Developmental control over the vertebrae beta-type globin genes is predominantly transcriptional. The differential transcriptional activity of each of the genes appears to be the direct consequence of a complex set of temporally determined interactions between the promoters of each gene and the locus control region (LCR). Most, but not all, investigators in this field subscribe to the contention that this promoter:enhancer interaction is physically direct, and that differential gene activation is a consequence of """"""""promoter competition"""""""" [i.e. that activation of the various genes within the locus is determined by the stage-specific activation of transcription factors which bind to the promoters and the LCR (a powerful, multifaceted enhancer), causing the enhancer to activate the thermodynamically most stable promoter interaction by DNA looping]. Most current experiments in the field are interpreted in terms of this hypothesis, but it has never actually been proven in the murine or human beta-globin loci. We continue to explore the molecular bases for developmental activation of the human (beta-globin genes. During the past grant period, we developed and then exploited the use of recombinant YACs containing the whole human beta-globin locus to examine the consequences of mutation of various cis-elements in the locus (presumptive enhancers, promoters, silencers) by incorporating site-specific mutations into a wild-type human (beta-globin YAC using homologous recombination in yeast. While providing compelling evidence in its support, these data did not actually prove or disprove the competition hypothesis in the human (beta-globin locus. In the immediate future, we propose to more fully examine the molecular basis for two of the discoveries we made during the recently completed funding period (i.e. synergy in LCR structure and directionality of the LCR). Secondly, we propose to thoroughly examine the contributions of the KLF family of transcription factors to globin gene switching. Finally, we propose experiments which, if successful, will provide conclusive, direct evidence for competition among beta-globin locus genes for the LCR.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
2R01HL024415-22
Application #
6200198
Study Section
Cell Development and Function Integrated Review Group (CDF)
Project Start
1979-07-01
Project End
2004-07-31
Budget Start
2000-08-01
Budget End
2001-07-31
Support Year
22
Fiscal Year
2000
Total Cost
$367,500
Indirect Cost
Name
Northwestern University at Chicago
Department
Biochemistry
Type
Schools of Arts and Sciences
DUNS #
City
Evanston
State
IL
Country
United States
Zip Code
60201
Cui, Shuaiying; Tanabe, Osamu; Sierant, Michael et al. (2015) Compound loss of function of nuclear receptors Tr2 and Tr4 leads to induction of murine embryonic ?-type globin genes. Blood 125:1477-87
Cui, Shuaiying; Lim, Kim-Chew; Shi, Lihong et al. (2015) The LSD1 inhibitor RN-1 induces fetal hemoglobin synthesis and reduces disease pathology in sickle cell mice. Blood 126:386-96
Shi, Lihong; Sierant, M C; Gurdziel, Katherine et al. (2014) Biased, non-equivalent gene-proximal and -distal binding motifs of orphan nuclear receptor TR4 in primary human erythroid cells. PLoS Genet 10:e1004339
Shi, Lihong; Lin, Yu-Hsuan; Sierant, M C et al. (2014) Developmental transcriptome analysis of human erythropoiesis. Hum Mol Genet 23:4528-42
Cui, Shuaiying; Tanabe, Osamu; Lim, Kim-Chew et al. (2014) PGC-1 coactivator activity is required for murine erythropoiesis. Mol Cell Biol 34:1956-65
Hosoya, Tomonori; Clifford, Mary; Losson, RĂ©gine et al. (2013) TRIM28 is essential for erythroblast differentiation in the mouse. Blood 122:3798-807
Suzuki, Mikiko; Yamazaki, Hiromi; Mukai, Harumi Y et al. (2013) Disruption of the Hbs1l-Myb locus causes hereditary persistence of fetal hemoglobin in a mouse model. Mol Cell Biol 33:1687-95
Shi, Lihong; Cui, Shuaiying; Engel, James D et al. (2013) Lysine-specific demethylase 1 is a therapeutic target for fetal hemoglobin induction. Nat Med 19:291-4
Campbell, Andrew D; Cui, Shuaiying; Shi, Lihong et al. (2011) Forced TR2/TR4 expression in sickle cell disease mice confers enhanced fetal hemoglobin synthesis and alleviated disease phenotypes. Proc Natl Acad Sci U S A 108:18808-13
Cui, Shuaiying; Kolodziej, Katarzyna E; Obara, Naoshi et al. (2011) Nuclear receptors TR2 and TR4 recruit multiple epigenetic transcriptional corepressors that associate specifically with the embryonic ?-type globin promoters in differentiated adult erythroid cells. Mol Cell Biol 31:3298-311

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