GATA transcription factors regulate the expression of the human eosinophil-derived neurotoxin (RNase 2) gene.
The transcription factors GATA-1 and GATA-2 have been implicated in promoting differentiation of eosinophilic leukocytes. In this study, we examined the roles of GATA-1 and GATA-2 in activating transcription of the secretory ribonuclease, the eosinophil-derived neurotoxin (EDN/RNase 2). Augmented expression of both GATA-1 and GATA-2 was detected in eosinophil promyelocyte HL-60 clone 15 cells in response to biochemical differentiation with butyric acid. Deletion or mutation of one or both of the two consensus GATA-binding sites in the extended 1000-bp 5' promoter of the EDN gene resulted in profound reduction in reporter gene activity. Antibody-augmented electrophoretic mobility shift and chromatin immunoprecipitation analyses indicate that GATA-1 and GATA-2 proteins bind to both functional GATA consensus sequences in the EDN promoter. Interestingly, RNA silencing of GATA-1 alone had no impact on EDN expression; silencing of GATA-2 resulted in diminished expression of EDN, and also diminished expression of GATA-1 in both butyric acid-induced HL-60 clone 15 cells and in differentiating human eosinophils derived from CD34(+) hematopoietic progenitors. Likewise, overexpression of GATA-2 in uninduced HL-60 clone 15 cells resulted in augmented transcription of both EDN and GATA-1. Taken together, our data suggest that GATA-2 functions directly via interactions with the EDN promoter and also indirectly, via its ability to regulate the expression of GATA-1 in differentiating eosinophils and eosinophil cell lines.
Qiu
Zhijun
Z
Laboratory of Allergic Diseases, NIAID, NIH, Bethesda, MD 20892, USA.
Dyer
Kimberly D
KD
Xie
Zhihui
Z
Rådinger
Madeleine
M
Rosenberg
Helene F
HF
D015153:Blotting, Western; D002478:Cells, Cultured; D047369:Chromatin Immunoprecipitation; D024202:Electrophoretic Mobility Shift Assay; D047208:Eosinophil-Derived Neurotoxin / Q000235:genetics* / Q000378:metabolism; D004804:Eosinophils / Q000378:metabolism; D050982:GATA1 Transcription Factor / Q000502:physiology*; D050989:GATA2 Transcription Factor / Q000502:physiology*; D015971:Gene Expression Regulation, Enzymologic; D006801:Humans; D015473:Leukemia, Promyelocytic, Acute / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D034741:RNA, Small Interfering / Q000494:pharmacology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014470:Umbilical Cord
D050982:GATA1 Transcription Factor; C494688:GATA1 protein, human; D050989:GATA2 Transcription Factor; C494711:GATA2 protein, human; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D047208:Eosinophil-Derived Neurotoxin; C479221:RNASE2 protein, human