Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Expression changes in MEL cells upon differentiation and Ldb1 knockdown

ABSTRACT: Carbonic anhydrase 1 (Car1), an early specific marker of the erythroid differentiation, has been used to distinguish fetal and adult erythroid cells since its production closely follows the γ- to β-globin transition, but the molecular mechanism underlying transcriptional regulation of Car1 is unclear. Here, we show that Car1 mRNA decreases significantly when erythroid differentiation is induced in MEL cells. The Ldb1 protein complex including GATA1/SCL/LMO2 binds to the Car1 promoter in uninduced cells and reduced enrichment of the complex during differentiation correlates with loss of Car1 expression. Knockdown of Ldb1 results in a reduction of Ser2 phosphorylated RNA Pol II and Cdk9 at the Car1 promoter region, suggesting that Ldb1 is required for recruitment of Pol II as well as the transcription regulator P-TEFb to enhance elongation of Car1 transcripts. Taken together, these data show that Ldb1 forms a regulatory complex to maintain Car1 expression in erythroid cells.

ORGANISM(S): Mus musculus

PROVIDER: GSE42839 | GEO | 2012/12/11

SECONDARY ACCESSION(S): PRJNA183613

REPOSITORIES: GEO

ACCESS DATA

Json Xml

Similar Datasets

Expression changes in MEL cells upon differentiation and Ldb1 knockdown

Project description:Carbonic anhydrase 1 (Car1), an early specific marker of the erythroid differentiation, has been used to distinguish fetal and adult erythroid cells since its production closely follows the γ- to β-globin transition, but the molecular mechanism underlying transcriptional regulation of Car1 is unclear. Here, we show that Car1 mRNA decreases significantly when erythroid differentiation is induced in MEL cells. The Ldb1 protein complex including GATA1/SCL/LMO2 binds to the Car1 promoter in uninduced cells and reduced enrichment of the complex during differentiation correlates with loss of Car1 expression. Knockdown of Ldb1 results in a reduction of Ser2 phosphorylated RNA Pol II and Cdk9 at the Car1 promoter region, suggesting that Ldb1 is required for recruitment of Pol II as well as the transcription regulator P-TEFb to enhance elongation of Car1 transcripts. Taken together, these data show that Ldb1 forms a regulatory complex to maintain Car1 expression in erythroid cells. Expression analysis of induced and uninduced MEL cells after control or Ldb1 shRNA knockdown.

2012-12-11 | E-GEOD-42839 | biostudies-arrayexpress

Distinct Ldb1/NLI complexes orchestrate γ-globin repression and re-activation through ETO2 in human adult erythroid cells.

Project description:The Ldb1/GATA-1/TAL1/LMO2 complex mediates long range interaction between the β-globin locus control region (LCR) and gene in adult mouse erythroid cells but whether this complex mediates chromatin interactions at other developmental stages or in human cells is unknown. We investigated human NLI (Ldb1 homologue) complex occupancy and chromatin conformation of the β-globin locus in human erythroid cells. In addition to the LCR, we find robust NLI complex occupancy at a site downstream of the Aγ-globin gene, within sequences of BGL3, an intergenic RNA transcript. In cells primarily transcribing β-globin, BGL3 is not transcribed and BGL3 sequences are occupied by NLI core complex members together with co-repressor ETO2 and γ-globin repressor BCL11A. The LCR and β-globin gene establish proximity in these cells. In contrast, when γ-globin transcription is re-activated by cytokines in these cells, ETO2 participation in the NLI complex at BGL3 is diminished, as is BCL11A occupancy, and both BGL3 and γ-globin are transcribed. In these cells, proximity between the BGL3/γ-globin region and the LCR is established. Thus, alternative NLI complexes mediate γ-globin transcription or silencing through long range LCR interactions involving an intergenic site of non-coding RNA transcription and ETO2 is critical to this process. ChIP-chip of GATA-1, NLI, and pol II in cell lines Comparison of GATA-1, NLI, and pol II binding on chromatin. 2 replicates for each protein; ChIP and input DNA for each replicate

2012-01-05 | E-GEOD-30047 | biostudies-arrayexpress

Role of LDB1 in the transition from chromatin looping to transcription activation

Project description:Many questions remain about how close association of genes and distant enhancers occurs and how this is linked to transcription activation. In erythroid cells, LDB1 is recruited to the β-globin locus via LMO2 and is required for looping of the β-globin locus control region (LCR) to the active β-globin promoter. We show that the LDB1 dimerization domain (DD) is necessary and, when fused to LMO2 is sufficient, to completely restore LCR-promoter looping and transcription in LDB1 depleted cells. The looping function of the DD is unique and irreplaceable by heterologous dimerization domains. Dissection of the DD revealed distinct functional properties of conserved subdomains. Notably, a conserved helical region (DD4/5) is dispensable for LDB1 dimerization and chromatin looping but essential for transcriptional activation. DD4/5 is required for the recruitment of the co-regulators FOG1 and NuRD complex. Lack of DD4/5 alters histone acetylation and RNA polymerase II recruitment and results in failure of the locus to migrate to the nuclear interior as normally occurs during erythroid maturation. These results uncouple enhancer-promoter looping from nuclear migration and transcription activation and reveal new roles for LDB1in these processes. RNA-seq in LDB1 knockdown, LDB1 delta4/5 construct, LDB1 full-length construct, and control in induced MEL cells; three replicates each.

