)-1 and MT-2 mRNAs were used to compare MT gene copy numbers, zinc-induced MT mRNA levels, and uninduced MT mRNA levels in cadmium-resistant (Cdr) Chinese hamster ovary cell lines. Quantitative hybridization analyses determined that the MT-1 and MT-2 genes are each present at approximately single-copy levels in the genome of cell line Cdr2C10 and are coordinately amplified approximately 7, 3, and 12 times over the Cdr2C10 value in the genomes of cell lines Cdr20F4, Cdr30F9, and Cdr200T1, respectively. The maximum zinc-induced MT-1 mRNA concentrations in cell lines Cdr20F4, Cdr30F9, and Cdr200T1 were equal to 1, 3, and 15 times that measured in Cdr2C10, respectively. Similarly, the maximum zinc-induced MT-2 mRNA concentrations were equal to 1, 3, and 14 times that measured in Cdr2C10, respectively, and in each instance they were 90 to 150 times greater than their respective concentrations in uninduced cells. Thus, relative MT gene numbers are closely correlated with both zinc-induced and uninduced MT mRNA levels in Cdr2C10, Cdr30F9, and Cdr200T1, but not in Cdr20F4. Each of the latter two lines possesses structurally altered chromosomes whose breakpoints are near the MT locus. Nonetheless, the ratio of the levels of MT-1 to MT-2 mRNAs was constant in each of the four cell lines, including Cdr20F4. These results demonstrate that MT-1 and MT-2 mRNAs are induced coordinately in each Cdr cell line. Therefore, the coordination of the induction of MT-1 and MT-2 mRNA is independent of MT gene amplification, MT gene rearrangement, and the relative inducibilities of amplified MT genes. However, MT mRNA and protein levels each indicate that MT-1 and MT-2 expression is non-coordinate in uninduced cells. Thus, regulation of MT expression may involve two different mechanisms which are differentially operative in induced and uninduced cells.

