Cell-restricted transcriptional modulators play critical roles in the process of selective gene regulation during hematopoiesis. We have been investigating the molecular and biological function of Erythroid Kr|ppel-like Factor (EKLF). EKLF is a cell-restricted transcription factor that is essential for completion of the erythroid program. Transcriptional activation is accomplished by its interaction with and modification by coactivators that lead to changes in chromatin structure and the onset of transcription, a process best established at the adult ?-globin locus. We find that EKLF also interacts with components of the nucleosome and of the transcriptional initiation complex, and propose in Aim 1 to illuminate how these varied interactions are integrated and properly assembled, leading to epigenetic modifications as a result of EKLF's actions. However, EKLF's general role is becoming increasingly more complex, as it is also expressed in the megakaryocyte-erythroid progenitor and interacts with two types of corepressors to repress transcription under constrained cell environments. Acetylation and sumoylation of EKLF play critical roles in the protein-protein contacts that are important for these effects, and the experiments of Aim 2 will decipher how these interactions are manifested within native repression targets. Finally, significant levels of EKLF reside in the cytoplasm of the erythroid cell in a form that shows subtle biochemical and functional differences compared to its nuclear version. The experiments of Aim 3 will address whether EKLF plays a role outside of the nucleus by isolating and characterizing cytoplasmic EKLF complexes. These studies will be aided by the use of in vivo chromatin binding assays and EKLF rescue systems in primary or minimally manipulated cells. Elucidating EKLF's role in regulatory phenomena will continue to illuminate novel aspects of erythroid biology and the essential mechanisms by which a cell-restricted transcription factor can exert varied yet highly controlled influences on expression that lead to genetic and epigenetic changes.

Public Health Relevance

This proposal focuses on a continuing investigation of EKLF structure/function and how its post- translational modifications, protein-protein interactions, and protein-DNA interactions relate to its ability to generate erythroid cell-specific control of gene expression. ? ? ?

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Research Project (R01)
Project #
2R01DK046865-16
Application #
7522821
Study Section
Erythrocyte and Leukocyte Biology Study Section (ELB)
Program Officer
Bishop, Terry Rogers
Project Start
1993-08-01
Project End
2012-05-31
Budget Start
2008-06-15
Budget End
2009-05-31
Support Year
16
Fiscal Year
2008
Total Cost
$340,591
Indirect Cost
Name
Icahn School of Medicine at Mount Sinai
Department
Biology
Type
Schools of Medicine
DUNS #
078861598
City
New York
State
NY
Country
United States
Zip Code
10029
Nébor, Danitza; Graber, Joel H; Ciciotte, Steven L et al. (2018) Mutant KLF1 in Adult Anemic Nan Mice Leads to Profound Transcriptome Changes and Disordered Erythropoiesis. Sci Rep 8:12793
Gnanapragasam, Merlin Nithya; Crispino, John D; Ali, Abdullah M et al. (2018) Survey and evaluation of mutations in the human KLF1 transcription unit. Sci Rep 8:6587
Gnanapragasam, Merlin Nithya; Bieker, James J (2017) Orchestration of late events in erythropoiesis by KLF1/EKLF. Curr Opin Hematol 24:183-190
Planutis, Antanas; Xue, Li; Trainor, Cecelia D et al. (2017) Neomorphic effects of the neonatal anemia (Nan-Eklf) mutation contribute to deficits throughout development. Development 144:430-440
Perkins, Andrew; Xu, Xiangmin; Higgs, Douglas R et al. (2016) Krüppeling erythropoiesis: an unexpected broad spectrum of human red blood cell disorders due to KLF1 variants. Blood 127:1856-62
Lohmann, Felix; Dangeti, Mohan; Soni, Shefali et al. (2015) The DEK Oncoprotein Is a Critical Component of the EKLF/KLF1 Enhancer in Erythroid Cells. Mol Cell Biol 35:3726-38
Siatecka, Miroslawa; Soni, Shefali; Planutis, Antanas et al. (2015) Transcriptional activity of erythroid Kruppel-like factor (EKLF/KLF1) modulated by PIAS3 (protein inhibitor of activated STAT3). J Biol Chem 290:9929-40
Yien, Yvette Y; Gnanapragasam, Merlin Nithya; Gupta, Ritama et al. (2015) Alternative splicing of EKLF/KLF1 in murine primary erythroid tissues. Exp Hematol 43:65-70
Varricchio, Lilian; Dell'Aversana, Carmela; Nebbioso, Angela et al. (2014) Identification of NuRSERY, a new functional HDAC complex composed by HDAC5, GATA1, EKLF and pERK present in human erythroid cells. Int J Biochem Cell Biol 50:112-22
Manwani, Deepa; Bieker, James J (2014) KLF1: when less is more. Blood 124:672-3

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