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Genome-wide binding of two new insulator-like proteins Pita and ZIPIC

ABSTRACT: Insulators are multiprotein–DNA complexes that regulate nuclear architecture. The Drosophila CP190 protein is a common cofactor of two main insulator complexes formed by the DNA-binding proteins Su(Hw) and dCTCF. Here, we have identified two new DNA-binding proteins, Pita and ZIPIC, that interact with CP190. In vitro, CP190 interacts with Pita through the BTB domain and with ZIPIC through the centrosomal targeting domain. The artificial binding sites for Pita or ZIPIC partially block enhancers and protect gene expression from PRE-mediated silencing in transgenic lines. Pita binds adjacent to dCTCF in the well-studied Mcp insulator and is required for its activity, which indicates that two insulator proteins can cooperate in organizing a functional insulator. Pita and ZIPIC preferentially bind to the promoter regions and extensively colocalize with dCTCF and BEAF. These results suggest that insulator proteins can fulfill multiple functions in chromosome architecture and gene expression.

ORGANISM(S): Drosophila melanogaster

PROVIDER: GSE54337 | GEO | 2014/10/01

SECONDARY ACCESSION(S): PRJNA236229

REPOSITORIES: GEO

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Mechanism and functional role of the interaction between CP190 and the architectural protein Pita in Drosophila melanogaster

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RNAi-independent role for Argonaute2 in CTCF/CP190 chromatin insulator function

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2011-08-15 | E-GEOD-22623 | biostudies-arrayexpress

RNAi-independent role for Argonaute2 in CTCF/CP190 chromatin insulator function

2011-08-15 | GSE22623 | GEO

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2013-01-21 | E-GEOD-32584 | biostudies-arrayexpress

Distribution of Drosophila insulator proteins during interphase and mitosis

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Project description:Here we examine changes in the distribution of Drosophila insulator proteins during the ecdysone response. We performed ChIP-seq analysis in Kc cells at 0, 3, and 48 hours of ecdysone treatment with antibodies against CP190, Su(Hw), dCTCF, and BEAF-32B. Examination of 4 different insulator proteins at 3 time points of ecdysone treatment.

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Expression analyses in Drosophila ovaries

Project description:Suppressor of Hairy-wing [Su(Hw)] is a multi-zinc finger DNA binding factor required for gypsy insulator function and female germline development in Drosophila. The enhancer-blocking and barrier functions of the gypsy retrotransposon involve Su(Hw) binding to twelve clustered Su(Hw) binding sites (SBSs) and recruitment of the Centrosomal Protein of 190 kD (CP190) and Modifier of mdg4 67.2 kD isoform (Mod67.2) insulator proteins. In contrast, the Su(Hw) germline function involves binding to non-clustered genomic SBSs and does not require CP190 or Mod67.2. Here, we use genome-wide expression analyses in the ovary to identify the first Su(Hw) regulated target genes.

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CP190 and CTCF mediated enhancer blocking is augmented by SUMOylation

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2017-08-07 | GSE96581 | GEO

Distribution of Drosophila insulator proteins after ecdysone treatment in Kc cells

2011-10-14 | GSE30740 | GEO

Genome-wide distribution of proteins Pita, ZIPIC, Zw5 in Drosophila embryos

Project description:According to recent models, as yet poorly studied architectural proteins appear to be required for local regulation of enhancer–promoter interactions, as well as for global chromosome organization. Transcription factors ZIPIC, Pita, and Zw5 belong to the class of chromatin insulator proteins and preferentially bind to promoters near the TSS. They are structurally similar in containing the N-terminal zinc finger-associated domain (ZAD) and different numbers of C2H2-type zinc fingers at the C-terminus. We have shown that the ZAD domains of ZIPIC, Pita, and Zw5 usually form homodimers. In Drosophila transgenic lines, these proteins can support long-distance interaction between GAL4 activator and the reporter gene promoter. However, no functional interaction between binding sites for different proteins has been revealed, suggesting that such interactions are highly specific. ZIPIC facilitates long-distance stimulation of reporter gene by GAL4 activator in yeast. Thus, ZAD-containing zinc-finger proteins probably belong to the class of architectural proteins.

2016-05-06 | GSE76997 | GEO

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