We have continued our studies of chromatin structure in the neighborhood of expressed genes. The globin gene family in chicken erythroid cells serves as a model system in which it is possible to study the mechanisms associated with regulation of the individual members of the family during erythroid development. We have extended our studies of the way in which hypersensitive sites are generated in the chicken beta globin enhancer and in constructions carrying various parts of the enhancer. A new assay allows separation of cells in which the enhancer is transcriptionally active from those in which it is not, so that the role of chromatin structure in switching can be explored. We have also exploited our earlier analysis of the binding of the erythroid regulatory factor GATA-1 carboxy-terminal zinc finger to DNA to study the way in which GATA-1 interacts with nucleosome core particles. Separate studies of the interactions of GATA-1 with target DNA have revealed an important role for the amino-terminal finger in binding to special sites found upstream of all the known GATA-1 genes. We have also studied the properties of the regulatory factor called the GAGA protein, which is implicated in disruption of chromatin structure. We find that the single zinc finger of this protein confers strong specific binding on the protein, mediated by a nearby sequence of basic residues. This is the first zinc finger of the class containing two cysteines and two histidines shown to bind as a single finger, and suggests that many other known proteins of this type might be studied for DNA binding properties. We have also continued studies of the way in which RNA polymerase transcribes through chromatin templates. We have extended our model system to isolate complexes in which the polymerase is arrested at the half way point on the template. It is immediately after this that the histone octamer transfers behind the nucleosome. The structure of this intermediate is being studied.

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Intramural Research (Z01)
Project #
1Z01DK034001-31
Application #
2573027
Study Section
Special Emphasis Panel (LMB)
Project Start
Project End
Budget Start
Budget End
Support Year
31
Fiscal Year
1996
Total Cost
Indirect Cost
City
State
Country
United States
Zip Code
Gaszner, Miklos; Felsenfeld, Gary (2006) Insulators: exploiting transcriptional and epigenetic mechanisms. Nat Rev Genet 7:703-13
Jin, Chunyuan; Felsenfeld, Gary (2006) Distribution of histone H3.3 in hematopoietic cell lineages. Proc Natl Acad Sci U S A 103:574-9
Huang, Suming; Litt, Michael; Felsenfeld, Gary (2005) Methylation of histone H4 by arginine methyltransferase PRMT1 is essential in vivo for many subsequent histone modifications. Genes Dev 19:1885-93
Studitsky, Vasily M; Walter, Wendy; Kireeva, Maria et al. (2004) Chromatin remodeling by RNA polymerases. Trends Biochem Sci 29:127-35
Yusufzai, Timur M; Tagami, Hideaki; Nakatani, Yoshihiro et al. (2004) CTCF tethers an insulator to subnuclear sites, suggesting shared insulator mechanisms across species. Mol Cell 13:291-8
Yusufzai, Timur M; Felsenfeld, Gary (2004) The 5'-HS4 chicken beta-globin insulator is a CTCF-dependent nuclear matrix-associated element. Proc Natl Acad Sci U S A 101:8620-4
Felsenfeld, G; Burgess-Beusse, B; Farrell, C et al. (2004) Chromatin boundaries and chromatin domains. Cold Spring Harb Symp Quant Biol 69:245-50
Felsenfeld, Gary (2004) Obituary. Robert Simpson. Nucleic Acids Res 32:2975-6
Magdinier, Frederique; Yusufzai, Timur M; Felsenfeld, Gary (2004) Both CTCF-dependent and -independent insulators are found between the mouse T cell receptor alpha and Dad1 genes. J Biol Chem 279:25381-9
Ghirlando, Rodolfo; Litt, Michael D; Prioleau, Marie-Noelle et al. (2004) Physical properties of a genomic condensed chromatin fragment. J Mol Biol 336:597-605

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