2014-07-02 | E-GEOD-54549 | biostudies-arrayexpress

Distinct Ldb1/NLI complexes orchestrate γ-globin repression and re-activation through ETO2 in human adult erythroid cells.

2012-01-05 | GSE30047 | GEO

The role of Ldb1 in hemangioblast development: genome-wide analysis shows that Ldb1 controls essential hematopoietic genes/pathways in mouse early development and reveals novel players in hematopoiesis (sequencing)

Project description:The first site exhibiting hematopoietic activity in mammalian development is the yolk sac blood island, which originates from the hemangioblast. Here we performed differentiation assays, as well as genome-wide molecular and functional studies in BL-CFCs to gain insight into the function of the essential Ldb1 factor in early primitive hematopoietic development. We show that the previously reported lack of yolk sac hematopoiesis and vascular development in Ldb1-/- mouse result from a decreased number of hemangioblasts and a block in their ability to differentiate into erythroid and endothelial progenitor cells. Transcriptome analysis and correlation with the genome wide binding pattern of Ldb1 in hemangioblasts revealed a number of direct target genes and pathways misregulated in the absence of Ldb1. The regulation of essential developmental factors by Ldb1 defines it as an upstream transcriptional regulator of hematopoietic/endothelial development. We show the complex interplay that exists between transcription factors and signaling pathways during the very early stages of hematopoietic/endothelial development and the specific signalling occurring in hemangioblasts in contrast to more advanced hematopoietic developmental stages. Finally, by revealing novel genes and pathways, not previously associated with early development, our study provides novel candidate targets to manipulate the differentiation of hematopoietic and/or endothelial cells. Examination of endogenous Ldb1 genome-wide binding sites comparsion between ChIP and Control on Flk1+ BL-CFCs RNA was isolated from Ldb1+/+ and Ldb1-/- Flk1+ cells with the QIAGEN RNeasy Mini Kit and integrity was checked on the Agilent 2100 Bioanalyzer. RNA sequencing was performed on Illumina HiSeq 2000 platform according to the manufacturer instructions.

2013-02-09 | E-GEOD-43041 | biostudies-arrayexpress

Role of LDB1 in the transition from chromatin looping to transcription activation

2014-07-02 | GSE54549 | GEO

Project description:The first site exhibiting hematopoietic activity in mammalian development is the yolk sac blood island, which originates from the hemangioblast. Here we performed differentiation assays, as well as genome-wide molecular and functional studies in BL-CFCs to gain insight into the function of the essential Ldb1 factor in early primitive hematopoietic development. We show that the previously reported lack of yolk sac hematopoiesis and vascular development in Ldb1-/- mouse result from a decreased number of hemangioblasts and a block in their ability to differentiate into erythroid and endothelial progenitor cells. Transcriptome analysis and correlation with the genome wide binding pattern of Ldb1 in hemangioblasts revealed a number of direct target genes and pathways misregulated in the absence of Ldb1. The regulation of essential developmental factors by Ldb1 defines it as an upstream transcriptional regulator of hematopoietic/endothelial development. We show the complex interplay that exists between transcription factors and signaling pathways during the very early stages of hematopoietic/endothelial development and the specific signalling occurring in hemangioblasts in contrast to more advanced hematopoietic developmental stages. Finally, by revealing novel genes and pathways, not previously associated with early development, our study provides novel candidate targets to manipulate the differentiation of hematopoietic and/or endothelial cells. We used microarrays to detail the global programme of gene expression underlying the Ldb1+/+ and Ldb1-/- in Flk1+ cells. RNA was isolated from Ldb1+/+ and Ldb1-/- Flk1+ cells with the QIAGEN RNeasy Mini Kit and integrity was checked on the Agilent 2100 Bioanalyzer. RNA was converted to biotin-labelled cRNA, hybridised on the Mouse Genome 430 2.0 Array and analyzed with the Affymetrix GeneChipÂ® Scanner 3000 according to the manufacturer protocol.

2013-02-09 | E-GEOD-43042 | biostudies-arrayexpress

Project description:The first site exhibiting hematopoietic activity in mammalian development is the yolk sac blood island, which originates from the hemangioblast. Here we performed differentiation assays, as well as genome-wide molecular and functional studies in BL-CFCs to gain insight into the function of the essential Ldb1 factor in early primitive hematopoietic development. We show that the previously reported lack of yolk sac hematopoiesis and vascular development in Ldb1-/- mouse result from a decreased number of hemangioblasts and a block in their ability to differentiate into erythroid and endothelial progenitor cells. Transcriptome analysis and correlation with the genome wide binding pattern of Ldb1 in hemangioblasts revealed a number of direct target genes and pathways misregulated in the absence of Ldb1. The regulation of essential developmental factors by Ldb1 defines it as an upstream transcriptional regulator of hematopoietic/endothelial development. We show the complex interplay that exists between transcription factors and signaling pathways during the very early stages of hematopoietic/endothelial development and the specific signalling occurring in hemangioblasts in contrast to more advanced hematopoietic developmental stages. Finally, by revealing novel genes and pathways, not previously associated with early development, our study provides novel candidate targets to manipulate the differentiation of hematopoietic and/or endothelial cells. We used microarrays to detail the global programme of gene expression underlying the Ldb1+/+ and Ldb1-/- in Flk1+ cells.

2013-02-09 | GSE43042 | GEO

2013-02-09 | GSE43041 | GEO

LDB1 complexes in erythroid differentiation

Project description:The Genome-Wide Dynamics of the Binding of Ldb1 Complexes during Erythroid Differentiation.

| PRJEB2019 | ENA