The myeloid-cell-specific c-fes promoter is regulated by Sp1, PU.1, and a novel transcription factor.
The protein product of the c-fps/fes (c-fes) proto-oncogene has been implicated in the normal development of myeloid cells (macrophages and neutrophils). mRNA for c-fes has been detected exclusively in myeloid cells and vascular endothelial cells in adult mammals. Although a 13-kilobase-pair (kb) human c-fes transgene exhibits high levels of expression in mice, the sequences that confer myeloid-cell-specific expression of the human c-fes gene have not been defined. Transient-transfection experiments demonstrated that plasmids containing 446 bp of c-fes 5'-flanking sequences linked to a luciferase reporter gene were active exclusively in myeloid cells. No other DNA element within the 13-kb human c-fes locus contained positive cis-acting elements, with the exception of a weakly active region within the 3'-flanking sequences. DNase I footprinting assays revealed four distinct sites that bind myeloid nuclear proteins (-408 to -386, -293 to -254, -76 to -65, and -34 to +3). However, the first two footprints resided in sequences that were largely dispensable for transient activity. Plasmids containing 151 bp of 5'-flanking sequences confer myeloid-cell-specific gene expression. Electrophoretic mobility shift analyses demonstrated that the 151-bp region contains nuclear protein binding sites for Sp1, PU.1, and/or Elf-1, and a novel factor. This unidentified factor binds immediately 3' of the PU.1/Elf-1 sites and appears to be myeloid cell specific. Mutation of the PU.1/Elf-1 site or the 3' site (FP4-3') within the context of the c-fes promoter resulted in substantially reduced activity in transient transfections. Furthermore, transient-cotransfection assay demonstrated that PU.1 (and not Elf-1) can transactivate the c-fes promoter in nonmyeloid cell lines. We conclude that the human c-fes gene contains a strong myeloid-cell-specific promoter that is regulated by Sp1, PU.1, and a novel transcription factor.
Heydemann
A
A
Department of Molecular Genetics and Cell Biology, University of Chicago, Illinois 60637, USA.
Juang
G
G
Hennessy
K
K
Parmacek
M S
MS
Simon
M C
MC
D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D006801:Humans; D008264:Macrophages / Q000378:metabolism; D051379:Mice; D008969:Molecular Sequence Data; D009504:Neutrophils / Q000378:metabolism; D011401:Promoter Regions, Genetic; D011505:Protein-Tyrosine Kinases / Q000235:genetics*; D000090063:Proto-Oncogene Mas; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D051578:Proto-Oncogene Proteins c-fes; D011519:Proto-Oncogenes; D016329:Sp1 Transcription Factor / Q000235:genetics*; D015534:Trans-Activators; D000099232:Proto-Oncogene Protein Spi-1
D011505:Protein-Tyrosine Kinases; D000090063:Proto-Oncogene Mas; D011518:Proto-Oncogene Proteins; D051578:Proto-Oncogene Proteins c-fes; D016329:Sp1 Transcription Factor; D015534:Trans-Activators; D000099232:Proto-Oncogene Protein Spi-1; C000715470:MAS1 protein, human; C496645:FES protein, human; C496646:Fes protein, mouse