A pair of adjacent glucocorticoid response elements regulate expression of two mouse metallothionein genes

A pair of adjacent glucocorticoid response elements regulate expression of two mouse metallothionein genes

^†Department of Biochemistry, Howard Hughes Medical Institute, University of Washington, Box 357370, Seattle, WA 98195; and ^§Laboratory of Reproductive Physiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104

Contributed by Richard D. Palmiter

Abstract

Synthesis of mouse metallothionein (MT)-I and MT-II is transcriptionally induced by the synthetic glucocorticoid, dexamethasone (DEX) or both in vivo as well as in numerous cell lines. However, the location(s) of a glucocorticoid response element (GRE) has not been described. The observation that a marked MT-I gene, as well as heterologous genes, when placed in the context of 17 kb of flanking sequence from the MT locus, are inducible by DEX and lipopolysaccharide in transgenic mice renewed the search for the GRE. Analysis of a series of deletion constructs from this 17-kb region in cultured cells identified a single 455-bp region that conferred DEX induction on a reporter gene. This 455-bp region contains two GREs that bind to the glucocorticoid receptor as assessed by gel mobility shift. Deletion of this fragment from the 17-kb flanking region eliminates the DEX responsiveness of reporter genes. The two GREs, which are located ≈1 kb upstream of the MT-II gene and ≈7 kb upstream of the MT-I gene, are necessary for induction of both genes and can function independently of elements within the proximal promoter region of either gene.

Footnotes

↵ ‡ Present address: Department of Environmental Health, University of Washington, Box 354695, Seattle, WA 98195.
↵ ¶ Present address: Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin, Madison, WI 53706.
↵ ‖ To whom reprint requests should be addressed. e-mail: palmiter{at}u.washington.edu.
Data deposition: The sequence reported in this paper has been deposited in the GenBank database (accession no. AF-012925).
ABBREVIATIONS:

MT,

metallothionein;

DEX,

dexamethasone;

GRE,

glucocorticoid response element;

MRE,

metal response element;

LPS,

lipopolysaccharide;

hGH,

human growth hormone;

BHK,

baby hamster kidney;

GR,

glucocorticoid receptor;

IL,

interleukin