Dominant-negative mutations in the DNA-binding domain of STAT3 cause hyper-IgE syndrome

Twist is a transcription factor that is required for mesodermal cell fates in all animals studied to date. Mutations of this locus in humans have been identified as the cause of the craniofacial disorder Saethre-Chotzen syndrome. The Caenorhabditis elegans Twist homolog is required for the development of a subset of the mesoderm. A semidominant allele of the gene that codes for CeTwist, hlh-8, has defects that occur earlier in the mesodermal lineage than a previously studied null allele of the gene. The semidominant allele has a charge change (E29K) in the basic DNA-binding domain of CeTwist. Surprisingly, the mutant protein retains DNA-binding activity as both a homodimer and a heterodimer with its partner E/Daughterless (CeE/DA). However, the mutant protein blocks the activation of the promoter of a target gene. Therefore, the mutant CeTwist may cause cellular defects as a dominant negative protein by binding to target promoters as a homo- or heterodimer and then blocking transcription. Similar phenotypes as those caused by the E29K mutation were observed when amino acid substitutions in the DNA-binding domain that are associated with the human Saethre-Chotzen syndrome were engineered into the C. elegans protein. These data suggest that Saethre-Chotzen syndrome may be caused, in some cases, by dominant negative proteins, rather than by haploinsufficiency of the locus.

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An IFN regulatory factor-2 DNA-binding domain dominant negative mutant exhibits altered cell growth and gene expression

Oncogene ◽

10.1038/sj.onc.1203435 ◽

2000 ◽

Vol 19 (11) ◽

pp. 1411-1418 ◽

Cited By ~ 3

Author(s):

Y R Rubinstein ◽

P H Driggers ◽

V V Ogryzko ◽

A M Thornton ◽

K Ozato ◽

...

Keyword(s):

Gene Expression ◽

Cell Growth ◽

Dna Binding ◽

Binding Domain ◽

Dominant Negative ◽

Dominant Negative Mutant ◽

Dna Binding Domain ◽

Regulatory Factor ◽

Altered Cell ◽

Negative Mutant

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trans-dominant inhibition of poly(ADP-ribosyl)ation sensitizes cells against gamma-irradiation and N-methyl-N'-nitro-N-nitrosoguanidine but does not limit DNA replication of a polyomavirus replicon.

Molecular and Cellular Biology ◽

10.1128/mcb.15.6.3154 ◽

1995 ◽

Vol 15 (6) ◽

pp. 3154-3163 ◽

Cited By ~ 72

Author(s):

J H Küpper ◽

M Müller ◽

M K Jacobson ◽

J Tatsumi-Miyajima ◽

D L Coyle ◽

...

Keyword(s):

Dna Replication ◽

Dna Binding ◽

Gamma Irradiation ◽

Cellular Proliferation ◽

Molecular Genetic ◽

Genetic System ◽

Binding Domain ◽

Dominant Negative ◽

Dominant Negative Mutant ◽

Dna Binding Domain

Poly(ADP-ribosyl)ation is a posttranslational modification of nuclear proteins catalyzed by poly(ADP-ribose) polymerase (PARP; EC 2.4.2.30), with NAD+ serving as the substrate. PARP is strongly activated upon recognition of DNA strand breaks by its DNA-binding domain. Experiments with low-molecular-weight inhibitors of PARP have led to the view that PARP activity plays a role in DNA repair and possibly also in DNA replication, cell proliferation, and differentiation. Accumulating evidence for nonspecific inhibitor effects prompted us to develop a molecular genetic system to inhibit PARP in living cells, i.e., to overexpress selectively the DNA-binding domain of PARP as a dominant negative mutant. Here we report on a cell culture system which allows inducible, high-level expression of the DNA-binding domain. Induction of this domain leads to about 90% reduction of poly(ADP-ribose) accumulation after gamma-irradiation and sensitizes cells to the cytotoxic effect of gamma-irradiation and of N-methyl-N'-nitro-N-nitrosoguanidine. In contrast, induction does not affect normal cellular proliferation or the replication of a transfected polyomavirus replicon. Thus, trans-dominant inhibition of the poly(ADP-ribose) accumulation occurring after gamma-irradiation or N-methyl-N'-nitro-N-nitrosoguanidine is specifically associated with a disturbance of the cellular recovery from the inflicted damage.

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