PP2A-B55-β Activators

PP2A-B55-β activators encompass a range of chemicals that can modulate the activity of PP2A, particularly the B55-β regulatory subunit. While direct activators are rare, several indirect modulators influence PP2A-B55-β activity through various mechanisms. These compounds include inhibitors of PP2A and PP1, which can shift the balance of cellular phosphatase activities, potentially enhancing PP2A-B55-β function.

Fostriecin, LB-100, and cantharidin are notable examples, known for their ability to selectively inhibit PP2A or its endogenous inhibitors. By altering the equilibrium between different phosphatases, these chemicals can indirectly promote the activity of PP2A-B55-β. Okadaic acid and tautomycin, on the other hand, are more broad-spectrum inhibitors, affecting both PP1 and PP2A. Their role in modulating PP2A-B55-β activity stems from the complex interplay of phosphatase activities within the cell. Other compounds like calyculin A, norcantharidin, and microcystin-LR, also function as inhibitors of PP2A, with potential repercussions for PP2A-B55-β. Endothall and DT-061 represent additional molecules that can influence PP2A indirectly; DT-061, in particular, does so by targeting PP2A's endogenous inhibitors. I-OMe-AG538 and phenothiazines, although not directly linked to PP2A-B55-β, are involved in modulating upstream signaling pathways that could ultimately impact PP2A-B55-β activity.