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Regulation of ZiRF1 and basal SP1 transcription factor MRE‐binding activity by transition metals
Author(s) -
Remondelli P.,
Moltedo O.,
Leone A.
Publication year - 1997
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(97)01212-x
Subject(s) - recombinant dna , transcription factor , metallothionein , sp1 transcription factor , binding site , chemistry , microbiology and biotechnology , promoter , dna binding protein , plasma protein binding , biology , biochemistry , gene , gene expression
The metal‐dependent activation of metallothionein (MT) genes requires the interaction of positive trans ‐activators (MRFs) with metal‐regulatory (MRE) regions of MT promoters. In this report, we examined the role of transition metals in modulating the MRE‐binding activities of two different MRE‐binding proteins: the metal‐regulated factor ZiRF1 and the basal factor SP1. We showed the ability of both proteins to interact with a similar sequence specificity with the cognate target site (MRE‐S) of another known MRE‐binding protein, mMTF1. We next evaluated the role of metal ions in modulating the MRE‐binding activity of recombinant ZiRF1 and basal SP1 proteins by measuring the effect of different metal chelators on DNA interaction. We observed a dose‐dependent inhibition of the GST‐ZiRF1/MRE‐binding activity using three different metal chelators: EDTA, 1,10 PHE and TPEN. Interestingly, EDTA treatment failed to inhibit the recombinant SP1 MRE‐binding activity while the effect of 1,10 PHE was comparable to that obtained analyzing 1,10 PHE‐treated GST‐ZiRF1. The MRE‐binding complexes detected in cell extracts showed a response to metal chelator treatment very similar to that displayed by the recombinant ZiRF1 and SP1 proteins. The hypothesis of mutual interactions of both basal and metal‐regulated transcription factors with the same metal‐regulatory regions is discussed.