Targets of the transcriptional repressor oncoprotein Gfi-1.
Gfi-1 is a zinc finger transcriptional repressor originally recognized for its role in T cell differentiation and lymphomas. Recent experiments reveal that gene-targeted Gfi-1-deficient mice are neutropenic and that Gfi-1 mutations cause human neutropenia. In both cases, myeloid progenitor cells lose the ability to distinctly differentiate granulocytes from monocytes. The molecular mechanism of the hematopoietic abnormalities caused by Gfi-1 deficiency remains undetermined because of a lack of known Gfi-1 target genes. To identify Gfi-1 targets in vivo, we performed large-scale chromatin immunoprecipitation analysis on a set of 34 candidate genes in myeloblast (KG-1 and HL-60), monoblast (U937), and T lymphocyte cell lines (Jurkat), in concert with RT-PCR-based expression profiling. We identified 32 Gfi-1 binding sites in a functionally variable set of 16 genes, including complements of cell-cycle regulators, transcription factors, and granulocyte-specific markers. Cluster analysis of expression patterns and chromatin immunoprecipitation data reveals that Gfi-1 targets a subset of genes differentiating hematopoietic lineages and therefore plays a relatively superior role in the hierarchy of factors governing stem cell differentiation.
Division of Medical Genetics, Department of Medicine, University of Washington School of Medicine, 1705 Northeast Pacific Street, HSB-K236B, P.O. Box 357720, Seattle, WA 98195, USA.
Zhijun
Z
Duan
Marshall
M
Horwitz
D016475:3T3 Cells; D000818:Animals; D001483:Base Sequence; D002454:Cell Differentiation / Q000235:genetics; D016384:Consensus Sequence; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism*; D006412:Hematopoietic Stem Cells / Q000166:cytology*; D006801:Humans; D019169:Jurkat Cells; D051379:Mice; D011401:Promoter Regions, Genetic; D051381:Rats; D011994:Recombinant Proteins / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013379:Substrate Specificity; D014157:Transcription Factors; D014162:Transfection; D020298:U937 Cells; D016335:Zinc Fingers / Q000235:genetics
D004268:DNA-Binding Proteins; C498275:GFI1 protein, human; C079873:Gfi1 protein, mouse; C498276:Gfi1 protein, rat; D011994:Recombinant Proteins; D014157:Transcription Factors