PT - JOURNAL ARTICLE AU - Judith A. Sharp AU - Wei Wang AU - Michael D. Blower TI - Prophase removal of chromosome-associated RNAs facilitates anaphase chromosome segregation AID - 10.1101/813527 DP - 2019 Jan 01 TA - bioRxiv PG - 813527 4099 - http://biorxiv.org/content/early/2019/10/21/813527.short 4100 - http://biorxiv.org/content/early/2019/10/21/813527.full AB - 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.