Reduces the ATPase activity of VCP. Necessary for the fragmentation of Golgi stacks during mitosis and for VCP-mediated reassembly of Golgi stacks after mitosis. May play a role in VCP-mediated formation of transitional endoplasmic reticulum (tER) (By similarity). Reduces the ATPase activity of VCP. Necessary for the fragmentation of Golgi stacks during mitosis and for VCP-mediated reassembly of Golgi stacks after mitosis. May play a role in VCP-mediated formation of transitional endoplasmic reticulum (tER). Regulates the centrosomal levels of kinase aurK/Aurora during mitotic progression by promoting aurK removal from centrosomes in prophase. Also, regulates spindle orientation during mitosis. Belongs to the NSFL1C family.