Erythroid specific activator GATA-1-dependent interactions between CTCF sites around the β-globin locus.
CTCF sites (binding motifs for CCCTC-binding factor, an insulator protein) are located considerable distances apart on genomes but are closely positioned in organized chromatin. The close positioning of CTCF sites is often cell type or tissue specific. Here we analyzed chromatin organization in eight CTCF sites around the β-globin locus by 3C assay and explored the roles of erythroid specific transcription activator GATA-1 and KLF1 in it. It was found five CTCF sites convergent to the locus interact with each other in erythroid K562 cells but not in non-erythroid 293 cells. The interaction was decreased by depletion of GATA-1 or KLF1. It accompanied reductions of CTCF and Rad21 occupancies and loss of active chromatin structure at the CTCF sites. Furthermore Rad21 occupancy was reduced in the β-globin locus control region (LCR) hypersensitive sites (HSs) by the depletion of GATA-1 or KLF1. The role of GATA-1 in interaction between CTCF sites was revealed by its ectopic expression in 293 cells and by deletion of a GATA-1 site in the LCR HS2. These findings indicate that erythroid specific activator GATA-1 acts at CTCF sites around the β-globin locus to establish tissue-specific chromatin organization.
Department of Molecular Biology, College of Natural Sciences, Pusan National University, Busan 46241, Republic of Korea.
Yujin
Y
Kang
Department of Molecular Biology, College of Natural Sciences, Pusan National University, Busan 46241, Republic of Korea.
Yea Woon
YW
Kim
Department of Molecular Biology, College of Natural Sciences, Pusan National University, Busan 46241, Republic of Korea.
Jin
J
Kang
Department of Molecular Biology, College of Natural Sciences, Pusan National University, Busan 46241, Republic of Korea.
Won Ju
WJ
Yun
Department of Molecular Biology, College of Natural Sciences, Pusan National University, Busan 46241, Republic of Korea. Electronic address: kimaeri@pusan.ac.kr.
AeRi
A
Kim
D001483:Base Sequence; D001665:Binding Sites / Q000235:genetics; D000076246:CCCTC-Binding Factor; D002843:Chromatin / Q000378:metabolism; D003850:Deoxyribonuclease I / Q000378:metabolism; D041905:Erythroid Cells / Q000378:metabolism*; D050982:GATA1 Transcription Factor / Q000378:metabolism*; D056426:Genetic Loci; D006801:Humans; D020014:K562 Cells; D051741:Kruppel-Like Transcription Factors / Q000378:metabolism; D019901:Locus Control Region / Q000235:genetics; D059372:Nucleotide Motifs / Q000235:genetics; D009928:Organ Specificity / Q000235:genetics; D011485:Protein Binding / Q000235:genetics; D012097:Repressor Proteins / Q000378:metabolism*; D017384:Sequence Deletion / Q000235:genetics; D055544:beta-Globins / Q000235:genetics*
D000076246:CCCTC-Binding Factor; C000619697:CTCF protein, human; D002843:Chromatin; D050982:GATA1 Transcription Factor; C494688:GATA1 protein, human; D051741:Kruppel-Like Transcription Factors; D012097:Repressor Proteins; D055544:beta-Globins; C080774:erythroid Kruppel-like factor; D003850:Deoxyribonuclease I
CTCF sites; Chromatin interaction; GATA-1; β-globin locus