ORGANIZATION AND EXPRESSION OF GLOBIN GENE LOCI

Project: Research project

Description

The long-term goal of this project is to understand the developmental and
coordinate regulation of globin genes in erythroid cells. These studies
provide therapeutic strategies for genetically inherited dysfunctions of
erythroid cells such as thalassemias and sickle cell anemia. Previous
efforts on this project culminated in the detailed comparison of alpha-
like and beta-like globin gene clusters between rabbit and human that
revealed several candidates for regulatory elements. (1) Despite the
requirement to balance production of alpha- and beta-globins, their genes
reside in radically different segments of the genome. The CpG islands
encompassing the rabbit alpha-globin gene may form an enhancer-
independent promoter, and this will be tested by measuring the levels of
expression in cells transfected with a series of constructs varying size,
number and composition of CpG islands, and by attempting to resurrect an
inactive CpG island by addition of active 5' flanking sequences. The
ability of fragments of the alpha-globin gene to serve as enhancers will
be tested, sequence-specific binding proteins will be purified, and cDNA
clones encoding them isolated to aid in structural characterization.
These proteins will be compared with those enriched in the CpG-rich
fraction of chromatin. (2) Strong regulatory elements located distally
in the rabbit beta- and alpha-like globin gene clusters (called locus
control regions) will be sequenced, compared to homologous regions in
humans and other mammals, and tested for enhancer function, independence
from position effects, impact on developmental control and scaffold
attachment. (3) Finally, striking patterns of sequence matches are seen
in comparisons of rabbit and human epsilon-globin genes and the enhancer
located 3' to the beta-globin gene. These conserved sequences will be
tested for ability to affect expression of linked reporter genes and to
bind nuclear proteins specifically. Novel proteins will be purified and
characterized.
StatusFinished
Effective start/end date12/1/806/30/02

Funding

  • National Institutes of Health
  • National Institutes of Health
  • National Institutes of Health
  • National Institutes of Health
  • National Institutes of Health: $153,842.00
  • National Institutes of Health
  • National Institutes of Health: $199,439.00
  • National Institutes of Health: $208,094.00
  • National Institutes of Health
  • National Institutes of Health: $202,033.00
  • National Institutes of Health
  • National Institutes of Health
  • National Institutes of Health
  • National Institutes of Health
  • National Institutes of Health: $214,338.00
  • National Institutes of Health: $49,105.00
  • National Institutes of Health: $162,738.00

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Globins
beta-Globins
Locus Control Region
Gene Expression
alpha-Globins
Genes
Deoxyribonucleases
Rabbits
Conserved Sequence
Chromatin
Thalassemia
Multigene Family
Proteins
Sickle Cell Anemia
CpG Islands
Erythroid Cells
Carrier Proteins
Developmental Biology
K562 Cells
Hematopoiesis