IFN-gamma and lipopolysaccharide induce DNA binding of transcription factor PU.1 in murine tissue macrophages.
The transcription factor PU.1, the Spi-1 oncogene product, is found principally in B cells and macrophages. PU.1 binds to a purine-rich sequence of DNA with a core consensus sequence of 5'-GAGGAA-3'. By using an electrophoretic mobility shift assay, we have been able to identify PU.1 in nuclear extracts of murine tissue macrophages. When macrophages are stimulated with IFN-gamma, an increase in PU.1 binding is observed. This increase is gradual, peaking at 6 to 9 h and decaying to basal levels 24 h after stimulation. The increase in PU.1 binding is unaffected by inhibiting protein synthesis, but is attenuated by either an inhibitor of the NA+/H+ antiporter or elevations in cAMP. In addition, we have found that low doses (1 ng/ml) of bacterial LPS induce PU.1 binding.
Shackelford
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Department of Pathology, Duke University Medical Center, Durham, NC 27710.
Adams
D O
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Johnson
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D000818:Animals; D001483:Base Sequence; D002478:Cells, Cultured; D000242:Cyclic AMP / Q000502:physiology; D004247:DNA / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D007371:Interferon-gamma / Q000502:physiology*; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008264:Macrophages / Q000187:drug effects / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D015682:Retroviridae Proteins, Oncogenic; D000254:Sodium-Potassium-Exchanging ATPase / Q000037:antagonists & inhibitors
D004268:DNA-Binding Proteins; D008070:Lipopolysaccharides; D015682:Retroviridae Proteins, Oncogenic; C062022:v-Spi-1 protein, Friend spleen focus-forming virus; D007371:Interferon-gamma; D004247:DNA; D000242:Cyclic AMP; D000254:Sodium-Potassium-Exchanging ATPase