title: Two new insulator proteins, Pita and ZIPIC, target CP190 to chromatin.
abstract: Insulators are multiprotein-DNA complexes that regulate the nuclear architecture. The Drosophila CP190 protein is a cofactor for the DNA-binding insulator proteins Su(Hw), CTCF, and BEAF-32. The fact that CP190 has been found at genomic sites devoid of either of the known insulator factors has until now been unexplained. We have identified two DNA-binding zinc-finger proteins, Pita, and a new factor named ZIPIC, that interact with CP190 in vivo and in vitro at specific interaction domains. Genomic binding sites for these proteins are clustered with CP190 as well as with CTCF and BEAF-32. Model binding sites for Pita or ZIPIC demonstrate a partial enhancer-blocking activity and protect gene expression from PRE-mediated silencing. The function of the CTCF-bound MCP insulator sequence requires binding of Pita. These results identify two new insulator proteins and emphasize the unifying function of CP190, which can be recruited by many DNA-binding insulator proteins.
authors.affiliation: Laboratory of Gene Expression Regulation in Development, Institute of Gene Biology, Russian Academy of Sciences, Moscow 119334, Russia;
authors.forename: Oksana
authors.initials: O
authors.lastname: Maksimenko
authors.affiliation: Institute for Genetics, Justus-Liebig-University Giessen, Heinrich-Buff-Ring, D-35392 Giessen, Germany;
authors.forename: Marek
authors.initials: M
authors.lastname: Bartkuhn
authors.affiliation: Laboratory of Gene Expression Regulation in Development, Institute of Gene Biology, Russian Academy of Sciences, Moscow 119334, Russia;
authors.forename: Viacheslav
authors.initials: V
authors.lastname: Stakhov
authors.affiliation: Institute for Genetics, Justus-Liebig-University Giessen, Heinrich-Buff-Ring, D-35392 Giessen, Germany;
authors.forename: Martin
authors.initials: M
authors.lastname: Herold
authors.affiliation: Laboratory of Gene Expression Regulation in Development, Institute of Gene Biology, Russian Academy of Sciences, Moscow 119334, Russia;
authors.forename: Nickolay
authors.initials: N
authors.lastname: Zolotarev
authors.affiliation: Institute for Genetics, Justus-Liebig-University Giessen, Heinrich-Buff-Ring, D-35392 Giessen, Germany;
authors.forename: Theresa
authors.initials: T
authors.lastname: Jox
authors.affiliation: Institute for Genetics, Justus-Liebig-University Giessen, Heinrich-Buff-Ring, D-35392 Giessen, Germany;
authors.forename: Melanie K
authors.initials: MK
authors.lastname: Buxa
authors.affiliation: Institute for Genetics, Justus-Liebig-University Giessen, Heinrich-Buff-Ring, D-35392 Giessen, Germany;
authors.forename: Ramona
authors.initials: R
authors.lastname: Kirsch
authors.affiliation: Group of Transcriptional Regulation, Institute of Gene Biology, Russian Academy of Sciences, Moscow 119334, Russia;
authors.forename: Artem
authors.initials: A
authors.lastname: Bonchuk
authors.affiliation: Laboratory of Gene Expression Regulation in Development, Institute of Gene Biology, Russian Academy of Sciences, Moscow 119334, Russia;
authors.forename: Anna
authors.initials: A
authors.lastname: Fedotova
authors.affiliation: Group of Transcriptional Regulation, Institute of Gene Biology, Russian Academy of Sciences, Moscow 119334, Russia;
authors.forename: Olga
authors.initials: O
authors.lastname: Kyrchanova
authors.affiliation: Institute for Genetics, Justus-Liebig-University Giessen, Heinrich-Buff-Ring, D-35392 Giessen, Germany; georgiev_p@mail.ru Rainer.Renkawitz@gen.bio.uni-giessen.de olgina73@yandex.ru.
authors.forename: Rainer
authors.initials: R
authors.lastname: Renkawitz
authors.affiliation: Department of the Control of Genetic Processes, Institute of Gene Biology, Russian Academy of Sciences, Moscow 119334, Russia georgiev_p@mail.ru Rainer.Renkawitz@gen.bio.uni-giessen.de olgina73@yandex.ru.
authors.forename: Pavel
authors.initials: P
authors.lastname: Georgiev
mesh_terms: D000818:Animals; D001665:Binding Sites; D002843:Chromatin / Q000235:genetics* / Q000378:metabolism; D002874:Chromosome Mapping; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D004330:Drosophila / Q000166:cytology / Q000235:genetics; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D015870:Gene Expression; D056726:Genetic Association Studies; D023281:Genomics; D008869:Microtubule-Associated Proteins / Q000235:genetics / Q000378:metabolism*; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D016335:Zinc Fingers
chemical_list: C107964:CP190 protein, Drosophila; D002843:Chromatin; D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D008869:Microtubule-Associated Proteins; D009687:Nuclear Proteins; D014157:Transcription Factors; C000620216:ZIPIC protein, Drosophila; C507658:pita protein, Drosophila