su(Hw)

Drosophila melanogaster

suppressor of Hairy wing (su(Hw)) encodes a zinc finger transcription factor that can function both as insulator protein and as transcriptional repressor, depending on the genomic context and motif sequence that it binds to. It is known to associate with Cp190 and mod(mdg4) to form an insulator complex, but the composition of the repressive su(Hw) complex is not known.

Cp190

Drosophila melanogaster

Centrosomal protein 190kD (Cp190) encodes a BTB-ZnF transcription factor that has both nuclear and centrosomal functions. It's an insulator protein required to form physical and regulatory boundaries in the genome, and is recruited by DNA-binding proteins such as CTCF, su(Hw) and others, with which it physically associates.

Phs

Drosophila melanogaster

Phaser (Phs) encodes a zinc finger transcription factor that mediates gene repression. The binding of Phs to the genome results in an array of regularly phased nucleosomes, densely packed around the binding motif, similar to the binding of su(Hw) and Saft.

HIPP1

Drosophila melanogaster

HP1 and insulator partner protein 1 (HIPP1) encodes a chromatin-associated protein, displaying strong protein-protein interaction with the product of Su(var)205. It is localized to pericentric heterochromatin, and potentially has a separate role bound to insulators along with the products of su(Hw), mod(mdg4) and Cp190.