Project description:Identification of genes regulated by GATA-1 independent of the cofactor FOG-1. Experiment Overall Design: A conditionally activated FOG-1-binding defective mutant of GATA-1, ER-GATA-1(V205G), was expressed in GATA-1-null G1E cells. Transcipt levels were compared in cells untreated or treated with estradiol to activate the GATA-1 mutant.
Project description:The transcription factor GATA-1 is essential for erythroid and megakaryocytic cell differentiation and maturation. Previous reports show that GATA-1 is modulated through acetylation modification and through FOG-1 mediated indirect intereaction with HDAC1/2 containing NuRD corepressor complexes. In this study, we found that NuRD does not deacetylate GATA-1. However, HDAC1 alone can efficiently deacetylates GATA-1 and the direct interaction of HDAC1 and GATA-1 is required for the deacetylation. Two arginines within GATA-1 linker region are important for this interaction and arginine to alanine mutations (2RA mutant) largely reduces GATA-1 binding to HDAC1 in FOG-1 independent manner. GATA-1 2RA mutant were then introduced into G1E cells, a GATA-1-null erythroid progenitor cells. The 2RA mutant is acetylated but fails to induce erythroid differentiation. Gene expression analysis shows that GATA-1 2RA mutant affects GATA-1 function in both GATA-1 activated and repressed genes. The gene expression pattern partially overlap with gene expression profile of GATA-1V205M, a GATA-1 mutant with defective FOG-1 binding. ChIP-seq analysis further reveal that 2RA mutation largely reduced GATA-1 chromatin binding, most profoundly at gene promoter regions. HDAC1 recruitment on those promoters are also strongly reduced. These results revealed that GATA-1 recruits HDAC1 to GATA-1 regulated gene promoters and HDAC1 is required for GATA-1 mediated transcription regulation.
Project description:We report ChIP-Seq data for GATA-1 and the FOG-binding mutant of GATA-1 (GATA-1^V205G) in G1ME cells, a Gata1-null cell line with both erythroid and megakaryocytic differentiation potential. We introduced HA-tagged GATA-1 or V205G into G1ME cells via retroviral transduction. The cells were crosslinked at 48h post-transduction, and an HA antibody was used for chromatin immunoprecipitation (ChIP). ChIP and input samples were sequenced on Illumina GAII high-throughput sequencer. The data reveal GATA-1-specific and V205G-specific bidning sites, indicating that FOG-1 both faacilitates and prohibits GATA-1 chromatin occupancy in a context-dependent manner. Examinaton of chromatin occupancy of GATA-1 anda FOG-binding mutant of GATA-1 in G1ME cells cultured in TPO.
Project description:We explored the role of FOG-1 in GATA-1 transcriptional regulation of megakaryocyte differentiation through expression of wild-type GATA-1 and the FOG-binding mutant of GATA-1 (GATA-1^V205G) in G1ME cells.
Project description:We employed a gene complementation strategy combined with microarray screening to identify miRNAs involved in the formation of erythroid (red blood) cells. To search for GATA-1-regulated erythroid miRNAs, we used the Gata-1– erythroblast line G1E. These cells proliferate in culture as immature erythroid precursors and undergo terminal maturation when GATA-1 activity is restored. G1E-ER4 is a sub-line stably expressing an estrogen-activated form of GATA-1 (GATA-1 fused to the ligand binding domain of the estrogen receptor). Treatment of G1E-ER4 cells with estradiol induces a GATA-1-regulated program of gene expression with concomitant cellular maturation. We used a microarray to evaluate the expression of 292 different miRNAs in G1E-ER4 cells at 0 versus 24 hours after GATA-1 activation. Affymetrix gene expression profiling has previously been deposited (GEO accession no. GSE628). Keywords: microRNA analysis of a cell-line model of erythroid maturation
Project description:We report ChIP-Seq data for GATA-1 and the FOG-binding mutant of GATA-1 (GATA-1^V205G) in G1ME cells, a Gata1-null cell line with both erythroid and megakaryocytic differentiation potential. We introduced HA-tagged GATA-1 or V205G into G1ME cells via retroviral transduction. The cells were crosslinked at 48h post-transduction, and an HA antibody was used for chromatin immunoprecipitation (ChIP). ChIP and input samples were sequenced on Illumina GAII high-throughput sequencer. The data reveal GATA-1-specific and V205G-specific bidning sites, indicating that FOG-1 both faacilitates and prohibits GATA-1 chromatin occupancy in a context-dependent manner.