Reactome will be unavailable due to host maintenance from Friday, April 27 at 6pm to Sunday, April 29 at 11:55pm.
During the outage, you may wish to use our mirror site at reactome.ncpsb.org.
The dissolution of the nuclear membrane marks the beginning of the prometaphase. Kinetochores are created when proteins attach to the centromeres. Microtubules then attach at the kinetochores, and the chromosomes begin to move to the metaphase plate.