Role of a 5'-enhancer in the transcriptional regulation of the human endothelial cell protein C receptor gene.
The endothelial cell protein C receptor (EPCR) is expressed by endothelial cells of large blood vessels and by hematopoietic stem cells. DNaseI hypersensitive (DH) site mapping across 38 kb of the human EPCR gene (hEPCR) locus identified 3 potential regulatory elements. By itself, the DH region spanning the proximal promoter (PP) was unable to direct cell-specific transcription in transgenic mice. A second DH element, located upstream of PP and termed -5.5HS was hypersensitive only in endothelial cells (ECs) and immature hematopoietic cell lines. Transgenes expressing LacZ under the control of -5.5HS coupled to either PP or the SV40 promoter were able to direct beta-galactosidase activity to the endothelium of large vessels during embryogenesis and adulthood. The -5.5HS exhibited enhancer activity that was conferred by the interplay of transcription factors interacting with conserved Ets and composite GATA/Tal1 motifs. The third DH element, located in intron 2, was primarily hypersensitive in EPCR-negative cells, and capable of initiating antisense transcription, suggesting a role in hEPCR silencing. This study identifies critical elements required for the tissue specificity of hEPCR and suggests a mechanism for endothelial and hematopoietic stem cell-specific transcriptional regulation that reflects the common origin of these cell types.
Mollica
Luigina R
LR
Department of Haematology, Imperial College London, UK. l.mollica@imperial.ac.uk
Crawley
James T B
JT
Liu
Ke
K
Rance
James B
JB
Cockerill
Peter N
PN
Follows
George A
GA
Landry
Josette-Renee
JR
Wells
Dominic J
DJ
Lane
David A
DA
D024506:5' Flanking Region / Q000235:genetics*; D000818:Animals; D015703:Antigens, CD / Q000096:biosynthesis / Q000235:genetics*; D042783:Endothelial Cells / Q000166:cytology / Q000502:physiology*; D000074283:Endothelial Protein C Receptor; D004742:Enhancer Elements, Genetic / Q000235:genetics*; D020868:Gene Silencing; D006367:HeLa Cells; D006412:Hematopoietic Stem Cells / Q000166:cytology / Q000502:physiology; D006801:Humans; D051379:Mice; D008822:Mice, Transgenic; D009928:Organ Specificity / Q000235:genetics; D011956:Receptors, Cell Surface / Q000096:biosynthesis / Q000235:genetics*; D014158:Transcription, Genetic / Q000235:genetics*; D019076:Transgenes / Q000235:genetics; D020298:U937 Cells
D015703:Antigens, CD; D000074283:Endothelial Protein C Receptor; C478370:PROCR protein, human; D011956:Receptors, Cell Surface