Biology subjects

Apostolova, G.

Publications and source records attributed to Apostolova, G..

3 recordsLinked to original sources

bioRxiv2022

SATB2 organizes the 3D genome architecture of cognition in cortical neurons

SATB2 is genetically associated with human intelligence. Since SATB2 protein structure predicts a function in DNA looping, we analyzed the impact of SATB2 on 3D genome architecture and chromatin accessibility in cortical neurons. Our data reveal strong effects of SATB2 on chromatin looping between enhancers and promoters of neuronal activity-regulated genes, which closely correlate with gene expression. We furthermore identify SATB2-dependent alterations at all 3D genome architectural levels, including compartments, Topologically Associated Domains and Frequently Interacting Regions. Genes linked to SATB2-dependent 3D genome changes are implicated in highly specialized neuronal functions and contribute to cognitive ability and risk for neuropsychiatric and neurodevelopmental disorders. The altered non-coding regions are enriched for common variants associated with educational attainment, intelligence and schizophrenia. Our data establish SATB2 as a 3D genome organizer, which operates both independently and in cooperation with CTCF to set up the chromatin landscape of pyramidal neurons for cognitive processes.

neuroscience↗

bioRxiv2020

Cell-type specialization in the brain is encoded by specific long-range chromatin topologies

Neurons and oligodendrocytes are terminally differentiated cells that sustain cascades of gene activation and repression to execute highly specialized functions, while retaining homeostatic control. To study long-range chromatin folding without disturbing the native tissue environment, we developed Genome Architecture Mapping in combination with immunoselection (immunoGAM), and applied it to three cell types from the adult murine brain: dopaminergic neurons (DNs) from the midbrain, pyramidal glutamatergic neurons (PGNs) from the hippocampus, and oligodendroglia (OLGs) from the cortex. We find cell-type specific 3D chromatin structures that relate with patterns of gene expression at multiple genomic scales, including extensive reorganization of topological domains (TADs) and chromatin compartments. We discover the loss of TAD insulation, or TAD melting, at long genes (>400 kb) when they are highly transcribed. We find many neuron-specific contacts which contain accessible chromatin regions enriched for putative binding sites for multiple neuronal transcription factors, and which connect cell-type specific genes that are associated with neurodegenerative disorders such as Parkinsons disease, or specialized functions such as synaptic plasticity and memory. Lastly, sensory receptor genes exhibit increased membership in heterochromatic compartments that establish strong contacts in brain cells. However, their silencing is compromised in a subpopulation of PGNs with molecular signatures of long-term potentiation. Overall, our work shows that the 3D organization of the genome is highly cell-type specific, and essential to better understand mechanisms of gene regulation in highly specialized tissues such as the brain.

molecular biology↗

bioRxiv2019

Chromatin reorganization during myoblast differentiation involves the caspase-dependent removal of SATB2

Induction of lineage-specific gene programs are strongly influenced by alterations in local chromatin architecture. However, key players that impact this genome reorganization remain largely unknown. Here, we report that removal of special AT-rich binding protein 2 (SATB2), a nuclear protein that binds matrix attachment regions, is a key event in initiating myogenic differentiation. Deletion of SATB2 in muscle cell culture models and in vivo, accelerates differentiation and depletes the muscle progenitor pool, respectively. Genome wide analysis indicates that SATB2 binding is both repressive and inductive, as loss of SATB2 leads to expression of differentiation regulatory factors and inhibition of genes that impair this process. Finally, we noted that the differentiation-specific decline in SATB2 protein is dependent on a caspase 7-mediated cleavage event. Taken together, this study demonstrates that temporal control of SATB2 protein is critical for shaping the chromatin environment and coordinating the myogenic differentiation program. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=114 SRC="FIGDIR/small/883579v1_ufig1.gif" ALT="Figure 1"> View larger version (30K): org.highwire.dtl.DTLVardef@12ca82corg.highwire.dtl.DTLVardef@d50a56org.highwire.dtl.DTLVardef@99ba7borg.highwire.dtl.DTLVardef@a216e3_HPS_FORMAT_FIGEXP M_FIG Graphical Abstract C_FIG

molecular biology↗