Possible hypotheses for a buffering mechanism. In the cluster-based model, high local concentration leads to the formation of slow diffusing clusters, thus reducing the decay length at cell poles with high amplitude (Saunders et al, 2012). A cis-phosphorylation model provides no buffering. By contrast, in a trans-phosphorylation model, phosphorylation (and thus detachment) increases with local Pom1 concentration, providing a buffering mechanism reducing decay length at cell poles with high amplitude. 