title: p120 nucleolar-proliferating antigen is a direct target of G-CSF signaling during myeloid differentiation.
abstract: Granulocyte-colony stimulating factor (G-CSF) is an essential cytokine, which contributes to proliferation and differentiation of granulocyte precursor cells in the bone marrow. Despite recent progress in understanding G-CSF signaling events, the mechanisms that underlie the distinct spectrum of biological functions attributed to G-CSF-mediated gene expression remain unclear. Previous studies have identified a number of genes, which are up-regulated in G-CSF-stimulated myeloid precursor cells. In this study, we sought to identify additional target genes of G-CSF-mediated proliferation and/or differentiation. cDNA representational difference analysis was used with the 32Dcl3 cell line as a model system to isolate genes, which are up-regulated in an immediate-early manner upon G-CSF stimualtion. We isolated p120 nucleolar-proliferation antigen (NOL1), a highly conserved, nucleolar-specific, RNA-binding protein of unknown function, and confirmed its expression by Northern blot analysis in 4-h, G-CSF-induced 32Dcl3 cells. Isolation of a mouse p120 genomic clone revealed the presence of a signal tranducer and activator of transcription (STAT)-binding site in the first intron of the gene. We demonstrate the importance of STAT3 and STAT5 in mediating the G-CSF response with respect to p120 expression by transient transfection analysis, oligonucleotide pull-down assays, and the loss of p120 expression in the bone marrow of mice lacking normal STAT3 signaling. In addition, overexpression of p120 in G-CSF-induced 32D cells revealed normal, morphologic maturation and growth characteristics but loss of lactoferrin expression, a marker of normal neutrophil maturation, suggesting that inappropriate expression of the p120 gene can result in aberrant neutrophil maturation.
authors.affiliation: Section of Hematology, Yale University School of Medicine, New Haven, CT 06510, USA. arati.gupta@yale.edu
authors.forename: Arati
authors.initials: A
authors.lastname: Khanna-Gupta
authors.forename: Hong
authors.initials: H
authors.lastname: Sun
authors.forename: Theresa
authors.initials: T
authors.lastname: Zibello
authors.forename: Larissa
authors.initials: L
authors.lastname: Lozovatsky
authors.forename: Prabhat K
authors.initials: PK
authors.lastname: Ghosh
authors.forename: Daniel C
authors.initials: DC
authors.lastname: Link
authors.forename: Morgan L
authors.initials: ML
authors.lastname: McLemore
authors.forename: Nancy
authors.initials: N
authors.lastname: Berliner
mesh_terms: D000818:Animals; D001483:Base Sequence / Q000235:genetics; D001665:Binding Sites / Q000235:genetics; D002454:Cell Differentiation / Q000235:genetics / Q000276:immunology*; D005786:Gene Expression Regulation / Q000235:genetics / Q000276:immunology; D016179:Granulocyte Colony-Stimulating Factor / Q000378:metabolism*; D006801:Humans; D007438:Introns / Q000235:genetics; D007781:Lactoferrin / Q000235:genetics / Q000378:metabolism; D007951:Leukemia, Myeloid / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D051379:Mice; D008822:Mice, Transgenic; D022423:Myeloid Cells / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D023461:Myeloid Progenitor Cells / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D041681:NIH 3T3 Cells; D009504:Neutrophils / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D011401:Promoter Regions, Genetic / Q000235:genetics; D011496:Protein Methyltransferases; D050796:STAT3 Transcription Factor / Q000235:genetics / Q000276:immunology; D050799:STAT5 Transcription Factor / Q000235:genetics / Q000276:immunology; D015398:Signal Transduction / Q000235:genetics / Q000276:immunology; D015854:Up-Regulation / Q000235:genetics / Q000276:immunology; D012359:tRNA Methyltransferases
chemical_list: D009687:Nuclear Proteins; D050796:STAT3 Transcription Factor; D050799:STAT5 Transcription Factor; C494087:Stat3 protein, mouse; D016179:Granulocyte Colony-Stimulating Factor; C065028:NOP2 protein, human; C512901:Nop2 protein, mouse; D011496:Protein Methyltransferases; D012359:tRNA Methyltransferases; D007781:Lactoferrin