Regulation of Gγ-globin gene by ATF2 and its associated proteins through the cAMP-response element.
The upstream Gγ-globin cAMP-response element (G-CRE) plays an important role in regulating Gγ-globin expression through binding of ATF2 and its DNA-binding partners defined in this study. ATF2 knockdown resulted in a significant reduction of γ-globin expression accompanied by decreased ATF2 binding to the G-CRE. By contrast, stable ATF2 expression in K562 cells increased γ-globin transcription which was reduced by ATF2 knockdown. Moreover, a similar effect of ATF2 on γ-globin expression was observed in primary erythroid progenitors. To understand the role of ATF2 in γ-globin expression, chromatographically purified G-CRE/ATF2-interacting proteins were subjected to mass spectrometry analysis; major binding partners included CREB1, cJun, Brg1, and histone deacetylases among others. Immunoprecipitation assays demonstrated interaction of these proteins with ATF2 and in vivo GCRE binding in CD34(+) cells undergoing erythroid differentiation which was correlated with γ-globin expression during development. These results suggest synergism between developmental stage-specific recruitments of the ATF2 protein complex and expression of γ-globin during erythropoiesis. Microarray studies in K562 cells support ATF2 plays diverse roles in hematopoiesis and chromatin remodeling.
Department of Molecular and Cell Biology, The University of Texas at Dallas, Richardson, Texas, United States of America.
Li
L
Liu
Subhradip
S
Karmakar
Ruby
R
Dhar
Milind
M
Mahajan
Alina
A
Choudhury
Sherman
S
Weissman
Betty S
BS
Pace
D051698:Activating Transcription Factor 2 / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism; D018952:Antigens, CD34 / Q000235:genetics / Q000378:metabolism; D001665:Binding Sites; D002454:Cell Differentiation; D000242:Cyclic AMP / Q000378:metabolism; D017362:Cyclic AMP Response Element-Binding Protein / Q000235:genetics / Q000378:metabolism; D004265:DNA Helicases / Q000235:genetics / Q000378:metabolism; D041905:Erythroid Cells / Q000166:cytology / Q000378:metabolism*; D004920:Erythropoiesis / Q000235:genetics*; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D006655:Histone Deacetylases / Q000235:genetics / Q000378:metabolism; D006801:Humans; D048031:JNK Mitogen-Activated Protein Kinases / Q000235:genetics / Q000378:metabolism; D020014:K562 Cells; D013058:Mass Spectrometry; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D025941:Protein Interaction Mapping; D012333:RNA, Messenger / Q000235:genetics* / Q000378:metabolism; D034741:RNA, Small Interfering / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D055545:gamma-Globins / Q000235:genetics* / Q000378:metabolism
C497105:ATF2 protein, human; D051698:Activating Transcription Factor 2; D018952:Antigens, CD34; C115163:CREB1 protein, human; D017362:Cyclic AMP Response Element-Binding Protein; D009687:Nuclear Proteins; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D014157:Transcription Factors; D055545:gamma-Globins; D000242:Cyclic AMP; D048031:JNK Mitogen-Activated Protein Kinases; D006655:Histone Deacetylases; C084108:SMARCA4 protein, human; D004265:DNA Helicases