ontrast, the CP190dC protein is no longer present at the y locus of the y2 polytene chro mosome in the mod mutant. This result supports the idea that the interaction between the BTB domains of Cp190 and Mod 67. 2 contributes to the binding of Cp190 with the Su insulator complex. BTB domains often mediate dimers with other BTB containing selleckchem proteins, and thus we posit that the Cp190 BTB domain interacts with the Mod 67. 2 BTB domain and that Mod 67. 2 recruits Cp190 lacking the C terminal E rich domain. ChIP assays with homozygous CP190En15 pupae indi cate that CP190dC associates with all sites that bind wild type Cp190, because the signals of all tested sites were significantly higher than the 1A6 negative control region.
The signals Inhibitors,Modulators,Libraries at 1A2 and 62D were stronger Inhibitors,Modulators,Libraries than Fab 8, whereas in the wild type Cp190 ChIP results the signals at 1A2 and 62D were weaker than Fab 8. The result suggests that the C terminal E rich domain con tributes partially to the association of Cp190 with the CTCF complexes at Fab 8. The CP190dC protein associates with all Cp190 containing insulator complexes but the GFP CP190BTB nls does not. We thus reasoned that another part of the Cp190 protein in addition to the BTB domain must also be essential for the association. We noticed that there is a D Rich acidic region between the zinc fingers and the BTB domain. This D rich region is in the CP190dC protein, but not in the GFP CP190BTB Inhibitors,Modulators,Libraries nls protein. We generated flies carrying the P which encodes a Cp190 fragment containing both the BTB and the D rich domain.
GFP CP190BTB D pro tein localizes to polytene chromosomes as distinct bands and not to extra chromosomal spaces in living salivary glands. In addition, this GFP fusion protein co localized completely with the mRFP CP190 on poly tene chromosomes. Inhibitors,Modulators,Libraries In diploid larval cells, e. g. brain cells and imaginal disc cells, the GFP CP190 BTB D protein exists as speckles and co localizes with mRFP CP190. These results indicate that this N terminal Cp190 fragment is sufficient to associate with most of the Cp190 containing insulator complexes in living cells. Although it associates with all Cp190 sites, GFP CP190BTB D, like the CP190dC, is not functional in the insulator complexes and lacks essential Cp190 functions. y2 w ct6, P, CP190H4 1 flies have the same y2 body cuticle pigmenta tion and Cilengitide ct6 wing shape phenotypes as the y2 w ct6, PCP190H4 1 flies.
The GFP CP190 BTB D transgene also does not rescue the lethality of homozygous CP1903. From at least 500 F1 offspring flies of the y2 w ct6, P, CP1903 TM6B, Tb parents, we obtained no CP1903 homozygous adults. The mRFP CP190 redistributed to extra chromosomal spaces during heat shock whereas Rapamycin Sirolimus the CP190BTB D fragment remained associated The heat shock response in the Drosophila melanogaster has been intensively studied. When fruit flies are stressed with heat, the transcription of most of the nor mal genes in cells is shut off and newly synthesized RNA species correspond to a small number of he