Dynactin is also required for microtubule anchoring at centrosomes and centrosome integrity. The most notable MTOCs are the centrosome at interphase and the mitotic spindle poles. Most of the microtubules that form the mitotic spindle originate from the centrosome. The sperm supplies the centriole that creates the centrosome and microtubule system of the zygote. The protein locates to the nucleus, centrosome, cytoplasm, mitochondria, axons and synapses. The maintenance of astral microtubules is dependent on the integrity of centrosome. Meanwhile, astral microtubules begin at each centrosome and join with the cell membrane. The centrosome is the coordinating center for the cell's microtubules. CP110 is another cyclin E/CDK2 substrate which involves in centriole duplication and centrosome separation. Movements of the microtubules are based on the actions of the centrosome. In 1895, Theodor Boveri named the organelle a "centrosome". Aneuploidy and tumorigenesis can also result from centrosome abnormality, particularly centrosome amplification defects. The SUMO modification of hNinein leads to its movement from the centrosome to the nucleus. Then NPM is released from binding to an unduplicated centrosome, thereby triggering duplication. This allows them to pull each centrosome closer to the cell membrane.