Molecular Basis of Drosophila Homeotic Gene Regulation The long-term goal of this research is to understand the molecular mechanisms underlying stable long-term maintenance of the patterns of homeotic gene expression during Drosophila development. The Trithorax Group (trxG) and Polycomb Group (PcG) proteins are directly involved in this process and are respectively required to maintain active and inactive transcriptional states established in the early embryo. Evidence suggests that they function by promoting stable changes in local chromatin structure. This proposal is to investigate the role of a Polycomb Group complex containing the ESC, E(Z), SU(Z)12 and p55 proteins as well as complexes containing TRX. These proteins have been highly conserved in diverse phyla, suggesting that their fundamental functions are ancient and highly conserved. Understanding how they function will provide new insights into the mechanisms of transcriptional regulation as well as the mechanisms underlying development of normal body plans in animals. Genetic, molecular and biochemical approaches will be used investigate their functions. We have identified ESC/E(Z) complexes associated with the histone deacetylase RPD3, implicating histone deacetylation in the mechanism of ESC/E(Z) action. TRX and PcG proteins act through the same DNA response elements, suggesting that their antagonistic activities must be managed locally at PREs. We are investigating a new protein that may provide some insights into how this regulation occurs. We will continue to investigate a number of newly identified proteins associated with ESC/E(Z) complexes and TRX complexes that are providing new insights into how the enzymatic activities of ESC/E(Z) complexes function in the epigenetic inheritance of repressed and active chromatin states. We are determining how they function in concert with TRX and ESC/E(Z) complexes to promote maintenance of transcriptional states. Mutations in the human TRX homolog MLL are associated with acute leukemias, while several human PeG proteins are implicated in immune system dysfunction and tumorigenesis. Understanding the fundamental mechanism of action of TRX and ESC/E(Z) complexes in the context of development should also provide insights into the role of their human homologs in disease.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM039255-15
Application #
6875753
Study Section
Genetics Study Section (GEN)
Program Officer
Carter, Anthony D
Project Start
1988-04-01
Project End
2008-03-31
Budget Start
2005-04-01
Budget End
2006-03-31
Support Year
15
Fiscal Year
2005
Total Cost
$399,483
Indirect Cost
Name
Case Western Reserve University
Department
Genetics
Type
Schools of Medicine
DUNS #
077758407
City
Cleveland
State
OH
Country
United States
Zip Code
44106
Tie, Feng; Banerjee, Rakhee; Fu, Chen et al. (2016) Polycomb inhibits histone acetylation by CBP by binding directly to its catalytic domain. Proc Natl Acad Sci U S A 113:E744-53
Du, Juan; Zhang, Junzheng; He, Tao et al. (2016) Stuxnet Facilitates the Degradation of Polycomb Protein during Development. Dev Cell 37:507-19
Tie, Feng; Banerjee, Rakhee; Saiakhova, Alina R et al. (2014) Trithorax monomethylates histone H3K4 and interacts directly with CBP to promote H3K27 acetylation and antagonize Polycomb silencing. Development 141:1129-39
Mason-Suares, Heather; Tie, Feng; Yan, Christopher M et al. (2013) Polycomb silencing of the Drosophila 4E-BP gene regulates imaginal disc cell growth. Dev Biol 380:111-24
Tie, Feng; Banerjee, Rakhee; Conrad, Patricia A et al. (2012) Histone demethylase UTX and chromatin remodeler BRM bind directly to CBP and modulate acetylation of histone H3 lysine 27. Mol Cell Biol 32:2323-34
Stepanik, Vincent A; Harte, Peter J (2012) A mutation in the E(Z) methyltransferase that increases trimethylation of histone H3 lysine 27 and causes inappropriate silencing of active Polycomb target genes. Dev Biol 364:249-58
Tie, Feng; Banerjee, Rakhee; Stratton, Carl A et al. (2009) CBP-mediated acetylation of histone H3 lysine 27 antagonizes Drosophila Polycomb silencing. Development 136:3131-41
Kurzhals, Rebeccah L; Tie, Feng; Stratton, Carl A et al. (2008) Drosophila ESC-like can substitute for ESC and becomes required for Polycomb silencing if ESC is absent. Dev Biol 313:293-306
Tie, Feng; Stratton, Carl A; Kurzhals, Rebeccah L et al. (2007) The N terminus of Drosophila ESC binds directly to histone H3 and is required for E(Z)-dependent trimethylation of H3 lysine 27. Mol Cell Biol 27:2014-26
Tie, Feng; Siebold, Alex P; Harte, Peter J (2005) The N-terminus of Drosophila ESC mediates its phosphorylation and dimerization. Biochem Biophys Res Commun 332:622-32

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