Insulators are multiprotein–DNA complexes that regulate the nuclear architecture. The Drosophila CP190 protein is a cofactor for DNA-binding insulator proteins Su(Hw), CTCF, and BEAF-32. fact has been found at genomic sites devoid of either known factors until now unexplained. We have identified two zinc-finger proteins, Pita, new factor named ZIPIC, interact with in vivo vitro specific interaction domains. Genomic binding these clustered as well CTCF Model Pita or ZIPIC demonstrate partial...

The Drosophila male-specific lethal (MSL) complex binds to the male X chromosome activate transcription. It comprises five proteins (MSL1, MSL2, MSL3, absent on first (MOF), and maleless (MLE)) two long noncoding RNAs (lncRNAs; roX1 roX2). MLE helicase remodels roX lncRNAs, enabling lncRNA-mediated assembly of dosage compensation complex. MSL2 is expressed only in males interacts with N-terminal zinc finger transcription factor chromatin-linked adapter for MSL (CLAMP), which important...

During the past two decades, there have been numerous attempts at using animals in order to produce recombinant human proteins and monoclonal antibodies. However, it is only recently that first therapeutic agents isolated from milk of transgenic animals, C1 inhibitor (Ruconest) antithrombin (ATryn), appeared on market. This inspires hope a considerable number new created such technology could become available for practical use near future. In this review, methods applied are described...

According to recent models, as yet poorly studied architectural proteins appear be required for local regulation of enhancer-promoter interactions, well global chromosome organization. Transcription factors ZIPIC, Pita and Zw5 belong the class chromatin insulator preferentially bind promoters near TSS extensively colocalize with cohesin condensin complexes. are structurally similar in containing N-terminal zinc finger-associated domain (ZAD) different numbers C2H2-type fingers at C-terminus....

Insulators play a central role in gene regulation, chromosomal architecture and genome function higher eukaryotes. To learn more about how insulators carry out their diverse functions, we have begun an analysis of the Drosophila CTCF (dCTCF). is one few insulator proteins known to be conserved from flies man. In studies reported here focused on identification characterization two dCTCF protein interaction modules. The first mediates multimerization, while second dCTCF–CP190 interactions....

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 promoter by enhancer. Here, we have demonstrated pairs well-studied such scs–scs, scs'–scs', 1A2–1A2 and Wari–Wari the white yeast GAL4 activator in orientation-dependent manner. The same is true for efficiency enhancer stimulates expression...

Expression of the genes Ubx , abd-A and Abd-B bithorax complex depends on its cis -regulatory region, which is divided into discrete functional domains ( iab ). Boundary/insulator elements, named Mcp, Fab-6, Fab-7 Fab-8 (PTS/F8), have been identified at borders domains. Recently, binding sites for a Drosophila homolog vertebrate insulator protein CTCF in Fab-6 also several regions that correspond to predicted boundaries, Fab-3 Fab-4 particular. Taking account inability yeast GAL4 activator...

Chromatin insulators block the action of transcriptional enhancers when interposed between an enhancer and a promoter. In this study, we examined role chromatin loops formed by two unrelated insulators, gypsy Fab-7, in their enhancer-blocking activity. To test for activity, selected white reporter gene that is activated eye-specific enhancer. The results showed one copy or Fab-7 insulator failed to eye most genomic sites, whereas loop flanking either completely blocked stimulation However,...

Transcription regulators select their genomic binding sites from a large pool of similar, non-functional sequences. Although general principles that allow such discrimination are known, the complexity DNA elements often precludes prediction functional sites. The process dosage compensation in Drosophila allows exploring rules underlying site selectivity. male-specific-lethal (MSL) Dosage Compensation Complex (DCC) selectively binds to some 300 X chromosomal 'High Affinity Sites' (HAS)...

Expression of the three bithorax complex homeotic genes is orchestrated by nine parasegment-specific regulatory domains. Autonomy each domain conferred boundary elements (insulators). Here, we have used an in situ replacement strategy to reanalyze sequences required for functioning one best-characterized fly boundaries, Fab-7. It was initially identified a deletion, Fab-71, that transformed parasegment (PS) 11 into duplicate copy PS12. Fab-71 deleted four nuclease hypersensitive sites, HS*,...

