Mechanism of inactivation of the tumor suppressor PP2A: an illusion shattered by reality
(c) Ingrid Frohner and Jiri Veis. Immunofluorescence stainings of human prostate cancer cells with PP2A A subunit antibody and nuclear counterstain with Hoechst.
Protein Phosphatase 2 (PP2A) is an enzyme that plays important roles in regulating cell proliferation and by that has been shown to be a tumor suppressor. Inactivation of PP2A has been observed in many diseases including cancer. Egon Ogris and his team have now found out that the prevailing model of PP2A inactivation by phosphorylation needs to be revised. Notably, decades of research on the tumor suppressive function of PP2A were based on antibodies that - as it turns out now - do not recognize phosphorylation but are rather blocked by a completely different post-translational modification.