title: Endoglin expression in blood and endothelium is differentially regulated by modular assembly of the Ets/Gata hemangioblast code.
abstract: Endoglin is an accessory receptor for TGF-beta signaling and is required for normal hemangioblast, early hematopoietic, and vascular development. We have previously shown that an upstream enhancer, Eng -8, together with the promoter region, mediates robust endothelial expression yet is inactive in blood. To identify hematopoietic regulatory elements, we used array-based methods to determine chromatin accessibility across the entire locus. Subsequent transgenic analysis of candidate elements showed that an endothelial enhancer at Eng +9 when combined with an element at Eng +7 functions as a strong hemato-endothelial enhancer. Chromatin immunoprecipitation (ChIP)-chip analysis demonstrated specific binding of Ets factors to the promoter as well as to the -8, +7+9 enhancers in both blood and endothelial cells. By contrast Pu.1, an Ets factor specific to the blood lineage, and Gata2 binding was only detected in blood. Gata2 was bound only at +7 and GATA motifs were required for hematopoietic activity. This modular assembly of regulators gives blood and endothelial cells the regulatory freedom to independently fine-tune gene expression and emphasizes the role of regulatory divergence in driving functional divergence.
authors.affiliation: Department of Haematology, Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom. jpimanda@unsw.edu.au
authors.forename: John E
authors.initials: JE
authors.lastname: Pimanda
authors.forename: Wan Y I
authors.initials: WY
authors.lastname: Chan
authors.forename: Nicola K
authors.initials: NK
authors.lastname: Wilson
authors.forename: Aileen M
authors.initials: AM
authors.lastname: Smith
authors.forename: Sarah
authors.initials: S
authors.lastname: Kinston
authors.forename: Kathy
authors.initials: K
authors.lastname: Knezevic
authors.forename: Mary E
authors.initials: ME
authors.lastname: Janes
authors.forename: Josette-Renée
authors.initials: JR
authors.lastname: Landry
authors.forename: Anja
authors.initials: A
authors.lastname: Kolb-Kokocinski
authors.forename: Jonathan
authors.initials: J
authors.lastname: Frampton
authors.forename: David
authors.initials: D
authors.lastname: Tannahill
authors.forename: Katrin
authors.initials: K
authors.lastname: Ottersbach
authors.forename: George A
authors.initials: GA
authors.lastname: Follows
authors.forename: Georges
authors.initials: G
authors.lastname: Lacaud
authors.forename: Valerie
authors.initials: V
authors.lastname: Kouskoff
authors.forename: Berthold
authors.initials: B
authors.lastname: Göttgens
mesh_terms: D000818:Animals; D015703:Antigens, CD / Q000235:genetics* / Q000378:metabolism; D001769:Blood / Q000378:metabolism*; D002454:Cell Differentiation / Q000235:genetics; D002478:Cells, Cultured; D004622:Embryo, Mammalian; D047108:Embryonic Development / Q000235:genetics; D000071063:Endoglin; D004727:Endothelium / Q000378:metabolism*; D050980:GATA Transcription Factors / Q000378:metabolism / Q000502:physiology*; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D055018:Hemangioblasts / Q000378:metabolism / Q000502:physiology*; D006413:Hematopoietic System / Q000378:metabolism; D006801:Humans; D051379:Mice; D008822:Mice, Transgenic; D020411:Oligonucleotide Array Sequence Analysis; D050784:Proto-Oncogene Protein c-ets-1 / Q000378:metabolism / Q000502:physiology*; D011956:Receptors, Cell Surface / Q000235:genetics* / Q000378:metabolism
chemical_list: D015703:Antigens, CD; C064206:ENG protein, human; D000071063:Endoglin; D050980:GATA Transcription Factors; D050784:Proto-Oncogene Protein c-ets-1; D011956:Receptors, Cell Surface