Metal-responsive transcription factor (MTF-1) handles both extremes, copper load and copper starvation, by activating different genes.
Genes Dev 2005;
19:891-6. [PMID:
15833915 PMCID:
PMC1080128 DOI:
10.1101/gad.1301805]
[Citation(s) in RCA: 119] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2005] [Accepted: 03/04/2005] [Indexed: 11/24/2022]
Abstract
From insects to mammals, metallothionein genes are induced in response to heavy metal load by the transcription factor MTF-1, which binds to short DNA sequence motifs, termed metal response elements (MREs). Here we describe a novel and seemingly paradoxical role for MTF-1 in Drosophila in that it also mediates transcriptional activation of Ctr1B, a copper importer, upon copper depletion. Activation depends on the same type of MRE motifs in the upstream region of the Ctr1B gene as are normally required for metal induction. Thus, a single transcription factor, MTF-1, plays a direct role in both copper detoxification and acquisition by inducing the expression of metallothioneins and of a copper importer, respectively.
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