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Orientation-dependent interaction between Drosophila insulators is a property of this class of regulatory elements.

Kyrchanova O, Chetverina D, Maksimenko O, Kullyev A, Georgiev P - Nucleic Acids Res. (2008)

Bottom Line: As shown previously, Zw5, Su(Hw) and dCTCF proteins are required for the functioning of different insulators that do not interact with each other.Here, strong functional interactions have been revealed between DNA fragments containing binding sites for either Zw5 or Su(Hw) or dCTCF protein but not between heterologous binding sites [Zw5-Su(Hw), dCTCF-Su(Hw), or dCTCF-Zw5].These results suggest that insulator proteins can support selective interactions between distant regulatory elements.

View Article: PubMed Central - PubMed

Affiliation: Department of the Control of Genetic Processes, Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia.

ABSTRACT
Insulators are defined as a class of regulatory elements that delimit independent transcriptional domains within eukaryotic genomes. According to previous data, an interaction (pairing) between some Drosophila insulators can support distant activation of a promoter by an enhancer. Here, we have demonstrated that pairs of well-studied insulators such as scs-scs, scs'-scs', 1A2-1A2 and Wari-Wari support distant activation of the white promoter by the yeast GAL4 activator in an orientation-dependent manner. The same is true for the efficiency of the enhancer that stimulates white expression in the eyes. In all insulator pairs tested, stimulation of the white gene was stronger when insulators were inserted between the eye enhancer or GAL4 and the white promoter in opposite orientations relative to each other. As shown previously, Zw5, Su(Hw) and dCTCF proteins are required for the functioning of different insulators that do not interact with each other. Here, strong functional interactions have been revealed between DNA fragments containing binding sites for either Zw5 or Su(Hw) or dCTCF protein but not between heterologous binding sites [Zw5-Su(Hw), dCTCF-Su(Hw), or dCTCF-Zw5]. These results suggest that insulator proteins can support selective interactions between distant regulatory elements.

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Testing the functional interaction between DNA fragments containing binding sites for different insulator proteins, dCTCF (black ovals), Zw5 (white ovals), Su(Hw) (white rectangles) or composite DNA fragments containing dCTCF and Su(Hw) binding sites (black ovals and white rectangles). For designations, see Figures 2 and 3. The results with G4(Cx4)Y(Cx4)W were taken from Kyrchanova et al. (51).
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Figure 6: Testing the functional interaction between DNA fragments containing binding sites for different insulator proteins, dCTCF (black ovals), Zw5 (white ovals), Su(Hw) (white rectangles) or composite DNA fragments containing dCTCF and Su(Hw) binding sites (black ovals and white rectangles). For designations, see Figures 2 and 3. The results with G4(Cx4)Y(Cx4)W were taken from Kyrchanova et al. (51).

Mentions: However, the gypsy, scs and Fab-8 insulators have a complex structure and may contain binding sites for additional proteins involved in the insulator activity. Hence, we decided to examine functional interactions between the oligos containing binding sites for Zw5, Su(Hw) and dCTCF proteins. Recently, we found that the functional interaction between two DNA fragments containing four consensus binding sites for the dCTCF protein (C×4) supported long-distance activation of white by the GAL4 activator (51) (Figure 6A). In this study, a functional interaction was revealed between DNA fragments Z×8 containing eight binding sites for Zw5 (Figures 3D and 6B).Figure 6.


Orientation-dependent interaction between Drosophila insulators is a property of this class of regulatory elements.

Kyrchanova O, Chetverina D, Maksimenko O, Kullyev A, Georgiev P - Nucleic Acids Res. (2008)

Testing the functional interaction between DNA fragments containing binding sites for different insulator proteins, dCTCF (black ovals), Zw5 (white ovals), Su(Hw) (white rectangles) or composite DNA fragments containing dCTCF and Su(Hw) binding sites (black ovals and white rectangles). For designations, see Figures 2 and 3. The results with G4(Cx4)Y(Cx4)W were taken from Kyrchanova et al. (51).
© Copyright Policy - creative-commons
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2602758&req=5

Figure 6: Testing the functional interaction between DNA fragments containing binding sites for different insulator proteins, dCTCF (black ovals), Zw5 (white ovals), Su(Hw) (white rectangles) or composite DNA fragments containing dCTCF and Su(Hw) binding sites (black ovals and white rectangles). For designations, see Figures 2 and 3. The results with G4(Cx4)Y(Cx4)W were taken from Kyrchanova et al. (51).
Mentions: However, the gypsy, scs and Fab-8 insulators have a complex structure and may contain binding sites for additional proteins involved in the insulator activity. Hence, we decided to examine functional interactions between the oligos containing binding sites for Zw5, Su(Hw) and dCTCF proteins. Recently, we found that the functional interaction between two DNA fragments containing four consensus binding sites for the dCTCF protein (C×4) supported long-distance activation of white by the GAL4 activator (51) (Figure 6A). In this study, a functional interaction was revealed between DNA fragments Z×8 containing eight binding sites for Zw5 (Figures 3D and 6B).Figure 6.

Bottom Line: As shown previously, Zw5, Su(Hw) and dCTCF proteins are required for the functioning of different insulators that do not interact with each other.Here, strong functional interactions have been revealed between DNA fragments containing binding sites for either Zw5 or Su(Hw) or dCTCF protein but not between heterologous binding sites [Zw5-Su(Hw), dCTCF-Su(Hw), or dCTCF-Zw5].These results suggest that insulator proteins can support selective interactions between distant regulatory elements.

View Article: PubMed Central - PubMed

Affiliation: Department of the Control of Genetic Processes, Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia.

ABSTRACT
Insulators are defined as a class of regulatory elements that delimit independent transcriptional domains within eukaryotic genomes. According to previous data, an interaction (pairing) between some Drosophila insulators can support distant activation of a promoter by an enhancer. Here, we have demonstrated that pairs of well-studied insulators such as scs-scs, scs'-scs', 1A2-1A2 and Wari-Wari support distant activation of the white promoter by the yeast GAL4 activator in an orientation-dependent manner. The same is true for the efficiency of the enhancer that stimulates white expression in the eyes. In all insulator pairs tested, stimulation of the white gene was stronger when insulators were inserted between the eye enhancer or GAL4 and the white promoter in opposite orientations relative to each other. As shown previously, Zw5, Su(Hw) and dCTCF proteins are required for the functioning of different insulators that do not interact with each other. Here, strong functional interactions have been revealed between DNA fragments containing binding sites for either Zw5 or Su(Hw) or dCTCF protein but not between heterologous binding sites [Zw5-Su(Hw), dCTCF-Su(Hw), or dCTCF-Zw5]. These results suggest that insulator proteins can support selective interactions between distant regulatory elements.

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