Figure 1. Model showing PP2A’s role in insulin secretion from the beta-cells. Upon stimulation, multiple pathways converge to increase insulin secretion. One such pathway is via the kinases, which are activated by insulin secretagogues and thus increase the phosphorylation state within the beta-cells. A complimentary regulatory pathway is via PP2A, which dephosphorylates and maintains a dephosphorylated state. Certain insulin secretagogues inactivate PP2A thus inhibiting the dephosphorylation event. However, the complex mechanisms involved in the regulation of this inactivation of PP2A and the substrate(s) through which PP2A increases insulin secretion within the betacell is not clearly defined.