tailieunhanh - Báo cáo khoa học: Recruitment of coregulator complexes to the b-globin gene locus by TFII-I and upstream stimulatory factor

Upstream stimulatory factor and TFII-I are ubiquitously expressed helix-loop-helix transcription factors that interact with E-box sequences and or initiator elements. We previously demonstrated that upstream stimulatory factor is an activator of b-globin gene expression whereas TFII-I is a repressor. | ỊFEBS Journal Recruitment of coregulator complexes to the b-globin gene locus by TFII-I and upstream stimulatory factor Valerie J. Crusselle-Davis Zhuo Zhou Archana Anantharaman Babak Moghimi Tihomir Dodev Suming Huang and Jorg Bungert Department of Biochemistry and Molecular Biology Center for Mammalian Genetics Shands Cancer Center PowellGene Therapy Center Genetics Institute University of Florida College of Medicine Gainesville FL USA Keywords coregulator globin genes locus control region transcription Correspondence J. Bungert Department of Biochemistry and Molecular Biology College of Medicine University of Florida 1600 SW Archer Road PO Box 100245 Gainesville FL 32610 USA Fax 1 352 392 2853 Tel 1 352 273 8098 E-mail jbungert@ Received 16 May 2007 revised 3 October 2007 accepted 5 October 2007 doi Upstream stimulatory factor and TFII-I are ubiquitously expressed helixloop-helix transcription factors that interact with E-box sequences and or initiator elements. We previously demonstrated that upstream stimulatory factor is an activator of b-globin gene expression whereas TFII-I is a repressor. In the present study we demonstrate that upstream stimulatory factor interacts with the coactivator p300 and that this interaction is restricted to erythroid cells expressing the adult b-globin gene. Furthermore we demonstrate that Suz12 a component of the polycomb repressor complex 2 is recruited to the b-globin gene. Reducing expression of Suz12 significantly activates b-globin gene expression in an erythroid cell line with an embryonic phenotype. Suz12 also interacts with the adult b-globin gene during early stages of erythroid differentiation of mouse embryonic stem cells. Our data suggest that TFII-I contributes to the recruitment of the polycomb repressor complex 2 complex to the b-globin gene. Together these data demonstrate that the antagonistic activities of upstream stimulatory factor and TFII-I on b-globin gene expression