Since the expression of globin genes is regulated in both a temporal and tissue-specific manner, the globin gene family represents a model system for the study of gene regulation in mammalian development. Insights into the molecular basis of hemoglobin switching may also lead to new therapies for inherited anemias such as sickle cell disease and beta- thalassemia. We have recently identified a DNA binding factor (pyr factor, or PYR-F) which is restricted to blood cells late in development and which binds to a putative regulatory site for fetal-to-adult globin gene switching. The PYR-F binding site is capable of adopting a complex secondary structure composed of triple-and single-stranded segments (H- DNA), which is believed to be important in gene regulation. The highly restricted tissue- and developmental stage-specific pattern of PYR-F DNA binding activity, the location of its binding site, and the ability of the binding site to adopt a non-B DNA structure suggests that PYR-F may function in hematopoietic cell development and hemoglobin switching. This proposal outlines a plan to determine the structure and function of PYR-F by: (1) studying the effect of deleting the PYR-F binding site on the control of human hemoglobin switching in transgenic mice; (2) purification of PYR-F to homogeneity, with the ultimate goal of using amino acid sequence data to obtain a cDNA clone; (3) using the mouse PYR- F cDNA clone is to isolate the human cDNA and mouse and human genomic DNA clones; and (4) studying the function of PYR-F in blood cell development by creating a targeted mutation of the PYR-F gene in mouse embryonic stem cells.

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Clinical Investigator Award (CIA) (K08)
Project #
5K08DK002260-05
Application #
2608336
Study Section
Diabetes, Endocrinology and Metabolic Diseases B Subcommittee (DDK)
Program Officer
Bishop, Terry Rogers
Project Start
1993-12-01
Project End
1998-11-30
Budget Start
1997-12-10
Budget End
1998-11-30
Support Year
5
Fiscal Year
1998
Total Cost
Indirect Cost
Name
Columbia University (N.Y.)
Department
Pathology
Type
Schools of Medicine
DUNS #
167204994
City
New York
State
NY
Country
United States
Zip Code
10032
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Xue, H; O'Neill, D; Morrow, J et al. (1999) A novel mouse gene, HemT, encoding an hematopoietic cell-specific transcript. Gene 231:49-58