title: A GM-colony-stimulating factor (CSF) activated ribonuclease system transregulates M-CSF receptor expression in the murine FDC-P1/MAC myeloid cell line.
abstract: The murine myeloid precursor cell line FDC-P1/MAC simultaneously expresses receptors for multi-colony-stimulating factor (CSF), granulocyte-macrophage (GM)-CSF, and macrophage (M)-CSF. Growth of FDC-P1/MAC cells in either multi-CSF or GM-CSF results in the posttranscriptional suppression of M-CSF receptor (c-fms proto-oncogene) expression. We use the term transregulation to describe this control of receptor expression and have further characterized this regulatory process. The removal of FDC-P1/MAC cells from GM-CSF stimulation resulted in the re-expression of c-fms mRNA independent of M-CSF stimulation and new protein synthesis. Switching FDC-P1/MAC cells from growth in M-CSF to GM-CSF caused the selective degradation of c-fms mRNA within 6 h after factor switching. Blocking protein synthesis or gene transcription with metabolic inhibitors effectively prevented GM-CSF stimulated degradation of c-fms mRNA. These results suggest that the transregulation of c-fms transcripts by GM-CSF requires the transcriptional activation of a selective mRNA degradation factor. In vitro analysis, the use of cytoplasmic cell extracts, provided evidence that a ribonuclease is preferentially active in GM-CSF stimulated cells, although the specificity for mRNA degradation in vitro is broader than seen in vivo. Together, these data suggest that GM-CSF can dominantly transregulate the level of c-fms transcript through the transcriptional activation of a ribonuclease degradation system.
authors.affiliation: Fred Hutchinson Cancer Research Center, Seattle, Washington 98104.
authors.forename: B C
authors.initials: BC
authors.lastname: Gliniak
authors.forename: L S
authors.initials: LS
authors.lastname: Park
authors.forename: L R
authors.initials: LR
authors.lastname: Rohrschneider
mesh_terms: D000818:Animals; D002460:Cell Line; D003513:Cycloheximide / Q000494:pharmacology; D003609:Dactinomycin / Q000494:pharmacology; D005786:Gene Expression Regulation / Q000502:physiology*; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000502:physiology*; D051379:Mice; D011499:Protein Processing, Post-Translational / Q000502:physiology*; D012333:RNA, Messenger / Q000378:metabolism; D016186:Receptor, Macrophage Colony-Stimulating Factor / Q000378:metabolism*; D016184:Receptors, Colony-Stimulating Factor; D012260:Ribonucleases / Q000378:metabolism; D014158:Transcription, Genetic / Q000502:physiology
chemical_list: D012333:RNA, Messenger; D016184:Receptors, Colony-Stimulating Factor; D003609:Dactinomycin; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D003513:Cycloheximide; D016186:Receptor, Macrophage Colony-Stimulating Factor; D012260:Ribonucleases