PP2A (Serine/threonine protein phosphatase 2A 59 kDa regulatory subunit B' gamma isoform) is required for the formation of the PP2A holoenzyme that negatively regulates brassinosteroid signaling by dephosphorylating and inactivating BRI1 in the cytoplasm and is involved in growth regulation and stress signaling. Alternative names: AtB' gamma, PP2A, B' subunit, gamma isoform