RESUMO

Extracts from Dictyostelium discoideum contain type 2A and 2C serine/threonine-specific protein phosphatases with properties very similar to those from mammals according to their sensitivity to okadaic acid and to their dependence for divalent cations. In contrast, no type 1 protein phosphatase is found at any time of development, neither in the cytosolic nor in the particulate fraction, using glycogen phosphorylase a, casein, histone or the non-proteinous 4-Methylumbelliferyl phosphate as substrates. Both type 2A and 2C protein phosphatase activities remain constant throughout the development cycle.

Assuntos

Dictyostelium/enzimologia , Isoenzimas/metabolismo , Fosfoproteínas Fosfatases/metabolismo , Animais , Cátions Bivalentes , Membrana Celular/enzimologia , Cromatografia de Afinidade , Citosol/enzimologia , Éteres Cíclicos/farmacologia , Isoenzimas/isolamento & purificação , Cinética , Ácido Okadáico , Fosfoproteínas Fosfatases/antagonistas & inibidores , Fosfoproteínas Fosfatases/isolamento & purificação , Radioisótopos de Fósforo