Project description:To study the effect of Notch 1 overexpression on cell funtion and to elucidate involved signalling pathways MLE12 cells tranfected with NICD1-pIRES-dsRed2 vector were analyzed for their transcript profiles 12, 24, and 48h after transfection and related to an empty vector (EV) transfected control cells
Project description:Notch signaling is a core patterning module for vascular morphogenesis, which co-determines the sprouting behaviour of endothelial cells (ECs). Tight quantitative and temporal control of Notch activity is essential for vascular development, yet the details of Notch regulation in ECs are incompletely understood. We found that ubiquitin-specific peptidase 10 (USP10) interacted with the NOTCH1 intracellular domain (NICD1) to slow the ubiquitin-dependent turnover of this short-lived form of the activated NOTCH1 receptor. Accordingly, inactivation of USP10 reduced NICD1 abundance and stability, and diminished Notch-induced target gene expression in ECs. In mice, loss of endothelial Usp10 increased vessel sprouting and partially restored the patterning defects caused by ectopic expression of NICD1. Thus, USP10 functions as an NICD1 deubiquitinase, which fine-tunes endothelial Notch responses during angiogenic sprouting.
Project description:To investigate the effect of hyperactivation of Notch signaling in hepatocytes, an immortalized human hepatocyte cell line THLE-2 was stably transduced with control vector or plasmid harborning intracellular domain of NOTCH1 (NICD1) and the transcriptomic profiles were analyzed by RNA-seq.
Project description:Notch signaling is an evolutionarily conserved signal transduction pathway that is essential for metazoan development. At the molecular level, the key components of the Notch pathway are the NOTCH-family receptors, the ligands of the DSL (Delta, Serrate, Lag-2) family and the transcription factor CSL [CBF1/RBPJ, Su(H), Lag-1]. Upon ligand binding, the NOTCH Intra-Cellular Domain (NOTCH ICD) translocates into the nucleus and forms a complex with RBPJ to activate the transcription of target genes. In the absence of NOTCH ICD, RBPJ acts as a transcriptional repressor. Using a proteomic approach, we identified L3MBTL3 as a novel interactor of RBPJ. We discovered that L3MBTL3 competes with NOTCH ICD for binding to RBPJ. In the absence of NOTCH ICD, RBPJ recruits L3MBTL3 and its co-factor KDM1A [lysine (K)-specific demethylase 1A] to the promoters/enhancers of Notch target genes to promote H3K4me2 demethylation and transcriptional repression. In three distinct cell contexts in which Notch signaling governs cell fate, i.e., mature T-cells as well as brain and breast tumor cells, the loss of L3MBTL3 results in the de-repression of Notch target genes. Finally, the genetic analyses of the homologs of RBPJ and L3MBTL3 in Drosophila melanogaster and Caenorhabditis elegans demonstrate that the functional link between RBPJ/Su(H)/lag-1 and L3MBTL3/dL(3)mbt/lin-61 is evolutionarily conserved, thus identifying L3MBTL3 as a universal modulator of Notch signaling in metazoans.
