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bioRxiv · 10.1101/813527

Prophase removal of chromosome-associated RNAs facilitates anaphase chromosome segregation

Sharp, J. A.·Wang, W.·Blower, M. D.
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Abstract

During mitosis, the genome is transformed from a decondensed, transcriptionally active state to a highly condensed, transcriptionally inactive state. Mitotic chromosome reorganization is marked by the general attenuation of transcription on chromosome arms, yet how the cell regulates nuclear and chromatin-associated RNAs after chromosome condensation and nuclear envelope breakdown is unknown. SAF-A/hnRNPU is an abundant nuclear protein with RNA-to-DNA tethering activity, coordinated by two spatially distinct nucleic acid binding domains. Here we show that RNA is evicted from prophase chromosomes through Aurora-B-dependent phosphorylation of the SAF-A DNA-binding domain; failure to execute this pathway leads to accumulation of SAF-A:RNA complexes on mitotic chromosomes and elevated rates of anaphase segregation defects. This work reveals a role for Aurora-B in removing chromatin-associated RNAs during prophase, and demonstrates that Aurora-B dependent relocalization of SAF-A during cell division contributes to the fidelity of chromosome segregation.

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Sharp, J. A., Wang, W., Blower, M. D.. 2019-10-21. Prophase removal of chromosome-associated RNAs facilitates anaphase chromosome segregation. https://doi.org/10.1101/813527

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