The chromatin structure of the beta-globin gene locus is dynamic. In erythroid cells, the chromatin structure of the locus undergoes a dramatic reorganization over approximately 2OOkb of DNA producing at least three erythroid-specific chromatin structures. This reorganization is thought to involve the """"""""opening-up"""""""" of chromatin to allow trans-acting factors to interact with regulatory elements. Understanding how these domains of altered chromatin structure are created is central to understanding the complex mechanisms by which globin gene expression is regulated. We hypothesize that there are specific functional elements within the beta- globin locus control region (LCR) which direct the formation of the erythroid-specific chromatin structures of the human beta-globin gene locus. Our long-term goals involve the identification and characterization of these functional elements. Just as assays of gene expression have been used to identify and characterize the active elements of globin promoters, enhancers, and LCR domains, we propose to use assays of chromatin structure to locate, and then characterize, the specific functional elements responsible for the formation of the chromatin structures of the globin locus. Specifically, experiments are planned to continue our characterization of an element which is necessary for the formation of the unique erythroid-specific structure of a DNase 1 HS of the LCR. Other experiments are designed to assess the role of the erythroid-specific chromatin structures in the regulation of globin gene expression. We hypothesize that the transcription factors GATA-1 and NF-E2 are the key factors in forming the erythroid specific chromatin structures of the globin locus. We will test this hypothesis. Experiments are also proposed to locate the boundaries of the globally-altered chromatin structure which characterizes the beta-globin locus. The original impetus for our studies of the chromatin structure of the beta-globin gene locus was to better understand how an """"""""active"""""""" chromatin structure is established surrounding the genes of the locus in erythroid cells. These studies were initiated as part of a larger effort to develop more efficient strategies for gene therapy of severe beta-thalassemia and sickle cell disease. One problem which has hampered the development of gene therapy for these conditions has been an inability to achieve consistent high-level, tissue-specific, expression of transferred gene constructs. We hope that by identifying of the functional elements which form the domains of active chromatin structure around the native beta- globin genes we will be able to incorporate these elements into future therapeutic constructs leading to clinically applicable globin expression vectors.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
5R01HL052243-03
Application #
2029113
Study Section
Hematology Subcommittee 2 (HEM)
Project Start
1994-12-01
Project End
1998-11-30
Budget Start
1996-12-01
Budget End
1997-11-30
Support Year
3
Fiscal Year
1997
Total Cost
Indirect Cost
Name
Dartmouth College
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
041027822
City
Hanover
State
NH
Country
United States
Zip Code
03755
Boosalis, Michael S; Castaneda, Serguei A; Trudel, Marie et al. (2011) Novel therapeutic candidates, identified by molecular modeling, induce ?-globin gene expression in vivo. Blood Cells Mol Dis 47:107-16
Mabaera, Rodwell; West, Rachel J; Conine, Sarah J et al. (2008) A cell stress signaling model of fetal hemoglobin induction: what doesn't kill red blood cells may make them stronger. Exp Hematol 36:1057-72
Layon, Michael E; Ackley, Catherine J; West, Rachel J et al. (2007) Expression of GATA-1 in a non-hematopoietic cell line induces beta-globin locus control region chromatin structure remodeling and an erythroid pattern of gene expression. J Mol Biol 366:737-44
Mabaera, Rodwell; Richardson, Christine A; Johnson, Kristin et al. (2007) Developmental- and differentiation-specific patterns of human gamma- and beta-globin promoter DNA methylation. Blood 110:1343-52
Ermentrout, R Mitchell; Layon, Michael E; Ackley, Catherine J et al. (2006) The effects of lead and cadmium on GATA-1 regulated erythroid gene expression. Blood Cells Mol Dis 37:164-72
Mankidy, Rishikesh; Faller, Douglas V; Mabaera, Rodwell et al. (2006) Short-chain fatty acids induce gamma-globin gene expression by displacement of a HDAC3-NCoR repressor complex. Blood 108:3179-86
Nemeth, Michael J; Lowrey, Christopher H (2004) An Erythroid-Specific Chromatin Opening Element Increases beta-Globin Gene Expression from Integrated Retroviral Gene Transfer Vectors. Gene Ther Mol Biol 8:475-486
Kitareewan, Sutisak; Pitha-Rowe, Ian; Sekula, David et al. (2002) UBE1L is a retinoid target that triggers PML/RARalpha degradation and apoptosis in acute promyelocytic leukemia. Proc Natl Acad Sci U S A 99:3806-11
Nemeth, M J; Bodine, D M; Garrett, L J et al. (2001) An erythroid-specific chromatin opening element reorganizes beta-globin promoter chromatin structure and augments gene expression. Blood Cells Mol Dis 27:767-80
Goodwin, A J; McInerney, J M; Glander, M A et al. (2001) In vivo formation of a human beta-globin locus control region core element requires binding sites for multiple factors including GATA-1, NF-E2, erythroid Kruppel-like factor, and Sp1. J Biol Chem 276:26883-92

Showing the most recent 10 out of 15 publications