RT Journal
A1 Maksimenko, Oksana
A1 Bartkuhn, Marek
A1 Stakhov, Viacheslav
A1 Herold, Martin
A1 Zolotarev, Nickolay
A1 Jox, Theresa
A1 Buxa, Melanie K.
A1 Kirsch, Ramona
A1 Bonchuk, Artem
A1 Fedotova, Anna
A1 Kyrchanova, Olga
A1 Renkawitz, Rainer
A1 Georgiev, Pavel
T1 Two new insulator proteins, Pita and ZIPIC, target CP190 to chromatin
JF Genome Research 
JO Genome Research 
YR 2015 
FD January 01 
VO 25 
IS 1 
SP 89 
OP 99 
DO 10.1101/gr.174169.114 
UL http://genome.cshlp.org/content/25/1/89.abstract 
AB 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.