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Published on: September 19, 2017
Interactions between the Su(Hw) and Mod(mdg4) proteins required for gypsy insulator function.
D Ghosh1, T I Gerasimova, V G Corces
1Department of Biology, The Johns Hopkins University, 3400 N. Charles Street, Baltimore, MD 21218, USA.
The EMBO Journal
|May 15, 2001
Summary
The gypsy insulator, involving Mod(mdg4) and Su(Hw) proteins, forms nuclear rosettes. This protein interaction is crucial for its role in nuclear organization and chromatin domain establishment.
Area of Science:
- Molecular Biology
- Genetics
- Cell Biology
Background:
- The gypsy insulator is implicated in nuclear organization and higher-order chromatin domain formation.
- It functions by aggregating individual insulator sites into rosette-like structures within the interphase nucleus.
- The Su(Hw) and Mod(mdg4) proteins are key components of the gypsy insulator, essential for its regulatory functions.
Purpose of the Study:
- To investigate the molecular mechanisms underlying the gypsy insulator's role in nuclear organization.
- To elucidate the protein-protein interactions between Mod(mdg4) and Su(Hw) and their functional domains.
- To understand how these interactions contribute to the formation of rosette-like structures.
Main Methods:
- Yeast two-hybrid system to study protein-protein interactions.
- Immunolocalization on polytene chromosomes to confirm domain involvement.
- Studies using diploid interphase cells to observe nuclear structures.
Main Results:
- Mod(mdg4) protein forms homodimers via its BTB domain.
- The C-terminal region of Mod(mdg4) interacts with the Su(Hw) protein's leucine zipper and adjacent regions.
- These interactions are confirmed in vivo and are linked to the formation of nuclear rosette structures.
Conclusions:
- The study provides a biochemical basis for the aggregation of multiple gypsy insulator sites.
- The identified protein interactions and domain functions support the role of the gypsy insulator in nuclear organization.
- The findings contribute to understanding how chromatin insulators establish higher-order structures.
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