Hematopoietic Regulation of GATA Switches

GATA 开关的造血调节

• 批准号: 7364584
• 负责人: Emery H Bresnick
• 金额: $ 23.55万
• 依托单位: UNIVERSITY OF WISCONSIN-MADISON
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-02-01 至 2011-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7364584
• 关键词: Affect; Attenuated; Binding; Blood Cells; Cell Differentiation process; Cell Line; Cell Survival; Cells; Chromatin; Chromatin Structure; Code; Complex; Coupled; DNA; Development; Developmental Process; Elements; Family; Friends; Gene Targeting; Genes; Genetic Transcription; Genome; Genomics; Half-Life; Hematopoiesis; Hematopoietic; Histone Acetylation; Histones; Homeostasis; In Vitro; Mediating; Modeling; Modification; Multipotent Stem Cells; Mus; Nucleoproteins; Null Lymphocytes; Output; Pattern; Population; Process; Proteasome Inhibitor; RNA Polymerase II; Rate; Regulation; Relative (related person); Repression; Site; Specific qualifier value; Specificity; Staging; Stem cells; Testing; Time; Ubiquitination; chromatin immunoprecipitation; embryonic stem cell; human GATA1 protein; in vivo; insight; progenitor; protein protein interaction; stem; transcription factor

GATA transcription factors (GATA-1-6) regulate mammalian development. GATA-2 is important for hematopoietic stem (HSC) and multipotent progenitor cell differentiation/survival. GATA-1 and GATA-2 occupy a small subset of the binding motifs in cells and can occupy the same chromatin region at distinct developmental times, but with different functional outputs. The following Aims will analyze mechanisms that regulate GATA-2 transcription, how changes in GATA-2 levels affect hematopoiesis, and mechanisms underlying GATA factor chromatin occupancy. 1. To analyze the mechanism of the GATA switch at chromatin sites during hematopoiesis. GATA-2 has a short half-life (~1 h) and is stabilized by treatment of cells with proteasome inhibitors. When GATA-2 is stabilized, GATA-1-mediated displacement of GATA-2 from chromatin is attenuated. We will test the hypothesis that ubiquitination destabilizes GATA-2, and instability is required for GATA-1 to access GATA-2-bound chromatin sites. We will also test whether an excess of GATA-1 versus GATA-2 is required for the switch. 2. To dissect the mechanism of GATA-2 transcription in vivo. GATA-2 occupies the-2.8 kband-1.8kb regions of the active GATA-2 locus, whereas GATA-1 occupies predominantly the -2.8 kb region of the inactive locus. GATA-1 binding displaces GATA-2 from both regions and is coupled to repression. We generated targeted deletions of the -2.8 kb and -1.8 kb regions to test the hypothesis that these regions confer activation and the -2.8 kb region mediates repression. We will determine if the deletions affect assembly of the histone modification pattern, RNA polymerase II recruitment, and transcription. 3. To test whether GATA-1 and GATA-2 have differentiation stage-specific target genes. Wepropose that intrinsic features of the motifs, nearby c/s-elements, protein-protein interactions and chromatin structure constitute a GATA Recognition Code (GRC) that specifies occupancy. Elucidating the GRC requires analysis of occupancy at multiple target genes. GATA factor occupancy will be defined by quantitative chromatin immunoprecipitation (ChIP) and ChIP coupled with genomic microarrays. The studies will reveal how GATA switches regulate GATA-2 transcription, how GATA-1 and GATA-2 select DMA motifs, and insights of broad relevance to diverse developmental processes.

GATA转录因子（GATA-1-6）调节哺乳动物的发育。GATA-2对于