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Rajarajan, P.

Publications and source records attributed to Rajarajan, P..

2 recordsLinked to original sources

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↗

NEURON-SPECIFIC CHROMOSOMAL MEGADOMAIN ORGANIZATION IS ADAPTIVE TO RECENT RETROTRANSPOSON EXPANSIONS

Here, we mapped cell-type specific chromatin domain organization in adult mouse cerebral cortex and report strong enrichment of Endogenous Retrovirus 2 (ERV2) repeat sequences in the neuron-specific heterochromatic B2NeuN+ megabase-scaling subcompartment. Comparative chromosomal conformation mapping in Mus spretus and Mus musculus revealed neuron-specific reconfigurations tracking recent ERV2 retrotransposon expansions in the murine germline, with significantly higher B2 megadomain contact frequencies at sites with ongoing ERV2 insertions in Mus musculus. Ablation of the retrotransposon silencer Kmt1e/Setdb1 triggered B2 megadomain disintegration and rewiring with open chromatin domains enriched for cellular stress response genes, along with severe neuroinflammation and proviral assembly of ERV2/Intracisternal-A-Particles (IAPs) infiltrating dendrites and spines. We conclude that neuronal megadomain architectures include evolutionarily adaptive heterochromatic organization which, upon perturbation, unleashes ERV proviruses with strong tropism within mature neurons.

neuroscience↗