sentences:  The phosphorylation of CENP-A by Aurora B reaches a maximum in prometaphase.In fact, Aurora A targets the same CENP-A phosphorylation site as Aurora B, and CENP-A phosphorylation by Aurora A is thought to precede that by Aurora B.Thus, a model has been proposed in which CENP-A phosphorylation by Aurora A recruits Aurora B to the centromere, the latter maintaining the phosphorylation state of CENP-A in a positive feedback loop.