Project description:ChIP-seq profiles for CTCF and TGF-beta signaling factors before and after treatment with DPP Examination of transcription factor dynamics during signaling
Project description:The dorsal patterning in Drosophila is controlled by an extracellular gradient of the morphogens Decapentlaplegic/Screw (Dpp/Scrw), which are members of BMP/TGF-β family. Dpp/Scrw signal is transduced to the nucleus by the transcription factors, Mad/Medea. The transcriptional effectors exert their regulation in a graded-manner eliciting at least three threshold responses: high, intermediate and low. However, the mechanism underlying differential response to Dpp is poorly understood, due in part to the insufficient number of well-studied target genes. Gene expression changes were analysed in ectopic overexpressing Dpp mutant embryos to identify new target genes of Dpp/Mad pathway.
Project description:Cytokines of the TGF-β superfamily control essential cell fate decisions via receptor regulated SMAD (R-SMAD) transcription factors. Ligand-induced R-SMAD phosphorylation in the cytosol triggers their activation and nuclear accumulation. We determined how R-SMADs are inactivated by dephosphorylation in the cell nucleus to counteract signaling by TGF-β superfamily ligands. We showed that R-SMAD dephosphorylation is mediated by an inner nuclear membrane associated complex containing the scaffold protein MAN1 and the CTDNEP1/NEP1R1 phosphatase. Structural prediction, domain mapping and mutagenesis revealed that MAN1 binds independently to the CTDNEP1/NEP1R1 phosphatase and R-SMADs to promote their inactivation by dephosphorylation. Disruption of this complex led to nuclear accumulation of R-SMADs and aberrant signaling, even in the absence of TGF-β ligands. These findings establish CTDNEP1/NEP1R1 as the elusive R-SMAD phosphatase and reveal the mechanistic basis for TGF-β signaling inactivation and how this process is disrupted by disease-associated MAN1 mutations.
Project description:Wnt/beta-catenin signaling is involved in various aspects of skeletal muscle development and regeneration. Using C2C12 cells, we examined intracellular signaling and gene transcription during myoblast proliferation and differentiation. The results of the present studies suggest that Wnt signaling is interacting with TGF-beta superfamily signaling through Smad activation. Single analysis for each condition (proliferating C2C12 cells, differentiating C2C12 cells, proliferating Wnt4-overexpressing C2C12 subline cells).
Project description:Our study shows that TGF-β signaling promotes tumorigenesis in the liver through upregulation of its target gene, Snail. We explored gene expression changes in tumors following TGF-β inhibition, and tumors ectopically expressing Snail with the TGF-β inhibition. RNA samples were harvested from tumors expressing Smad7 (S7HP tumors), firefly luciferase (LHP tumors), and Smad7 plus Snail (S7HP+Snail), respectively. Differentially expressed genes were investigated in LHP and S7HP+Snail tumors, compared with S7HP tumors.