Functional domains of the heavy metal-responsive transcription regulator MTF-1

Autor: Freddy Radtke, Hans-Peter Müller, Walter Schaffner, Enrico Brugnera, Oleg Georgiev
Rok vydání: 1995
Předmět:
Metallothionein/*genetics
Threonine
Transcriptional Activation
Saccharomyces cerevisiae Proteins
HMG-box
Proline
Recombinant Fusion Proteins
Molecular Sequence Data
Serine/analysis
Fungal Proteins/chemistry/genetics/metabolism
Biology
DNA-binding protein
Fungal Proteins
DNA/*metabolism
Genetics
Serine
Humans
Promoter Regions
Genetic
Transcription factor
Proline/analysis
Zinc finger
Herpes Simplex Virus Protein Vmw65/chemistry/genetics
Binding Sites
Base Sequence
GATA2
Promoter
Herpes Simplex Virus Protein Vmw65
Zinc Fingers
DNA-binding domain
DNA
Transcription Factors/*chemistry/genetics/metabolism
Hydrogen-Ion Concentration
Trans-Activation (Genetics)
Threonine/analysis
DNA-Binding Proteins
Biochemistry
Metals
Mutagenesis
Metallothionein
Metals/*pharmacology
Promoter Regions (Genetics)
Recombinant Fusion Proteins/chemistry/metabolism
Gene Deletion
Binding domain
HeLa Cells
Plasmids
Transcription Factors
Zdroj: Nucleic acids research. 23(12)
ISSN: 0305-1048
Popis: Metallothioneins (MTs) constitute a class of low molecular weight, cysteine-rich, metal binding proteins which are regulated at the level of gene transcription in response to heavy metals and other adverse treatments. We have previously cloned a zinc finger factor (MTF-1) that binds specifically to heavy metal-responsive DNA sequence elements in metallothionein promoters and shown that this factor is essential for basal and heavy metal-induced transcription. Here we report that the C-terminal part of MTF-1 downstream of the DNA binding zinc fingers harbours three different transactivation domains, namely an acidic domain, a proline-rich domain and a domain rich in serine and threonine. When fused to the heterologous DNA binding domain of the yeast factor GAL4 these activation domains function constitutively, i.e. transcription of a GAL4-driven reporter gene is not induced by heavy metals. In search of the region(s) responsible for metal induction, external and internal deletion mutations of mouse and human MTF-1 and chimeric variants thereof were tested with a reporter gene driven by a metal-responsive promoter. The N-terminal part of MTF-1 containing the zinc fingers, which are dependent on zinc for efficient DNA binding, can indeed confer a limited (3- to 4-fold) zinc-responsive transcription when fused to the heterologous activation domain of the viral VP16 protein. Another region containing the acidic and proline-rich activation domains also contributes to metal inducibility, but only in the context of intact MTF-1. This indicates that the activity of MTF-1 results from a complex interplay of different functional domains.
Databáze: OpenAIRE
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