Characterization of the MTF-1 transcription factor from zebrafish and trout cells.
The metal response element (MRE)-binding transcription factor-1, MTF-1, is a zinc-responsive protein that controls transcription of metallothionein (MT) genes in many cell types. In addition, MTF-1 is also hypothesized to regulate transcription of a battery of genes involved in the defense against oxidative stress. Manipulating the Zn concentration in the low microM range reversibly modulates the DNA-binding activity of the mammalian MTF-1; this effect is inhibited at low temperature. This report examines the presence and binding properties of MTF-1 in cell lines derived from warm- and cold-water fishes (zebrafish and trout, respectively). We found that both species of fish express MRE-specific binding activities that are immunologically similar to mouse MTF-1. MTF-1-binding from the cells of both species of fish was activated when cells were treated with Zn but not with Cd. Zebrafish cells contained a single isoform of MTF-1 with binding properties similar to mammalian MTF-1. Trout cells, on the other hand, contained two isoforms of MTF-1: MTF-1H and MTF-1L. Zn reversibly modulated MTF-1H binding in a temperature-dependent manner. Similarly, Zn reversibly modulated MTF-1L binding, but, in contrast, such modulation occurred readily at 4 degrees C. This data demonstrate the conservation of binding specificity, binding properties, and regulation of MTF-1 in fishes.
Dalton
T P
TP
Department of Environmental Health, Center for Environmental Genetics (CEG), University of Cincinnati Medical Center, OH 45267-0056, USA.
Solis
W A
WA
Nebert
D W
DW
Carvan
M J
MJ
D000818:Animals; D004268:DNA-Binding Proteins; D051379:Mice; D014157:Transcription Factors / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D014337:Trout / Q000235:genetics / Q000378:metabolism*; D015027:Zebrafish / Q000235:genetics / Q000378:metabolism*; D000097809:Transcription Factor MTF-1
D004268:DNA-Binding Proteins; D014157:Transcription Factors; D000097809:Transcription Factor MTF-1