Control of granulocyte-macrophage colony-stimulating factor production in normal endothelial cells by positive and negative regulatory elements.
Granulocyte-macrophage (GM)-CSF is an acidic glycoprotein involved in the hemopoietic response to inflammation and in the functional activation of mature blood cells. The protein is produced in response to a number of inflammatory mediators by mesenchymal cells present in the hemopoietic microenvironment and at peripheral sites of inflammation. To understand the molecular basis for the regulation of GM-CSF gene expression, nuclear run-on assays and a functional analysis of potential regulatory sequences were performed in normal human endothelial cells. These studies suggest that GM-CSF is regulated by both transcriptional and post-transcriptional mechanisms. By using hybrid constructs containing a reporter gene and varying lengths of the regions flanking the human GM-CSF gene, a 14-bp sequence was identified in the region upstream of the GM-CSF cap site which increased reporter expression in response to a number of inflammatory mediators. In addition, despite a failure to detect GM-CSF-specific RNA or protein in unstimulated cells, basal transcription from the GM-CSF promoter was readily detectable. To account for this apparent discrepancy, sequences present in the 3' untranslated region of the GM-CSF gene were found to substantially reduce the level of reporter gene expression in a number of cell types. Homologous sequences are found in other genes which share a similar pattern of expression, and may provide the molecular basis for the coordinate regulation of multiple inflammatory response genes.
Kaushansky
K
K
Department of Medicine, University of Washington, Seattle 98195.
D001483:Base Sequence; D003115:Colony-Stimulating Factors / Q000096:biosynthesis* / Q000235:genetics; D004730:Endothelium, Vascular / Q000378:metabolism* / Q000502:physiology; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D006133:Growth Substances / Q000096:biosynthesis* / Q000235:genetics; D006801:Humans; D007375:Interleukin-1 / Q000494:pharmacology; D007399:Interphase; D008969:Molecular Sequence Data; D009928:Organ Specificity; D011401:Promoter Regions, Genetic; D012045:Regulatory Sequences, Nucleic Acid; D014158:Transcription, Genetic
D003115:Colony-Stimulating Factors; D006133:Growth Substances; D007375:Interleukin-1; D016178:Granulocyte-Macrophage Colony-Stimulating Factor