Project description:Chromatin is partitioned into distinct topological domains in an activity-dependent manner, with topological boundaries limiting the interaction between adjacent domains. Recent studies support the concept that several well-established nuclear compartments are assembled as ribonucleoprotein condensates. Here we ask whether the physical processes driving the assembly of the nuclear condensates play any role in three-dimensional chromatin architecture. We report that the insulation of approximately 20% of topological boundaries in human embryonic stem cells is substantially weakened following brief treatment with 1,6-hexanediol, a chemical known to disrupt several nuclear condensates. The disrupted boundaries are characterized by a high level of transcription, striking spatial clustering, and the augmented presence of transcription units widely expressed in diverse cell types. These topological boundary regions tend to be spatially associated, even inter-chromosomally, and segregate with nuclear speckles. These observations reveal a previously unappreciated mode of genome organization mediated by conserved boundary elements harboring widely-expressed transcription units and associated transcriptional condensates.
Project description:Chromatin is partitioned into distinct topological domains in an activity-dependent manner, with topological boundaries limiting the interaction between adjacent domains. Recent studies support the concept that several well-established nuclear compartments are assembled as ribonucleoprotein condensates. Here we ask whether the physical processes driving the assembly of the nuclear condensates play any role in three-dimensional chromatin architecture. We report that the insulation of approximately 20% of topological boundaries in human embryonic stem cells is substantially weakened following brief treatment with 1,6-hexanediol, a chemical known to disrupt several nuclear condensates. The disrupted boundaries are characterized by a high level of transcription, striking spatial clustering, and the augmented presence of transcription units widely expressed in diverse cell types. These topological boundary regions tend to be spatially associated, even inter-chromosomally, and segregate with nuclear speckles. These observations reveal a previously unappreciated mode of genome organization mediated by conserved boundary elements harboring widely-expressed transcription units and associated transcriptional condensates.
Project description:Chromatin is partitioned into distinct topological domains in an activity-dependent manner, with topological boundaries limiting the interaction between adjacent domains. Recent studies support the concept that several well-established nuclear compartments are assembled as ribonucleoprotein condensates. Here we ask whether the physical processes driving the assembly of the nuclear condensates play any role in three-dimensional chromatin architecture. We report that the insulation of approximately 20% of topological boundaries in human embryonic stem cells is substantially weakened following brief treatment with 1,6-hexanediol, a chemical known to disrupt several nuclear condensates. The disrupted boundaries are characterized by a high level of transcription, striking spatial clustering, and the augmented presence of transcription units widely expressed in diverse cell types. These topological boundary regions tend to be spatially associated, even inter-chromosomally, and segregate with nuclear speckles. These observations reveal a previously unappreciated mode of genome organization mediated by conserved boundary elements harboring widely-expressed transcription units and associated transcriptional condensates.
Project description:Chromatin is partitioned into distinct topological domains in an activity-dependent manner, with topological boundaries limiting the interaction between adjacent domains. Recent studies support the concept that several well-established nuclear compartments are assembled as ribonucleoprotein condensates. Here we ask whether the physical processes driving the assembly of the nuclear condensates play any role in three-dimensional chromatin architecture. We report that the insulation of approximately 20% of topological boundaries in human embryonic stem cells is substantially weakened following brief treatment with 1,6-hexanediol, a chemical known to disrupt several nuclear condensates. The disrupted boundaries are characterized by a high level of transcription, striking spatial clustering, and the augmented presence of transcription units widely expressed in diverse cell types. These topological boundary regions tend to be spatially associated, even inter-chromosomally, and segregate with nuclear speckles. These observations reveal a previously unappreciated mode of genome organization mediated by conserved boundary elements harboring widely-expressed transcription units and associated transcriptional condensates.
Project description:This study investigates the role of SMXL7 protein condensates in regulating gene expression and chromatin organization in the model plant Arabidopsis thaliana. The researchers found that SMXL7 forms phase-separated nuclear condensates that sequester transcription factors and histone demethylases, thereby repressing gene expression. These condensates also associate with and modulate levels of the repressive histone mark H3K27me3, influencing higher-order chromatin structure. The findings reveal a novel mechanism linking plant hormone signaling to epigenetic regulation and nuclear architecture, with implications for understanding how plants control development in response to environmental cues. This work provides new insights into the functions of biomolecular condensates in transcriptional control and hormone signaling in plants.
Project description:This study investigates the role of SMXL7 protein condensates in regulating gene expression and chromatin organization in the model plant Arabidopsis thaliana. The researchers found that SMXL7 forms phase-separated nuclear condensates that sequester transcription factors and histone demethylases, thereby repressing gene expression. These condensates also associate with and modulate levels of the repressive histone mark H3K27me3, influencing higher-order chromatin structure. The findings reveal a novel mechanism linking plant hormone signaling to epigenetic regulation and nuclear architecture, with implications for understanding how plants control development in response to environmental cues. This work provides new insights into the functions of biomolecular condensates in transcriptional control and hormone signaling in plants.
Project description:This study investigates the role of SMXL7 protein condensates in regulating gene expression and chromatin organization in the model plant Arabidopsis thaliana. The researchers found that SMXL7 forms phase-separated nuclear condensates that sequester transcription factors and histone demethylases, thereby repressing gene expression. These condensates also associate with and modulate levels of the repressive histone mark H3K27me3, influencing higher-order chromatin structure. The findings reveal a novel mechanism linking plant hormone signaling to epigenetic regulation and nuclear architecture, with implications for understanding how plants control development in response to environmental cues. This work provides new insights into the functions of biomolecular condensates in transcriptional control and hormone signaling in plants.
Project description:This study investigates the role of SMXL7 protein condensates in regulating gene expression and chromatin organization in the model plant Arabidopsis thaliana. The researchers found that SMXL7 forms phase-separated nuclear condensates that sequester transcription factors and histone demethylases, thereby repressing gene expression. These condensates also associate with and modulate levels of the repressive histone mark H3K27me3, influencing higher-order chromatin structure. The findings reveal a novel mechanism linking plant hormone signaling to epigenetic regulation and nuclear architecture, with implications for understanding how plants control development in response to environmental cues. This work provides new insights into the functions of biomolecular condensates in transcriptional control and hormone signaling in plants.