The human beta 2 integrin CD18 promoter consists of two inverted Ets cis elements.
To define the minimal promoter responsible for expression of CD18 in myeloid and lymphoid cells, we generated 5' and 3' deletion constructs of a segment extending 785 bp upstream and 19 bp downstream of a major transcription start site and determined their effects on driving expression of the luciferase reporter gene in transfected hematopoietic cell lines. A region extending from nucleotides (nt) -302 to +19 was sufficient for cell-restricted and phorbol ester-inducible expression. DNase I footprinting of this region revealed two adjacent protected segments extending from nt -81 to -68 (box A) and -55 to -41 (box B). When a construct of 47 nt in length containing box A and box B and lacking other 3' or 5' elements was cloned into a promoterless vector, it conferred tissue-specific and phorbol ester-inducible expression. Gel retardation revealed that the protein components of two major protein-DNA complexes that form on both box A and box B and are required for transcriptional activation are members of the Ets oncoprotein family; one is related to the GA-binding protein (GABP), and the other is related to PU.1/Spi-1. The minimal CD18 promoter, lacking TATA, CAAT, and initiator elements and consisting primarily of Ets repeats, may exemplify an emerging class of promoters with which the concerted binding of Ets factors is necessary and sufficient to mediate transcriptional activation through direct recruitment of the basal transcription machinery.
Böttinger
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EP
Department of Medicine, Harvard Medical School, Charlestown, Massachusetts.
Shelley
C S
CS
Farokhzad
O C
OC
Arnaout
M A
MA
D015703:Antigens, CD / Q000235:genetics*; D001483:Base Sequence; D001665:Binding Sites; D018821:CD18 Antigens; D002454:Cell Differentiation; D003001:Cloning, Molecular; D017931:DNA Primers; D006367:HeLa Cells; D006801:Humans; D016023:Integrins / Q000235:genetics*; D008156:Luciferases / Q000096:biosynthesis; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000378:metabolism; D016133:Polymerase Chain Reaction; D011401:Promoter Regions, Genetic; D011518:Proto-Oncogene Proteins / Q000378:metabolism*; D050783:Proto-Oncogene Proteins c-ets; D016028:Receptors, Leukocyte-Adhesion / Q000235:genetics*; D012091:Repetitive Sequences, Nucleic Acid; D017384:Sequence Deletion; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014157:Transcription Factors / Q000378:metabolism*; D014158:Transcription, Genetic; D014162:Transfection; D014407:Tumor Cells, Cultured
D015703:Antigens, CD; D018821:CD18 Antigens; D017931:DNA Primers; D016023:Integrins; D009687:Nuclear Proteins; D011518:Proto-Oncogene Proteins; D050783:Proto-Oncogene Proteins c-ets; D016028:Receptors, Leukocyte-Adhesion; D014157:Transcription Factors; D008156:Luciferases; D013755:Tetradecanoylphorbol Acetate