Fig. 2

A PP2A-B56⍺ dephosphorylates mTOR downregulating its activity. mTOR, alternatively, can inhibit PP2A leading to dephosphorylation of IRS1. p-IRS1 activates PI3K/Akt signaling leading to increased protein synthesis. B Some of the PP2A-B56⍺ downstream signaling. 56⍺ dephosphorylates GSK-3β activating it and allowing GSK-3β to phosphorylate β-catenin resulting in ubiquitin tagging for degradation in the ubiquitin–proteasome pathway. B56⍺ also dephosphorylates c-Myc resulting in it being tagged by ubiquitin for degradation. PP2A-B56⍺ can also dephosphorylate Akt, inhibiting mTORC1, and resulting in the inhibition of translation and the cell cycle progression. C PP2A-B55⍺, on the other hand, can dephosphorylate β-catenin allowing it to activate the Wnt responsive genes (WRE) and transcribe the Cyclin D1 and c-Myc. B55⍺ dephosphorylates KSR1 causing its disassociation from the 14-3-3 complex and binding to the RAS-RAF complex, which phosphorylates MEK1. Activated MEK1 then phosphorylates ERK1/2 activating it for downstream regulation. PP2A-B56β/γ is the subunit known to dephosphorylate ERK1/2 reversing these activations