E-GEOD-50165 - Regulation of Gamma globin gene expression by AT2 and its associated proteins through the cAMP response element.
Released on 24 October 2013, last updated on 3 June 2014
The upstream Gg-globin cAMP-response element (G-CRE) plays a role in regulating Gg-globin expression through binding of CREB1, cJun and ATF2. In this study we identified the ATF2 DNA-binding partners. ATF2 knockdown resulted in a significant reduction of g-globin expression accompanied by decreased ATF2 binding to the G-CRE. By contrast, stably expressed ATF2 in K562 cells increased g-globin, which was reduced by ATF2 knockdown. Moreover, a similar role for ATF2 on g-globin expression was observed in primary erythroid progenitors. To understand the role of ATF2 in g-globin expression, chromatographically purified G-CRE/ATF2-interacting proteins were subjected to mass spectrometry analysis; binding partners included CREB1, cJun, Brg1, and histone deacetylases among others. Co-immunoprecipitation and chromatin immunoprecipitation assay demonstrated interaction of these proteins with ATF2 in CD34+ cells undergoing erythroid differentiation which was correlated with g-globin expression during development. These results suggest synergism between developmental stage-specific recruitments of the ATF2 protein complex and expression of g-globin during erythropoiesis. Microarray studies in K562 cells support additional roles for ATF2 in hematopoiesis and chromatin remodeling Total RNA was isolated from K562 cells in culture following transfection with scrambled siRNA or ATF2 siRNA following which RNA was isolated and gene expression monitored
transcription profiling by array