Permanent URL to this publication: http://dx.doi.org/10.5167/uzh-53023
Günther, V; Davis, A M; Georgiev, O; Schaffner, W (2012). A conserved cysteine cluster, essential for transcriptional activity, mediates homodimerization of human metal-responsive transcription factor-1 (MTF-1). Biochimica et Biophysica Acta, 1823(2):476-483.
Metal-responsive transcription factor-1 (MTF-1) is a zinc finger protein that activates transcription in response to heavy metals such as Zn(II), Cd(II) and Cu(I) and is also involved in the response to hypoxia and oxidative stress. MTF-1 recognizes a specific DNA sequence motif termed the metal response element (MRE), located in the promoter/enhancer region of its target genes. The functional domains of MTF-1 include, besides the DNA-binding and activation domains and signals for subcellular localization (NLS and NES), a cysteine cluster (632)CQCQCAC(638) located near the C-terminus. Here we show that this cysteine cluster mediates homodimerization of human MTF-1, and that dimer formation in vivo is important for basal and especially metal-induced transcriptional activity. Neither nuclear translocation nor DNA binding is impaired in a mutant protein in which these cysteines are replaced by alanines. Although zinc supplementation induces MTF-1 dependent transcription it does not per se enhance dimerization, implying that actual zinc sensing is mediated by another domain. By contrast copper, which on its own activates MTF-1 only weakly in the cell lines tested, stabilizes the dimer by inducing intermolecular disulfide bond formation and synergizes with zinc to boost MTF-1 dependent transcription.
|Item Type:||Journal Article, refereed, original work|
|Communities & Collections:||07 Faculty of Science > Institute of Molecular Life Sciences|
|DDC:||570 Life sciences; biology|
|Deposited On:||09 Jan 2012 15:26|
|Last Modified:||23 Nov 2012 23:11|
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