In mammals, a C2H2 zinc finger (C2H2) protein, CTCF, acts as the master regulator of chromosomal architecture and expression Hox gene clusters. Like mammalian Drosophila homolog, dCTCF, localizes to boundaries in bithorax complex (BX-C). Here, we have determined minimal requirements for assembly functional boundary by dCTCF two other proteins, Pita Su(Hw). Although binding sites these proteins are essential insulator activity BX-C boundaries, alone insufficient create boundary. cannot...

Abstract CTCF is the main architectural protein found in most of examined bilaterian organisms. The cluster C2H2 zinc-finger domains involved recognition long DNA-binding motif only part that evolutionarily conserved, while N-terminal domain (NTD) has different sequences. Here, we performed biophysical characterization NTDs from various species representing all major phylogenetic clades higher metazoans. With exception Drosophilides, CTCFs show an unstructured organization and absence folded...

Abstract Background Pita is required for Drosophila development and binds specifically to a long motif in active promoters insulators. belongs the family of zinc-finger architectural proteins, which also includes Su(Hw) conserved among higher eukaryotes CTCF. The proteins maintain state regulatory elements long-distance interactions between them. In particular, involved formation several boundaries domains that controlled expression three hox genes Bithorax complex (BX-C). CP190 protein...

In Drosophila, architectural proteins are frequently found in promoters, including those of genes with extremely high expression levels, such as ribosomal protein (RPGs). The involvement several these gene regulation Drosophila has been shown, but the exact mechanisms their possible cooperative action have not fully elucidated. this study we dissected contribution Opbp and M1BP, which co-localized at RPG promoters near transcription start site, to promoter functioning. We that two domains...

Much of the research on insulators in Drosophila has been done with transgenic constructs using white gene (mini-white) as reporter. Hereby we report that sequence between and CG32795 genes melanogaster contains an insulator a novel kind. Its functional core is within 368 bp segment almost contiguous to 3'UTR, hence name it Wari (white-abutting resident insulator). Though no binding sites for known proteins does not require Su(Hw) or Mod(mdg4) its activity, can equally well interact another...

A special class of poorly characterized architectural proteins is required for chromatin topology and enhancer-promoter interactions. Here, we identify Opbp as a new Drosophila protein, interacting with CP190 both in vivo vitro. binds to very restrictive set genomic regions, through rare sequence specific motif. These sites are co-bound by vivo, generally located at bidirectional promoters ribosomal protein genes. We show that essential viability, loss opbp function, or destruction its...

Boundaries in the Bithorax complex (BX-C) of Drosophila delimit autonomous regulatory domains that drive parasegment-specific expression homeotic genes. BX-C boundaries have two crucial functions: they must block crosstalk between adjacent and at same time facilitate boundary bypass. The C2H2 zinc-finger protein Pita binds to several boundaries, including Fab-7 Mcp. To study functions, we used a replacement strategy by substituting modified DNAs for boundary, which is located iab-6 iab-7...

Significance Three Hox genes— Ubx , abd-A, and Abd-B —in the Drosophila bithorax complex are regulated by enhancer domains that drive parasegment-specific expression. The boundary/insulator elements flank regulatory domains, ensuring their autonomous activity. presence of boundaries poses a paradox how enhancers located in can bypass intervening to properly regulate one genes. Here we constructed vivo consisting multimerized binding sites for several architectural proteins block cross-talk...

In mammals, most of the boundaries topologically associating domains and all well-studied insulators are rich in binding sites for CTCF protein. According to existing experimental data, is a key factor organization architecture mammalian chromosomes. A characteristic feature that central part protein contains cluster consisting eleven C2H2-type zinc fingers, five which specifically bind long DNA sequence conserved animals. The class transcription factors carry fingers or more (C2H2 proteins)...

CTCF is highly likely to be the ancestor of proteins that contain large clusters C2H2 zinc finger domains, and its conservation observed across most bilaterian organisms. In mammals, primary architectural protein involved in organizing chromosome topology mediating enhancer-promoter interactions over long distances. Drosophila, (dCTCF) cooperates with other establish long-range chromatin boundaries. CTCFs various organisms an unstructured N-terminal dimerization domain (DD) comprising eleven...