GONUTS has been updated to MW1.31 Most things seem to be working but be sure to report problems.

Have any questions? Please email us at ecoliwiki@gmail.com

PMID:10233885

From GONUTS
Jump to: navigation, search
Citation

Verbeek, W, Gombart, AF, Chumakov, AM, Müller, C, Friedman, AD and Koeffler, HP (1999) C/EBPepsilon directly interacts with the DNA binding domain of c-myb and cooperatively activates transcription of myeloid promoters. Blood 93:3327-37

Abstract

C/EBPepsilon is essential for granulocytic differentiation. We investigated the role of C/EBPepsilon in the transcriptional activation of various myeloid-specific genes. We found that two C/EBPepsilon isoforms, p32 and p30, possessing transcriptional activation domains were coexpressed in myeloid cells. Interestingly, isoform C/EBPepsilon p30 but not p32 was differentially upregulated in NB-4 promyelocytic leukemia cells treated with retinoids. Both isoforms bound specifically to C/EBP sites in myeloid promoters. The kd for C/EBPepsilon binding to the C/EBP site of the neutrophil elastase promoter was 4.2 nmol/L. In transfection assays using the nonhematopoietic cell line, CV-1, the p32 isoform activated promoters from the myeloid-specific mim-1, neutrophil elastase, and granulocyte colony-stimulating factor (G-CSF) receptor genes by 2.5-, 1.8-, and 1.6-fold, respectively. The p30 isoform lacked significant transcriptional activity, suggesting that other hematopoietic-specific factors were required for its function. Consistent with this prediction, transfections into the hematopoietic cell line Jurkat showed a 9.0- and 2.5-fold activation of the mim-1 promoter by the p32 and p30 isoforms, respectively. The additional 32 NH2-terminal residues made p32 a significantly more potent transcriptional activator than p30. T lymphoblasts (Jurkat cells) and immature myeloid cells (eg, Kcl22 cells) expressed high levels of the c-myb hematopoietic transcription factor. Cotransfection of c-myb with either the p32 or p30 isoform of C/EBPepsilon in CV-1 cells cooperatively transactivated the mim-1 promoter by 20- and 16-fold, respectively, and the neutrophil elastase promoter by 10-and 7-fold, respectively. Pulldown assays showed that each C/EBPepsilon isoform interacted directly with the DNA binding domain of the c-myb protein. Further studies showed that Kcl22 myeloid cells only contained active C/EBPepsilon, but not C/EBPalpha, C/EBPbeta, or C/EBPdelta. A mutation of the C/EBP site in the neutrophil elastase promoter markedly decreased the transactivation of the promoter in Kcl22 myeloblasts. These results demonstrate a role for C/EBPepsilon in regulating myeloid promoters, such as neutrophil elastase, probably through a direct interaction with c-myb.

Links

PubMed

Keywords

Animals; Binding Sites; CCAAT-Enhancer-Binding Proteins; COS Cells; Cell Nucleus/metabolism; Cloning, Molecular; DNA-Binding Proteins/metabolism; Genes, Reporter; Hematopoiesis/genetics; Humans; Jurkat Cells; Leukocyte Elastase/genetics; Mice; Oncogenes; Promoter Regions, Genetic; Protein Biosynthesis; Protein Isoforms/genetics; Protein Isoforms/metabolism; Proto-Oncogene Proteins/genetics; Proto-Oncogene Proteins/metabolism; Proto-Oncogene Proteins c-myb; Recombinant Fusion Proteins/biosynthesis; Trans-Activators/genetics; Trans-Activators/metabolism; Transcription Factors/genetics; Transcription Factors/metabolism; Transcription, Genetic; Transcriptional Activation; Transfection; U937 Cells

Significance

Annotations

Gene product Qualifier GO Term Evidence Code with/from Aspect Extension Notes Status

HUMAN:MYB

enables

GO:0001228: DNA-binding transcription activator activity, RNA polymerase II-specific

ECO:0000314: direct assay evidence used in manual assertion

F

  • has_input:(NCBI_Gene:1991)

Seeded From UniProt

complete

HUMAN:MYB

involved_in

GO:0045944: positive regulation of transcription by RNA polymerase II

ECO:0000314: direct assay evidence used in manual assertion

P

  • has_input:(NCBI_Gene:1991)

Seeded From UniProt

complete

MOUSE:CEBPA

enables

GO:0000978: RNA polymerase II cis-regulatory region sequence-specific DNA binding

ECO:0000314: direct assay evidence used in manual assertion

F

Seeded From UniProt

complete

MOUSE:CEBPA

enables

GO:0001228: DNA-binding transcription activator activity, RNA polymerase II-specific

ECO:0000314: direct assay evidence used in manual assertion

F

  • occurs_at:(SO:0001952)

Seeded From UniProt

complete

MOUSE:CEBPA

involved_in

GO:0045944: positive regulation of transcription by RNA polymerase II

ECO:0000314: direct assay evidence used in manual assertion

P

  • has_input:(NCBI_Gene:1441)

Seeded From UniProt

complete

HUMAN:CEBPE

enables

GO:0000978: RNA polymerase II cis-regulatory region sequence-specific DNA binding

ECO:0000314: direct assay evidence used in manual assertion

F

Seeded From UniProt

complete

HUMAN:CEBPE

enables

GO:0001228: DNA-binding transcription activator activity, RNA polymerase II-specific

ECO:0000314: direct assay evidence used in manual assertion

F

  • occurs_at:(SO:0001952)

Seeded From UniProt

complete

HUMAN:CEBPE

involved_in

GO:0045944: positive regulation of transcription by RNA polymerase II

ECO:0000314: direct assay evidence used in manual assertion

P

  • has_input:(NCBI_Gene:1441)

Seeded From UniProt

complete

MOUSE:CEBPA

enables

GO:0000978: RNA polymerase II proximal promoter sequence-specific DNA binding

ECO:0000314: direct assay evidence used in manual assertion

F

Seeded From UniProt

complete

MOUSE:CEBPA

enables

GO:0001228: DNA-binding transcription activator activity, RNA polymerase II-specific

ECO:0000314: direct assay evidence used in manual assertion

F

occurs_at:(SO:0001952)

Seeded From UniProt

complete

MOUSE:CEBPA

involved_in

GO:0045944: positive regulation of transcription by RNA polymerase II

ECO:0000314: direct assay evidence used in manual assertion

P

has_regulation_target:(NCBI_Gene:1441)

Seeded From UniProt

complete

Notes

See also

References

See Help:References for how to manage references in GONUTS.