Project description:The replication timing program, or the order in which DNA is duplicated during S-phase, is associated with various features of chromosome structure and function, including gene expression, histone modifications, and 3-D compartmentalization of chromatin.
Project description:Cellular differentiation requires cells to undergo dramatic but strictly controlled changes in chromatin organization, transcriptional regulation, and protein production and interaction. To understand the regulatory connections between these processes, we applied a multi-omics approach integrating proteomic, transcriptomic, chromatin accessibility, protein occupancy, and protein-chromatin interaction data acquired during differentiation of mouse embryonic stem cells (ESCs) into post-mitotic neurons. We found extensive remodeling of the chromatin that was preceding changes on RNA and protein levels. We found the pluripotency factor Sox2 as regulator of neuron-specific genes and, as a potential mechanism, revealed its genomic redistribution from pluripotency enhancers to neuronal promoters and concomitant change of its protein interaction network upon differentiation. We identified Atrx as a major Sox2 partner in neurons, whose co-localisation correlated with an increase in active enhancer marks and increased expression of nearby genes, and where deletion of a Sox2-Atrx co-bound site resulted in reduced expression of the proximal gene. Collectively, these findings provide key insights into the regulatory transformation of Sox2 during neuronal differentiation and highlight the significance of multi-omic approaches in understanding gene regulation in complex systems.
Project description:Neuronal development is a multistep process with different regulatory programs that shapes neurons to form dendrites, axons and synapses. To date, knowledge on neuronal development is largely based on murine data and largely restricted to the genomic and transcriptomic level. Advances in stem cell differentiation now enable the study of human neuronal development, and here we provide a mass spectrometry-based quantitative proteomic signature, at high temporal resolution, of human stem cell-derived neurons. To reveal proteomic changes during neuronal development we make use of two different differentiation approaches, leading to glutamatergic induced neurons (iN) or small molecule-derived patterned motor neurons. Our analysis revealed key proteins that show significant expression changes (FDR <0.001) during neuronal differentiation. We overlay our proteomics data with available transcriptomic data during neuronal differentiation and show distinct, datatype-specific, signatures. Overall, we provide a rich resource of information on proteins associated with human neuronal development, and moreover, highlight several signaling pathways involved, such as Wnt and Notch.
Project description:The evolution of brain complexity correlates with an increased expression of long, non-coding (lnc) RNAs in neuronal tissues. Although prominent examples illustrate the potential of lncRNAs to scaffold and target epigenetic regulators to chromatin loci, only few cases have been described to function during neurogenesis. We present a first functional characterization of the lncRNA LINC01322, which we term RUS for ‘RNA upstream of Slitrk3’. The RUS gene is well conserved in mammals by sequence and synteny next to the neurodevelopmental gene Slitrk3. RUS is exclusively expressed in neural cells and its expression increases along with neuronal markers during neuronal differentiation of mouse embryonic cortical neural stem cells. Depletion of RUS locks neuronal precursors in an intermediate state towards neuronal differentiation, with arrested cell cycle and increased apoptosis. RUS associates with chromatin in the vicinity of genes involved in neurogenesis, most of which change their expression upon RUS depletion. The identification of a range of epigenetic regulators as specific RUS interactors suggests that the lncRNA may mediate gene activation and repression in a highly context-dependent manner.