Access

You are not currently logged in.

Access your personal account or get JSTOR access through your library or other institution:

login

Log in to your personal account or through your institution.

If You Use a Screen Reader

This content is available through Read Online (Free) program, which relies on page scans. Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.

Zinc Rapidly Induces a Metal Response Element-Binding Factor

Marta Czupryn, Willis E. Brown and Bert L. Vallee
Proceedings of the National Academy of Sciences of the United States of America
Vol. 89, No. 21 (Nov. 1, 1992), pp. 10395-10399
Stable URL: http://www.jstor.org/stable/2360616
Page Count: 5
  • Read Online (Free)
  • Subscribe ($19.50)
  • Cite this Item
Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Zinc Rapidly Induces a Metal Response Element-Binding Factor
Preview not available

Abstract

Metal activation of metallothionein gene transcription is mediated by specific promoter sequences, termed metal regulatory elements (MREs). Nuclear extracts prepared from various human cell lines were assayed for their capacity to bind to a synthetic human MREa (hMREa) oligomer. Electrophoretic mobility-shift assays with extracts from control cells detected a single hMREa-containing complex. Addition to the growth medium of zinc, cadmium, or copper-metals known to induce MT biosynthesis in vivo-resulted in the rapid but reversible appearance of a second distinct hMREa-protein complex in all cell lines studied. This result was not seen when the metals were added directly to the extracts from control cells. DNA-binding protein blotting, UV crosslinking, and electroelution experiments were used to characterize the two hMREa-binding factors, termed BF1 and BF2. MRE-BF1 has an apparent molecular mass of ≈86 kDa and binds to the hMREa in control cells, whereas MRE-BF2 consists of two molecules of ≈28 kDa and binds to the hMREa in metal-treated cells. EDTA and o-phenanthroline inhibited binding of both factors to hMREa in a dose-dependent manner, indicating that a metal atom or atoms are essential for interaction of the factors with DNA.

Page Thumbnails

  • Thumbnail: Page 
10395
    10395
  • Thumbnail: Page 
10396
    10396
  • Thumbnail: Page 
10397
    10397
  • Thumbnail: Page 
10398
    10398
  • Thumbnail: Page 
10399
    10399