Where does CTCF colocalize with cohesin?
['In human cells, Pol III genes and transcription factors have also been shown to colocalize with cohesin and the transcription regulator and genome organizer CCCTC-binding factor (CTCF).', 'To investigate cohesin-non-CTCF (CNC) binding events in vivo we mapped cohesin and CTCF, as well as a collection of tissue-specific and ubiquitous transcriptional regulators using ChIP-seq in primary mouse liver.', ' In contrast to regions of the genome where cohesin and CTCF colocalize, CNC sites coincide with the binding of master regulators and enhancer-markers and are significantly associated with liver-specific expressed genes. ', 'Finally, we observe that the presence of mirrored CTCF binding events at promoters and their nearby cohesin-bound enhancers is associated with elevated expression levels.', 'Recently, cohesins have been implicated in transcriptional regulation and insulation through genome-wide colocalization with the insulator protein CTCF, including involvement at the imprinted H19/Igf2 locus.', 'Here we report that cohesins colocalize with CTCF at two additional imprinted loci, the Dlk1-Dio3 and the Kcnq1/Kcnq1ot1 loci. ', ' To determine the functional importance of the binding of CTCF and cohesins at the three imprinted loci, CTCF and cohesins were depleted in mouse embryonic fibroblast cells.', 'Results of these experiments demonstrate an unappreciated role for CTCF and cohesins in the repression of imprinted genes in somatic cells.', 'Here, we show in different cell types that cohesin functionally behaves as a tissue-specific transcriptional regulator, independent of CTCF binding.', 'By performing matched genome-wide binding assays (ChIP-seq) in human breast cancer cells (MCF-7), we discovered thousands of genomic sites that share cohesin and estrogen receptor alpha (ER) yet lack CTCF binding', 'By use of human hepatocellular carcinoma cells (HepG2), we found that liver-specific transcription factors colocalize with cohesin independently of CTCF at liver-specific targets that are distinct from those found in breast cancer cells', 'Together, our data show that cohesin cobinds across the genome with transcription factors independently of CTCF, plays a functional role in estrogen-regulated transcription, and may help to mediate tissue-specific transcriptional responses via long-range chromosomal interactions.', ' Because cohesin can colocalize with CTCF, we performed chromatin immunoprecipitation for the cohesin subunit Rad21 and found lineage and stage-specific Rad21 recruitment to CTCF in all Ig loci. The differential binding of cohesin to CTCF sites may promote multiple loop formation and thus effective V(D)J recombination', 'These numerous CTCF/cohesin sites potentially form the bases of the multiloop rosette structures at the Igh locus that compact during Ig heavy chain rearrangement.', 'We conclude that cohesins interact with CTCF in mid-S phase and repress CTCF-regulated genes in a cell cycle-dependent manner.', 'We propose that the CTCF-cohesin complex plays a critical role in regulating the cell cycle control of viral gene expression during latency and that failure to maintain cell cycle control of latent transcripts inhibits host cell proliferation and survival', 'We conclude that cohesin subunits associate with viral and cellular CTCF sites involved in complex gene regulation and chromatin organization.', 'Because cohesin can colocalize with CTCF, we performed chromatin immunoprecipitation for the cohesin subunit Rad21 and found lineage and stage-specific Rad21 recruitment to CTCF in all Ig loci.', 'In human cells, Pol III genes and transcription factors have also been shown to colocalize with cohesin and the transcription regulator and genome organizer CCCTC-binding factor (CTCF).', 'Here, we show that ATRX, MeCP2, and cohesin, chromatin regulators implicated in ATR-X, RTT, and CdLS syndromes, respectively, interact in the brain and colocalize at the H19 imprinting control region (ICR) with preferential binding on the maternal allele.', 'Subcellular distribution of CTCF and colocalization with cohesins also varied across the cell cycle. ', 'ChIP sequencing was performed on pro-B cells, revealing colocalization of CTCF and Rad21 binding at ~60 sites throughout the V(H) region and 2 other sites within the Igh locus. ', 'Recently, cohesins have been implicated in transcriptional regulation and insulation through genome-wide colocalization with the insulator protein CTCF, including involvement at the imprinted H19/Igf2 locus. ', 'CTCF colocalizes with cohesin but not RNA Polymerase II. ', 'Because cohesin can colocalize with CTCF, we performed chromatin immunoprecipitation for the cohesin subunit Rad21 and found lineage and stage-specific Rad21 recruitment to CTCF in all Ig loci. ', 'Because cohesin can colocalize with CTCF, we performed chromatin immunoprecipitation for the cohesin subunit Rad21 and found lineage and stage-specific Rad21 recruitment to CTCF in all Ig loci. The differential binding of cohesin to CTCF sites may promote multiple loop formation and thus effective V(D)J recombination.', 'Here we report that cohesins colocalize with CTCF at two additional imprinted loci,']
['Cohesin subunits associate with viral and cellular CTCF sites involved in complex gene regulation and chromatin organization. Cohesin cobinds across the genome with transcription factors independently of CTCF, plays a functional role in estrogen-regulated transcription, and may help to mediate tissue-specific transcriptional responses via long-range chromosomal interactions.\nNumerous CTCF/cohesin sites potentially form the bases of the multiloop rosette structures at the Igh locus that compact during Ig heavy chain rearrangement. Cohesins colocalize with CTCF at two additional imprinted loci, the Dlk1-Dio3 and the Kcnq1/Kcnq1ot1 loci.']
['In imprinted and repressed, highly compacted loci that are prone to recombination events.']