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Selected References

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  1. Britten R. J., Graham D. E., Neufeld B. R. Analysis of repeating DNA sequences by reassociation. Methods Enzymol. 1974;29:363–418. doi: 10.1016/0076-6879(74)29033-5. [DOI] [PubMed] [Google Scholar]
  2. Cox D. R., Palmiter R. D. The metallothionein-I gene maps to mouse chromosome 8: implications for human Menkes' disease. Hum Genet. 1983;64(1):61–64. doi: 10.1007/BF00289481. [DOI] [PubMed] [Google Scholar]
  3. Crawford B. D., Enger M. D., Griffith B. B., Griffith J. K., Hanners J. L., Longmire J. L., Munk A. C., Stallings R. L., Tesmer J. G., Walters R. A. Coordinate amplification of metallothionein I and II genes in cadmium-resistant Chinese hamster cells: implications for mechanisms regulating metallothionein gene expression. Mol Cell Biol. 1985 Feb;5(2):320–329. doi: 10.1128/mcb.5.2.320. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Enger M. D., Ferzoco L. T., Tobey R. A., Hildebrand C. E. Cadmium resistance correlated with cadmium uptake and thionein binding in CHO cell variants Cdr20f4 and Cdr30f9. J Toxicol Environ Health. 1981 May;7(5):675–690. doi: 10.1080/15287398109530011. [DOI] [PubMed] [Google Scholar]
  5. Friedman R. L., Stark G. R. alpha-Interferon-induced transcription of HLA and metallothionein genes containing homologous upstream sequences. Nature. 1985 Apr 18;314(6012):637–639. doi: 10.1038/314637a0. [DOI] [PubMed] [Google Scholar]
  6. Griffith B. B., Walters R. A., Enger M. D., Hildebrand C. E., Griffith J. K. cDNA cloning and nucleotide sequence comparison of Chinese hamster metallothionein I and II mRNAs. Nucleic Acids Res. 1983 Feb 11;11(3):901–910. doi: 10.1093/nar/11.3.901. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Griffith J. K., Enger M. D., Hildebrand C. E., Walters R. A. Differential induction by cadmium of a low-complexity ribonucleic acid class in cadmium-resistant and cadmium-sensitive mammalian cells. Biochemistry. 1981 Aug 4;20(16):4755–4761. doi: 10.1021/bi00519a035. [DOI] [PubMed] [Google Scholar]
  8. Hamer D. H., Walling M. Regulation in vivo of a cloned mammalian gene: cadmium induces the transcription of a mouse metallothionein gene in SV40 vectors. J Mol Appl Genet. 1982;1(4):273–288. [PubMed] [Google Scholar]
  9. Hildebrand C. E., Enger M. D. Regulation of Cd2+/Zn2+-stimulated metallothionein synthesis during induction, deinduction, and superinduction. Biochemistry. 1980 Dec 9;19(25):5850–5857. doi: 10.1021/bi00566a029. [DOI] [PubMed] [Google Scholar]
  10. Hildebrand C. E., Tobey R. A., Campbell E. W., Enger M. D. A cadmium-resistant variant of the Chinese hamster (CHO) cell with increased metallothionein induction capacity. Exp Cell Res. 1979 Dec;124(2):237–246. doi: 10.1016/0014-4827(79)90199-x. [DOI] [PubMed] [Google Scholar]
  11. Karin M., Haslinger A., Holtgreve H., Cathala G., Slater E., Baxter J. D. Activation of a heterologous promoter in response to dexamethasone and cadmium by metallothionein gene 5'-flanking DNA. Cell. 1984 Feb;36(2):371–379. doi: 10.1016/0092-8674(84)90230-7. [DOI] [PubMed] [Google Scholar]
  12. Mayo K. E., Palmiter R. D. Glucocorticoid regulation of the mouse metallothionein I gene is selectively lost following amplification of the gene. J Biol Chem. 1982 Mar 25;257(6):3061–3067. [PubMed] [Google Scholar]
  13. Mayo K. E., Warren R., Palmiter R. D. The mouse metallothionein-I gene is transcriptionally regulated by cadmium following transfection into human or mouse cells. Cell. 1982 May;29(1):99–108. doi: 10.1016/0092-8674(82)90094-0. [DOI] [PubMed] [Google Scholar]
  14. Richards R. I., Heguy A., Karin M. Structural and functional analysis of the human metallothionein-IA gene: differential induction by metal ions and glucocorticoids. Cell. 1984 May;37(1):263–272. doi: 10.1016/0092-8674(84)90322-2. [DOI] [PubMed] [Google Scholar]
  15. Schmidt C. J., Hamer D. H., McBride O. W. Chromosomal location of human metallothionein genes: implications for Menkes' disease. Science. 1984 Jun 8;224(4653):1104–1106. doi: 10.1126/science.6719135. [DOI] [PubMed] [Google Scholar]
  16. Searle P. F., Davison B. L., Stuart G. W., Wilkie T. M., Norstedt G., Palmiter R. D. Regulation, linkage, and sequence of mouse metallothionein I and II genes. Mol Cell Biol. 1984 Jul;4(7):1221–1230. doi: 10.1128/mcb.4.7.1221. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Stallings R. L., Munk A. C., Longmire J. L., Hildebrand C. E., Crawford B. D. Assignment of genes encoding metallothioneins I and II to Chinese hamster chromosome 3: evidence for the role of chromosome rearrangement in gene amplification. Mol Cell Biol. 1984 Dec;4(12):2932–2936. doi: 10.1128/mcb.4.12.2932. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. Séguin C., Felber B. K., Carter A. D., Hamer D. H. Competition for cellular factors that activate metallothionein gene transcription. Nature. 1984 Dec 20;312(5996):781–785. doi: 10.1038/312781a0. [DOI] [PubMed] [Google Scholar]
  19. Wetmur J. G., Davidson N. Kinetics of renaturation of DNA. J Mol Biol. 1968 Feb 14;31(3):349–370. doi: 10.1016/0022-2836(68)90414-2. [DOI] [PubMed] [Google Scholar]
  20. Yagle M. K., Palmiter R. D. Coordinate regulation of mouse metallothionein I and II genes by heavy metals and glucocorticoids. Mol Cell Biol. 1985 Feb;5(2):291–294. doi: 10.1128/mcb.5.2.291. [DOI] [PMC free article] [PubMed] [Google Scholar]

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