Project description:Nodal signaling, mediated through SMAD transcription factors, is necessary for pluripotency maintenance and endoderm commitment. We have identified a new motif, termed SMAD Complex Associated (SCA) that is bound by SMAD2/3/4 and FOXH1 in human embryonic stem cells (hESCs) and derived endoderm. We demonstrate that two bHLH proteins - HEB and E2A - bind the SCA motif at regions overlapping SMAD2/3 and FOXH1. Further, we show that HEB and E2A associate with SMAD2/3 and FOXH1, suggesting they form a complex at critical target regions. This association is biologically important, as E2A is critical for mesendoderm specification, gastrulation, and Nodal signal transduction in Xenopus tropicalis embryos. Taken together, E2A is a novel Nodal signaling cofactor that associates with SMAD2/3 and FOXH1 and is necessary for mesendoderm differentiation. ChIP-seq of Smad2/3 and Input in X.tropicalis, stage 10.5 embryo.
Project description:Nodal signaling, mediated through SMAD transcription factors, is necessary for pluripotency maintenance and endoderm commitment. We have identified a new motif, termed SMAD Complex Associated (SCA) that is bound by SMAD2/3/4 and FOXH1 in human embryonic stem cells (hESCs) and derived endoderm. We demonstrate that two bHLH proteins - HEB and E2A - bind the SCA motif at regions overlapping SMAD2/3 and FOXH1. Further, we show that HEB and E2A associate with SMAD2/3 and FOXH1, suggesting they form a complex at critical target regions. This association is biologically important, as E2A is critical for mesendoderm specification, gastrulation, and Nodal signal transduction in Xenopus tropicalis embryos. Taken together, E2A is a novel Nodal signaling cofactor that associates with SMAD2/3 and FOXH1 and is necessary for mesendoderm differentiation.
Project description:AML1-ETO, a fusion protein generated by the t(8;21) translocation in acute myeloid leukemia, is a transcription factor implicated in both gene repression and activation. We now show that, in leukemic cells, AML1-ETO resides in and functions through a stable protein complex (AETFC) that contains several hematopoietic transcription factors and cofactors. In conjunction with biochemical and leukemia pathological studies, the ChIP-seq and RNA-seq analyses of the AETFC components in leukemic cells reveal that these components stabilize the complex through multivalent interactions, provide multiple DNA-binding domains for diverse target genes, colocalize genome-wide, cooperatively regulate gene expression, and contribute to leukemogenesis. RNA-seq analyses gene expression upon knockdown of each AETFC component, including AML1-ETO, HEB, E2A, LYL1, LDB1 and LMO2, and double-knockdown of HEB and E2A, in Kasumi-1 cells. ChIP-seq analyses of four AETFC components, namely AML1-ETO, HEB, E2A and LMO2, in Kasumi-1 cells.
Project description:To investigate gene targets of the E-proteins HEB and E2A during the CD4+CD8+ double positive (DP) stage of T cell development. We examined E-protein function by simultaneous removal of both HEB (Tcf12) and E2A (Tcfe2a) genes at the DP stage. This was done by crossing mice containing HEB floxed and E2A floxed alleles to a CD4Cre background (Tcf12f/fTcfe2af/fCD4Cre mice). Microarray analysis was used to compare gene expression in HEB and E2A double deficient DP thymocytes (Cre+) to Cre- control DP thymocytes. Keywords: genetic modification
Project description:We wanted to test the role of mammalian E proteins E2A and HEB in the development of T cells. Using a conditional deletion system in which these proteins are deleted at the DP stage of T cell development, we compared DP thymocytes deficient for E2A, HEB or both to wild-type thymocytes
Project description:The lymphoid branch of the immune defense is composed of innate and adaptive immune cells. Using multiple genetic strategies we demonstrate that in the thymus E2A and HEB act in synergy to establish T cell identity and to suppress the aberrant development of innate lymphoid cells that include ILC2 and LTi-like cells. We found that E2A and HEB induce T cell fate by activating the expression of an ensemble of genes encoding for proteins associated with Notch- and pre-TCR signaling and to promote TCRβ antigen receptor assembly. We show that E2A and HEB act in early T progenitors (ETPs) to establish and maintain a T-lineage specific enhancer repertoire, including regulatory elements associated with the Notch1/3 and Rag1/2 gene loci. Based on these and previous observations we propose that the E-Id protein axis specifies innate versus adaptive lymphoid cell fate.