Project description:As cells enter mitosis, the genome is restructured to facilitate chromosome segregation, accompanied by dramatic changes in gene expression. However, the mechanisms that underlie mitotic transcriptional regulation are unclear. In contrast to transcribed genes, centromere regions retain transcriptionally active RNA polymerase II (Pol II) in mitosis. Here, we demonstrate that chromatin-bound cohesin is necessary to retain elongating Pol II at centromeres. We find that WAPL-mediated removal of cohesin from chromosome arms during prophase is required for the dissociation of Pol II and nascent transcripts, and failure of this process dramatically alters mitotic gene expression. Removal of cohesin/Pol II from chromosome arms in prophase is important for accurate chromosome segregation and normal activation of gene expression in G1. We propose that prophase cohesin removal is a key step in reprogramming gene expression as cells transition from G2 through mitosis to G1.
Project description:During mitosis, the genome is restructured to facilitate chromosome segregation, accompanied by dramatic changes in gene expression. However, the mechanisms that underlie mitotic transcriptional regulation are unclear. In contrast to transcribed genes, centromere regions retain transcriptionally active RNA Polymerase II (RNAPII) in mitosis. Here, we demonstrate that chromosome-localized cohesin is necessary and sufficient to retain active RNAPII on mitotic centromeres. Failure to remove cohesin from mitotic chromosome arms dramatically alters mitotic gene expression, and results in a failure to release elongating RNAPII and nascent transcripts from mitotic chromosomes. We propose that prophase cohesin removal is the key step in reprogramming gene expression as cells transition from G2 to mitosis, and is temporally coupled with chromosome condensation to coordinate chromosome segregation with changes in gene expression.
Project description:During mitosis, the genome is restructured to facilitate chromosome segregation, accompanied by dramatic changes in gene expression. However, the mechanisms that underlie mitotic transcriptional regulation are unclear. In contrast to transcribed genes, centromere regions retain transcriptionally active RNA Polymerase II (RNAPII) in mitosis. Here, we demonstrate that chromosome-localized cohesin is necessary and sufficient to retain active RNAPII on mitotic centromeres. Failure to remove cohesin from mitotic chromosome arms dramatically alters mitotic gene expression, and results in a failure to release elongating RNAPII and nascent transcripts from mitotic chromosomes. We propose that prophase cohesin removal is the key step in reprogramming gene expression as cells transition from G2 to mitosis, and is temporally coupled with chromosome condensation to coordinate chromosome segregation with changes in gene expression.
Project description:During mitosis, the genome is restructured to facilitate chromosome segregation, accompanied by dramatic changes in gene expression. However, the mechanisms that underlie mitotic transcriptional regulation are unclear. In contrast to transcribed genes, centromere regions retain transcriptionally active RNA Polymerase II (RNAPII) in mitosis. Here, we demonstrate that chromosome-localized cohesin is necessary and sufficient to retain active RNAPII on mitotic centromeres. Failure to remove cohesin from mitotic chromosome arms dramatically alters mitotic gene expression, and results in a failure to release elongating RNAPII and nascent transcripts from mitotic chromosomes. We propose that prophase cohesin removal is the key step in reprogramming gene expression as cells transition from G2 to mitosis, and is temporally coupled with chromosome condensation to coordinate chromosome segregation with changes in gene expression.
