Reversible activation of mouse metal response element-binding transcription factor 1 DNA binding involves zinc interaction with the zinc finger domain.
The DNA-binding activity of the Zn finger protein metal response element-binding transcription factor 1 (MTF-1) was rapidly induced both in vivo in mouse Hepa cells, canine MDCK, and human HeLa cells after incubation in medium containing zinc and in vitro in whole-cell extracts to which zinc was added. Acquisition of DNA-binding capacity in the presence of free zinc was temperature and time dependent and did not occur at 4 degrees C. In contrast, activated MTF-1 binding to the metal response element occurred at 4 degrees C. After Zn activation, mouse MTF-1 binding activity was more sensitive to EDTA and was stabilized by DNA binding relative to the Zn finger transcription factor Sp1. After dilution of nuclear or whole-cell extracts from Zn-treated cells and incubation at 37 degrees C, mouse MTF-1 DNA-binding activity was no longer detected but could be completely reconstituted by the subsequent readdition of zinc. In vitro-synthesized, recombinant mouse MTF-1 displayed a similar, reversible temperature- and Zn-dependent activation of DNA-binding activity. Analysis of deletion mutants of recombinant MTF-1 suggests that the Zn finger domain is important for the Zn-dependent activation of DNA-binding capacity. Thus, mouse MTF-1 functions as a reversibly activated sensor of free zinc pools in the cell.
Dalton
T P
TP
Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City 66160-7421, USA.
Bittel
D
D
Andrews
G K
GK
D000818:Animals; D000975:Antioxidants / Q000494:pharmacology; D001483:Base Sequence; D004247:DNA / Q000378:metabolism*; D004268:DNA-Binding Proteins; D004285:Dogs; D004591:Electrophoresis, Polyacrylamide Gel; D006367:HeLa Cells; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology; D006873:Hydroquinones / Q000494:pharmacology; D051379:Mice; D008969:Molecular Sequence Data; D016329:Sp1 Transcription Factor / Q000378:metabolism; D013696:Temperature; D014157:Transcription Factors / Q000378:metabolism*; D015032:Zinc / Q000378:metabolism*; D016335:Zinc Fingers; D000097809:Transcription Factor MTF-1
D000975:Antioxidants; D004247:DNA; D004268:DNA-Binding Proteins; D006861:Hydrogen Peroxide; D006873:Hydroquinones; D016329:Sp1 Transcription Factor; D014157:Transcription Factors; D015032:Zinc; D000097809:Transcription Factor MTF-1; C018855:2-tert-butylhydroquinone