High impact information on Dsp1

• We found that DSP1 protein can act as a potent transcriptional repressor for multiple activator families in vitro and in transfection studies [1].
• We also show that in HeLa cells, as assayed by transient transfection, expression of DSP1 increases activation by Dorsal from the twist promoter and inhibits that activation from the zen promoter, consistent with the previously proposed idea that DSP1 can affect the action of Dorsal in a promoter-specific fashion [2].
• The expression pattern of Scr is altered in dsp1 mutant imaginal discs, indicating that dsp1 is required for normal expression of this gene [3].
• Genetic interaction studies reveal that a null allele of dsp1 enhances trithorax-group gene (trx-G) mutations and partially suppresses Polycomb-group gene (Pc-G) mutations [3].
• DSP1, an HMG-like protein, is involved in the regulation of homeotic genes [3].

Biological context of Dsp1

• DSP1 is an HMG-box protein which has been implicated in the regulation of homeotic genes in Drosophila melanogaster [4].
• Analysis of the phenotype of a null mutation of dsp1 (dsp1(1)) reveals that the absence of maternal DSP1 results in A4 segmentation defects that are correlated with a diminution of the kni expression domain [4].
• We propose that DSP1 protein is a chromatin remodeling factor, acting as a trx-G or a Pc-G protein depending on the considered function [3].
• Using P-element mutagenesis, we have isolated a mutant deficient in DSP1 functions [5].
• The gene that encodes the dorsal switch protein (DSP1) has been isolated from a Drosophila melanogaster cosmid library [6].

Regulatory relationships of Dsp1

• CONCLUSION: These results provide strong evidence that the Scr gene expression is influenced by direct interaction between DSP1 and two Scr regulation elements [7].

Other interactions of Dsp1

• Here we report that DSP1 is also involved in the regulation of the kni gap gene [4].
• We present in vitro and in vivo evidences for a direct interaction between DSP1 and Bicoid, mediated by the BCD homeodomain and the HMG box of DSP1 [4].
• RESULTS: In the present study, we attempted to characterize the regulatory sequences involved in the maintenance of the Scr activation by DSP1 [7].
• Recruitment of Drosophila Polycomb group proteins to chromatin by DSP1 [8].
• Comparison of the chromatin structure at the Mcp locus in wild-type and dsp1 mutant embryos reveals that the 300-bp DNase I hypersensitive region is absent in a dsp1 mutant context [3].

Analytical, diagnostic and therapeutic context of Dsp1

• Moreover, using chromatin immunoprecipitation experiments, we identify two regions of 1 kb in Scr10.0XbaI as the main DSP1 targets [7].

References